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[Analysis of clinical characteristics and risk factors of postoperative complications in infants with early-onset necrotizing enterocolitis after enterostomy]. ZHONGHUA YI XUE ZA ZHI 2024; 104:38-44. [PMID: 38178766 DOI: 10.3760/cma.j.cn112137-20230926-00577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Objective: To investigate the clinical characteristics of children with early-onset necrotizing enterocolitis (NEC) undergoing enterostomy and analyze the risk factors for postoperative complications. Methods: Retrospective analysis was conducted on the clinical data (perinatal conditions, clinical characteristics, clinical outcomes, etc.) of NEC patients who underwent enterostomy at Beijing Children's Hospital from May 2016 to May 2023. The patients were divided into two groups based on the age of onset: an early-onset enterostomy group (<14 days) and a late-onset enterostomy group (≥14 days). Furthermore, the children with NEC were categorized into complication group and non-complication group based on whether there were complications after enterostomy. The differences in clinical data between these groups were analyzed, and the clinical characteristics of children with early-onset NEC and enterostomy were summarized. Multivariate logistic regression model was employed to analyze the risk factors for postoperative complications in NEC children with enterostomy. Results: A total of 68 cases were enrolled, including 43 cases in the early-onset enterostomy group [26 males and 17 females, aged (6.5±3.0) days] and 25 cases in the late-onset enterostomy group [15 males and 10 females, aged (21.0±3.0) days]. There were 28 cases (17 males and 11 females), age [M (Q1, Q3)] 9 (5, 14) days in the complication group and 33 cases (22 males and 11 females), aged of 14 (6, 21) days in the non-complication group. Compared to the late-onset enterostomy group, the early-onset enterostomy group had significantly higher rates of intraventricular hemorrhage [30.2% (13/43) vs 8.0% (2/25)], hemodynamically significant patent ductus arteriosus [37.2% (16/43) vs 12.0% (3/25)], mechanical ventilation≥72 hours after birth [39.5% (17/43) vs 16.0% (4/25)], stage Ⅲ NEC [(69.8% (30/43) vs 40.0% (10/25)], extensive NEC [27.9% (12/43) vs 8.0% (2/25)], and short-term postoperative complications [56.8% (21/37) vs 29.2% (7/24)] (all P<0.05).Multivariate logistic regression model analysis revealed that residual length of proximal small intestine was a protective factor for postoperative complications after enterostomy in NEC infants (OR=0.764, 95%CI: 0.648-0.901, P=0.001), but stage Ⅲ NEC was a risk factor (OR=1.042, 95%CI: 1.004-5.585, P=0.017). Conclusions: The incidence of postoperative complications is high, and the prognosis is poor in children with early-onset NEC enterostomy. The residual length of proximal enterostomy is a protective factor for postoperative complications of NEC enterostomy, but stage Ⅲ NEC is a risk factor.
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Supratentorial hemangioblastoma: A rare case report and literature review. Radiol Case Rep 2022; 17:4156-4160. [PMID: 36105844 PMCID: PMC9464762 DOI: 10.1016/j.radcr.2022.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/30/2022] [Accepted: 07/03/2022] [Indexed: 12/04/2022] Open
Abstract
Hemangioblastomas are rare and benign tumors of the central nervous system. They account for 1.5%-2.5% of all intracranial tumors and have an incidence of 3.2%. The resemblance of hemangioblastomas to other tumors renders preoperative diagnosis and management challenging. Herein, we report a case of a supratentorial hemangioblastoma accompanied by extensive reactive gliosis and diagnosed through magnetic resonance imaging. In addition, we review the relevant literature.
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Optical coherence tomography as a useful adjunct in the early detection of meningioma with optic nerve compression. Taiwan J Ophthalmol 2022; 12:354-359. [PMID: 36248089 PMCID: PMC9558474 DOI: 10.4103/tjo.tjo_54_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022] Open
Abstract
A 48-year-old woman presented with persistent clouding vision in her lower field in the right eye for 5 months. A small retinal hemorrhage was initially reported. Her visual acuity was 20/30 in the right eye and 20/20 in the left, with normal color vision and pupil response. Fundus examination did not reveal any retinal hemorrhage. Although optical coherence tomography (OCT) showed normal macula and retinal nerve fiber layers in both eyes, asymmetric thinning of the ganglion cell inner plexiform layer was found in the superior macula of the right eye in ganglion cell analysis (GCA). Visual field examination revealed a subtle inferonasal scotoma. Compressive optic neuropathy (CON) was suspected. The visual evoked potential test revealed delayed P100 latency. A tuberculum sellae meningioma was found with right medial optic canal extension. The visual acuity of the right eye returned to 20/25 after decompression surgery. OCT can be used to differentiate between retinopathy and optic neuropathy. GCA can help in the early detection of CON and achieve a good visual outcome after surgery.
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Electroencephalogram-Based Motor Imagery Classification Using Deep Residual Convolutional Networks. Front Neurosci 2021; 15:774857. [PMID: 34867174 PMCID: PMC8635693 DOI: 10.3389/fnins.2021.774857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/22/2021] [Indexed: 11/25/2022] Open
Abstract
The classification of electroencephalogram (EEG) signals is of significant importance in brain-computer interface (BCI) systems. Aiming to achieve intelligent classification of motor imagery EEG types with high accuracy, a classification methodology using the wavelet packet decomposition (WPD) and the proposed deep residual convolutional networks (DRes-CNN) is proposed. Firstly, EEG waveforms are segmented into sub-signals. Then the EEG signal features are obtained through the WPD algorithm, and some selected wavelet coefficients are retained and reconstructed into EEG signals in their respective frequency bands. Subsequently, the reconstructed EEG signals were utilized as input of the proposed deep residual convolutional networks to classify EEG signals. Finally, EEG types of motor imagination are classified by the DRes-CNN classifier intelligently. The datasets from BCI Competition were used to test the performance of the proposed deep learning classifier. Classification experiments show that the average recognition accuracy of this method reaches 98.76%. The proposed method can be further applied to the BCI system of motor imagination control.
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Unusual magnetization process and magnetocaloric effect in α-CoV 2O 6driven by pulsed magnetic fields. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:435703. [PMID: 34343981 DOI: 10.1088/1361-648x/ac1a31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/03/2021] [Indexed: 06/13/2023]
Abstract
In low-dimensional Ising spin systems, an interesting observation is the presence of step magnetization at low temperatures. Here we combine both DC and pulsed magnetic fields to study the 1/3 magnetization plateau and multiple steps in the Ising spin-chain material α-CoV2O6. Magnetization in pulsed fields is quite different from that in DC fields, showing multiple steps in an intermediate range of 4.2-6 K, inverted hysteresis below 4.2 K and asymmetric magnetization in negative fields below 11 K. We demonstrate that these unusual behaviors in magnetization are caused by the spin dynamics and the anomalous magnetocaloric effect (MCE) in α-CoV2O6, i.e., abrupt changes of sample temperature in adiabatic conditions. We successfully separate the influence between the intrinsic slow spin dynamics and the quasi-extrinsic temperature change. From the MCE, we find that some irreversible behavior is originated from the slow spin dynamics. Two different slow dynamics associated with the metastable steps are observed: one is sensitive to the slow field sweep rate at the order of ∼mT s-1and weakly depends on temperature, while the other responds to the rapid field sweep rate of ∼kT s-1and dominates at lowest temperature. We also distinguish that the metastable transition atH4is the first order and crucial for the ferrimagnetic to ferromagnetic transition. This study is useful to the understanding of multistep magnetization in α-CoV2O6and sheds light on recent experimental findings of related compounds.
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An Intelligent EEG Classification Methodology Based on Sparse Representation Enhanced Deep Learning Networks. Front Neurosci 2020; 14:808. [PMID: 33177970 PMCID: PMC7596898 DOI: 10.3389/fnins.2020.00808] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/10/2020] [Indexed: 11/13/2022] Open
Abstract
The classification of electroencephalogram (EEG) signals is of significant importance in brain-computer interface (BCI) systems. Aiming to achieve intelligent classification of EEG types with high accuracy, a classification methodology using sparse representation (SR) and fast compression residual convolutional neural networks (FCRes-CNNs) is proposed. In the proposed methodology, EEG waveforms of classes 1 and 2 are segmented into subsignals, and 140 experimental samples were achieved for each type of EEG signal. The common spatial patterns algorithm is used to obtain the features of the EEG signal. Subsequently, the redundant dictionary with sparse representation is constructed based on these features. Finally, the samples of the EEG types were imported into the FCRes-CNN model having fast down-sampling module and residual block structural units to be identified and classified. The datasets from BCI Competition 2005 (dataset IVa) and BCI Competition 2003 (dataset III) were used to test the performance of the proposed deep learning classifier. The classification experiments show that the recognition averaged accuracy of the proposed method is 98.82%. The experimental results show that the classification method provides better classification performance compared with sparse representation classification (SRC) method. The method can be applied successfully to BCI systems where the amount of data is large due to daily recording.
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Determination of Strong-Phase Parameters in D→K_{S,L}^{0}π^{+}π^{-}. PHYSICAL REVIEW LETTERS 2020; 124:241802. [PMID: 32639796 DOI: 10.1103/physrevlett.124.241802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/20/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
We report the most precise measurements to date of the strong-phase parameters between D^{0} and D[over ¯]^{0} decays to K_{S,L}^{0}π^{+}π^{-} using a sample of 2.93 fb^{-1} of e^{+}e^{-} annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. Our results provide the key inputs for a binned model-independent determination of the Cabibbo-Kobayashi-Maskawa angle γ/ϕ_{3} with B decays. Using our results, the decay model sensitivity to the γ/ϕ_{3} measurement is expected to be between 0.7° and 1.2°, approximately a factor of three smaller than that achievable with previous measurements, based on the studies of the simulated data. The improved precision of this work ensures that measurements of γ/ϕ_{3} will not be limited by knowledge of strong phases for the next decade. Furthermore, our results provide critical input for other flavor-physics investigations, including charm mixing, other measurements of CP violation, and the measurement of strong-phase parameters for other D-decay modes.
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Measurement of Proton Electromagnetic Form Factors in e^{+}e^{-}→pp[over ¯] in the Energy Region 2.00-3.08 GeV. PHYSICAL REVIEW LETTERS 2020; 124:042001. [PMID: 32058790 DOI: 10.1103/physrevlett.124.042001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/19/2019] [Indexed: 06/10/2023]
Abstract
The process of e^{+}e^{-}→pp[over ¯] is studied at 22 center-of-mass energy points (sqrt[s]) from 2.00 to 3.08 GeV, exploiting 688.5 pb^{-1} of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section (σ_{pp[over ¯]}) of e^{+}e^{-}→pp[over ¯] is measured with the energy-scan technique and it is found to be consistent with previously published data, but with much improved accuracy. In addition, the electromagnetic form-factor ratio (|G_{E}/G_{M}|) and the value of the effective (|G_{eff}|), electric (|G_{E}|), and magnetic (|G_{M}|) form factors are measured by studying the helicity angle of the proton at 16 center-of-mass energy points. |G_{E}/G_{M}| and |G_{M}| are determined with high accuracy, providing uncertainties comparable to data in the spacelike region, and |G_{E}| is measured for the first time. We reach unprecedented accuracy, and precision results in the timelike region provide information to improve our understanding of the proton inner structure and to test theoretical models which depend on nonperturbative quantum chromodynamics.
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Measurement of the Cross Section for e^{+}e^{-}→Ξ^{-}Ξ[over ¯]^{+} and Observation of an Excited Ξ Baryon. PHYSICAL REVIEW LETTERS 2020; 124:032002. [PMID: 32031834 DOI: 10.1103/physrevlett.124.032002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/05/2019] [Indexed: 06/10/2023]
Abstract
Using a total of 11.0 fb^{-1} of e^{+}e^{-} collision data with center-of-mass energies between 4.009 and 4.6 GeV and collected with the BESIII detector at BEPCII, we measure fifteen exclusive cross sections and effective form factors for the process e^{+}e^{-}→Ξ^{-}Ξ[over ¯]^{+} by means of a single baryon-tag method. After performing a fit to the dressed cross section of e^{+}e^{-}→Ξ^{-}Ξ[over ¯]^{+}, no significant ψ(4230) or ψ(4260) resonance is observed in the Ξ^{-}Ξ[over ¯]^{+} final states, and upper limits at the 90% confidence level on Γ_{ee}B for the processes ψ(4230)/ψ(4260)→Ξ^{-}Ξ[over ¯]^{+} are determined. In addition, an excited Ξ baryon at 1820 MeV/c^{2} is observed with a statistical significance of 6.2-6.5σ by including the systematic uncertainty, and the mass and width are measured to be M=(1825.5±4.7±4.7) MeV/c^{2} and Γ=(17.0±15.0±7.9) MeV, which confirms the existence of the J^{P}=3/2^{-} state Ξ(1820).
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Observation of the Semileptonic D^{+} Decay into the K[over ¯]_{1}(1270)^{0} Axial-Vector Meson. PHYSICAL REVIEW LETTERS 2019; 123:231801. [PMID: 31868427 DOI: 10.1103/physrevlett.123.231801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/01/2019] [Indexed: 06/10/2023]
Abstract
By analyzing a 2.93 fb^{-1} data sample of e^{+}e^{-} collisions, recorded at a center-of-mass energy of 3.773 GeV with the BESIII detector operated at the BEPCII collider, we report the first observation of the semileptonic D^{+} transition into the axial-vector meson D^{+}→K[over ¯]_{1}(1270)^{0}e^{+}ν_{e} with a statistical significance greater than 10σ. Its decay branching fraction is determined to be B[D^{+}→K[over ¯]_{1}(1270)^{0}e^{+}ν_{e}]=(2.30±0.26_{-0.21}^{+0.18}±0.25)×10^{-3}, where the first and second uncertainties are statistical and systematic, respectively, and the third originates from the input branching fraction of K[over ¯]_{1}(1270)^{0}→K^{-}π^{+}π^{0}.
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[The mid-term outcomes of minimally invasive plasty for severe tricuspid regurgitation after cardiac surgery]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 2019; 57:902-907. [PMID: 31826593 DOI: 10.3760/cma.j.issn.0529-5815.2019.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objectives: To evaluate the efficacy of minimally invasive surgery in patients with late severe tricuspid regurgitation after cardiac surgery, and to evaluate the role of leaflets augmentation technique in tricuspid valvuloplasty. Methods: From January 2015 to June 2019, 85 patients undergoing tricuspid valve repair procedure with minimally invasive approach at Department of Cardiovascular Surgery, Guangdong provincial People's Hospital were enrolled. There were 22 males and 63 females, aging of (53.6±12.4) years (range: 15 to 75 years). The interval between the prior and current operations was (16.0±7.3) years (range: 0.2 to 35.0 years). The diameter of right atrium and right ventricle was (77.3±17.2) mm and (61.0±8.4) mm, respectively. Tricuspid regurgitation was severe or extremely severe, the tricuspid regurgitation area was (19.0±10.3) cm(2). All patients underwent minimally invasive tricuspid valvuloplasty or tricuspid valve replacement on beating-heart with totally endoscopic technique and port-access approach through right chest wall. The operations included tricuspid valve replacement and tricuspid valvuloplasty, the technique of tricuspid valvuloplasty including leaflets augmentation with patch, ring implantation, chordae tendineaes reconstruction, release of papillary muscle, edge to edge method, etc. Postoperative hospitalization days, the time of ICU stay, blood transfusion rate, ventilator time and the results of echocardiography were recorded. Follow-up was completed regularly by WeChat, telephone and outpatient visit. Results: Sixty-five patients underwent tricuspid valve repair, and 20 patients underwent tricuspid valve replacement because of prosthetic failure and plasty failure. Five patients died during hospitalization, with mortality rate 5.9%. One patient was transferred to local hospital for anti-infection treatment, the other 79 patients were discharged from hospital in well condition and followed-up. The postoperative hospitalization time was 7.0 (5.5) days (M(Q(R))) days, the mean ventilator time was 18.0 (16.2) hours, and the mean ICU stay time was 68.0 (75.5) hours. There were 35 patients without blood conduction transfusion, the transfusion rate was only 58.9% (50/85). Four cases of severe, 9 cases of moderate and 67 cases of mild to zero tricuspid regurgitation were examined before being discharged, with tricuspid regurgitation area of (2.8±3.5) cm(2) (range: 0 to 19.1 cm(2)). The follow-up time was 1 to 38 months. Two patients died during follow-up, one patient died from infective endocarditis and mitral perivalvular leakage, the other one died of intractable right heart failure. One patient was implanted with permanent pacemaker due to Ⅲ atrioventricular block. Valvular re-replacement was performed in 2 patients who were re-admitted for the artificial valve infection and mechanical valve obstruction. No re-operation of tricuspid valve. Conclusions: Totally endoscopic minimally invasive technique provided satisfactory surgical outcomes for critically sick patients with severe tricuspid regurgitation following cardiac surgery. The application of leaflets augmentation technique achieved ideal repair effect for previously unrepairable lesions.
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Observation of the Leptonic Decay D^{+}→τ^{+}ν_{τ}. PHYSICAL REVIEW LETTERS 2019; 123:211802. [PMID: 31809130 DOI: 10.1103/physrevlett.123.211802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Indexed: 06/10/2023]
Abstract
We report the first observation of D^{+}→τ^{+}ν_{τ} with a significance of 5.1σ. We measure B(D^{+}→τ^{+}ν_{τ})=(1.20±0.24_{stat}±0.12_{syst})×10^{-3}. Taking the world average B(D^{+}→μ^{+}ν_{μ})=(3.74±0.17)×10^{-4}, we obtain R_{τ/μ}=Γ(D^{+}→τ^{+}ν_{τ})/Γ(D^{+}→μ^{+}ν_{μ})=3.21±0.64_{stat}±0.43_{syst}., which is consistent with the standard model expectation of lepton flavor universality. Using external inputs, our results give values for the D^{+} decay constant f_{D^{+}} and the Cabibbo-Kobayashi-Maskawa matrix element |V_{cd}| that are consistent with, but less precise than, other determinations.
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Complete Measurement of the Λ Electromagnetic Form Factors. PHYSICAL REVIEW LETTERS 2019; 123:122003. [PMID: 31633986 DOI: 10.1103/physrevlett.123.122003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/26/2019] [Indexed: 06/10/2023]
Abstract
The exclusive process e^{+}e^{-}→ΛΛ[over ¯], with Λ→pπ^{-} and Λ[over ¯]→p[over ¯]π^{+}, has been studied at sqrt[s]=2.396 GeV for measurement of the timelike Λ electric and magnetic form factors, G_{E} and G_{M}. A data sample, corresponding to an integrated luminosity of 66.9 pb^{-1}, was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R=|G_{E}/G_{M}| and, for the first time for any baryon, the relative phase ΔΦ=Φ_{E}-Φ_{M}. The resulting values are R=0.96±0.14(stat)±0.02(syst) and ΔΦ=37°±12°(stat)±6°(syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter α_{Λ}=0.750±0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be σ=118.7±5.3(stat)±5.1(syst) pb, which corresponds to an effective form factor of |G|=0.123±0.003(stat)±0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.
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Amplitude Analysis of D_{s}^{+}→π^{+}π^{0}η and First Observation of the W-Annihilation Dominant Decays D_{s}^{+}→a_{0}(980)^{+}π^{0} and D_{s}^{+}→a_{0}(980)^{0}π^{+}. PHYSICAL REVIEW LETTERS 2019; 123:112001. [PMID: 31573268 DOI: 10.1103/physrevlett.123.112001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 06/25/2019] [Indexed: 06/10/2023]
Abstract
We present the first amplitude analysis of the decay D_{s}^{+}→π^{+}π^{0}η. We use an e^{+}e^{-} collision data sample corresponding to an integrated luminosity of 3.19 fb^{-1} collected with the BESIII detector at a center-of-mass energy of 4.178 GeV. We observe for the first time the W-annihilation dominant decays D_{s}^{+}→a_{0}(980)^{+}π^{0} and D_{s}^{+}→a_{0}(980)^{0}π^{+}. We measure the absolute branching fraction B(D_{s}^{+}→a_{0}(980)^{+(0)}π^{0^{(}+)},a_{0}(980)^{+(0)}→π^{+(0)}η)=(1.46±0.15_{stat}±0.23_{sys})%, which is larger than the branching fractions of other measured pure W-annihilation decays by at least one order of magnitude. In addition, we measure the branching fraction of D_{s}^{+}→π^{+}π^{0}η with significantly improved precision.
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Study of e^{+}e^{-}→γωJ/ψ and Observation of X(3872)→ωJ/ψ. PHYSICAL REVIEW LETTERS 2019; 122:232002. [PMID: 31298909 DOI: 10.1103/physrevlett.122.232002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/25/2019] [Indexed: 06/10/2023]
Abstract
We study the e^{+}e^{-}→γωJ/ψ process using 11.6 fb^{-1} e^{+}e^{-} annihilation data taken at center-of-mass energies from sqrt[s]=4.008 GeV to 4.600 GeV with the BESIII detector at the BEPCII storage ring. The X(3872) resonance is observed for the first time in the ωJ/ψ system with a significance of more than 5σ. The relative decay ratio of X(3872)→ωJ/ψ and π^{+}π^{-}J/ψ is measured to be R=1.6_{-0.3}^{+0.4}±0.2, where the first uncertainty is statistical and the second systematic (the same hereafter). The sqrt[s]-dependent cross section of e^{+}e^{-}→γX(3872) is also measured and investigated, and it can be described by a single Breit-Wigner resonance, referred to as the Y(4200), with a mass of 4200.6_{-13.3}^{+7.9}±3.0 MeV/c^{2} and a width of 115_{-26}^{+38}±12 MeV. In addition, to describe the ωJ/ψ mass distribution above 3.9 GeV/c^{2}, we need at least one additional Breit-Wigner resonance, labeled as X(3915), in the fit. The mass and width of the X(3915) are determined. The resonant parameters of the X(3915) agree with those of the Y(3940) in B→KωJ/ψ and of the X(3915) in γγ→ωJ/ψ observed by the Belle and BABAR experiments within errors.
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Observation of the Decay X(3872)→π^{0}χ_{c1}(1P). PHYSICAL REVIEW LETTERS 2019; 122:202001. [PMID: 31172749 DOI: 10.1103/physrevlett.122.202001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 04/15/2019] [Indexed: 06/09/2023]
Abstract
Using a total of 9.0 fb^{-1} of e^{+}e^{-} collision data with center-of-mass energies between 4.15 and 4.30 GeV collected by the BESIII detector, we search for the processes e^{+}e^{-}→γX(3872) with X(3872)→π^{0}χ_{cJ} for J=0, 1, 2. We report the first observation of X(3872)→π^{0}χ_{c1}, a new decay mode of the X(3872), with a statistical significance of more than 5σ for all systematic fit variations. Normalizing to the previously established process e^{+}e^{-}→γX(3872) with X(3872)→π^{+}π^{-}J/ψ, we find B(X(3872)→π^{0}χ_{c1})/B(X(3872)→π^{+}π^{-}J/ψ)=0.88_{-0.27}^{+0.33}±0.10, where the first error is statistical and the second is systematic. We set 90% confidence level upper limits on the corresponding ratios for the decays to π^{0}χ_{c0} and π^{0}χ_{c2} of 19 and 1.1, respectively.
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Transfemoral Approach for Intraoperative Angiography in the Prone or Three-quarter Prone Position : A Revisited Protocol for Intracranial Arteriovenous Malformation and Fistula Surgery. Clin Neuroradiol 2019; 30:373-379. [PMID: 31037364 DOI: 10.1007/s00062-019-00783-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 04/12/2019] [Indexed: 11/26/2022]
Abstract
PURPOSE Among the different arterial accesses, the femoral access is the main approach for intraoperative angiography (IOA) performed in a prone position. Without a standardized protocol, however, the application of prone IOAs in intracranial arteriovenous malformation (AVM) or arteriovenous fistula (AVF) surgery remains limited by its procedural complexity. This study describes the detailed protocol for prone IOA through a transfemoral approach and highlights several refinements in preparing this procedure. METHODS This study retrospectively reviewed the intracranial or high cervical AVM/AVF surgical cases in which both resection and IOA were performed in the prone or three-quarter prone position. Extended femoral sheath approaches and radiolucent head clamps were used in all cases. An aneurysm clip, serving as a localization landmark in IOA, was routinely placed within the surgical field. The IOA imaging, clinical impact of IOA, and complications related to the procedure were recorded. RESULTS A total of six AVM and three AVF cases, operated on in the prone (n = 7) or three-quarter prone (n = 2) positions, were included. Multiple vessel injections were required in 66.7% of cases, and IOA was successfully performed in every intended vessel. All IOA images were adequate for interpretation, except for two cases in which the non-radiolucent component of the head clamp obscured the region of interest in the lateral views. Incomplete occlusion was identified in two patients, and the aneurysm clip provided precise guidance in localizing the residual nidus. Final IOA confirmed complete lesion removal in all cases, and there were no IOA-related complications. CONCLUSION Three key steps in setting-up a prone IOA procedure for intracranial AVM/AVF surgery are proposed: (1) utilize an extended femoral sheath approach, (2) establish a localization landmark with an aneurysm clip and (3) avoid possible image interference from the non-radiolucent component of the head clamp.
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Precision Measurement of the Branching Fractions of η^{'} Decays. PHYSICAL REVIEW LETTERS 2019; 122:142002. [PMID: 31050481 DOI: 10.1103/physrevlett.122.142002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Indexed: 06/09/2023]
Abstract
Based on a sample of (1310.6±7.0)×10^{6}J/ψ events collected with the BESIII detector, we present measurements of J/ψ and η^{'} absolute branching fractions using the process J/ψ→γη^{'}. By analyzing events where the radiative photon converts into an e^{+}e^{-} pair, the branching fraction for J/ψ→γη^{'} is measured to be (5.27±0.03±0.05)×10^{-3}. The absolute branching fractions of the five dominant decay channels of the η^{'} are then measured for the first time and are determined to be B(η^{'}→γπ^{+}π^{-})=(29.90±0.03±0.55)%, B(η^{'}→ηπ^{+}π^{-})=(41.24±0.08±1.24)%, B(η^{'}→ηπ^{0}π^{0})=(21.36±0.10±0.92)%, B(η^{'}→γω)=(2.489±0.018±0.074)%, and B(η^{'}→γγ)=(2.331±0.012±0.035)%, where the first uncertainties are statistical and the second systematic.
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Measurement of the Dynamics of the Decays D_{s}^{+}→η^{(')}e^{+}ν_{e}. PHYSICAL REVIEW LETTERS 2019; 122:121801. [PMID: 30978074 DOI: 10.1103/physrevlett.122.121801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/27/2019] [Indexed: 06/09/2023]
Abstract
Using e^{+}e^{-} annihilation data corresponding to an integrated luminosity of 3.19 fb^{-1} collected at a center-of-mass energy of 4.178 GeV with the BESIII detector, we measure the absolute branching fractions B_{D_{s}^{+}→ηe^{+}ν_{e}}=(2.323±0.063_{stat}±0.063_{syst})% and B_{D_{s}^{+}→η^{'}e^{+}ν_{e}}=(0.824±0.073_{stat}±0.027_{syst})% via a tagged analysis technique, where one D_{s} is fully reconstructed in a hadronic mode. Combining these measurements with previous BESIII measurements of B_{D^{+}→η^{(')}e^{+}ν_{e}}, the η-η^{'} mixing angle in the quark flavor basis is determined to be ϕ_{P}=(40.1±2.1_{stat}±0.7_{syst})°. From the first measurements of the dynamics of D_{s}^{+}→η^{(')}e^{+}ν_{e} decays, the products of the hadronic form factors f_{+}^{η^{(')}}(0) and the Cabibbo-Kobayashi-Maskawa matrix element |V_{cs}| are determined with different form factor parametrizations. For the two-parameter series expansion, the results are f_{+}^{η}(0)|V_{cs}|=0.4455±0.0053_{stat}±0.0044_{syst} and f_{+}^{η^{'}}(0)|V_{cs}|=0.477±0.049_{stat}±0.011_{syst}.
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Evidence of a Resonant Structure in the e^{+}e^{-}→π^{+}D^{0}D^{*-} Cross Section between 4.05 and 4.60 GeV. PHYSICAL REVIEW LETTERS 2019; 122:102002. [PMID: 30932669 DOI: 10.1103/physrevlett.122.102002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 02/10/2019] [Indexed: 06/09/2023]
Abstract
The cross section of the process e^{+}e^{-}→π^{+}D^{0}D^{*-} for center-of-mass energies from 4.05 to 4.60 GeV is measured precisely using data samples collected with the BESIII detector operating at the BEPCII storage ring. Two enhancements are clearly visible in the cross section around 4.23 and 4.40 GeV. Using several models to describe the dressed cross section yields stable parameters for the first enhancement, which has a mass of 4228.6±4.1±6.3 MeV/c^{2} and a width of 77.0±6.8±6.3 MeV, where the first uncertainties are statistical and the second ones are systematic. Our resonant mass is consistent with previous observations of the Y(4220) state and the theoretical prediction of a DD[over ¯]_{1}(2420) molecule. This result is the first observation of Y(4220) associated with an open-charm final state. Fits with three resonance functions with additional Y(4260), Y(4320), Y(4360), ψ(4415), or a new resonance do not show significant contributions from either of these resonances. The second enhancement is not from a single known resonance. It could contain contributions from ψ(4415) and other resonances, and a detailed amplitude analysis is required to better understand this enhancement.
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Determination of the Pseudoscalar Decay Constant f_{D_{s}^{+}} via D_{s}^{+}→μ^{+}ν_{μ}. PHYSICAL REVIEW LETTERS 2019; 122:071802. [PMID: 30848637 DOI: 10.1103/physrevlett.122.071802] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/18/2019] [Indexed: 06/09/2023]
Abstract
Using a 3.19 fb^{-1} data sample collected at an e^{+}e^{-} center-of-mass energy of E_{cm}=4.178 GeV with the BESIII detector, we measure the branching fraction of the leptonic decay D_{s}^{+}→μ^{+}ν_{μ} to be B_{D_{s}^{+}→μ^{+}ν_{μ}}=(5.49±0.16_{stat}±0.15_{syst})×10^{-3}. Combining our branching fraction with the masses of the D_{s}^{+} and μ^{+} and the lifetime of the D_{s}^{+}, we determine f_{D_{s}^{+}}|V_{cs}|=246.2±3.6_{stat}±3.5_{syst} MeV. Using the c→s quark mixing matrix element |V_{cs}| determined from a global standard model fit, we evaluate the D_{s}^{+} decay constant f_{D_{s}^{+}}=252.9±3.7_{stat}±3.6_{syst} MeV. Alternatively, using the value of f_{D_{s}^{+}} calculated by lattice quantum chromodynamics, we find |V_{cs}|=0.985±0.014_{stat}±0.014_{syst}. These values of B_{D_{s}^{+}→μ^{+}ν_{μ}}, f_{D_{s}^{+}}|V_{cs}|, f_{D_{s}^{+}} and |V_{cs}| are each the most precise results to date.
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First Measurement of the Form Factors in D_{s}^{+}→K^{0}e^{+}ν_{e} and D_{s}^{+}→K^{*0}e^{+}ν_{e} Decays. PHYSICAL REVIEW LETTERS 2019; 122:061801. [PMID: 30822077 DOI: 10.1103/physrevlett.122.061801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Indexed: 06/09/2023]
Abstract
We report on new measurements of Cabibbo-suppressed semileptonic D_{s}^{+} decays using 3.19 fb^{-1} of e^{+}e^{-} annihilation data sample collected at a center-of-mass energy of 4.178 GeV with the BESIII detector at the BEPCII collider. Our results include branching fractions B(D_{s}^{+}→K^{0}e^{+}ν_{e})=[3.25±0.38(stat)±0.16(syst)]×10^{-3} and B(D_{s}^{+}→K^{*0}e^{+}ν_{e})=[2.37±0.26(stat)±0.20(syst)]×10^{-3}, which are much improved relative to previous measurements, and the first measurements of the hadronic form-factor parameters for these decays. For D_{s}^{+}→K^{0}e^{+}ν_{e}, we obtain f_{+}(0)=0.720±0.084(stat)±0.013(syst), and for D_{s}^{+}→K^{*0}e^{+}ν_{e}, we find form-factor ratios r_{V}=V(0)/A_{1}(0)=1.67±0.34(stat)±0.16(syst) and r_{2}=A_{2}(0)/A_{1}(0)=0.77±0.28(stat)±0.07(syst).
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Observation of D^{+}→f_{0}(500)e^{+}ν_{e} and Improved Measurements of D→ρe^{+}ν_{e}. PHYSICAL REVIEW LETTERS 2019; 122:062001. [PMID: 30822062 DOI: 10.1103/physrevlett.122.062001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/03/2019] [Indexed: 06/09/2023]
Abstract
Using a data sample corresponding to an integrated luminosity of 2.93 fb^{-1} recorded by the BESIII detector at a center-of-mass energy of 3.773 GeV, we present an analysis of the decays D^{0}→π^{-}π^{0}e^{+}ν_{e} and D^{+}→π^{-}π^{+}e^{+}ν_{e}. By performing a partial wave analysis, the π^{+}π^{-} S-wave contribution to D^{+}→π^{-}π^{+}e^{+}ν_{e} is observed to be (25.7±1.6±1.1)% with a statistical significance greater than 10σ, besides the dominant P-wave contribution. This is the first observation of the S-wave contribution. We measure the branching fractions B(D^{0}→ρ^{-}e^{+}ν_{e})=(1.445±0.058±0.039)×10^{-3}, B(D^{+}→ρ^{0}e^{+}ν_{e})=(1.860±0.070±0.061)×10^{-3}, and B(D^{+}→f_{0}(500)e^{+}ν_{e},f_{0}(500)→π^{+}π^{-})=(6.30±0.43±0.32)×10^{-4}. An upper limit of B(D^{+}→f_{0}(980)e^{+}ν_{e},f_{0}(980)→π^{+}π^{-})<2.8×10^{-5} is set at the 90% confidence level. We also obtain the hadronic form factor ratios of D→ρe^{+}ν_{e} at q^{2}=0 assuming the single-pole dominance parametrization: r_{V}={[V(0)]/[A_{1}(0)]}=1.695±0.083±0.051, r_{2}={[A_{2}(0)]/[A_{1}(0)]}=0.845±0.056±0.039.
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Hierarchical measurement structure in the Women's Health Questionnaire: a confirmatory factor analysis. Climacteric 2019; 22:448-453. [PMID: 30712399 DOI: 10.1080/13697137.2018.1564270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Purpose: This study conducted confirmatory factor analysis (CFA) to examine the measurement structure of the Women's Health Questionnaire (WHQ) and how its components were organized. Methods: Participants were 448 postmenopausal women, with a mean age of 63.3 years. CFA was conducted to test how well several proposed measurement models fit the data. Results: The single-factor model performed poorly, indicating the presence of multiple factors. The model with seven correlated factors fit the data well, although the varying degrees of inter-factor correlations suggested grouping of similar factors. The hierarchical measurement structure, with seven first-order factors organized under two second-order factors of physical health and mental health functioning, demonstrated a good fit with the data (χ2(367) = 694.05, p < 0.001; root mean square error of approximation = 0.05; comparative fit index = 0.95) and a meaningful pattern. The Mental Health factor was represented by Depressed Mood, Anxiety/Fear, Memory/Concentration Problems, and Sleep Problems. The Physical Health factor was manifested mainly by Somatic Symptoms, Menstrual Symptoms, and Vasomotor Symptoms, and, to a lesser extent, also by Sleep Problems and Memory/Concentration Problems. Conclusion: Findings suggested that, in addition to a global index and subscale scores, the WHQ may produce summary scores of physical health and mental health functioning in evaluation of well-being among postmenopausal women.
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Study of the D^{0}→K^{-}μ^{+}ν_{μ} Dynamics and Test of Lepton Flavor Universality with D^{0}→K^{-}ℓ^{+}ν_{ℓ} Decays. PHYSICAL REVIEW LETTERS 2019; 122:011804. [PMID: 31012671 DOI: 10.1103/physrevlett.122.011804] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 11/30/2018] [Indexed: 06/09/2023]
Abstract
Using e^{+}e^{-} annihilation data of 2.93 fb^{-1} collected at center-of-mass energy sqrt[s]=3.773 GeV with the BESIII detector, we measure the absolute branching fraction of D^{0}→K^{-}μ^{+}ν_{μ} with significantly improved precision: B_{D^{0}→K^{-}μ^{+}ν_{μ}}=(3.413±0.019_{stat}±0.035_{syst})%. Combining with our previous measurement of B_{D^{0}→K^{-}e^{+}ν_{e}}, the ratio of the two branching fractions is determined to be B_{D^{0}→K^{-}μ^{+}ν_{μ}}/B_{D^{0}→K^{-}e^{+}ν_{e}}=0.974±0.007_{stat}±0.012_{syst}, which agrees with the theoretical expectation of lepton flavor universality within the uncertainty. A study of the ratio of the two branching fractions in different four-momentum transfer regions is also performed, and no evidence for lepton flavor universality violation is found with current statistics. Taking inputs from global fit in the standard model and lattice quantum chromodynamics separately, we determine f_{+}^{K}(0)=0.7327±0.0039_{stat}±0.0030_{syst} and |V_{cs}|=0.955±0.005_{stat}±0.004_{syst}±0.024_{LQCD}.
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Measurement of the Absolute Branching Fraction of the Inclusive Semileptonic Λ_{c}^{+} Decay. PHYSICAL REVIEW LETTERS 2018; 121:251801. [PMID: 30608802 DOI: 10.1103/physrevlett.121.251801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Indexed: 06/09/2023]
Abstract
Using a data sample of e^{+}e^{-} collisions corresponding to an integrated luminosity of 567 pb^{-1} collected at a center-of-mass energy of sqrt[s]=4.6 GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive semileptonic Λ_{c}^{+} decay with a double-tag method. We obtain B(Λ_{c}^{+}→Xe^{+}ν_{e})=(3.95±0.34±0.09)%, where the first uncertainty is statistical and the second systematic. Using the known Λ_{c}^{+} lifetime and the charge-averaged semileptonic decay width of nonstrange charmed mesons (D^{0} and D^{+}), we obtain the ratio of the inclusive semileptonic decay widths Γ(Λ_{c}^{+}→Xe^{+}ν_{e})/Γ[over ¯](D→Xe^{+}ν_{e})=1.26±0.12.
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Measurement of the Branching Fraction For the Semileptonic Decay D^{0(+)}→π^{-(0)}μ^{+}ν_{μ} and Test of Lepton Flavor Universality. PHYSICAL REVIEW LETTERS 2018; 121:171803. [PMID: 30411926 DOI: 10.1103/physrevlett.121.171803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 09/26/2018] [Indexed: 06/08/2023]
Abstract
Using a data sample corresponding to an integrated luminosity of 2.93 fb^{-1} taken at a center-of-mass energy of 3.773 GeV with the BESIII detector operated at the BEPCII collider, we perform an analysis of the semileptonic decays D^{0(+)}→π^{-(0)}μ^{+}ν_{μ}. The branching fractions of D^{0}→π^{-}μ^{+}ν_{μ} and D^{+}→π^{0}μ^{+}ν_{μ} are measured to be (0.272±0.008_{stat}±0.006_{syst})% and (0.350±0.011_{stat}±0.010_{syst})%, respectively, where the former is of much improved precision compared to previous results and the latter is determined for the first time. Using these results along with previous BESIII measurements of D^{0(+)}→π^{-(0)}e^{+}ν_{e}, we calculate the branching fraction ratios to be R^{0}≡B_{D^{0}→π^{-}μ^{+}ν_{μ}}/B_{D^{0}→π^{-}e^{+}ν_{e}}=0.922±0.030_{stat}±0.022_{syst} and R^{+}≡B_{D^{+}→π^{0}μ^{+}ν_{μ}}/B_{D^{+}→π^{0}e^{+}ν_{e}}=0.964±0.037_{stat}±0.026_{syst}, which are compatible with the theoretical expectation of lepton flavor universality within 1.7σ and 0.5σ, respectively. We also examine the branching fraction ratios in different four-momentum transfer square regions, and find no significant deviations from the standard model predictions.
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Observation of the Semileptonic Decay D^{0}→a_{0}(980)^{-}e^{+}ν_{e} and Evidence for D^{+}→a_{0}(980)^{0}e^{+}ν_{e}. PHYSICAL REVIEW LETTERS 2018; 121:081802. [PMID: 30192571 DOI: 10.1103/physrevlett.121.081802] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/20/2018] [Indexed: 06/08/2023]
Abstract
Using an e^{+}e^{-} collision data sample of 2.93 fb^{-1} collected at a center-of-mass energy of 3.773 GeV by the BESIII detector at BEPCII, we report the observation of D^{0}→a_{0}(980)^{-}e^{+}ν_{e} and evidence for D^{+}→a_{0}(980)^{0}e^{+}ν_{e} with significances of 6.4σ and 2.9σ, respectively. The absolute branching fractions are determined to be B(D^{0}→a_{0}(980)^{-}e^{+}ν_{e})×B(a_{0}(980)^{-}→ηπ^{-})=[1.33_{-0.29}^{+0.33}(stat)±0.09(syst)]×10^{-4} and B(D^{+}→a_{0}(980)^{0}e^{+}ν_{e})×B(a_{0}(980)^{0}→ηπ^{0})=[1.66_{-0.66}^{+0.81}(stat)±0.11(syst)]×10^{-4}. This is the first time the a_{0}(980) meson has been measured in a D^{0} semileptonic decay, which would open one more interesting page in the investigation of the nature of the puzzling a_{0}(980) states.
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Measurement of the Absolute Branching Fraction of the Inclusive Decay Λ_{c}^{+}→Λ+X. PHYSICAL REVIEW LETTERS 2018; 121:062003. [PMID: 30141643 DOI: 10.1103/physrevlett.121.062003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 06/11/2018] [Indexed: 06/08/2023]
Abstract
Based on an e^{+}e^{-} collision data sample corresponding to an integrated luminosity of 567 pb^{-1} taken at the center-of-mass energy of sqrt[s]=4.6 GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive decay Λ_{c}^{+}→Λ+X to be B(Λ_{c}^{+}→Λ+X)=(38.2_{-2.2}^{+2.8}±0.9)% using the double-tag method, where X refers to any possible final state particles. In addition, we search for direct CP violation in the charge asymmetry of this inclusive decay for the first time, and obtain A_{CP}≡[B(Λ_{c}^{+}→Λ+X)-B(Λ[over ¯]_{c}^{-}→Λ[over ¯]+X)]/[B(Λ_{c}^{+}→Λ+X)+B(Λ[over ¯]_{c}^{-}→Λ[over ¯]+X)]=(2.1_{-6.6}^{+7.0}±1.6)%, a statistically limited result with no evidence of CP violation.
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Observation of a_{0}^{0}(980)-f_{0}(980) Mixing. PHYSICAL REVIEW LETTERS 2018; 121:022001. [PMID: 30085761 DOI: 10.1103/physrevlett.121.022001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/08/2018] [Indexed: 06/08/2023]
Abstract
We report the first observation of a_{0}^{0}(980)-f_{0}(980) mixing in the decays of J/ψ→ϕf_{0}(980)→ϕa_{0}^{0}(980)→ϕηπ^{0} and χ_{c1}→a_{0}^{0}(980)π^{0}→f_{0}(980)π^{0}→π^{+}π^{-}π^{0}, using data samples of 1.31×10^{9} J/ψ events and 4.48×10^{8} ψ(3686) events accumulated with the BESIII detector. The signals of f_{0}(980)→a_{0}^{0}(980) and a_{0}^{0}(980)→f_{0}(980) mixing are observed at levels of statistical significance of 7.4σ and 5.5σ, respectively. The corresponding branching fractions and mixing intensities are measured and the constraint regions on the coupling constants, g_{a_{0}K^{+}K^{-}} and g_{f_{0}K^{+}K^{-}}, are estimated. The results improve the understanding of the nature of a_{0}^{0}(980) and f_{0}(980).
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Precision Study of η^{'}→γπ^{+}π^{-} Decay Dynamics. PHYSICAL REVIEW LETTERS 2018; 120:242003. [PMID: 29956981 DOI: 10.1103/physrevlett.120.242003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/25/2018] [Indexed: 06/08/2023]
Abstract
Using a low background data sample of 9.7×10^{5} J/ψ→γη^{'}, η^{'}→γπ^{+}π^{-} events, which are 2 orders of magnitude larger than those from the previous experiments, recorded with the BESIII detector at BEPCII, the decay dynamics of η^{'}→γπ^{+}π^{-} are studied with both model-dependent and model-independent approaches. The contributions of ω and the ρ(770)-ω interference are observed for the first time in the decays η^{'}→γπ^{+}π^{-} in both approaches. Additionally, a contribution from the box anomaly or the ρ(1450) resonance is required in the model-dependent approach, while the process specific part of the decay amplitude is determined in the model-independent approach.
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Impact of Intraoperative 3-Dimensional Volume-Rendering Rotational Angiography on Clip Repositioning Rates in Aneurysmal Surgery. World Neurosurg 2018; 114:e573-e580. [DOI: 10.1016/j.wneu.2018.03.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/02/2018] [Accepted: 03/05/2018] [Indexed: 12/20/2022]
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Precision Measurement of the e^{+}e^{-}→Λ_{c}^{+}Λ[over ¯]_{c}^{-} Cross Section Near Threshold. PHYSICAL REVIEW LETTERS 2018; 120:132001. [PMID: 29694170 DOI: 10.1103/physrevlett.120.132001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/18/2017] [Indexed: 06/08/2023]
Abstract
The cross section of the e^{+}e^{-}→Λ_{c}^{+}Λ[over ¯]_{c}^{-} process is measured with unprecedented precision using data collected with the BESIII detector at sqrt[s]=4574.5, 4580.0, 4590.0 and 4599.5 MeV. The nonzero cross section near the Λ_{c}^{+}Λ[over ¯]_{c}^{-} production threshold is cleared. At center-of-mass energies sqrt[s]=4574.5 and 4599.5 MeV, the higher statistics data enable us to measure the Λ_{c} polar angle distributions. From these, the Λ_{c} electric over magnetic form-factor ratios (|G_{E}/G_{M}|) are measured for the first time. They are found to be 1.14±0.14±0.07 and 1.23±0.05±0.03, respectively, where the first uncertainties are statistical and the second are systematic.
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Determination of the Spin and Parity of the Z_{c}(3900). PHYSICAL REVIEW LETTERS 2017; 119:072001. [PMID: 28949653 DOI: 10.1103/physrevlett.119.072001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Indexed: 06/07/2023]
Abstract
The spin and parity of the Z_{c}(3900)^{±} state are determined to be J^{P}=1^{+} with a statistical significance larger than 7σ over other quantum numbers in a partial wave analysis of the process e^{+}e^{-}→π^{+}π^{-}J/ψ. We use a data sample of 1.92 fb^{-1} accumulated at sqrt[s]=4.23 and 4.26 GeV with the BESIII experiment. When parametrizing the Z_{c}(3900)^{±} with a Flatté-like formula, we determine its pole mass M_{pole}=(3881.2±4.2_{stat}±52.7_{syst}) MeV/c^{2} and pole width Γ_{pole}=(51.8±4.6_{stat}±36.0_{syst}) MeV. We also measure cross sections for the process e^{+}e^{-}→Z_{c}(3900)^{+}π^{-}+c.c.→J/ψπ^{+}π^{-} and determine an upper limit at the 90% confidence level for the process e^{+}e^{-}→Z_{c}(4020)^{+}π^{-}+c.c.→J/ψπ^{+}π^{-}.
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Observation of Λ_{c}^{+}→nK_{S}^{0}π^{+}. PHYSICAL REVIEW LETTERS 2017; 118:112001. [PMID: 28368651 DOI: 10.1103/physrevlett.118.112001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Indexed: 06/07/2023]
Abstract
We report the first direct measurement of decays of the Λ_{c}^{+} baryon involving the neutron. The analysis is performed using 567 pb^{-1} of e^{+}e^{-} collision data collected at sqrt[s]=4.599 GeV with the BESIII detector at the BEPCII collider. We observe the decay Λ_{c}^{+}→nK_{S}^{0}π^{+} and measure the absolute branching fraction to be B(Λ_{c}^{+}→nK_{S}^{0}π^{+})=[1.82±0.23(stat)±0.11(syst)]%. A comparison to B[Λ_{c}^{+}→p(K[over ¯]π)^{0}] provides an important test of isospin symmetry and final state interactions.
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Precise Measurement of the e^{+}e^{-}→π^{+}π^{-}J/ψ Cross Section at Center-of-Mass Energies from 3.77 to 4.60 GeV. PHYSICAL REVIEW LETTERS 2017; 118:092001. [PMID: 28306266 DOI: 10.1103/physrevlett.118.092001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Indexed: 06/06/2023]
Abstract
The cross section for the process e^{+}e^{-}→π^{+}π^{-}J/ψ is measured precisely at center-of-mass energies from 3.77 to 4.60 GeV using 9 fb^{-1} of data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of (4222.0±3.1±1.4) MeV/c^{2} and a width of (44.1±4.3±2.0) MeV, while the second one has a mass of (4320.0±10.4±7.0) MeV/c^{2} and a width of (101.4_{-19.7}^{+25.3}±10.2) MeV, where the first errors are statistical and second ones are systematic. The first resonance agrees with the Y(4260) resonance reported by previous experiments. The precision of its resonant parameters is improved significantly. The second resonance is observed in e^{+}e^{-}→π^{+}π^{-}J/ψ for the first time. The statistical significance of this resonance is estimated to be larger than 7.6σ. The mass and width of the second resonance agree with the Y(4360) resonance reported by the BABAR and Belle experiments within errors. Finally, the Y(4008) resonance previously observed by the Belle experiment is not confirmed in the description of the BESIII data.
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Evidence of Two Resonant Structures in e^{+}e^{-}→π^{+}π^{-}h_{c}. PHYSICAL REVIEW LETTERS 2017; 118:092002. [PMID: 28306302 DOI: 10.1103/physrevlett.118.092002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Indexed: 06/06/2023]
Abstract
The cross sections of e^{+}e^{-}→π^{+}π^{-}h_{c} at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e^{+}e^{-}→π^{+}π^{-}J/ψ and e^{+}e^{-}→π^{+}π^{-}ψ(2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e^{+}e^{-}→π^{+}π^{-}h_{c} cross sections around 4.22 and 4.39 GeV/c^{2}, which we call Y(4220) and Y(4390), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4_{-4.5}^{+5.5}±0.9) MeV/c^{2} and a width of (66.0_{-8.3}^{+12.3}±0.4) MeV for the Y(4220), and a mass of (4391.5_{-6.8}^{+6.3}±1.0) MeV/c^{2} and a width of (139.5_{-20.6}^{+16.2}±0.6) MeV for the Y(4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y(4220) and Y(4390) is 10σ over one structure assumption.
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Amplitude Analysis of the Decays η^{'}→π^{+}π^{-}π^{0} and η^{'}→π^{0}π^{0}π^{0}. PHYSICAL REVIEW LETTERS 2017; 118:012001. [PMID: 28106414 DOI: 10.1103/physrevlett.118.012001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Indexed: 06/06/2023]
Abstract
Based on a sample of 1.31×10^{9} J/ψ events collected with the BESIII detector, an amplitude analysis of the isospin-violating decays η^{'}→π^{+}π^{-}π^{0} and η^{'}→π^{0}π^{0}π^{0} is performed. A significant P-wave contribution from η^{'}→ρ^{±}π^{∓} is observed for the first time in η^{'}→π^{+}π^{-}π^{0}. The branching fraction is determined to be B(η^{'}→ρ^{±}π^{∓})=(7.44±0.60±1.26±1.84)×10^{-4}, where the first uncertainty is statistical, the second systematic, and the third model dependent. In addition to the nonresonant S-wave component, there is a significant σ meson component. The branching fractions of the combined S-wave components are determined to be B(η^{'}→π^{+}π^{-}π^{0})_{S}=(37.63±0.77±2.22±4.48)×10^{-4} and B(η^{'}→π^{0}π^{0}π^{0})=(35.22±0.82±2.54)×10^{-4}, respectively. The latter one is consistent with previous BESIII measurements.
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Measurement of Singly Cabibbo Suppressed Decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}. PHYSICAL REVIEW LETTERS 2016; 117:232002. [PMID: 27982610 DOI: 10.1103/physrevlett.117.232002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Indexed: 06/06/2023]
Abstract
Using 567 pb^{-1} of data collected with the BESIII detector at a center-of-mass energy of sqrt[s]=4.599 GeV, near the Λ_{c}^{+}Λ[over ¯]_{c}^{-} threshold, we study the singly Cabibbo-suppressed decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}. By normalizing with respect to the Cabibbo-favored decay Λ_{c}^{+}→pK^{-}π^{+}, we obtain ratios of branching fractions: [B(Λ_{c}^{+}→pπ^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(6.70±0.48±0.25)%, [B(Λ_{c}^{+}→pϕ)/B(Λ_{c}^{+}→pK^{-}π^{+})]=(1.81±0.33±0.13)%, and [B(Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(9.36±2.22±0.71)×10^{-3}, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay Λ_{c}^{+}→pπ^{+}π^{-} is observed for the first time, and the precision of the branching fraction for Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-} and Λ_{c}^{+}→pϕ is significantly improved.
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[Clinical analysis of acute dimethylformamide poisoning]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2016; 34:854-855. [PMID: 28043282 DOI: 10.3760/cma.j.issn.1001-9391.2016.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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[Occupational hazard risk assessment of workers exposed to benzene in a petrochemical enterprise in Shanghai, China]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2016; 34:746-749. [PMID: 28043246 DOI: 10.3760/cma.j.issn.1001-9391.2016.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Objective: To investigate the exposure to benzene, methylbenzene, and dimethylbenzene in workers in a petrochemical enterprise in Shanghai, China, and to conduct occupational hazard risk assessment. Methods: The environmental monitoring data on benzene series in the workplace of this petrochemical enterprise from 2010 to 2014 were collected, as well as workers' general status. The inhalation risk assessment model developed by United States Environmental Protection Agency (EPA) was used for risk assessment to determine the occupational hazard risk level of benzene, methylbenzene, and dimethylbenzene. Results: The pass rate of the monitoring concentration of benzene, methylbenzene, and dimethylbenzene in the workplace of this petrochemical enterprise was 100%. The results of the EPA model showed that benzene had a high carcinogenic risk, benzene and dimethylbenzene had a high non-carcinogenic risk, and methylbenzene had a low non-carcinogenic risk. Conclusion: The workers exposed to benzene in this petrochemical enterprise have a high health risk, and the EPA model can be used for occupational hazard risk assessment in chemical industry.
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The effect of an integrated education model on anxiety and uncertainty in patients undergoing cervical disc herniation surgery. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2016; 133:17-23. [PMID: 27393796 DOI: 10.1016/j.cmpb.2016.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 05/11/2016] [Accepted: 05/14/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Educating patients about receiving surgical procedures is becoming an important issue, as it can reduce anxiety and uncertainty while helping to hasten decisions for undergoing time sensitive surgeries. We evaluated a new integrated education model for patients undergoing cervical disc herniation surgery using a quasi-experimental design. METHODS The participants were grouped into either the new integrated educational model (n = 32) or the standard group (n = 32) on the basis of their ward numbers assigned at admission. Anxiety, uncertainty, and patient satisfaction were measured before (pre-test) and after the educational intervention (post-test-1) and post-surgery (post-test-2) to assess the effectiveness of the model in this intervention. RESULTS We found that the generalized estimating equation modeling demonstrated this new integrated education model was more effective than the conventional model in reducing patients' anxiety and uncertainty (p <0.05). Patients were also more satisfied with our newly developed model as it takes a more holistic approach to individual health. CONCLUSION This novel systemic educational model enhances patient's understanding of the medical condition and surgery while promoting patient-caregiver interaction for optimal patient health outcomes. We present a comprehensive and consistent platform for educational purposes in patients undergoing surgery as well as reducing the psychological burden from anxiety and uncertainty. Integrating medicine, nursing, and new technologies into an e-practice and e-learning platform offers the potential of easier understanding and usage. It could revolutionize patient education in the future.
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Observation of an Anomalous Line Shape of the η^{'}π^{+}π^{-} Mass Spectrum near the pp[over ¯] Mass Threshold in J/ψ→γη^{'}π^{+}π^{-}. PHYSICAL REVIEW LETTERS 2016; 117:042002. [PMID: 27494467 DOI: 10.1103/physrevlett.117.042002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Indexed: 06/06/2023]
Abstract
Using 1.09×10^{9} J/ψ events collected by the BESIII experiment in 2012, we study the J/ψ→γη^{'}π^{+}π^{-} process and observe a significant abrupt change in the slope of the η^{'}π^{+}π^{-} invariant mass distribution at the proton-antiproton (pp[over ¯]) mass threshold. We use two models to characterize the η^{'}π^{+}π^{-} line shape around 1.85 GeV/c^{2}: one that explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatté formula), and another that is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around 1.85 GeV/c^{2} with strong couplings to the pp[over ¯] final states or a narrow state just below the pp[over ¯] mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a pp[over ¯] moleculelike state or bound state with greater than 7σ significance.
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Novel treatment of symptomatic pontine Virchow-Robin space. Kaohsiung J Med Sci 2016; 32:336-7. [PMID: 27377849 DOI: 10.1016/j.kjms.2016.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 02/19/2016] [Accepted: 02/24/2016] [Indexed: 11/18/2022] Open
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Observation of h_{c} Radiative Decay h_{c}→γη^{'} and Evidence for h_{c}→γη. PHYSICAL REVIEW LETTERS 2016; 116:251802. [PMID: 27391715 DOI: 10.1103/physrevlett.116.251802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Indexed: 06/06/2023]
Abstract
A search for radiative decays of the P-wave spin singlet charmonium resonance h_{c} is performed based on 4.48×10^{8} ψ^{'} events collected with the BESIII detector operating at the BEPCII storage ring. Events of the reaction channels h_{c}→γη^{'} and γη are observed with a statistical significance of 8.4σ and 4.0σ, respectively, for the first time. The branching fractions of h_{c}→γη^{'} and h_{c}→γη are measured to be B(h_{c}→γη^{'})=(1.52±0.27±0.29)×10^{-3} and B(h_{c}→γη)=(4.7±1.5±1.4)×10^{-4}, respectively, where the first errors are statistical and the second are systematic uncertainties.
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[Clinical analysis on 473 cases of occupational acute acrylonitrile poisoning]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2016; 34:367-369. [PMID: 27514420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Observation of the Singly Cabibbo-Suppressed Decay D^{+}→ωπ^{+} and Evidence for D^{0}→ωπ^{0}. PHYSICAL REVIEW LETTERS 2016; 116:082001. [PMID: 26967411 DOI: 10.1103/physrevlett.116.082001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Indexed: 06/05/2023]
Abstract
Based on 2.93 fb^{-1} e^{+}e^{-} collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report searches for the singly Cabibbo-suppressed decays D^{+}→ωπ^{+} and D^{0}→ωπ^{0}. A double tag technique is used to measure the absolute branching fractions B(D^{+}→ωπ^{+})=(2.79±0.57±0.16)×10^{-4} and B(D^{0}→ωπ^{0})=(1.17±0.34±0.07)×10^{-4}, with statistical significances of 5.5σ and 4.1σ, where the first and second uncertainties are statistical and systematic, respectively.
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Measurements of Absolute Hadronic Branching Fractions of the Λ_{c}^{+} Baryon. PHYSICAL REVIEW LETTERS 2016; 116:052001. [PMID: 26894702 DOI: 10.1103/physrevlett.116.052001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Indexed: 06/05/2023]
Abstract
We report the first measurement of absolute hadronic branching fractions of Λ_{c}^{+} baryon at the Λ_{c}^{+}Λ[over ¯]_{c}^{-} production threshold, in the 30 years since the Λ_{c}^{+} discovery. In total, 12 Cabibbo-favored Λ_{c}^{+} hadronic decay modes are analyzed with a double-tag technique, based on a sample of 567 pb^{-1} of e^{+}e^{-} collisions at sqrt[s]=4.599 GeV recorded with the BESIII detector. A global least-squares fitter is utilized to improve the measured precision. Among the measurements for twelve Λ_{c}^{+} decay modes, the branching fraction for Λ_{c}^{+}→pK^{-}π^{+} is determined to be (5.84±0.27±0.23)%, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other 11 Cabibbo-favored hadronic decay modes are significantly improved.
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Measurement of Azimuthal Asymmetries in Inclusive Charged Dipion Production in e^{+}e^{-} Annihilations at sqrt[s]=3.65 GeV. PHYSICAL REVIEW LETTERS 2016; 116:042001. [PMID: 26871323 DOI: 10.1103/physrevlett.116.042001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 06/05/2023]
Abstract
We present a measurement of the azimuthal asymmetries of two charged pions in the inclusive process e^{+}e^{-}→ππX, based on a data set of 62 pb^{-1} at the center-of-mass energy of 3.65 GeV collected with the BESIII detector. These asymmetries can be attributed to the Collins fragmentation function. We observe a nonzero asymmetry, which increases with increasing pion momentum. As our energy scale is close to that of the existing semi-inclusive deep inelastic scattering experimental data, the measured asymmetries are important inputs for the global analysis of extracting the quark transversity distribution inside the nucleon and are valuable to explore the energy evolution of the spin-dependent fragmentation function.
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Observation of a Neutral Structure near the DD[over ¯]^{*} Mass Threshold in e^{+}e^{-}→(DD[over ¯]^{*})^{0}π^{0} at sqrt[s]=4.226 and 4.257 GeV. PHYSICAL REVIEW LETTERS 2015; 115:222002. [PMID: 26650295 DOI: 10.1103/physrevlett.115.222002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Indexed: 06/05/2023]
Abstract
A neutral structure in the DD[over ¯]^{*} system around the DD[over ¯]^{*} mass threshold is observed with a statistical significance greater than 10σ in the processes e^{+}e^{-}→D^{+}D^{*-}π^{0}+c.c. and e^{+}e^{-}→D^{0}D[over ¯]^{*0}π^{0}+c.c. at sqrt[s]=4.226 and 4.257 GeV in the BESIII experiment. The structure is denoted as Z_{c}(3885)^{0}. Assuming the presence of a resonance, its pole mass and width are determined to be [3885.7_{-5.7}^{+4.3}(stat)±8.4(syst)] MeV/c^{2} and [35_{-12}^{+11}(stat)±15(syst)] MeV, respectively. The Born cross sections are measured to be σ[e^{+}e^{-}→Z_{c}(3885)^{0}π^{0},Z_{c}(3885)^{0}→DD[over ¯]^{*}]=[77±13(stat)±17(syst)] pb at 4.226 GeV and [47±9(stat)±10(syst)] pb at 4.257 GeV. The ratio of decay rates B[Z_{c}(3885)^{0}→D^{+}D^{*-}+c.c.]/B[Z_{c}(3885)^{0}→D^{0}D[over ¯]^{*0}+c.c.] is determined to be 0.96±0.18(stat)±0.12(syst), consistent with no isospin violation in the process, Z_{c}(3885)^{0}→DD[over ¯]^{*}.
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