Physics Commons^™

Differential Cross Section Measurements For The Production Of Awboson In Association With Jets In Proton–Proton Collisions At √S=7tev, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0fb−1. The measured cross sections …

Measurement Of The Pp→Zzproduction Cross Section And Constraints On Anomalous Triple Gauge Couplings In Four-Lepton Final States At √S=8tev, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A measurement of the inclusive ZZproduction cross section and constraints on anomalous triple gauge couplings in proton–proton collisions at √s=8TeVare presented. The analysis is based on a data sample, corresponding to an integrated luminosity of 19.6fb−1, collected with the CMS experiment at the LHC. The measurements are performed in the leptonic decay modes ZZ →, where=e, μand =e, μ, τ. The measured total cross section σ(pp →ZZ) =7.7 ±0.5(stat)+0.5−0.4(syst)±0.4 (theo) ±0.2(lumi)pb, for both Zbosons produced in the mass range 60

Search For New Resonances Decaying Via Wz To Leptons In Proton–Proton Collisions At √S=8 Tev, Cms Collaboration, Cern, Switzerland, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A search is performed in proton–proton collisions at √s=8TeVfor exotic particles decaying via WZ to fully leptonic final states with electrons, muons, and neutrinos. The data set corresponds to an integrated luminosity of 19.5fb−1. No significant excess is observed above the expected standard model background. Upper bounds at 95% confidence level are set on the production cross section of a Wboson as predicted by an extended gauge model, and on the WW Zcoupling. The expected and observed mass limits for a Wboson, as predicted by this model, are 1.55 and 1.47TeV, respectively. Stringent limits are also set in the context …

Search For Pair Production Of Third-Generation Scalar Leptoquarks And Top Squarks In Proton–Proton Collisions At √S=8tev, Cms Collaboration, Cern, Switzerland, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A search for pair production of third-generation scalar leptoquarks and supersymmetric top quark partners, top squarks, in final states involving tau leptons and bottom quarks is presented. The search uses events from a data sample of proton–proton collisions corresponding to an integrated luminosity of 19.7fb−1, collected with the CMS detector at the LHC with √s=8TeV. The number of observed events is found to be in agreement with the expected standard model background. Third-generation scalar leptoquarks with masses below 740GeV are excluded at 95% confidence level, assuming a 100% branching fraction for the leptoquark decay to a tau lepton and a …

Measurement Of The Ttproduction Cross Section In Pp Collisions At√S=8 Tev In Dilepton Final States Containing One Τ Lepton, Cms Collaboration, Cern, Switzerland, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

The top-quark pair production cross section is measured in final states with one electron or muon and one hadronically decaying τlepton from the process tt→(ν)(τντ)bb, where =e, μ. The data sample corresponds to an integrated luminosity of 19.6fb−1collected with the CMS detector in proton–proton collisions at √s=8TeV. The measured cross section σtt=257 ±3(stat)±24(syst)±7(lumi)pb, assuming a top-quark mass of 172.5GeV, is consistent with the standard model prediction.

Search For Excited Quarks In The Γ+Jet Final State In Proton–Proton Collisions At √S=8tev, Cms Collaboration, Cern, Switzerland, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A search for excited quarks decaying into the γ+jetfinal state is presented. The analysis is based on data corresponding to an integrated luminosity of 19.7fb−1collected by the CMS experiment in proton–proton collisions at √s=8TeVat the LHC. Events with photons and jets with high transverse momenta are selected and the γ+jetinvariant mass distribution is studied to search for a resonance peak. The 95% confidence level upper limits on the product of cross section and branching fraction are evaluated as a function of the excited quark mass. Limits on excited quarks are presented as a function of their mass and coupling strength; …

Search For Top-Squark Pairs Decaying Into Higgs Or Z Bosons In Pp Collisions At √S=8tev, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A search for supersymmetry through the direct pair production of top squarks, with Higgs (H) or Z bosons in the decay chain, is performed using a data sample of proton–proton collisions at √s=8TeVcollected in 2012 with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 19.5fb−1. The search is performed using a selection of events containing leptons and bottom-quark jets. No evidence for a significant excess of events over the standard model background prediction is observed. The results are interpreted in the context of simplified supersymmetric models with pair production of a heavier top-squark mass …

Constraints On The Higgs Boson Width From Off-Shell Production And Decay To Z-Boson Pairs, Cms Collaboration, Cern, Switzerland, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz

Department of Physics

Constraints are presented on the total width of the recently discovered Higgs boson, ΓH, using its relative on-shell and off-shell production and decay rates to a pair of Z bosons, where one Z boson decays to an electron or muon pair, and the other to an electron, muon, or neutrino pair. The analysis is based on the data collected by the CMS experiment at the LHC in 2011 and 2012, corresponding to integrated luminosities of 5.1fb−1at a center-of-mass energy √s=7TeVand 19.7fb−1at √s=8TeV. A simultaneous maximum likelihood fit to the measured kinematic distributions near the resonance peak and above the Z-boson …

Measurement Of The Ratio B(T →Wb)/B(T →Wq)In Pp Collisions At √S=8tev, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

The ratio of the top-quark branching fractions R =B(t →Wb)/B(t →Wq), where the denominator includes the sum over all down-type quarks (q =b, s, d), is measured in the t¯tdilepton final state with proton–proton collision data at √s=8TeVfrom an integrated luminosity of 19.7fb−1, collected with the CMS detector. In order to quantify the purity of the signal sample, the cross section is measured by fitting the observed jet multiplicity, thereby constraining the signal and background contributions. By counting the number of b jets per event, an unconstrained value of R =1.014 ±0.003 (stat.)±0.032 (syst.)is measured, in a good agreement with …

Measurement Of The Production Cross Section For A Wboson And Two Bjets In Ppcollisions At √S=7tev, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

The production cross section for a Wboson and two b jets is measured using proton–proton collisions at √s=7TeVin a data sample collected with the CMS experiment at the LHC corresponding to an integrated luminosity of 5.0fb−1. The W +bbevents are selected in the W →μνdecay mode by requiring a muon with transverse momentum pT>25GeVand pseudorapidity |η| <2.1, and exactly two b-tagged jets with pT>25GeVand |η| <2.4. The measured W +bbproduction cross section in the fiducial region, calculated at the level of final-state particles, is σ(pp →W +bb) ×B(W →μν) =0.53 ±0.05 (stat.)±0.09 (syst.)±0.06 (theo.)±0.01 (lum.)pb, in agreement with the standard model prediction. In addition, kinematic distributions of the W +bbsystem are in agreement with the predictions of a simulation using MadGraph and pythia.

Statistical Algorithms For Ontology-Based Annotation Of Scientific Literature, Chayan Chakrabarti, Thomas B. Jones, George F. Luger, Jiawei F. Xu, Matthew D. Turner, Angela R. Laird, Jessica A. Turner

Department of Physics

Background

Ontologies encode relationships within a domain in robust data structures that can be used to annotate data objects, including scientific papers, in ways that ease tasks such as search and meta-analysis. However, the annotation process requires significant time and effort when performed by humans. Text mining algorithms can facilitate this process, but they render an analysis mainly based upon keyword, synonym and semantic matching. They do not leverage information embedded in an ontology's structure.

Methods

We present a probabilistic framework that facilitates the automatic annotation of literature by indirectly modeling the restrictions among the different classes in the ontology. …

Observation Of A Peaking Structure In The J/Ψφmass Spectrum From B±→J/Ψφk±Decays, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, L.M. Lebolo, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A peaking structure in the J/ψφmass spectrum near threshold is observed in B±→J/ψφK±decays, produced in pp collisions at √s=7TeVcollected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/ψ, corresponds to an integrated luminosity of 5.2fb−1. Fitting the structure to an S-wave relativistic Breit–Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m =4148.0 ±2.4 (stat.) ±6.3 (syst.) MeVand Γ=28+15−11(stat.) ±19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/ψφmass …

Observation Of A Peaking Structure In The J/Ψφmass Spectrum From B±→J/Ψφk±Decays, Cms Collaboration, Cern, Switzerland

Department of Physics

A peaking structure in the J/ψφmass spectrum near threshold is observed in B±→J/ψφK±decays, produced in pp collisions at √s=7TeVcollected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/ψ, corresponds to an integrated luminosity of 5.2fb−1. Fitting the structure to an S-wave relativistic Breit–Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m =4148.0 ±2.4 (stat.) ±6.3 (syst.) MeVand Γ=28+15−11(stat.) ±19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/ψφmass …

Synthesis And Structure Of Undoped And Indium-Doped Thermoelectric Lead Telluride Nanoparticles, Kamel Kadel, Latha Kumari, Xuewen Wang, Wenzhi Li, Jian Yu Huang, Paula Polyak Provencio

Department of Physics

Undoped and indium (In)-doped lead telluride (PbTe) nanostructures were synthesized via solvothermal/hydrothermal route. The crystalline structure of the as-prepared undoped and In-doped PbTe samples was examined by X-ray diffraction (XRD) which indicated the formation of face-centered single-phase cubic crystal. A first principle calculation on indium doping shows that the indium atoms are more likely to replace lead (Pb) rather than to take the interstitial sites. Laser-induced breakdown spectroscopy (LIBS) analysis confirms that indium is incorporated into the PbTe matrix of the indium-doped PbTe samples. The effects of surfactant and synthesis temperature on the structure and morphology of the undoped PbTe …

Search For Supersymmetry In Pp Collisions At View The Mathml Sources=8 Tev In Events With A Single Lepton, Large Jet Multiplicity, And Multiple B Jets, Cms Collabortaion, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

Results are reported from a search for supersymmetry in pppp collisions at a center-of-mass energy of 8 TeV, based on events with a single isolated lepton (electron or muon) and multiple jets, at least two of which are identified as b jets. The data sample corresponds to an integrated luminosity of 19.3 fb⁻¹recorded by the CMS experiment at the LHC in 2012. The search is motivated by supersymmetric models that involve strong-production processes and cascade decays of new particles. The resulting final states contain multiple jets as well as missing transverse momentum from weakly interacting particles. The event …

Search For Baryon Number Violation In Top-Quark Decays, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A search for baryon number violation (BNV) in top-quark decays is performed using pp collisions produced by the LHC at √ s = 8 TeV. The top-quark decay considered in this search results in one light lepton (muon or electron), two jets, but no neutrino in the final state. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.5 fb−1. The event selection is optimized for top quarks produced in pairs, with one undergoing the BNV decay and the other the standard model hadronic decay to three jets. No significant excess …

Searches For Light- And Heavy-Flavour Three-Jet Resonances In Pp Collisions At √ S = 8 Tev, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A search for three-jet hadronic resonance production in pp collisions at a centre-of-mass energy of 8 TeV has been conducted by the CMS Collaboration at the LHC with a data sample corresponding to an integrated luminosity of 19.4 fb−1. The search method is model independent, and events are selected that have high jet multiplicity and large values of jet transverse momenta. The signal models explored assume R-parity-violating supersymmetric gluino pair production and have final states with either only light-flavour jets or both light- and heavy-flavour jets. No significant deviation is found between the selected events and the expected standard model …

Modification Of Jet Shapes In Pbpb Collisions At √ Snn = 2.76 Tev, Cms Collaboration, Cern, Switzerland, V. Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

The first measurement of jet shapes, defined as the fractional transverse momentum radial distribution, for inclusive jets produced in heavy-ion collisions is presented. Data samples of PbPb and pp collisions, corresponding to integrated luminosities of 150 μb−1 and 5.3 pb−1 respectively, were collected at a nucleon–nucleon centre-of-mass energy of √ sNN = 2.76 TeV with the CMS detector at the LHC. The jets are reconstructed with the anti-kT algorithm with a distance parameter R = 0.3, and the jet shapes are measured for charged particles with transverse momentum pT > 1 GeV/c. The jet shapes measured in PbPb collisions in different …

Inclusive Search For A Vector-Like T Quark With Charge 23 In Pp Collisions At P S = 8 Tev, Cms Collaboration, Vanessa Gaultney, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

A search is performed for a massive new vector-like quark T, with charge 2 3 , that is pair produced together with its antiparticle in proton-proton collisions. The data were collected by the CMS experiment at the Large Hadron Collider in 2012 at p s = 8 TeV and correspond to an integrated luminosity of 19.5 fb�1. The T quark is assumed to decay into three different final states, bW, tZ, and tH. The search is carried out using events with at least one isolated lepton. No deviations from standard model expectations are observed, and lower limits are set on …

Delayed Pion Spectroscopy Of Hypernuclei, Amur Margaryan, Patrick Achenbach, Robert Ajvazyan, John Annand, Franco Garibaldi, Nersik Grigoryan, Yuu Fuji, Osamu Hashimoto, Lubomir Majling, Satoshi N. Nakamura, Josef Pochodzalla, Joerg Reinhold, Liguang Tang, Kyo Tsukuda, Henrik Vardanyan, Simon Zhamkochyan

Department of Physics

New possibilities of hypernuclear studies at modern electron accelerators based on recently developed radio frequency photomultiplier tubes are discussed.

Protons In High Density Neutron Matter, Misak M. Sargsian

Department of Physics

We discuss the possible implication of the recent predictions of two new properties of high momentum distribution of nucleons in asymmetric nuclei for neutron star dynamics. The first property is about the approximate scaling relation between proton and neutron high momentum distributions weighted by their relative fractions (xp and xn) in the nucleus. The second is the existence of inverse proportionality of the high momentum distribution strength of protons and neutrons to xp/n. Based on these predictions we model the high momentum distribution functions for asymmetric nuclei and demonstrate that it describes reasonably well the high momentum characteristics of light …

Distributing Cms Data Between The Florida T2 And T3 Centers Using Lustre And Xrootd-Fs, Gary Kaganas, Jorge Luis Rodriguez, Mengxing Chen, P. Avery, D. Bourilkov, Y. Fu, J. Palencia

Department of Physics

We have developed remote data access for large volumes of data over the Wide Area Network based on the Lustre filesystem and Kerberos authentication for security. In this paper we explore a prototype for two-step data access from worker nodes at Florida Tier3 centers, located behind a firewall and using a private network, to data hosted on the Lustre filesystem at the University of Florida CMS Tier2 center. At the Tier3 center we use a client which mounts securely the Lustre filesystem and hosts an XrootD server. The worker nodes access the data from the Tier3 client using POSIX compliant …

Light Controlling Light In A Coupled Cavity-Atom System, Bichen Zhou, Zheng Tan, Yifu Zhu

Department of Physics

We present a theoretical model of light controlling light in a multi-atom cavity QED system consisting of three-level atoms confined in a cavity and interacting with a control laser from free space. A signal laser is coupled into the cavity and provides two output light channels: the transmitted signal light through the cavity and the reflected signal light from the cavity. We show that with the cavity electromagnetically induced transparency manifested by the free-space control light, the amplitude and the phase of the intra-cavity signal light can be manipulated by the free-space control laser. We analyze the cavity transmitted signal …

Inclusive And Exclusive Scatterings From Tensor Polarized Deuteron, Misak M. Sargsian, M. I. Strikman

Department of Physics

The possibility of using a tensor polarized deuteron target in electroproduction reactions creates new opportunities for studying different phenomena related to the short-range hadronic and nuclear physics. The use of the tensor polarized deuteron allows us to isolate smaller than average inter-nucleon distances for the bound two-nucleon system. In this report we consider several high Q² reactions which are particularly sensitive to the short-range two- nucleon configurations in the deuteron. One is the relativistic dynamics of electron-bound- nucleon scattering, which can be studied in both inclusive and exclusive reactions, and the other is the strong final state interaction in …

Electro-Disintegration Of Tensor Polarized Deuterium, Werner U. Boeglin

Department of Physics

A tensor polarized target in Hall A at Jefferson Lab would offer the possibility to measure the D(e, e'p)n cross section for the M_s = 0 and the M_s = ±1 states separately (the quantization axis is along the momentum transfer). These data would serve as a new, stringent test of our current understanding of the deuteron structure for missing momenta up to 450 MeV/c, a region where the deuteron wave function is dominated by the D-state. No data exist to date for missing momenta above 150 MeV/c. The technique to separate these cross sections, possible kinematic settings, …

Search For H-Dibaryon At J-Parc With A Large Acceptance Tpc, H. Sako, J. K. Ahn, K. Y. Baek, B. Bassalleck, H. Fujioka, Lei Guo, S. Hasegawa, K. Hicks, R. Honda, S. H. Hwang, Y. Ichikawa, M. Ieri, K. Imai, S. H. Kim, R. Kiuchi, H. S. Lee, K. Nakazawa, M. Naruki, A. Ni, M. Niiyama, K. Ozawa, J. Y. Park, S. Y. Ryu, S. Sato, K. Shirotori, H. Sugimura, M. Sumihara, K. Tanida, H. Takahashi, T. Takahashi

Department of Physics

H-dibaryon has been predicted as a stable 6-quark color-singlet state. It has been searched for by many experiments but has never been discovered. Recent lattice QCD calculations predict H-dibaryon as a weakly bound or a resonant state close to the  threshold. E224 and E522 experiments at KEK observed peaks in  invariant mass spectra near the threshold in (K-, K+) reactions, which were statistically not significant. Therefore, we proposed a new experiment E42 at J-PARC. It will measure decay products of  and p in a (K-, K+) reaction. We design a large acceptance spectrometer based on a Time …