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Lithium salts cytotoxicity and accumulation in melanoma cells in vitro. J Appl Toxicol 2024; 44:712-719. [PMID: 38146629 DOI: 10.1002/jat.4576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/29/2023] [Accepted: 12/13/2023] [Indexed: 12/27/2023]
Abstract
Boron neutron capture therapy is a perspective selective technology for the destruction of cancer cells, while the use of lithium instead of boron may represent a new and promising vector for the development of neutron capture therapy (NCT). The aim of the study was a comparative assessment of the cytotoxicity of various lithium salts, as well as an analysis of the accumulation of lithium in tumor cells in vitro to determine the possibility of using lithium in NCT. The cytotoxicity of lithium salts was determined using MTT-test and colony forming assay on human fibroblasts BJ-5ta, human skin melanoma SK-Mel-28, and mouse skin melanoma B16 cell lines. An assessment of lithium concentration in cells was performed using inductively coupled plasma atomic emission spectrometry. Our results showed that three different lithium salts at a concentration of 40 μg/ml are not toxic for both tumor and normal cells. The highest uptake values were obtained on murine melanoma B16 cells when exposed to lithium carbonate (0.8 μg/106 cells); however, human melanoma SK-Mel-28 cells effectively accumulated both lithium carbonate and lithium citrate (about 0.46 μg/106 cells for two salts). Thus, our results demonstrate a range of non-toxic doses of lithium salts and a high uptake of lithium by tumor cells, which indicates the possibility to use the lithium in NCT.
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Building HEP Software with Spack: Experiences from Pilot Builds for Key4hep and Outlook for LCG Releases. EPJ WEB OF CONFERENCES 2021. [DOI: 10.1051/epjconf/202125103056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Consistent, efficient software builds and deployments are a common concern for all HEP experiments. This paper describes the evolution of the usage of the Spack package manager in HEP in the context of the LCG stacks and the current Spack-based management of Key4hep software. Whereas previously Key4hep software used Spack only for a thin layer of FCC experiment software on top of the LCG releases, it is now possible to build the complete stack, from system libraries to FCC-, iLCSoft- and CEPC software packages with Spack. This pilot build doubles as a prototype for a Spack-based LCG release. The workflows and mechanisms that can be used for this purpose, potential for improvement as well as the roadmap towards a complete LCG release in spack are discussed.
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Odderon Exchange from Elastic Scattering Differences between pp and pp[over ¯] Data at 1.96 TeV and from pp Forward Scattering Measurements. PHYSICAL REVIEW LETTERS 2021; 127:062003. [PMID: 34420329 DOI: 10.1103/physrevlett.127.062003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/19/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
We describe an analysis comparing the pp[over ¯] elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM cross sections, extrapolated to a center-of-mass energy of sqrt[s]=1.96 TeV, are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the pp cross section. The two data sets disagree at the 3.4σ level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in pp scattering for which the significance is between 3.4σ and 4.6σ. The combined significance is larger than 5σ and is interpreted as the first observation of the exchange of a colorless, C-odd gluonic compound.
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Accelerator-based boron neutron capture therapy for malignant glioma: a pilot neutron irradiation study using boron phenylalanine, sodium borocaptate and liposomal borocaptate with a heterotopic U87 glioblastoma model in SCID mice. Int J Radiat Biol 2020; 96:868-878. [PMID: 32339057 DOI: 10.1080/09553002.2020.1761039] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Purpose: To evaluate the efficacy of boron neutron capture therapy (BNCT) for a heterotopic U87 glioblastoma model in SCID mice using boron phenylalanine (BPA), sodium borocaptate (BSH) and liposomal BSH as boron compounds at a unique, accelerator-based neutron source.Materials and methods: Glioblastoma models were obtained by subcutaneous implantation of U87 cells in the right thighs of SCID mice before administration of 350 mg/kg of BPA (BPA-group), 100 mg/kg of BSH (BSH-group) or 100 mg/kg of BSH in PEGylated liposomes (liposomal BSH-group) into the retroorbital sinus. Liposomes were prepared by reverse-phase evaporation. Neutron irradiation was carried out at a proton accelerator with a lithium target developed for BNCT at the Budker Institute of Nuclear Physics, Novosibirsk, Russian Federation. A proton beam current integral of 3 mA/h and energy of 2.05 MeV were used for neutron generation.Results: Boron compound accumulation in tumor tissues at the beginning of irradiation was higher in the BPA group, followed by the Liposomal BSH and BSH groups. Tumor growth was significantly slower in all irradiated mice from the 7th day after BNCT compared to untreated controls (p < .05). Tumor growth in all treated groups showed no large variation, apart from the Irradiation only group and the BPA group on the 7th day after BNCT. The overall trend of tumor growth was clear and the differences between treatment groups became significant from the 50th day after BNCT. Tumor growth was significantly slower in the Liposomal BSH group compared to the Irradiation only group on the 50th (p = .012), 53rd (p = .005), and the 57th (p = .021) days after treatment. Tumor growth in the Liposomal BSH group was significantly different from that in the BPA group on the 53rd day after BNCT (p = .021) and in the BSH group on the 50th (p = .024), 53rd (p = .015), and 57th (p = .038) days after BNCT. Skin reactions in the form of erosions and ulcers in the tumor area developed in treated as well as untreated animals with further formation of fistulas and necrotic decay cavities in most irradiated mice.Conclusions: We observed a tendency of BNCT at the accelerator-based neutron source to reduce or suspend the growth of human glioblastoma in immunodeficient animals. Liposomal BSH showed better long-term results compared to BPA and non-liposomal BSH. Further modifications in liposomal boron delivery are being studied to improve treatment outcomes.
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Optimizing Provisioning of LCG Software Stacks with Kubernetes. EPJ WEB OF CONFERENCES 2020. [DOI: 10.1051/epjconf/202024505030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The building, testing and deployment of coherent large software stacks is very challenging, in particular when they consist of the diverse set of packages required by the LHC*** experiments, the CERN Beams department and data analysis services such as SWAN. These software stacks comprise a large number of packages (Monte Carlo generators, machine learning tools, Python modules, HEP**** specific software), all available for several compilers, operating systems and hardware architectures. Along with several releases per year, development builds are provided each night to allow for quick updates and testing of development versions of packages such as ROOT, Geant4, etc. It also provides the possibility to test new compilers and new configurations.
Timely provisioning of these development and release stacks requires a large amount of computing resources. A dedicated infrastructure, based on the Jenkins continuous integration system, has been developed to this purpose. Resources are taken from the CERN OpenStack cloud; Puppet configurations are used to control the environment on virtual machines, which are either used directly as resource nodes or as hosts for Docker containers. Containers are used more and more to optimize the usage of our resources and ensure a consistent build environment while providing quick access to new Linux flavours and specific configurations.
In order to add build resources on demand more easily, we investigated the integration of a CERN provided Kubernetes cluster into the existing infrastructure. In this contribution we present the status of this prototype, focusing on the new challenges faced, such as the integration of these ephemeral build nodes into CERN’s IT infrastructure, job priority control, and debugging of job failures.
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Abstract
One of the key factors for the successful development of Monte-
Carlo programs for physics simulations is to properly organize regression testing
and validation. Geant4, the world-standard toolkit for HEP detector simulation,
heavily relies on this activity. The CERN SFT group, which contributes
to the development, testing, deployment and support of the toolkit, is also in
charge of running on a monthly basis a set of community-developed tests using
the development releases of Geant4. We present the web application Geant-val
developed for visualizing the results of these tests so that comparisons between
different Geant4 releases can be made. The application is written using the
Express.js, Node.js and Angular frameworks and uses PostgreSQL for storing
test results. Test results are visualised using ROOT and JSROOT. In addition to
pure visual comparisons, we perform different statistical tests (χ2, Kolmogorov-
Smirnov, etc.) on the client side using JavaScript Web Workers.
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Abstract
Building, testing and deploying of coherent large software stacks is very challenging, in particular when they consist of the diverse set of packages required by the LHC experiments, the CERN Beams Department and data analysis services such as SWAN. These software stacks include several packages (Grid middleware, Monte Carlo generators, Machine Learning tools, Python modules) all available for a large number of compilers, operating systems and hardware architectures.
To address this challenge, we developed an infrastructure around a tool called lcgcmake. Dedicated modules are responsible for building the packages, con-trolling the dependencies in a reliable and scalable way. The distribution relies on a robust and automatic system, responsible for building and testing the packages, installing them on CernVM-FS and packaging the binaries in RPMs and tarballs. This system is orchestrated through Jenkins on build machines provided by the CERN Openstack facility. The results are published through user-friendly web pages.
In this paper we will present an overview of these infrastructure tools and policies. We also discuss the role of this effort within the HEP Software Foundation (HSF). Finally we will discuss the evolution of the infrastructure towards container (Docker) technologies and the future directions and challenges of the project.
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Measurement of the Effective Weak Mixing Angle in pp[over ¯]→Z/γ^{*}→ℓ^{+}ℓ^{-} Events. PHYSICAL REVIEW LETTERS 2018; 120:241802. [PMID: 29956986 DOI: 10.1103/physrevlett.120.241802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Indexed: 06/08/2023]
Abstract
We present a measurement of the effective weak mixing angle parameter sin^{2}θ_{eff}^{ℓ} in pp[over ¯]→Z/γ^{*}→μ^{+}μ^{-} events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at the Fermilab Tevatron Collider and corresponding to 8.6 fb^{-1} of integrated luminosity. The measured value of sin^{2}θ_{eff}^{ℓ}[μμ]=0.23016±0.00064 is further combined with the result from the D0 measurement in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} events, resulting in sin^{2}θ_{eff}^{ℓ}[comb]=0.23095±0.00040. This combined result is the most precise measurement from a single experiment at a hadron collider and is the most precise determination using the coupling of the Z/γ^{*} to light quarks.
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Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron. PHYSICAL REVIEW LETTERS 2018; 120:042001. [PMID: 29437406 DOI: 10.1103/physrevlett.120.042001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Indexed: 06/08/2023]
Abstract
The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of sqrt[s]=1.96 TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is A_{FB}^{tt[over ¯]}=0.128±0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.
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11
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Measurement of the top quark mass using the matrix element technique in dilepton final states. Int J Clin Exp Med 2016. [DOI: 10.1103/physrevd.94.032004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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12
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Abstract
We report evidence for a narrow structure, X(5568), in the decay sequence X(5568)→B_{s}^{0}π^{±}, B_{s}^{0}→J/ψϕ, J/ψ→μ^{+}μ^{-}, ϕ→K^{+}K^{-}. This is evidence for the first instance of a hadronic state with valence quarks of four different flavors. The mass and natural width of this state are measured to be m=5567.8±2.9(stat)_{-1.9}^{+0.9}(syst) MeV/c^{2} and Γ=21.9±6.4(stat)_{-2.5}^{+5.0}(syst) MeV/c^{2}. If the decay is X(5568)→B_{s}^{*}π^{±}→B_{s}^{0}γπ^{±} with an unseen γ, m(X(5568)) will be shifted up by m(B_{s}^{*})-m(B_{s}^{0})∼49 MeV/c^{2}. This measurement is based on 10.4 fb^{-1} of pp[over ¯] collision data at sqrt[s]=1.96 TeV collected by the D0 experiment at the Fermilab Tevatron collider.
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13
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Evidence for Simultaneous Production of J/ψ and ϒ Mesons. PHYSICAL REVIEW LETTERS 2016; 116:082002. [PMID: 26967412 DOI: 10.1103/physrevlett.116.082002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Indexed: 06/05/2023]
Abstract
We report evidence for the simultaneous production of J/ψ and ϒ mesons in 8.1 fb^{-1} of data collected at sqrt[s]=1.96 TeV by the D0 experiment at the Fermilab pp[over ¯] Tevatron Collider. Events with these characteristics are expected to be produced predominantly by gluon-gluon interactions. In this analysis, we extract the effective cross section characterizing the initial parton spatial distribution, σ_{eff}=2.2±0.7(stat)±0.9(syst) mb.
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Inclusive Production of the X(4140) State in pp[over ¯] Collisions at D0. PHYSICAL REVIEW LETTERS 2015; 115:232001. [PMID: 26684112 DOI: 10.1103/physrevlett.115.232001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Indexed: 06/05/2023]
Abstract
We present a study of the inclusive production of the X(4140) state with the decay to the J/ψϕ final state in hadronic collisions. Based on 10.4 fb^{-1} of pp[over ¯] collision data collected by the D0 experiment at the Fermilab Tevatron collider, we report the first evidence for the prompt production of an X(4140) state and find the fraction of X(4140) events originating from b hadrons to be f_{b}=0.39±0.07(stat)±0.10(syst). The ratio of the nonprompt X(4140) production rate to the B_{s}^{0} yield in the same channel is R=0.19±0.05(stat)±0.07(syst). The values of the mass M=4152.5±1.7(stat)_{-5.4}^{+6.2}(syst) MeV and width Γ=16.3±5.6(stat)±11.4(syst) MeV are consistent with previous measurements.
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Search for Violation of CPT and Lorentz Invariance in Bs(0) Meson Oscillations. PHYSICAL REVIEW LETTERS 2015; 115:161601. [PMID: 26550864 DOI: 10.1103/physrevlett.115.161601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Indexed: 06/05/2023]
Abstract
We present the first search for CPT-violating effects in the mixing of Bs(0) mesons using the full Run II data set with an integrated luminosity of 10.4 fb(-1) of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. We measure the CPT-violating asymmetry in the decay Bs(0)→μ(±)Ds(±) as a function of celestial direction and sidereal phase. We find no evidence for CPT-violating effects and place limits on the direction and magnitude of flavor-dependent CPT- and Lorentz-invariance violating coupling coefficients. We find 95% confidence intervals of Δa⊥<1.2×10(-12) GeV and (-0.8<ΔaT-0.396ΔaZ<3.9)×10(-13) GeV.
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Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element V_{tb}. PHYSICAL REVIEW LETTERS 2015; 115:152003. [PMID: 26550718 DOI: 10.1103/physrevlett.115.152003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Indexed: 06/05/2023]
Abstract
We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb^{-1} per experiment. The t-channel cross section is measured to be σ_{t}=2.25_{-0.31}^{+0.29} pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in σ_{s+t}=3.30_{-0.40}^{+0.52} pb, without assuming the standard model value for the ratio σ_{s}/σ_{t}. The resulting value of the magnitude of the top-to-bottom quark coupling is |V_{tb}|=1.02_{-0.05}^{+0.06}, corresponding to |V_{tb}|>0.92 at the 95% C.L.
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Measurement of the Effective Weak Mixing Angle in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} Events. PHYSICAL REVIEW LETTERS 2015; 115:041801. [PMID: 26252676 DOI: 10.1103/physrevlett.115.041801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Indexed: 06/04/2023]
Abstract
We present a measurement of the fundamental parameter of the standard model, the weak mixing angle sin^{2}θ_{eff}^{ℓ} which determines the relative strength of weak and electromagnetic interactions, in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} events at a center of mass energy of 1.96 TeV, using data corresponding to 9.7 fb^{-1} of integrated luminosity collected by the D0 detector at the Fermilab Tevatron. The effective weak mixing angle is extracted from the forward-backward charge asymmetry as a function of the invariant mass around the Z boson pole. The measured value of sin^{2}θ_{eff}^{ℓ}=0.23147±0.00047 is the most precise measurement from light quark interactions to date, with a precision close to the best LEP and SLD results.
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19
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Measurement of the forward-backward asymmetry in Λb0and Λ¯b0baryon production in pp¯collisions at s=1.96TeV. Int J Clin Exp Med 2015. [DOI: 10.1103/physrevd.91.072008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tevatron constraints on models of the Higgs boson with exotic spin and parity using decays to bottom-antibottom quark pairs. PHYSICAL REVIEW LETTERS 2015; 114:151802. [PMID: 25933309 DOI: 10.1103/physrevlett.114.151802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Indexed: 06/04/2023]
Abstract
Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value JP=0+. Both collaborations analyzed approximately 10 fb(-) of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with JP=0- and JP=2+ are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the JP=0- hypothesis and the JP=2+ hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the JP=0- and JP=2+ hypotheses, respectively.
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Measurement of the ratio of inclusive cross sectionsσ(pp¯→Z+2b jets /σ(pp¯→Z+2 jets)inpp¯collisions ats=1.96 TeV. Int J Clin Exp Med 2015. [DOI: 10.1103/physrevd.91.052010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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22
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Measurement of the B(s)(0) lifetime in the flavor-specific decay channel B(s)(0)→D(s)(-)μ(+)νX. PHYSICAL REVIEW LETTERS 2015; 114:062001. [PMID: 25723207 DOI: 10.1103/physrevlett.114.062001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Indexed: 06/04/2023]
Abstract
We present an updated measurement of the B(s)(0) lifetime using the semileptonic decays B(s)(0)→D(s)(-)μ(+)νX, with D(s)(-)→ϕπ(-) and ϕ→K(+)K(-) (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at √[s]=1.96 TeV, comprising an integrated luminosity of 10.4 fb(-1). We find a flavor-specific lifetime τ(fs)(B(s)(0))=1.479±0.010(stat)±0.021(syst) ps. This technique is also used to determine the B(0) lifetime using the analogous B(0)→D(-)μ(+)νX decay with D(-)→ϕπ(-) and ϕ→K(+)K(-), yielding τ(B(0))=1.534±0.019(stat)±0.021(syst) ps. Both measurements are consistent with the current world averages, and the B(s)(0) lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio τ(fs)(B(s)(0))/τ(B(0))=0.964±0.013(stat)±0.007(syst).
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Measurement of the forward-backward asymmetry in the production of B(±) mesons in pp̄ collisions at √s=1.96 TeV. PHYSICAL REVIEW LETTERS 2015; 114:051803. [PMID: 25699435 DOI: 10.1103/physrevlett.114.051803] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Indexed: 06/04/2023]
Abstract
We present a measurement of the forward-backward asymmetry in the production of B(±) mesons, A(FB)(B(±)), using B(±)→J/ψK(±) decays in 10.4 fb(-1) of pp̄ collisions at sqrt[s]=1.96 TeV collected by the D0 experiment during Run II of the Tevatron collider. A nonzero asymmetry would indicate a preference for a particular flavor, i.e., b quark or ̄b antiquark, to be produced in the direction of the proton beam. We extract A(FB)(B(±)) from a maximum likelihood fit to the difference between the numbers of forward- and backward-produced B(±) mesons. We measure an asymmetry consistent with zero: A(FB)(B(±))=[-0.24±0.41 (stat)±0.19 (syst)]%.
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Constraints on models for the Higgs boson with exotic spin and parity in VH → Vbb final states. PHYSICAL REVIEW LETTERS 2014; 113:161802. [PMID: 25361251 DOI: 10.1103/physrevlett.113.161802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Indexed: 06/04/2023]
Abstract
We present constraints on models containing non-standard-model values for the spin J and parity P of the Higgs boson H in up to 9.7 fb(-1) of pp collisions at sqrt[s] = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. These are the first studies of Higgs boson J(P) with fermions in the final state. In the ZH → ℓℓbb, WH → ℓνbb, and ZH → ννbb final states, we compare the standard model (SM) Higgs boson prediction, J(P) = 0(+), with two alternative hypotheses, J(P) = 0(-) and J(P) = 2(+). We use a likelihood ratio to quantify the degree to which our data are incompatible with non-SM J(P) predictions for a range of possible production rates. Assuming that the production rate in the signal models considered is equal to the SM prediction, we reject the J(P) = 0(-) and J(P) = 2(+) hypotheses at the 97.6% CL and at the 99.0% CL, respectively. The expected exclusion sensitivity for a J(P) = 0(-) (J(P) = 2(+)) state is at the 99.86% (99.94%) CL. Under the hypothesis that our data are the result of a combination of the SM-like Higgs boson and either a J(P) = 0(-) or a J(P) = 2(+) signal, we exclude a J(P) = 0(-) fraction above 0.80 and a J(P) = 2(+) fraction above 0.67 at the 95% CL. The expected exclusion covers J(P) = 0(-) (J(P) = 2(+)) fractions above 0.54 (0.47).
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Precision measurement of the top quark mass in lepton + jets final States. PHYSICAL REVIEW LETTERS 2014; 113:032002. [PMID: 25083634 DOI: 10.1103/physrevlett.113.032002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Indexed: 06/03/2023]
Abstract
We measure the mass of the top quark in lepton+jets final states using the full sample of pp collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at sqrt[s] = 1.96 TeV, corresponding to 9.7 fb(-1) of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from tt production or background. The overall jet energy scale is constrained in situ by the mass of the W boson. We measure m(t) = 174.98 ± 0.76 GeV. This constitutes the most precise single measurement of the top-quark mass.
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Observation of s-channel production of single top quarks at the Tevatron. PHYSICAL REVIEW LETTERS 2014; 112:231803. [PMID: 24972197 DOI: 10.1103/physrevlett.112.231803] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Indexed: 06/03/2023]
Abstract
We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb(-1) per experiment. The measured cross section is σ(s) = 1.29(-0.24)(+0.26) pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8 × 10(-10), corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.
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Measurement of the W boson production charge asymmetry in pp̄→W+X→eν+X events at √s=1.96 TeV. PHYSICAL REVIEW LETTERS 2014; 112:151803. [PMID: 24785031 DOI: 10.1103/physrevlett.112.151803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Indexed: 06/03/2023]
Abstract
We present a measurement of the W boson production charge asymmetry in pp̄→W+X→eν+X events at a center of mass energy of 1.96 TeV, using 9.7 fb-1 of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The neutrino longitudinal momentum is determined by using a neutrino weighting method, and the asymmetry is measured as a function of the W boson rapidity. The measurement extends over wider electron pseudorapidity region than previous results and is the most precise to date, allowing for precise determination of proton parton distribution functions in global fits.
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30
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Double parton interactions inγ+3jet andγ+b/cjet+2jet events inpp¯collisions ats=1.96 TeV. Int J Clin Exp Med 2014. [DOI: 10.1103/physrevd.89.072006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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31
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Measurement of the direct CP-violating charge asymmetry in Ds ± → ϕ π ± decays. PHYSICAL REVIEW LETTERS 2014; 112:111804. [PMID: 24702352 DOI: 10.1103/physrevlett.112.111804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Indexed: 06/03/2023]
Abstract
We present a measurement of the direct CP-violating charge asymmetry in Ds+ → ϕ π(±) decays where the ϕ meson decays to K(+)K(-), using the full Run II data set with an integrated luminosity of 10.4 fb-1 of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. The normalized difference A(CP) in the yield of D(s)(+) and D(s)(-) mesons in these decays is measured by fitting the difference between their reconstructed invariant mass distributions. This results in an asymmetry of A(CP) = [-0.38 ± 0.27]%, which is the most precise measurement of this quantity to date. The result is consistent with the standard model prediction of zero CP asymmetry in this decay.
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Measurement of associated production of z bosons with charm quark jets in pp collisions at √s=1.96 TeV. PHYSICAL REVIEW LETTERS 2014; 112:042001. [PMID: 24580440 DOI: 10.1103/physrevlett.112.042001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Indexed: 06/03/2023]
Abstract
We present the first measurements of the ratios of cross sections σ(pp → Z+c jet)/σ(pp → Z+jet) and σ(pp → Z+c jet)/σ(pp → Z+b jet) for the associated production of a Z boson with at least one charm or bottom quark jet. Jets have transverse momentum pT(jet)>20 GeV and pseudorapidity |η(jet)|<2.5. These cross section ratios are measured differentially as a function of jet and Z boson transverse momenta, based on 9.7 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider at √s=1.96 TeV. The measurements show significant deviations from perturbative QCD calculations and predictions from various event generators.
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34
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35
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Measurement of theZZproduction cross section and search for the standard model Higgs boson in the four lepton final state inpp¯collisions. Int J Clin Exp Med 2013. [DOI: 10.1103/physrevd.88.032008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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36
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Measurement of direct CP violation parameters in B± → J/ψK± and B± → J/ψπ± decays with 10.4 fb-1 of Tevatron data. PHYSICAL REVIEW LETTERS 2013; 110:241801. [PMID: 25165913 DOI: 10.1103/physrevlett.110.241801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Indexed: 06/03/2023]
Abstract
We present a measurement of the direct CP-violating charge asymmetry in B(±) mesons decaying to J/ψK(±) and J/ψπ(±) where J/ψ decays to μ(+) μ(-), using the full run II data set of 10.4 fb(-1) of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. A difference in the yield of B(-) and B(+) mesons in these decays is found by fitting to the difference between their reconstructed invariant mass distributions resulting in asymmetries of A(J/ψK) = [0.59 ± 0.37]%, which is the most precise measurement to date, and A(J/ψπ) = [-4.2 ± 4.5]%. Both measurements are consistent with standard model predictions.
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37
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Measurement of the semileptonic charge asymmetry using B(s)(0) → D(s)μX decays. PHYSICAL REVIEW LETTERS 2013; 110:011801. [PMID: 23383778 DOI: 10.1103/physrevlett.110.011801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 09/14/2012] [Indexed: 06/01/2023]
Abstract
We present a measurement of the time-integrated flavor-specific semileptonic charge asymmetry in the decays of B(s)(0) mesons that have undergone flavor mixing, a(sl)(s), using B(s)(0)(B(s)(0)) → D(s)(-/+) μ(±) X decays, with D(s)(-/+) → [symbol: see text]π(-/+) and [symbol: see text]→ K(+) K(-), using 10.4 fb(-1) of proton-antiproton collisions collected by the D0 detector during Run II at the Fermilab Tevatron Collider. A fit to the difference between the time-integrated D(s)(-) and D(s)(+) mass distributions of the B(s)(0) and B(s)(0) candidates yields the flavor-specific asymmetry a(sl)(s) = [-1.12 ± 0.74(stat) ± 0.17(syst)]%, which is the most precise measurement and in agreement with the standard model prediction.
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40
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Search for the standard model Higgs boson in associated WH production in 9.7 fb(-1) of pp collisions with the D0 detector. PHYSICAL REVIEW LETTERS 2012; 109:121804. [PMID: 23005940 DOI: 10.1103/physrevlett.109.121804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Indexed: 06/01/2023]
Abstract
We present a search for the standard model Higgs boson in final states with a charged lepton (electron or muon), missing transverse energy, and two or three jets, at least one of which is identified as a b-quark jet. The search is primarily sensitive to WH→ℓνbb production and uses data corresponding to 9.7 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp Collider at √s = 1.96 TeV. We observe agreement between the data and the expected background. For a Higgs boson mass of 125 GeV, we set a 95% C.L. upper limit on the production of a standard model Higgs boson of 5.2 × σ(SM), where σ(SM) is the standard model Higgs boson production cross section, while the expected limit is 4.7 × σ(SM).
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41
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Combined search for the standard model Higgs boson decaying to bb using the D0 run II data set. PHYSICAL REVIEW LETTERS 2012; 109:121802. [PMID: 23005938 DOI: 10.1103/physrevlett.109.121802] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Indexed: 06/01/2023]
Abstract
We present the results of the combination of searches for the standard model Higgs boson produced in association with a W or Z boson and decaying into bb using the data sample collected with the D0 detector in pp collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. We derive 95% C.L. upper limits on the Higgs boson cross section relative to the standard model prediction in the mass range 100 GeV ≤ M(H) ≤ 150 GeV, and we exclude Higgs bosons with masses smaller than 102 GeV at the 95% C.L. In the mass range 120 GeV ≤ M(H) ≤145 GeV, the data exhibit an excess above the background prediction with a global significance of 1.5 standard deviations, consistent with the expectation in the presence of a standard model Higgs boson.
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42
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Search for the standard model Higgs boson in ZH→ℓ(+)ℓ(-)bb production with the D0 detector in 9.7 fb(-1) of pp collisions at √s = 1.96 TeV. PHYSICAL REVIEW LETTERS 2012; 109:121803. [PMID: 23005939 DOI: 10.1103/physrevlett.109.121803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Indexed: 06/01/2023]
Abstract
We present a search for the standard model (SM) Higgs boson produced in association with a Z boson in 9.7 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider at √s = 1.96 TeV. Selected events contain one reconstructed Z→e(+)e(-) or Z→μ(+)μ(-) candidate and at least two jets, including at least one jet identified as likely to contain a b quark. To validate the search procedure, we also measure the cross section for ZZ production in the same final state. It is found to be consistent with its SM prediction. We set upper limits on the ZH production cross section times branching ratio for H→bb at the 95% C.L. for Higgs boson masses 90 ≤ M(H) ≤ 150 GeV. The observed (expected) limit for M(H) = 125 GeV is 7.1 (5.1) times the SM cross section.
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43
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Evidence for a particle produced in association with weak bosons and decaying to a bottom-antibottom quark pair in higgs boson searches at the tevatron. PHYSICAL REVIEW LETTERS 2012; 109:071804. [PMID: 23006359 DOI: 10.1103/physrevlett.109.071804] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Indexed: 06/01/2023]
Abstract
We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab Tevatron pp collisions at √s = 1.96 TeV, correspond to integrated luminosities of up to 9.7 fb(-1). The searches are conducted for a Higgs boson with mass in the range 100-150 GeV/c(2). We observe an excess of events in the data compared with the background predictions, which is most significant in the mass range between 120 and 135 GeV/c(2). The largest local significance is 3.3 standard deviations, corresponding to a global significance of 3.1 standard deviations. We interpret this as evidence for the presence of a new particle consistent with the standard model Higgs boson, which is produced in association with a weak vector boson and decays to a bottom-antibottom quark pair.
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44
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Search for violation of Lorentz invariance in top quark pair production and decay. PHYSICAL REVIEW LETTERS 2012; 108:261603. [PMID: 23004960 DOI: 10.1103/physrevlett.108.261603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Indexed: 06/01/2023]
Abstract
Using data collected with the D0 detector at the Fermilab Tevatron Collider, corresponding to 5.3 fb(-1) of integrated luminosity, we search for violation of Lorentz invariance by examining the tt[over ¯] production cross section in lepton+jets final states. We quantify this violation using the standard-model extension framework, which predicts a dependence of the tt[over ¯] production cross section on sidereal time as the orientation of the detector changes with the rotation of the Earth. Within this framework, we measure components of the matrices (c(Q))(μν33) and (c(U))(μν33) containing coefficients used to parametrize violation of Lorentz invariance in the top quark sector. Within uncertainties, these coefficients are found to be consistent with zero.
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45
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Measurements of WW and WZ production in W + jets final states in pp collisions. PHYSICAL REVIEW LETTERS 2012; 108:181803. [PMID: 22681058 DOI: 10.1103/physrevlett.108.181803] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Indexed: 06/01/2023]
Abstract
We study WW and WZ production with ℓνqq (ℓ=e,μ) final states using data collected by the D0 detector at the Fermilab Tevatron Collider corresponding to 4.3 fb(-1) of integrated luminosity from pp collisions at sqrt[s]=1.96 TeV. Assuming the ratio between the production cross sections σ(WW) and σ(WZ) as predicted by the standard model, we measure the total WV (V=W,Z) cross section to be σ(WV)=19.6(-3.0)(+3.2) pb and reject the background-only hypothesis at a level of 7.9 standard deviations. We also use b-jet discrimination to separate the WZ component from the dominant WW component. Simultaneously fitting WW and WZ contributions, we measure σ(WW)=15.9(-3.2)(+3.7) pb and σ(WZ)=3.3(-3.3)(+4.1) pb, which is consistent with the standard model predictions.
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47
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Measurement of the W boson mass with the D0 detector. PHYSICAL REVIEW LETTERS 2012; 108:151804. [PMID: 22587244 DOI: 10.1103/physrevlett.108.151804] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Indexed: 05/31/2023]
Abstract
We present a measurement of the W boson mass using data corresponding to 4.3 fb(-1) of integrated luminosity collected with the D0 detector during Run II at the Fermilab Tevatron pp collider. With a sample of 1,677,394 W → eν candidate events, we measure M(W) = 80.367 ± 0.026 GeV. This result is combined with an earlier D0 result determined using an independent Run II data sample, corresponding to 1 fb(-1) of integrated luminosity, to yield M(W) = 80.375 ± 0.023 GeV.
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48
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Search for universal extra dimensions in pp collisions. PHYSICAL REVIEW LETTERS 2012; 108:131802. [PMID: 22540694 DOI: 10.1103/physrevlett.108.131802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Indexed: 05/31/2023]
Abstract
We present a search for Kaluza-Klein (KK) particles predicted by models with universal extra dimensions (UED) using a data set corresponding to an integrated luminosity of 7.3 fb(-1), collected by the D0 detector at a pp center-of-mass energy of 1.96 TeV. The decay chain of KK particles can lead to a final state with two muons of the same charge. This signature is used to set a lower limit on the compactification scale of R(-1)>260 GeV in a minimal UED model.
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49
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Search for charged massive long-lived particles. PHYSICAL REVIEW LETTERS 2012; 108:121802. [PMID: 22540571 DOI: 10.1103/physrevlett.108.121802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Indexed: 05/31/2023]
Abstract
We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss (dE/dx) inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We exclude pair-produced long-lived gauginolike charginos below 267 GeV and Higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar top quarks with mass below 285 GeV.
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Evidence for spin correlation in t ̅t production. PHYSICAL REVIEW LETTERS 2012; 108:032004. [PMID: 22400731 DOI: 10.1103/physrevlett.108.032004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Indexed: 05/31/2023]
Abstract
We present a measurement of the ratio of events with correlated t and t ̅t spins to the total number of t ̅t events. This ratio f is evaluated using a matrix-element-based approach in 729 t ̅t candidate events with a single lepton ℓ (electron or muon) and at least four jets. The analyzed p ̅p collisions data correspond to an integrated luminosity of 5.3 fb(-1) and were collected with the D0 detector at the Fermilab Tevatron collider operating at a center-of-mass energy √s=1.96 TeV. Combining this result with a recent measurement of f in dileptonic final states, we find f in agreement with the standard model. In addition, the combination provides evidence for the presence of spin correlation in t ̅t events with a significance of more than 3 standard deviations.
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