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Comparison of the Efficacy of Three Natural Surfactants in Preterm Turkish Newborns with Respiratory Distress Syndrome. THE JOURNAL OF PEDIATRIC RESEARCH 2021. [DOI: 10.4274/jpr.galenos.2020.04864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Is there a relationship between causative microorganisms and hearing loss in neonatal sepsis? Birth Defects Res 2021; 113:894-900. [PMID: 33427412 DOI: 10.1002/bdr2.1867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 11/27/2020] [Accepted: 12/21/2020] [Indexed: 11/12/2022]
Abstract
BACKGROUND The aim of the present study was to determine the possible relationship between cultured microorganisms and hearing loss in infants admitted to the neonatal intensive care unit (NICU) who could not pass a standard hearing test. METHOD The medical records of infants treated at the NICU were retrospectively evaluated. The patients were first divided into two groups, and group 1 was divided into two subgroups: Group 1 included patients with hearing loss accompanied by proven sepsis caused by either gram-negative (group 1A) or gram-positive (group 1B) bacteria, and group 2 included patients with clinical sepsis. The groups were compared with potential risk factors related to hearing loss. RESULTS Between January 2014 and January 2019, the cases of 3,800 infants admitted to the NICU were reviewed. Of 3,548 living babies, the Auditory Brainstem Response (ABR) test showed that 35 infants (0.98%) were diagnosed with hearing loss. In 12 infants with hearing loss, microbial growth in the blood cultures was detected, whereas in the remaining 23, the blood cultures were negative. Of the cases with microbial growth, five were gram negative and seven were gram positive. In the comparison of groups 1A, 1B, and 2, there were statistically significant differences in terms of risk factors such as low birth weight (p = .048), neonatal hospitalization time (p = .001), free oxygen support (p = .001), intraventricular bleeding (p = .001), loop diuretic use (p = .001), and blood transfusion (p = .048). CONCLUSION The relationship between hearing loss and microorganisms causing sepsis could not be determined in this research.
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Clinical characteristics and neonatal outcomes of liveborn newborns with hydrops fetalis treated in a tertiary level neonatal intensive care unit. Birth Defects Res 2020; 112:515-522. [PMID: 32212385 DOI: 10.1002/bdr2.1640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 12/06/2019] [Accepted: 12/17/2019] [Indexed: 01/30/2023]
Abstract
BACKGROUND This study was performed for examining the neonatal results and aetiological factors of neonates with hydrops fetalis (HF) and determining the factors affecting mortality. METHODS The medical records of liveborn neonates with HF who were admitted to a tertiary Neonatal Intensive Care Unit (NICU) in Konya, Turkey, between 2013 and 2019 were reviewed retrospectively. The demographic data, prenatal intervention, clinical findings, and results of the patients were recorded. RESULTS A total of 32.6% of the 46 liveborn HF infants had immune HF (IHF), while 67.4% had nonimmune HF (NIHF); there was prenatal diagnoses in 39 (84.7%) cases. Cordocentesis and blood transfusion (n = 14; 30.4%) were the prenatal diagnosis and treatment interventions with the highest rate. A total of 16 patients (34.7%) received in utero interventional treatment. It was determined that the mean gestational age was not associated with mortality; moreover, birthweight (BW), Apgar score and the need for mechanical ventilation affected mortality. CONCLUSION The prognosis changes according to different etiologies of HF. However, despite the developments in neonatal care, mortality is still high in HF infants.
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A single-blind, randomised controlled trial on the effects of lithium and quetiapine monotherapy on the trajectory of cognitive functioning in first episode mania: A 12-month follow-up study. Eur Psychiatry 2020; 31:20-8. [DOI: 10.1016/j.eurpsy.2015.09.460] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/25/2015] [Accepted: 09/27/2015] [Indexed: 11/30/2022] Open
Abstract
AbstractBackgroundCognitive deficits have been reported during the early stages of bipolar disorder; however, the role of medication on such deficits remains unclear. The aim of this study was to compare the effects of lithium and quetiapine monotherapy on cognitive performance in people following first episode mania.MethodsThe design was a single-blind, randomised controlled trial on a cohort of 61 participants following first episode mania. Participants received either lithium or quetiapine monotherapy as maintenance treatment over a 12-month follow-up period. The groups were compared on performance outcomes using an extensive cognitive assessment battery conducted at baseline, month 3 and month 12 follow-up time-points.ResultsThere was a significant interaction between group and time in phonemic fluency at the 3-month and 12-month endpoints, reflecting greater improvements in performance in lithium-treated participants relative to quetiapine-treated participants. After controlling for multiple comparisons, there were no other significant interactions between group and time for other measures of cognition.ConclusionAlthough the effects of lithium and quetiapine treatment were similar for most cognitive domains, the findings imply that early initiation of lithium treatment may benefit the trajectory of cognition, specifically verbal fluency in young people with bipolar disorder. Given that cognition is a major symptomatic domain of bipolar disorder and has substantive effects on general functioning, the ability to influence the trajectory of cognitive change is of considerable clinical importance.
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Prediction of the development of pulmonary arterial hypertension with Tei Index in congenital heart diseases with left-to-right shunt. Turk Kardiyol Dern Ars 2020; 47:466-475. [PMID: 31483301 DOI: 10.5543/tkda.2019.33558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE The aim of this study was to determine the usefulness of the Tei Index, an echocardiographic parameter, in the early determination of pulmonary artery pressure (PAP) in congenital heart disease (CHD) with a left-to-right shunt. METHODS Right and left ventricular functions were evaluated using Tei Index values determined with tissue Doppler echocardiography. Cardiac catheterization was performed in all cases. The presence of pulmonary arterial hypertension (PAH) was defined as a mean PAP of ≥25 mm Hg and a pulmonary vascular resistance index of >3 WU/m2. Patients with a pulmonary/systemic blood flow ratio of ≥2 were considered candidates for surgery. RESULTS The Tei Index values measured from the left ventricular posterior wall and the right ventricular anterior wall were found to be significantly higher in the patients with PAH (0.68±0.18, 0.67±0.16, respectively) compared with the patients without PAH (0.56±0.16, p=0.027; 0.51±0.12 p=0.001). A significant correlation was detected between the Tei Index value measured from the left ventricular posterior wall and the mean PAP (correlation coefficient: 0.491). CONCLUSION The right ventricular Tei Index values in children with CHD and a left-to-right shunt can be used as a parameter to follow up on the potential development of PAH, to make a diagnosis in the early period, and to make a timely decision about surgery.
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Author Correction: Forearc carbon sink reduces long-term volatile recycling into the mantle. Nature 2019; 575:E6. [PMID: 31712624 DOI: 10.1038/s41586-019-1756-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An Amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Manifesto for a European research network into Problematic Usage of the Internet. Eur Neuropsychopharmacol 2018; 28:1232-1246. [PMID: 30509450 PMCID: PMC6276981 DOI: 10.1016/j.euroneuro.2018.08.004] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/18/2018] [Accepted: 08/07/2018] [Indexed: 12/24/2022]
Abstract
The Internet is now all-pervasive across much of the globe. While it has positive uses (e.g. prompt access to information, rapid news dissemination), many individuals develop Problematic Use of the Internet (PUI), an umbrella term incorporating a range of repetitive impairing behaviours. The Internet can act as a conduit for, and may contribute to, functionally impairing behaviours including excessive and compulsive video gaming, compulsive sexual behaviour, buying, gambling, streaming or social networks use. There is growing public and National health authority concern about the health and societal costs of PUI across the lifespan. Gaming Disorder is being considered for inclusion as a mental disorder in diagnostic classification systems, and was listed in the ICD-11 version released for consideration by Member States (http://www.who.int/classifications/icd/revision/timeline/en/). More research is needed into disorder definitions, validation of clinical tools, prevalence, clinical parameters, brain-based biology, socio-health-economic impact, and empirically validated intervention and policy approaches. Potential cultural differences in the magnitudes and natures of types and patterns of PUI need to be better understood, to inform optimal health policy and service development. To this end, the EU under Horizon 2020 has launched a new four-year European Cooperation in Science and Technology (COST) Action Programme (CA 16207), bringing together scientists and clinicians from across the fields of impulsive, compulsive, and addictive disorders, to advance networked interdisciplinary research into PUI across Europe and beyond, ultimately seeking to inform regulatory policies and clinical practice. This paper describes nine critical and achievable research priorities identified by the Network, needed in order to advance understanding of PUI, with a view towards identifying vulnerable individuals for early intervention. The network shall enable collaborative research networks, shared multinational databases, multicentre studies and joint publications.
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Single laboratory method performance evaluation for the analysis of Roundup Ready® soy flour by qualitative and quantitative detection methods. QUALITY ASSURANCE AND SAFETY OF CROPS & FOODS 2017. [DOI: 10.3920/qas2016.0983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Abstract
BACKGROUND Cannabis exposure, particularly heavy cannabis use, has been associated with neuroanatomical alterations in regions rich with cannabinoid receptors such as the hippocampus in some but not in other (mainly cross-sectional) studies. However, it remains unclear whether continued heavy cannabis use alters hippocampal volume, and whether an earlier age of onset and/or a higher dosage exacerbate these changes. METHODS Twenty heavy cannabis users (mean age 21 years, range 18-24 years) and 23 matched non-cannabis using healthy controls were submitted to a comprehensive psychological assessment and magnetic resonance imaging scan at baseline and at follow-up (average of 39 months post-baseline; standard deviation=2.4). Cannabis users started smoking around 16 years and smoked on average five days per week. A novel aspect of the current study is that hippocampal volume estimates were obtained from manual tracing the hippocampus on T1-weighted anatomical magnetic resonance imaging scans, using a previously validated protocol. RESULTS Compared to controls, cannabis users did not show hippocampal volume alterations at either baseline or follow-up. Hippocampal volumes increased over time in both cannabis users and controls, following similar trajectories of increase. Cannabis dose and age of onset of cannabis use did not affect hippocampal volumes. CONCLUSIONS Continued heavy cannabis use did not affect hippocampal neuroanatomical changes in early adulthood. This contrasts with prior evidence on alterations in this region in samples of older adult cannabis users. In young adults using cannabis at this level, cannabis use may not be heavy enough to affect hippocampal neuroanatomy.
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Transcriptional signatures of connectomic subregions of the human striatum. GENES BRAIN AND BEHAVIOR 2017; 16:647-663. [DOI: 10.1111/gbb.12386] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/27/2017] [Accepted: 04/10/2017] [Indexed: 01/01/2023]
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Anconeus interposition arthroplasty in acute multiligamentous elbow injuries with irreparable radial head fractures: a novel approach. ACTA ORTHOPAEDICA ET TRAUMATOLOGICA TURCICA 2017; 50:303-8. [PMID: 27130386 DOI: 10.3944/aott.2015.15.0092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the results of a new reconstruction with anconeus interposition arthroplasty in acute multiligamentous elbow injuries with irreparable radial head fractures. METHODS Five patients (3 males, 2 females) with a mean age of 42.6 years who underwent reconstruction with anconeus arhtroplasty were evaluated. With lateral approach, lateral capsuloligamentous structures were repaired, the radial head was excised, and anconeus interposition arthroplasty was performed. With medial intervention, the medial collateral ligament was repaired, and the ulnar nerve was transposed anteriorly. Clinical and radiological evaluation was performed the end of a mean follow-up period of 63 months. RESULTS Mean Mayo Elbow Performance, Oxford Elbow, and Disabilities of the Arm, Shoulder and Hand (DASH) scores were 91, 41.4, and 13.76, respectively. Average elbow extension loss was 10.2° and average forearm supination loss was 5.2°. Dynamic elbow instability tests were within normal limits. On elbow radiographs, the average increase in cubitus valgus angle was 5.4°. No patient reported limitation in daily activities. There was no heterotopic ossification in any patient. Mean radial shortening was 1.39 mm, and no patient suffered from wrist pain at final follow-up. Average Mayo wrist score was 91 points. CONCLUSION The combination of repair of the medial and lateral structures, radial head resection, and anconeus interposition arthroplasty may be a good alternative in the treatment of acute multiligamentous elbow injuries with irreparable radial head fracture.
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Meralgia paresthetica after the fragmentation of renal stone using extracorporeal shock wave lithotripsy: a case report. Acta Neurol Belg 2016; 116:423-4. [PMID: 26661478 DOI: 10.1007/s13760-015-0574-1] [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: 10/28/2015] [Accepted: 11/21/2015] [Indexed: 11/28/2022]
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Violence against emergency department employees and the attitude of employees towards violence. Hong Kong Med J 2016; 22:464-71. [PMID: 27562985 DOI: 10.12809/hkmj154714] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION This study was conducted to evaluate the occurrence of violent incidents in the workplace among the various professional groups working in the emergency department. We characterised the types of violence encountered by different occupation groups and the attitude of individuals working in different capacities. METHODS This cross-sectional study included 323 people representing various professional groups working in two distinct emergency departments in Turkey. The participants were asked to complete questionnaires prepared in advance by the researchers. The data were analysed using the Statistical Package for the Social Sciences (Windows version 15.0). RESULTS A total of 323 subjects including 189 (58.5%) men and 134 (41.5%) women participated in the study. Their mean (± standard deviation) age was 31.5 ± 6.5 years and 32.0 ± 6.9 years, respectively. In all, 74.0% of participants had been subjected to verbal or physical violence at any point since starting employment in a medical profession. Moreover, 50.2% of participants stated that they had been subjected to violence for more than 5 times. Among those who reported being subjected to violence, 42.7% had formally reported the incident(s). Besides, 74.3% of participants did not enjoy their profession, did not want to work in the emergency department, or would prefer employment in a non-health care field after being subjected to violence. According to the study participants, the most common cause of violence was the attitude of patients or their family members (28.7%). In addition, 79.6% (n=257) of participants stated that they did not have adequate safety protection in their working area. According to the study participants, there is a need for legal regulations to effectively deter violence and increased safety measures designed to reduce the incidence of violence in the emergency department. CONCLUSION Violence against employees in the emergency department is a widespread problem. This situation has a strong negative effect on employee satisfaction and work performance. In order to reduce the incidence of violence in the emergency department, both patients and their families should be better informed so they have realistic expectations as an emergency patient, deterrent legal regulations should be put in place, and increased efforts should be made to provide enhanced security for emergency department personnel. These measures will reduce workplace violence and the stress experienced by emergency workers. We expect this to have a positive impact on emergency health care service delivery.
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Effect of ukrain on ischemia/reperfusion-induced kidney injury in rats. J Surg Res 2016; 202:267-75. [PMID: 27229100 DOI: 10.1016/j.jss.2015.12.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/06/2015] [Accepted: 12/22/2015] [Indexed: 11/27/2022]
Abstract
BACKGROUND The aim of this study was to investigate the potential protective effect of ukrain on an experimental kidney injury model induced by ischemia and reperfusion (IR) in rats. MATERIAL AND METHODS A total of 24 male Sprague-Dawley rats were equally and randomly separated into three groups as follows: group-1: controls (C; only laparotomy); group 2: renal ischemia-reperfusion (IR; occlusion of the renal artery for 30 min and 2 h of reperfusion); and group 3: ukrain treatment and IR applied group (U + IR; occlusion of the renal artery for 30 min and 2 h of reperfusion; ukrain was intraperitoneally administered 1 h before the IR process). RESULTS Serum total oxidant status (TOS) and total antioxidant status (TAS) levels were measured. The oxidative stress index was determined by calculating the TOS/TAS ratio. TAS serum levels significantly increased, and TOS serum levels also prominently decreased in U + IR group, when compared with the IR group (P < 0.001). Mean NGAL level was remarkably higher in IR group, when compared with the U + IR group (P < 0.001). Caspase-3 messenger RNA (mRNA) expression level increased in IR and decreased in U + IR group (P < 0.001). Bcl-xL serum and mRNA expression levels increased in the U + IR group (P < 0.001). In addition, serum iNOS and mRNA expression levels increased in IR group and decreased in U + IR group (P < 0.001). CONCLUSIONS Data established from the present study suggest that ukrain may exhibit protective effect against IR-induced kidney injury and that antioxidant activity primarily modulates this effect.
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Serum levels of endocan, claudin-5 and cytokines in migraine. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2016; 20:930-936. [PMID: 27010153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
OBJECTIVE Endothelial dysfunction is involved in inflammatory disorders, migration, angiogenesis, and tumor progression. There is a known relationship between migraine and inflammation; however, there are conflicting data as to whether there is a link between migraine and endothelial dysfunction. The current study aimed to determine the relationships between migraine and levels of serum Endocan (ESM-1), Claudin-5 (CLDN5), IL-1β, IL-6 and TNF-α levels, which are proven indicators of endothelial dysfunction and inflammation in patients with migraine. PATIENTS AND METHODS Thirty-one patients and 24 healthy subjects were included in this study. Participants underwent thorough physical and neurological evaluations, and levels of serum ESM-1, CLDN5, IL-1β, IL-6 and TNF-α were measured for each patient. RESULTS The levels of ESM-1, CLDN5, IL-1β, IL-6, and TNF-α were significantly higher in the migraine attack group than in the control group (p: 0.006, p: 0.002, p: 0.002, p: 0.003, p: 0.036, respectively). Additionally, there were significant differences in the ESM-1 levels of the visual analog scale (VAS) subgroup (p = 0.041), and there were moderate differences in the CLDN5 levels of the VAS subgroup (p = 0.064). CONCLUSIONS High serum levels of IL-1β, IL-6 and TNF-α in the migraine attack group indicate that inflammation plays a major role in migraine pathogenesis. In particular, the high ESM-1 and CLDN5 levels in patients with migraine suggest that inflammation should be investigated further, it may be a useful tool in the differential diagnosis of migraine.
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BNP shows myocardial injury earlier than Troponin-I in experimental carbon monoxide poisoning. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2016; 20:1149-1154. [PMID: 27049270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
OBJECTIVE In this study, our purpose was to determine whether plasma BNP level can be useful or not in determining the severity of myocardial injury formed by CO poisoning and to compare plasma BNP level with serum cTnI level. MATERIALS AND METHODS In the study, 46 female Wistar Albino rats were used. Rats were divided into four groups, one control group and three poisoning groups. The mixture of pure CO and air was injected for 60 minutes to provide 3000 ppm CO concentration. Blood samples of groups were collected to measure COHb, BNP and cTnI levels. Blood samples of poisoning groups were collected at the 1st, 6th and 12th hours after poisoning. After biochemical procedures, findings were analysed statistically and compared with each other. RESULTS Eight rats which died in poisoning groups were excluded and 38 rats were evaluated. BNP levels were high in all poisoning groups compared to control group and the difference between them was statistically significant (p < 0.05). cTnI levels were high in 6th and 12th hours poisoning groups compared to control and 1st hour group but only 12th hour group had statistically significant difference (p < 0.05). A statistically positive relation was established between BNP and cTnI levels in 6th and 12th hour groups (R: 0.76 - p < 0.05 - n:38). CONCLUSIONS It was found that BNP levels increased earlier than cTnI levels in acute severe CO poisoning. BNP levels of the cases which were determined to have increased cTnI levels showing myocardial injury increased as well. BNP can show myocardial injury and its severity in acute CO poisoning.
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Search for dark matter, extra dimensions, and unparticles in monojet events in proton-proton collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:235. [PMID: 26069461 PMCID: PMC4455910 DOI: 10.1140/epjc/s10052-015-3451-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 05/11/2015] [Indexed: 06/02/2023]
Abstract
Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing a jet and an imbalance in transverse momentum. The data were collected by the CMS detector in proton-proton collisions at the LHC and correspond to an integrated luminosity of 19.7[Formula: see text]at a centre-of-mass energy of 8[Formula: see text]. The number of observed events is found to be consistent with the standard model prediction. Limits are placed on the DM-nucleon scattering cross section as a function of the DM particle mass for spin-dependent and spin-independent interactions. Limits are also placed on the scale parameter [Formula: see text] in the Arkani-Hamed, Dimopoulos, and Dvali (ADD) model of large extra dimensions, and on the unparticle model parameter [Formula: see text]. The constraints on ADD models and unparticles are the most stringent limits in this channel and those on the DM-nucleon scattering cross section are an improvement over previous collider results.
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Measurement of prompt ψ(2S) to J/ψ yield ratios in Pb-Pb and p-p collisions at sqrt[sNN]=2.76 TeV. PHYSICAL REVIEW LETTERS 2014; 113:262301. [PMID: 25615312 DOI: 10.1103/physrevlett.113.262301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Indexed: 06/04/2023]
Abstract
The ratio between the prompt ψ(2S) and J/ψ yields, reconstructed via their decays into μ+ μ-, is measured in Pb-Pb and p-p collisions at sqrt[sNN]=2.76 TeV. The analysis is based on Pb-Pb and p-p data samples collected by CMS at the Large Hadron Collider, corresponding to integrated luminosities of 150 μb(-1) and 5.4 pb(-1), respectively. The double ratio of measured yields (Nψ(2S)/N(J/ψ))(Pb-Pb)/(Nψ(2S)/N(J/ψ))(p-p) is computed in three Pb-Pb collision centrality bins and two kinematic ranges: one at midrapidity, |y|<1.6, covering the transverse momentum range 6.5<pT<30 GeV/c, and the other at forward rapidity, 1.6<|y|<2.4, extending to lower pT values, 3<pT<30 GeV/c. The centrality-integrated double ratio changes from 0.45±0.13(stat)±0.07(syst) in the first range to 1.67±0.34(stat)±0.27(syst) in the second. This difference is most pronounced in the most central collisions.
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Searches for heavy Higgs bosons in two-Higgs-doublet models and fort→chdecay using multilepton and diphoton final states inppcollisions at 8 TeV. Int J Clin Exp Med 2014. [DOI: 10.1103/physrevd.90.112013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Search for heavy neutrinos and [Formula: see text] bosons with right-handed couplings in proton-proton collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:3149. [PMID: 25814876 PMCID: PMC4371073 DOI: 10.1140/epjc/s10052-014-3149-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 10/22/2014] [Indexed: 06/04/2023]
Abstract
A search for heavy, right-handed neutrinos, [Formula: see text] ([Formula: see text]), and right-handed [Formula: see text] bosons, which arise in the left-right symmetric extensions of the standard model, has been performed by the CMS experiment. The search was based on a sample of two lepton plus two jet events collected in proton-proton collisions at a center-of-mass energy of 8[Formula: see text] corresponding to an integrated luminosity of 19.7 [Formula: see text]. For models with strict left-right symmetry, and assuming only one [Formula: see text] flavor contributes significantly to the [Formula: see text] decay width, the region in the two-dimensional [Formula: see text] mass plane excluded at a 95 % confidence level extends to approximately [Formula: see text] and covers a large range of neutrino masses below the [Formula: see text] boson mass, depending on the value of [Formula: see text]. This search significantly extends the [Formula: see text] exclusion region beyond previous results.
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Measurement of differential cross sections for the production of a pair of isolated photons in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:3129. [PMID: 25814874 PMCID: PMC4371070 DOI: 10.1140/epjc/s10052-014-3129-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 10/14/2014] [Indexed: 06/04/2023]
Abstract
A measurement of differential cross sections for the production of a pair of isolated photons in proton-proton collisions at [Formula: see text] is presented. The data sample corresponds to an integrated luminosity of 5.0[Formula: see text] collected with the CMS detector. A data-driven isolation template method is used to extract the prompt diphoton yield. The measured cross section for two isolated photons, with transverse energy above 40 and 25[Formula: see text] respectively, in the pseudorapidity range [Formula: see text], [Formula: see text] and with an angular separation [Formula: see text], is [Formula: see text][Formula: see text]. Differential cross sections are measured as a function of the diphoton invariant mass, the diphoton transverse momentum, the azimuthal angle difference between the two photons, and the cosine of the polar angle in the Collins-Soper reference frame of the diphoton system. The results are compared to theoretical predictions at leading, next-to-leading, and next-to-next-to-leading order in quantum chromodynamics.
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Observation of the diphoton decay of the Higgs boson and measurement of its properties. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:3076. [PMID: 25814871 PMCID: PMC4370889 DOI: 10.1140/epjc/s10052-014-3076-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/12/2014] [Indexed: 05/30/2023]
Abstract
Observation of the diphoton decay mode of the recently discovered Higgs boson and measurement of some of its properties are reported. The analysis uses the entire dataset collected by the CMS experiment in proton-proton collisions during the 2011 and 2012 LHC running periods. The data samples correspond to integrated luminosities of 5.1[Formula: see text]at [Formula: see text] and 19.7[Formula: see text]at 8[Formula: see text] . A clear signal is observed in the diphoton channel at a mass close to 125[Formula: see text] with a local significance of [Formula: see text], where a significance of [Formula: see text] is expected for the standard model Higgs boson. The mass is measured to be [Formula: see text] , and the best-fit signal strength relative to the standard model prediction is [Formula: see text][Formula: see text][Formula: see text]. Additional measurements include the signal strength modifiers associated with different production mechanisms, and hypothesis tests between spin-0 and spin-2 models.
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Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:3036. [PMID: 25814912 PMCID: PMC4370929 DOI: 10.1140/epjc/s10052-014-3036-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/16/2014] [Indexed: 05/23/2023]
Abstract
Searches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and [Formula: see text], [Formula: see text], and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy [Formula: see text] with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 [Formula: see text]. The observed event rates are in agreement with expectations from the standard model. These results probe charginos and neutralinos with masses up to 720 [Formula: see text], and sleptons up to 260 [Formula: see text], depending on the model details.
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Evidence of b-jet quenching in PbPb collisions at √(s(NN))=2.76 TeV. PHYSICAL REVIEW LETTERS 2014; 113:132301. [PMID: 25302881 DOI: 10.1103/physrevlett.113.132301] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Indexed: 06/04/2023]
Abstract
The production of jets associated to bottom quarks is measured for the first time in PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair. Jet spectra are reported in the transverse momentum (p(T)) range of 80-250 GeV/c, and within pseudorapidity |η|<2. The nuclear modification factor (R(AA)) calculated from these spectra shows a strong suppression in the b-jet yield in PbPb collisions relative to the yield observed in pp collisions at the same energy. The suppression persists to the largest values of p(T) studied, and is centrality dependent. The R(AA) is about 0.4 in the most central events, similar to previous observations for inclusive jets. This implies that jet quenching does not have a strong dependence on parton mass and flavor in the jet p(T) range studied.
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Measurement of top quark-antiquark pair production in association with a W or Z boson in pp collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:3060. [PMID: 25814914 PMCID: PMC4370853 DOI: 10.1140/epjc/s10052-014-3060-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/31/2014] [Indexed: 06/04/2023]
Abstract
A measurement of the cross section for the production of top quark-antiquark pairs ([Formula: see text]) in association with a vector boson V (W or Z) in proton-proton collisions at [Formula: see text][Formula: see text] is presented. The results are based on a dataset corresponding to an integrated luminosity of 19.5 fb[Formula: see text] recorded with the CMS detector at the LHC. The measurement is performed in three leptonic (e and [Formula: see text]) channels: a same-sign dilepton analysis targeting [Formula: see text] events, and trilepton and four-lepton analyses designed for [Formula: see text] events. In the same-sign dilepton channel, the [Formula: see text] cross section is measured as [Formula: see text], corresponding to a significance of 1.6 standard deviations over the background-only hypothesis. Combining the trilepton and four-lepton channels, a direct measurement of the [Formula: see text] cross section, [Formula: see text], is obtained with a significance of 3.1 standard deviations. The measured cross sections are compatible with standard model predictions within their experimental uncertainties. The inclusive [Formula: see text] process is observed with a significance of 3.7 standard deviations from the combination of all three leptonic channels.
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Measurement of jet multiplicity distributions in [Formula: see text] production in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:3014. [PMID: 25814909 PMCID: PMC4371091 DOI: 10.1140/epjc/s10052-014-3014-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/30/2014] [Indexed: 06/02/2023]
Abstract
The normalised differential top quark-antiquark production cross section is measured as a function of the jet multiplicity in proton-proton collisions at a centre-of-mass energy of 7[Formula: see text] at the LHC with the CMS detector. The measurement is performed in both the dilepton and lepton+jets decay channels using data corresponding to an integrated luminosity of 5.0[Formula: see text]. Using a procedure to associate jets to decay products of the top quarks, the differential cross section of the [Formula: see text] production is determined as a function of the additional jet multiplicity in the lepton+jets channel. Furthermore, the fraction of events with no additional jets is measured in the dilepton channel, as a function of the threshold on the jet transverse momentum. The measurements are compared with predictions from perturbative quantum chromodynamics and no significant deviations are observed.
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Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:2980. [PMID: 25814906 PMCID: PMC4370888 DOI: 10.1140/epjc/s10052-014-2980-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 07/13/2014] [Indexed: 06/01/2023]
Abstract
A search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a [Formula: see text] quark pair. The searches use the 8 [Formula: see text] pp collision dataset collected by the CMS detector at the LHC, corresponding to an integrated luminosity of up to 19.7 [Formula: see text]. Certain channels include data from 7 [Formula: see text] collisions corresponding to an integrated luminosity of 4.9 [Formula: see text]. The searches are sensitive to non-standard-model invisible decays of the recently observed Higgs boson, as well as additional Higgs bosons with similar production modes and large invisible branching fractions. In all channels, the observed data are consistent with the expected standard model backgrounds. Limits are set on the production cross section times invisible branching fraction, as a function of the Higgs boson mass, for the vector boson fusion and ZH production modes. By combining all channels, and assuming standard model Higgs boson cross sections and acceptances, the observed (expected) upper limit on the invisible branching fraction at [Formula: see text] [Formula: see text] is found to be 0.58 (0.44) at 95 % confidence level. We interpret this limit in terms of a Higgs-portal model of dark matter interactions.
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Measurement of WZ and ZZ production in pp collisions at [Formula: see text] in final states with b-tagged jets. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:2973. [PMID: 25814904 PMCID: PMC4370898 DOI: 10.1140/epjc/s10052-014-2973-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 07/09/2014] [Indexed: 06/04/2023]
Abstract
Measurements are reported of the WZ and ZZ production cross sections in proton-proton collisions at [Formula: see text][Formula: see text] in final states where one Z boson decays to b-tagged jets. The other gauge boson, either W or Z, is detected through its leptonic decay (either [Formula: see text], [Formula: see text] or [Formula: see text], [Formula: see text], or [Formula: see text]). The results are based on data corresponding to an integrated luminosity of 18.9 fb[Formula: see text] collected with the CMS detector at the Large Hadron Collider. The measured cross sections, [Formula: see text] and [Formula: see text], are consistent with next-to-leading order quantum chromodynamics calculations.
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Observation of the associated production of a single top quark and a W boson in pp collisions at sqrt[s] = 8 TeV. PHYSICAL REVIEW LETTERS 2014; 112:231802. [PMID: 24972196 DOI: 10.1103/physrevlett.112.231802] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Indexed: 06/03/2023]
Abstract
The first observation of the associated production of a single top quark and a W boson is presented. The analysis is based on a data set corresponding to an integrated luminosity of 12.2 fb(-1) of proton-proton collisions at sqrt[s] = 8 TeV recorded by the CMS experiment at the LHC. Events with two leptons and a jet originating from a b quark are selected. A multivariate analysis based on kinematic and topological properties is used to separate the signal from the dominant tt background. An excess consistent with the signal hypothesis is observed, with a significance which corresponds to 6.1 standard deviations above a background-only hypothesis. The measured production cross section is 23.4 ± 5.4 pb, in agreement with the standard model prediction.
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Probing color coherence effects in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:2901. [PMID: 25814895 PMCID: PMC4370765 DOI: 10.1140/epjc/s10052-014-2901-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 05/14/2014] [Indexed: 05/31/2023]
Abstract
A study of color coherence effects in pp collisions at a center-of-mass energy of 7[Formula: see text] is presented. The data used in the analysis were collected in 2010 with the CMS detector at the LHC and correspond to an integrated luminosity of 36 pb[Formula: see text]. Events are selected that contain at least three jets and where the two jets with the largest transverse momentum exhibit a back-to-back topology. The measured angular correlation between the second- and third-leading jet is shown to be sensitive to color coherence effects, and is compared to the predictions of Monte Carlo models with various implementations of color coherence. None of the models describe the data satisfactorily.
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Study of the production of charged pions, kaons, and protons in pPb collisions at [Formula: see text]5.02[Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:2847. [PMID: 25814892 PMCID: PMC4370925 DOI: 10.1140/epjc/s10052-014-2847-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 04/04/2014] [Indexed: 05/28/2023]
Abstract
Spectra of identified charged hadrons are measured in pPb collisions with the CMS detector at the LHC at [Formula: see text]. Charged pions, kaons, and protons in the transverse-momentum range [Formula: see text]-1.7[Formula: see text] and laboratory rapidity [Formula: see text] are identified via their energy loss in the silicon tracker. The average [Formula: see text] increases with particle mass and the charged multiplicity of the event. The increase of the average [Formula: see text] with charged multiplicity is greater for heavier hadrons. Comparisons to Monte Carlo event generators reveal that Epos Lhc, which incorporates additional hydrodynamic evolution of the created system, is able to reproduce most of the data features, unlike Hijing and Ampt. The [Formula: see text] spectra and integrated yields are also compared to those measured in pp and PbPb collisions at various energies. The average transverse momentum and particle ratio measurements indicate that particle production at LHC energies is strongly correlated with event particle multiplicity.
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Measurement of inclusive W and Z boson production cross sections in pp collisions at sqrt[s] = 8 TeV. PHYSICAL REVIEW LETTERS 2014; 112:191802. [PMID: 24877930 DOI: 10.1103/physrevlett.112.191802] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Indexed: 06/03/2023]
Abstract
A measurement of total and fiducial inclusive W and Z boson production cross sections in pp collisions at sqrt[s] = 8 TeV is presented. Electron and muon final states are analyzed in a data sample collected with the CMS detector corresponding to an integrated luminosity of 18.2 ± 0.5 pb(-1). The measured total inclusive cross sections times branching fractions are σ(pp → WX)×B(W → ℓν) = 12.21 ± 0.03(stat) ± 0.24(syst) ± 0.32(lum) nb and σ(pp → ZX) × B(Z → ℓ+ℓ-) = 1.15 ± 0.01(stat) ± 0.02(syst) ± 0.03(lum) nb for the dilepton mass in the range of 60-120 GeV. The measured values agree with next-to-next-to-leading-order QCD cross section calculations. Ratios of cross sections are reported with a precision of 2%. This is the first measurement of inclusive W and Z boson production in proton-proton collisions at sqrt[s] = 8 TeV.
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Measurement of theWγandZγinclusive cross sections inppcollisions ats=7 TeVand limits on anomalous triple gauge boson couplings. Int J Clin Exp Med 2014. [DOI: 10.1103/physrevd.89.092005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Measurements of tt spin correlations and top-quark polarization using dilepton final states in pp collisions at sqrt[s]=7 TeV. PHYSICAL REVIEW LETTERS 2014; 112:182001. [PMID: 24856688 DOI: 10.1103/physrevlett.112.182001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Indexed: 06/03/2023]
Abstract
Spin correlations and polarization in the top quark-antiquark system are measured using dilepton final states produced in pp collisions at the LHC at sqrt[s]=7 TeV. The data correspond to an integrated luminosity of 5.0 fb(-1) collected with the CMS detector. The measurements are performed using events with two oppositely charged leptons (electrons or muons), a significant imbalance in transverse momentum, and two or more jets, where at least one of the jets is identified as originating from a b quark. The spin correlations and polarization are measured through asymmetries in angular distributions of the two selected leptons, unfolded to the parton level. All measurements are found to be in agreement with predictions of the standard model.
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Search for top-quark partners with charge 5/3 in the same-sign dilepton final state. PHYSICAL REVIEW LETTERS 2014; 112:171801. [PMID: 24836237 DOI: 10.1103/physrevlett.112.171801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Indexed: 06/03/2023]
Abstract
A search for the production of heavy partners of the top quark with charge 5/3 is performed in events with a pair of same-sign leptons. The data sample corresponds to an integrated luminosity of 19.5 fb(-1) and was collected at sqrt[s] = 8 TeV by the CMS experiment. No significant excess is observed in the data above the expected background, and the existence of top-quark partners with masses below 800 GeV is excluded at a 95% confidence level, assuming they decay exclusively to tW. This is the first limit on these particles from the LHC, and it is significantly more restrictive than previous limits.
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Search for flavor-changing neutral currents in top-quark decays t → Zq in pp collisions at sqrt[s] = 8 TeV. PHYSICAL REVIEW LETTERS 2014; 112:171802. [PMID: 24836238 DOI: 10.1103/physrevlett.112.171802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Indexed: 06/03/2023]
Abstract
A search for flavor-changing neutral currents in top-quark decays t → Zq is performed in events produced from the decay chain tt → Zq+Wb, where both vector bosons decay leptonically, producing a final state with three leptons (electrons or muons). A data set collected with the CMS detector at the LHC is used, corresponding to an integrated luminosity of 19.7 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV. No excess is seen in the observed number of events relative to the standard model prediction; thus, no evidence for flavor-changing neutral currents in top-quark decays is found. A combination with a previous search at 7 TeV excludes a t → Zq branching fraction greater than 0.05% at the 95% confidence level.
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Search for top squark and Higgsino production using diphoton Higgs boson decays. PHYSICAL REVIEW LETTERS 2014; 112:161802. [PMID: 24815637 DOI: 10.1103/physrevlett.112.161802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Indexed: 06/03/2023]
Abstract
Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top quark (the top squark) and the Higgs boson (Higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 fb-1 of proton-proton collision data at s=8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the top squark mass below 360 to 410 GeV, depending on the Higgsino mass.
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Vacuum Infiltration Based Agrobacterium Mediated Gene Transfer to Lentil (Lens CulinarisM.) Tissues. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.1080/13102818.2002.10819151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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41
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Measurement of the top-quark mass in all-jets [Formula: see text] events in pp collisions at [Formula: see text] TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2014; 74:2758. [PMID: 25814885 PMCID: PMC4370827 DOI: 10.1140/epjc/s10052-014-2758-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 12/31/2013] [Indexed: 06/04/2023]
Abstract
The mass of the top quark is measured using a sample of [Formula: see text] candidate events with at least six jets in the final state. The sample is selected from data collected with the CMS detector in pp collisions at [Formula: see text] TeV in 2011 and corresponds to an integrated luminosity of 3.54 [Formula: see text]. The mass is reconstructed for each event employing a kinematic fit of the jets to a [Formula: see text] hypothesis. The top-quark mass is measured to be [Formula: see text] GeV. A combination with previously published measurements in other decay modes by CMS yields a mass of [Formula: see text] GeV.
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Jet and underlying event properties as a function of charged-particle multiplicity in proton-proton collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2013; 73:2674. [PMID: 25814851 PMCID: PMC4371079 DOI: 10.1140/epjc/s10052-013-2674-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/18/2013] [Indexed: 06/04/2023]
Abstract
Characteristics of multi-particle production in proton-proton collisions at [Formula: see text] are studied as a function of the charged-particle multiplicity, Nch. The produced particles are separated into two classes: those belonging to jets and those belonging to the underlying event. Charged particles are measured with pseudorapidity |η|<2.4 and transverse momentum pT>0.25 GeV/c. Jets are reconstructed from charged-particles only and required to have pT>5 GeV/c. The distributions of jet pT, average pT of charged particles belonging to the underlying event or to jets, jet rates, and jet shapes are presented as functions of Nch and compared to the predictions of the pythia and herwig event generators. Predictions without multi-parton interactions fail completely to describe the Nch-dependence observed in the data. For increasing Nch, pythia systematically predicts higher jet rates and harder pT spectra than seen in the data, whereas herwig shows the opposite trends. At the highest multiplicity, the data-model agreement is worse for most observables, indicating the need for further tuning and/or new model ingredients.
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Search for top squarks in R-parity-violating supersymmetry using three or more leptons and b-tagged jets. PHYSICAL REVIEW LETTERS 2013; 111:221801. [PMID: 24329437 DOI: 10.1103/physrevlett.111.221801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Indexed: 06/03/2023]
Abstract
A search for anomalous production of events with three or more isolated leptons and bottom-quark jets produced in pp collisions at √s=8 TeV is presented. The analysis is based on a data sample corresponding to an integrated luminosity of 19.5 fb(-1) collected by the CMS experiment at the LHC in 2012. No excess above the standard model expectations is observed. The results are interpreted in the context of supersymmetric models with signatures that have low missing transverse energy arising from light top-squark pair production with R-parity-violating decays of the lightest supersymmetric particle. In two models with different R-parity-violating couplings, top squarks are excluded below masses of 1020 GeV and 820 GeV when the lightest supersymmetric particle has a mass of 200 GeV.
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Searches for new physics using the tt¯ invariant mass distribution in pp collisions at √s=8 TeV. PHYSICAL REVIEW LETTERS 2013; 111:211804. [PMID: 24313480 DOI: 10.1103/physrevlett.111.211804] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Indexed: 06/02/2023]
Abstract
Searches for anomalous top quark-antiquark production are presented, based on pp collisions at √s=8 TeV. The data, corresponding to an integrated luminosity of 19.7 fb(-1), were collected with the CMS detector at the LHC. The observed tt¯ invariant mass spectrum is found to be compatible with the standard model prediction. Limits on the production cross section times branching fraction probe, for the first time, a region of parameter space for certain models of new physics not yet constrained by precision measurements.
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Abstract
BACKGROUND There is evidence to suggest that cognitive deficits might persist beyond the acute stages of illness in major depressive disorder (MDD). However, the findings are somewhat inconsistent across the individual studies conducted to date. Our aim was to conduct a systematic review and meta-analysis of existing studies that have examined cognition in euthymic MDD patients. METHOD Following a systematic search across several publication databases, meta-analyses were conducted for 27 empirical studies that compared euthymic adult MDD patients (895 participants) and healthy controls (997 participants) across a range of cognitive domains. The influence of demographic variables and confounding factors, including age of onset and recurrent episodes, was examined. RESULTS Compared with healthy controls, euthymic MDD patients were characterized by significantly poorer cognitive functions. However, the magnitude of observed deficits, with the exception of inhibitory control, were generally modest when late-onset cases were excuded. Late-onset cases demonstrated significantly more pronounced deficits in verbal memory, speed of information processing and some executive functions. CONCLUSIONS Cognitive deficits, especially poor response inhibition, are likely to be persistent features, at least of some forms, of adult-onset MDD. More studies are necessary to examine cognitive dysfunction in remitted psychotic, melancholic and bipolar spectrum MDD. Cognitive deficits overall appear to be more common among patients with late-onset depression, supporting the theories suggesting that possible vascular and neurodegenerative factors play a role in a substantial number of these patients.
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Search for supersymmetry in hadronic final states with missing transverse energy using the variables αT and b-quark multiplicity in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2013; 73:2568. [PMID: 25814868 PMCID: PMC4371056 DOI: 10.1140/epjc/s10052-013-2568-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 08/14/2013] [Indexed: 06/01/2023]
Abstract
An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb-1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, αT, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.
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Measurement of the Bs(0)→μ+ μ- branching fraction and search for B(0)→μ+ μ- with the CMS experiment. PHYSICAL REVIEW LETTERS 2013; 111:101804. [PMID: 25166654 DOI: 10.1103/physrevlett.111.101804] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Indexed: 06/03/2023]
Abstract
Results are presented from a search for the rare decays Bs(0)→μ+ μ- and B(0)→μ+ μ- in pp collisions at sqrt[s]=7 and 8 TeV, with data samples corresponding to integrated luminosities of 5 and 20 fb(-1), respectively, collected by the CMS experiment at the LHC. An unbinned maximum-likelihood fit to the dimuon invariant mass distribution gives a branching fraction B(Bs(0)→μ+ μ-)=(3.0(-0.9)(+1.0))×10(-9), where the uncertainty includes both statistical and systematic contributions. An excess of Bs(0)→μ+ μ- events with respect to background is observed with a significance of 4.3 standard deviations. For the decay B(0)→μ+ μ- an upper limit of B(B(0)→μ+ μ-)<1.1×10(-9) at the 95% confidence level is determined. Both results are in agreement with the expectations from the standard model.
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Measurement of masses in the [Formula: see text] system by kinematic endpoints in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2013; 73:2494. [PMID: 25814866 PMCID: PMC4371053 DOI: 10.1140/epjc/s10052-013-2494-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 06/18/2013] [Indexed: 06/04/2023]
Abstract
A simultaneous measurement of the top-quark, W-boson, and neutrino masses is reported for [Formula: see text] events selected in the dilepton final state from a data sample corresponding to an integrated luminosity of 5.0 fb-1 collected by the CMS experiment in pp collisions at [Formula: see text]. The analysis is based on endpoint determinations in kinematic distributions. When the neutrino and W-boson masses are constrained to their world-average values, a top-quark mass value of [Formula: see text] is obtained. When such constraints are not used, the three particle masses are obtained in a simultaneous fit. In this unconstrained mode the study serves as a test of mass determination methods that may be used in beyond standard model physics scenarios where several masses in a decay chain may be unknown and undetected particles lead to underconstrained kinematics.
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