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Full-Text Articles in Physical Sciences and Mathematics

Principal-Component Analysis Of Two-Particle Azimuthal Correlations In Pbpb And Ppb Collisions At Cms, A. M. Sirunyam, A. R. Tumasyan, Adam Wolfgang, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin S. Roy, Francisco X. Yumiceva Dec 2017

Principal-Component Analysis Of Two-Particle Azimuthal Correlations In Pbpb And Ppb Collisions At Cms, A. M. Sirunyam, A. R. Tumasyan, Adam Wolfgang, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin S. Roy, Francisco X. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

For the first time a principle-component analysis is used to separate out different orthogonal modes of the two-particle correlation matrix from heavy ion collisions. The analysis uses data from sNN=2.76TeV PbPb and sNN=5.02TeV pPb collisions collected by the CMS experiment at the CERN Large Hadron Collider. Two-particle azimuthal correlations have been extensively used to study hydrodynamic flow in heavy ion collisions. Recently it was shown that the expected factorization of two-particle results into a product of the constituent single-particle anisotropies is broken. The new information provided by these modes may shed light on the breakdown of flow factorization in heavy …


Search For Pair Production Of Vector-Like T And B Quarks In Single-Lepton Final States Using Boosted Jet Substructure In Proton-Proton Collisions At √S=13 Tev, Cms Collaboration, A. M. Sirunyan, A. Tumasyan, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin Roy, Francisco X. Yumiceva Nov 2017

Search For Pair Production Of Vector-Like T And B Quarks In Single-Lepton Final States Using Boosted Jet Substructure In Proton-Proton Collisions At √S=13 Tev, Cms Collaboration, A. M. Sirunyan, A. Tumasyan, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin Roy, Francisco X. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A search for pair production of massive vector-like T and B quarks in proton-proton collisions at s=13" role="presentation" style="box-sizing: inherit; display: inline-block; line-height: normal; word-spacing: normal; overflow-wrap: normal; text-wrap: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">�=13 TeV is presented. The data set was collected in 2015 by the CMS experiment at the LHC and corresponds to an integrated luminosity of up to 2.6 fb−1. The T and B quarks are assumed to decay through three possible channels into a heavy boson (either a …


Measurements Of Differential Cross Sections For Associated Production Of A W Boson And Jets In Proton-Proton Collisions At Square Root Of S = 8 Tev, A. M. Sirunyan, A. R. Tumasyan, W. Adam, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin S. Roy, Francisco X. Yumiceva Oct 2017

Measurements Of Differential Cross Sections For Associated Production Of A W Boson And Jets In Proton-Proton Collisions At Square Root Of S = 8 Tev, A. M. Sirunyan, A. R. Tumasyan, W. Adam, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin S. Roy, Francisco X. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A measurement of the differential cross sections for a W boson produced in association with jets in the muon decay channel is presented. The measurement is based on 13 TeV proton-proton collision data corresponding to an integrated luminosity of 2.2 fb-1, recorded by the CMS detector at the LHC. The cross sections are reported as functions of jet multiplicity, jet transverse momentum pT, jet rapidity, the scalar pT sum of the jets, and angular correlations between the muon and each jet for different jet multiplicities. The measured cross sections are in agreement with predictions that include multileg leading-order (LO) and …


Measurement Of The B± Meson Nuclear Modification Factor In Pb-Pb Collisions At Snn =5.02 Tev, A. M. Sirunyam, A. R. Tumasyan, Adam Wolfgang, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Toohin S. Roy, Francisco X. Yumiceva Oct 2017

Measurement Of The B± Meson Nuclear Modification Factor In Pb-Pb Collisions At Snn =5.02 Tev, A. M. Sirunyam, A. R. Tumasyan, Adam Wolfgang, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Toohin S. Roy, Francisco X. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

The differential production cross sections of B± mesons are measured via the exclusive decay channels B±→J/ψK±→μ+μ-K± as a function of transverse momentum in pp and Pb-Pb collisions at a center-of-mass energy sNN=5.02 TeV per nucleon pair with the CMS detector at the LHC. The pp(Pb-Pb) data set used for this analysis corresponds to an integrated luminosity of 28.0 pb-1 (351 μb-1). The measurement is performed in the B± meson transverse momentum range of 7 to 50 GeV/c, in the rapidity interval |y|<2.4. In this kinematic range, a strong suppression of the production cross section by about a factor of 2 is observed in the Pb-Pb system in comparison to the expectation from pp reference data. These results are found to be roughly compatible with theoretical calculations incorporating beauty quark diffusion and energy loss in a quark-gluon plasma. © 2017 CERN, for the CMS Collaboration. Published by the American Physical Society under the terms of the «https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.


Search For Direct Production Of Supersymmetric Partners Of The Top Quark In The All-Jets Final State In Proton-Proton Collisions At √S=13 Tev, A. M. Sirunyan, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin S. Roy, F. Yumiceva, The Cms Collaboration Oct 2017

Search For Direct Production Of Supersymmetric Partners Of The Top Quark In The All-Jets Final State In Proton-Proton Collisions At √S=13 Tev, A. M. Sirunyan, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin S. Roy, F. Yumiceva, The Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for direct production of top squark pairs in events with jets and large transverse momentum imbalance is presented. The data are based on proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector in 2016 at the CERN LHC, and correspond to an integrated luminosity of 35.9 fb−1. The search considers a variety of R-parity conserving supersymmetric models, including ones for which the top squark and neutralino masses are nearly degenerate. Specialized jet reconstruction tools are developed to exploit the unique characteristics of the signal topologies. With no significant excess of events observed above …


Search For Low Mass Vector Resonances Decaying To Quark-Antiquark Pairs In Proton-Proton Collisions At √ S = 13 Tev, A. M. Sirunyan, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin Roy, Francisco Yumiceva Sep 2017

Search For Low Mass Vector Resonances Decaying To Quark-Antiquark Pairs In Proton-Proton Collisions At √ S = 13 Tev, A. M. Sirunyan, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin Roy, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A search is reported for a narrow vector resonance decaying to quark-antiquark pairs in proton-proton collisions at ffiffiffi s p ¼ 13 TeV, collected with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.7 fb−1. The vector resonance is produced at large transverse momenta, with its decay products merged into a single jet. The resulting signature is a peak over background in the distribution of the invariant mass of the jet. The results are interpreted in the framework of a leptophobic vector resonance and no evidence is found for such particles in the …


Measurement Of The T T ¯ Production Cross Section Using Events With One Lepton And At Least One Jet In Pp Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Sep 2017

Measurement Of The T T ¯ Production Cross Section Using Events With One Lepton And At Least One Jet In Pp Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A measurement of the t t ¯ production cross section at s=13 TeV is presented using proton-proton collisions, corresponding to an integrated luminosity of 2.2 fb−1, collected with the CMS detector at the LHC. Final states with one isolated charged lepton (electron or muon) and at least one jet are selected and categorized according to the accompanying jet multiplicity. From a likelihood fit to the invariant mass distribution of the isolated lepton and a jet identified as coming from the hadronization of a bottom quark, the cross section is measured to be σtt¯=888±2,(stat)−28+26(syst)±20(lumi) pb, in agreement with the standard model …


Measurements Of E+E− Pairs From Open Heavy Flavor In P + P And D + A Collisions At √ Snn = 200 Gev, Gyöngyi Baksay, László A. Baksay, C. Baumann, Klaus Dehmelt, Marcus Hohlmann, Jun Kikuchi, Christian Klein-Boesing, S. Rembeczki, Klaus Johannes Reygers, Baldo Sahlmueller, Johannes P. Wessels, Yoshio Yamaguchi, A. Adare Aug 2017

Measurements Of E+E− Pairs From Open Heavy Flavor In P + P And D + A Collisions At √ Snn = 200 Gev, Gyöngyi Baksay, László A. Baksay, C. Baumann, Klaus Dehmelt, Marcus Hohlmann, Jun Kikuchi, Christian Klein-Boesing, S. Rembeczki, Klaus Johannes Reygers, Baldo Sahlmueller, Johannes P. Wessels, Yoshio Yamaguchi, A. Adare

Aerospace, Physics, and Space Science Faculty Publications

We report a measurement of e+e- pairs from semileptonic heavy-flavor decays in p+p collisions at sNN=200 GeV. The e+e- pair yield from bb and cc is separated by exploiting a double differential fit done simultaneously in dielectron invariant mass and pT. We used three different event generators, pythia, mc@nlo, and powheg, to simulate the e+e- spectra from cc and bb production. The data can be well described by all three generators within the detector acceptance. However, when using the generators to extrapolate to 4π, significant differences are observed for the total cross section. These difference are less pronounced for bb …


Search For Top Quark Partners With Charge 5/3 In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Aug 2017

Search For Top Quark Partners With Charge 5/3 In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for the production of heavy partners of the top quark with charge 5/3 (X5/3) decaying into a top quark and a W boson is performed with a data sample corresponding to an integrated luminosity of 2.3 fb−1, collected in proton-proton collisions at a center-of-mass energy of 13 TeV with the CMS detector at the CERN LHC. Final states with either a pair of same-sign leptons or a single lepton, along with jets, are considered. No significant excess is observed in the data above the expected standard model background contribution and an X5/3 quark with right-handed (left-handed) couplings is …


Measurement Of The Inclusive Energy Spectrum In The Very Forward Direction In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Aug 2017

Measurement Of The Inclusive Energy Spectrum In The Very Forward Direction In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

The differential cross section for inclusive particle production as a function of energy in proton-proton collisions at a center-of-mass energy of 13 TeV is measured in the very forward region of the CMS detector. The measurement is based on data collected with the CMS apparatus at the LHC, and corresponds to an integrated luminosity of 0.34 μb−1. The energy is measured in the CASTOR calorimeter, which covers the pseudorapidity region −6.6 < η < −5.2. The results are given as a function of the total energy deposited in CASTOR, as well as of its electromagnetic and hadronic components. The spectra are sensitive to the modeling of multiparton interactions in pp collisions, and provide new constraints for hadronic interaction models used in collider and in high energy cosmic ray physics.


Do Cosmic Ray Air Showers Initiate Lightning?: A Statistical Analysis Of Cosmic Ray Air Showers And Lightning Mapping Array Data, B. M. Hare, Hamid K. Rassoul Aug 2017

Do Cosmic Ray Air Showers Initiate Lightning?: A Statistical Analysis Of Cosmic Ray Air Showers And Lightning Mapping Array Data, B. M. Hare, Hamid K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

It has been argued in the technical literature, and widely reported in the popular press, that cosmic ray air showers (CRASs) can initiate lightning via a mechanism known as relativistic runaway electron avalanche (RREA), where large numbers of high-energy and low-energy electrons can, somehow, cause the local atmosphere in a thundercloud to transition to a conducting state. In response to this claim, other researchers have published simulations showing that the electron density produced by RREA is far too small to be able to affect the conductivity in the cloud sufficiently to initiate lightning. In this paper, we compare 74 days …


Searches For W′ Bosons Decaying To A Top Quark And A Bottom Quark In Proton-Proton Collisions At 13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Aug 2017

Searches For W′ Bosons Decaying To A Top Quark And A Bottom Quark In Proton-Proton Collisions At 13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Searches are presented for heavy gauge bosons decaying into a top and a bottom quark in data collected by the CMS experiment at s=13 TeV that correspond to an integrated luminosity of 2.2 and 2.6 fb−1 in the leptonic and hadronic analyses, respectively. Two final states are analyzed, one containing a single electron, or muon, and missing transverse momentum, and the other containing multiple jets and no electrons or muons. No evidence is found for a right-handed W′ boson (W′R) and the combined analyses exclude at 95% confidence level W′R with masses below 2.4 TeV if MW′R≫MνR (mass of the …


Pseudorapidity Dependence Of Long-Range Two-Particle Correlations In Ppb Collisions At √ Snn = 5.02 Tev, V. Khachatryan, A. M. Sirunyan, Daniel Noonan, Marc M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, Stefano Colafranceschi, Tuhin S. Roy, Francisco X. Yumiceva, H Kalakhety Jul 2017

Pseudorapidity Dependence Of Long-Range Two-Particle Correlations In Ppb Collisions At √ Snn = 5.02 Tev, V. Khachatryan, A. M. Sirunyan, Daniel Noonan, Marc M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, Stefano Colafranceschi, Tuhin S. Roy, Francisco X. Yumiceva, H Kalakhety

Aerospace, Physics, and Space Science Faculty Publications

Two-particle correlations in pPb collisions at a nucleon-nucleon center-of-mass energy of 5.02TeV are studied as a function of the pseudorapidity separation (Δη) of the particle pair at small relative azimuthal angle (|Δφ|<π/3). The correlations are decomposed into a jet component that dominates the short-range correlations (|Δη|<1), and a component that persists at large Δη and may originate from collective behavior of the produced system. The events are classified in terms of the multiplicity of the produced particles. Finite azimuthal anisotropies are observed in high-multiplicity events. The second and third Fourier components of the particle-pair azimuthal correlations, V2 and V3, are extracted after subtraction of the jet component. The single-particle anisotropy parameters v2 and v3 are normalized by their laboratory frame midrapidity value and are studied as a function of ηc.m.. The normalized v2 distribution is found to be asymmetric about ηc.m.=0, with smaller values observed at forward pseudorapidity, corresponding to the direction of the proton beam, while no significant pseudorapidity dependence is observed for the normalized v3 distribution within the statistical uncertainties.


Search For Third-Generation Scalar Leptoquarks And Heavy Right-Handed Neutrinos In Final States With Two Tau Leptons And Two Jets In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jul 2017

Search For Third-Generation Scalar Leptoquarks And Heavy Right-Handed Neutrinos In Final States With Two Tau Leptons And Two Jets In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search is performed for third-generation scalar leptoquarks and heavy right-handed neutrinos in events containing one electron or muon, one hadronically decaying τ lepton, and at least two jets, using a s=13 TeV pp collision data sample corresponding to an integrated luminosity of 12.9 fb-1 collected with the CMS detector at the LHC in 2016. The number of observed events is found to be in agreement with the standard model prediction. A limit is set at 95% confidence level on the product of the leptoquark pair production cross section and β2, where β is the branching fraction of leptoquark decay …


Search For Supersymmetry In The All-Hadronic Final State Using Top Quark Tagging In Pp Collisions At Square Root Of S = 13 Tev, V. Khachatryan, A. M. Sirunyan, A. R. Tumasyan, Marc M. Baarmand, Stefano Colafranceschi, Vallary Bhopatkar, Daniel Noonan, Marcus Hohlmann, Tuhin S. Roy, Francisco X. Yumiceva Jul 2017

Search For Supersymmetry In The All-Hadronic Final State Using Top Quark Tagging In Pp Collisions At Square Root Of S = 13 Tev, V. Khachatryan, A. M. Sirunyan, A. R. Tumasyan, Marc M. Baarmand, Stefano Colafranceschi, Vallary Bhopatkar, Daniel Noonan, Marcus Hohlmann, Tuhin S. Roy, Francisco X. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A search is presented for supersymmetry in all-hadronic events with missing transverse momentum and tagged top quarks. The data sample was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 2.3 fb-1 of proton-proton collisions at a center-of-mass energy of 13 TeV. Search regions are defined using the properties of reconstructed jets, the multiplicity of bottom and top quark candidates, and an imbalance in transverse momentum. With no statistically significant excess of events observed beyond the expected contributions from the standard model, we set exclusion limits at 95% confidence level on the masses of …


Search For Physics Beyond The Standard Model In Events With Two Leptons Of Same Sign, Missing Transverse Momentum, And Jets In Proton–Proton Collisions At √S=13tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jul 2017

Search For Physics Beyond The Standard Model In Events With Two Leptons Of Same Sign, Missing Transverse Momentum, And Jets In Proton–Proton Collisions At √S=13tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A data sample of events from proton–proton collisions with two isolated same-sign leptons, missing transverse momentum, and jets is studied in a search for signatures of new physics phenomena by the CMS Collaboration at the LHC. The data correspond to an integrated luminosity of 35.9fb-1, and a center-of-mass energy of 13TeV. The properties of the events are consistent with expectations from standard model processes, and no excess yield is observed. Exclusion limits at 95% confidence level are set on cross sections for the pair production of gluinos, squarks, and same-sign top quarks, as well as top-quark associated production of a …


Measurement Of Inclusive Jet Cross Sections In Pp And Pbpb Collisions At √ Snn = 2.76 Tev, V. Khachatryan, A. M. Sirunyan, A. R. Tumasyan, Marc M. Baarmand, Vallary Bhopatkar, Daniel Noonan, Stefano Colafranceschi, Marcus Hohlmann, Tuhin S. Roy, Francisco X. Yumiceva Jul 2017

Measurement Of Inclusive Jet Cross Sections In Pp And Pbpb Collisions At √ Snn = 2.76 Tev, V. Khachatryan, A. M. Sirunyan, A. R. Tumasyan, Marc M. Baarmand, Vallary Bhopatkar, Daniel Noonan, Stefano Colafranceschi, Marcus Hohlmann, Tuhin S. Roy, Francisco X. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

Inclusive jet spectra from pp and PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76TeV, collected with the CMS detector at the CERN Large Hadron Collider, are presented. Jets are reconstructed with three different distance parameters (R=0.2, 0.3, and 0.4) for transverse momentum (pT) greater than 70GeV/c and pseudorapidity |η|<2. Next-to-leading-order quantum chromodynamic calculations with nonperturbative corrections are found to overpredict jet production cross sections in pp for small distance parameters. The jet nuclear modification factors for PbPb compared to pp collisions, show a steady decrease from peripheral to central events, along with a weak dependence on the jet pT. They are found to be independent of the distance parameter in the measured kinematic range. ©2017 CERN, for the CMS Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation.


Measurement Of The Jet Mass In Highly Boosted T T ¯ Events From Pp Collisions At √S=8tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jul 2017

Measurement Of The Jet Mass In Highly Boosted T T ¯ Events From Pp Collisions At √S=8tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

The first measurement of the jet mass mjet of top quark jets produced in t t ¯ events from pp collisions at s=8TeV is reported for the jet with the largest transverse momentum pT in highly boosted hadronic top quark decays. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 19.7fb-1. The measurement is performed in the lepton+jets channel in which the products of the semileptonic decay t → b W with W → ℓν where ℓ is an electron or muon, are used to select t t ¯ events with large Lorentz boosts. The …


Measurement Of Double-Differential Cross Sections For Top Quark Pair Production In Pp Collisions At √S=8tev And Impact On Parton Distribution Functions, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jul 2017

Measurement Of Double-Differential Cross Sections For Top Quark Pair Production In Pp Collisions At √S=8tev And Impact On Parton Distribution Functions, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Normalized double-differential cross sections for top quark pair (t t ¯) production are measured in pp collisions at a centre-of-mass energy of 8TeV with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 19.7fb-1. The measurement is performed in the dilepton e ±μ∓ final state. The t t ¯ cross section is determined as a function of various pairs of observables characterizing the kinematics of the top quark and t t ¯ system. The data are compared to calculations using perturbative quantum chromodynamics at next-to-leading and approximate next-to-next-to-leading orders. They are also compared to …


Search For New Physics With Dijet Angular Distributions In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jul 2017

Search For New Physics With Dijet Angular Distributions In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search is presented for extra spatial dimensions, quantum black holes, and quark contact interactions in measurements of dijet angular distributions in proton-proton collisions at s=13 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 2.6 fb−1. The distributions are found to be in agreement with predictions from perturbative quantum chromodynamics that include electroweak corrections. Limits for different contact interaction models are obtained. In a benchmark model, valid to next-to-leading order in QCD and in which only left-handed quarks participate, quark contact interactions are excluded up to a scale of …


Search For Dark Matter Produced With An Energetic Jet Or A Hadronically Decaying W Or Z Boson At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jul 2017

Search For Dark Matter Produced With An Energetic Jet Or A Hadronically Decaying W Or Z Boson At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for dark matter particles is performed using events with large missing transverse momentum, at least one energetic jet, and no leptons, in proton-proton collisions at s=13 TeV collected with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 12.9 fb−1. The search includes events with jets from the hadronic decays of a W or Z boson. The data are found to be in agreement with the predicted background contributions from standard model processes. The results are presented in terms of simplified models in which dark matter particles are produced through interactions involving …


Search For Associated Production Of A Z Boson With A Single Top Quark And For Tz Flavour-Changing Interactions In Pp Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jul 2017

Search For Associated Production Of A Z Boson With A Single Top Quark And For Tz Flavour-Changing Interactions In Pp Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for the production of a single top quark in association with a Z boson is presented, both to identify the expected standard model process and to search for flavour-changing neutral current interactions. The data sample corresponds to an integrated luminosity of 19.7 fb−1 recorded by the CMS experiment at the LHC in proton-proton collisions at s=8 TeV. Final states with three leptons (electrons or muons) and at least one jet are investigated. An events yield compatible with tZq standard model production is observed, and the corresponding cross section is measured to be σ(pp → tZq → ℓνbℓ+ℓ−q) = …


Search For T T ¯ Resonances In Highly Boosted Lepton+Jets And Fully Hadronic Final States In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jul 2017

Search For T T ¯ Resonances In Highly Boosted Lepton+Jets And Fully Hadronic Final States In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for the production of heavy resonances decaying into top quark-antiquark pairs is presented. The analysis is performed in the lepton+jets and fully hadronic channels using data collected in proton-proton collisions at s=13 TeV using the CMS detector at the LHC, corresponding to an integrated luminosity of 2.6 fb−1. The selection is optimized for massive resonances, where the top quarks have large Lorentz boosts. No evidence for resonant t t ¯ production is found in the data, and upper limits on the production cross section of heavy resonances are set. The exclusion limits for resonances with masses above 2 …


Compact Resolved Ejecta In The Nearest Tidal Disruption Event, Eric S. Perlman, Eileen T. Meyer, Q. Daniel Wang, Qiang Yuan, Richard N. Henriksen, Judith A. Irwin, Marita Krause, Theresa Wiegert, Eric J. Murphy, George H. Heald, Ralf-Jürgen Dettmar Jun 2017

Compact Resolved Ejecta In The Nearest Tidal Disruption Event, Eric S. Perlman, Eileen T. Meyer, Q. Daniel Wang, Qiang Yuan, Richard N. Henriksen, Judith A. Irwin, Marita Krause, Theresa Wiegert, Eric J. Murphy, George H. Heald, Ralf-Jürgen Dettmar

Aerospace, Physics, and Space Science Faculty Publications

Tidal disruption events (TDEs) occur when a star or substellar object passes close enough to a galaxy's supermassive black hole to be disrupted by tidal forces. NGC 4845 (d = 17 Mpc) was host to a TDE, IGR J12580+0134, detected in 2010 November. Its proximity offers us a unique close-up of the TDE and its aftermath. We discuss new Very Long Baseline Array (VLBA) and Karl G. Jansky Very Large Array observations, which show that the radio flux from the active nucleus created by the TDE has decayed in a manner consistent with predictions from a jet-circumnuclear medium interaction model. …


Measurement Of Electroweak-Induced Production Of Wγ With Two Jets In Pp Collisions At √S=8 Tev And Constraints On Anomalous Quartic Gauge Couplings, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Jun 2017

Measurement Of Electroweak-Induced Production Of Wγ With Two Jets In Pp Collisions At √S=8 Tev And Constraints On Anomalous Quartic Gauge Couplings, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A measurement of electroweak-induced production of Wγ and two jets is performed, where the W boson decays leptonically. The data used in the analysis correspond to an integrated luminosity of 19.7 fb−1 collected by the CMS experiment in s=8 TeV proton-proton collisions produced at the LHC. Candidate events are selected with exactly one muon or electron, missing transverse momentum, one photon, and two jets with large rapidity separation. An excess over the hypothesis of the standard model without electroweak production of Wγ with two jets is observed with a significance of 2.7 standard deviations. The cross section measured in the …


Measurement Of The Top Quark Mass Using Single Top Quark Events In Proton-Proton Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration May 2017

Measurement Of The Top Quark Mass Using Single Top Quark Events In Proton-Proton Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A measurement of the top quark mass is reported in events containing a single top quark produced via the electroweak t channel. The analysis is performed using data from proton-proton collisions collected with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb- 1. Top quark candidates are reconstructed from their decay to a W boson and a b quark, with the W boson decaying leptonically to a muon and a neutrino. The final state signature and kinematic properties of single top quark events in the t channel are …


Searches For Pair Production Of Third-Generation Squarks In √S=13tev Pp Collisions, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration May 2017

Searches For Pair Production Of Third-Generation Squarks In √S=13tev Pp Collisions, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Searches are presented for direct production of top or bottom squark pairs in proton–proton collisions at the CERN LHC. Two searches, based on complementary techniques, are performed in all-jet final states that are characterized by a significant imbalance in transverse momentum. An additional search requires the presence of a charged lepton isolated from other activity in the event. The data were collected in 2015 at a centre-of-mass energy of 13TeV with the CMS detector and correspond to an integrated luminosity of 2.3fb-1. No statistically significant excess of events is found beyond the expected contribution from standard model processes. Exclusion limits …


A Search For New Phenomena In Pp Collisions At √S=13tev In Final States With Missing Transverse Momentum And At Least One Jet Using The Αt Variable, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration May 2017

A Search For New Phenomena In Pp Collisions At √S=13tev In Final States With Missing Transverse Momentum And At Least One Jet Using The Αt Variable, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for new phenomena is performed in final states containing one or more jets and an imbalance in transverse momentum in pp collisions at a centre-of-mass energy of 13TeV. The analysed data sample, recorded with the CMS detector at the CERN LHC, corresponds to an integrated luminosity of 2.3fb-1. Several kinematic variables are employed to suppress the dominant background, multijet production, as well as to discriminate between other standard model and new physics processes. The search provides sensitivity to a broad range of new-physics models that yield a stable weakly interacting massive particle. The number of observed candidate events …


Search For Single Production Of Vector-Like Quarks Decaying To A Z Boson And A Top Or A Bottom Quark In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration May 2017

Search For Single Production Of Vector-Like Quarks Decaying To A Z Boson And A Top Or A Bottom Quark In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for single production of vector-like quarks, T and B, decaying into a Z boson and a top or a bottom quark, respectively, is presented. The search is performed using data collected by the CMS experiment at the LHC in proton-proton collisions at s=13 TeV, corresponding to an integrated luminosity of 2.3fb−1. An exotic T quark production mode through the decay of a heavy Z′ resonance is also considered. The search is performed in events with a Z boson decaying leptonically, accompanied by a bottom or a top quark decaying hadronically. No excess of events is observed over the …


Observation Of Y(1s) Pair Production In Proton-Proton Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration May 2017

Observation Of Y(1s) Pair Production In Proton-Proton Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Pair production of Y(1S) mesons is observed at the LHC in proton-proton collisions at s=8 TeV by the CMS experiment in a data sample corresponding to an integrated luminosity of 20.7 fb−1. Both Y(1S) candidates are fully reconstructed via their decays to μ+μ−. The fiducial acceptance region is defined by an absolute Y(1S) rapidity smaller than 2.0. The fiducial cross section for the production of Y(1S) pairs, assuming that both mesons decay isotropically, is measured to be 68.8±12.7 (stat)±7.4 (syst)±2.8 (ℬ) pb, where the third uncertainty comes from the uncertainty in the branching fraction of Y(1S) decays to μ+μ−. Assuming …