272 results match your criteria: "National Science Center "Kharkov Institute of Physics and Technology"[Affiliation]"
Eur Phys J C Part Fields
March 2019
University of Wisconsin-Madison, Madison, WI USA.
The exclusive photoproduction of meson states from protons, (with ), is studied in ultraperipheral Pb collisions at a centre-of-mass energy per nucleon pair of . The measurement is performed using the decay mode, with data collected by the CMS experiment corresponding to an integrated luminosity of 32.6 .
View Article and Find Full Text PDFPhys Rev Lett
March 2019
University of Wisconsin-Madison, Madison, Wisconsin, USA.
Eur Phys J C Part Fields
March 2019
University of Wisconsin-Madison, Madison, WI USA.
Measurements are presented of associated production of a boson and a charm quark ( ) in proton-proton collisions at a center-of-mass energy of 13 . The data correspond to an integrated luminosity of 35.7 collected by the CMS experiment at the CERN LHC.
View Article and Find Full Text PDFPhys Rev Lett
March 2019
University of Wisconsin - Madison, Madison, Wisconsin, USA.
A search for heavy, narrow resonances decaying to a Higgs boson and a photon (Hγ) has been performed in proton-proton collision data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb^{-1} collected with the CMS detector at the LHC in 2016. Events containing a photon and a Lorentz-boosted hadronically decaying Higgs boson reconstructed as a single, large-radius jet are considered, and the γ+jet invariant mass spectrum is analyzed for the presence of narrow resonances.
View Article and Find Full Text PDFEur Phys J C Part Fields
January 2019
University of Wisconsin - Madison, Madison, WI USA.
A search is presented for decays of and Higgs bosons to a meson and a photon, with the subsequent decay of the to . The analysis uses data from proton-proton collisions with an integrated luminosity of 35.9 at collected with the CMS detector at the LHC.
View Article and Find Full Text PDFEur Phys J C Part Fields
January 2019
University of Wisconsin-Madison, Madison, WI USA.
Eur Phys J C Part Fields
February 2019
180University of Wisconsin-Madison, Madison, WI USA.
Measurements of normalized differential cross sections as functions of the multiplicity and kinematic variables of charged-particle tracks from the underlying event in top quark and antiquark pair production are presented. The measurements are performed in proton-proton collisions at a center-of-mass energy of 13 , and are based on data collected by the CMS experiment at the LHC in 2016 corresponding to an integrated luminosity of 35.9 .
View Article and Find Full Text PDFEur Phys J C Part Fields
January 2019
University of Wisconsin, Madison, Madison, WI USA.
A search is presented for the single production of vector-like quarks in proton-proton collisions at . The data, corresponding to an integrated luminosity of 35.9 , were recorded with the CMS experiment at the LHC.
View Article and Find Full Text PDFPhys Rev Lett
January 2019
University of Wisconsin-Madison, Madison, Wisconsin, USA.
A search for the Higgs boson decaying to two oppositely charged muons is presented using data recorded by the CMS experiment at the CERN LHC in 2016 at a center-of-mass energy sqrt[s]=13 TeV, corresponding to an integrated luminosity of 35.9 fb^{-1}. Data are found to be compatible with the predicted background.
View Article and Find Full Text PDFPhys Rev Lett
December 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
Measurements of fragmentation functions for jets associated with an isolated photon are presented for the first time in pp and Pb-Pb collisions. The analysis uses data collected with the CMS detector at the CERN LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV.
View Article and Find Full Text PDFPhys Rev Lett
December 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
Three of the most significant measured deviations from standard model predictions, the enhanced decay rate for B→D^{(*)}τν, hints of lepton universality violation in B→K^{(*)}ℓℓ decays, and the anomalous magnetic moment of the muon, can be explained by the existence of leptoquarks (LQs) with large couplings to third-generation quarks and masses at the TeV scale. The existence of these states can be probed at the LHC in high energy proton-proton collisions. A novel search is presented for pair production of LQs coupled to a top quark and a muon using data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.
View Article and Find Full Text PDFPhys Rev Lett
November 2018
University of Wisconsin, Madison, Wisconsin, USA.
The first evidence of events consistent with the production of a single top quark in association with a photon is reported. The analysis is based on proton-proton collisions at sqrt[s]=13 TeV and recorded by the CMS experiment in 2016, corresponding to an integrated luminosity of 35.9 fb^{-1}.
View Article and Find Full Text PDFPhys Rev Lett
October 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
This Letter presents the results of a search for pair-produced particles of masses above 100 GeV that each decay into at least four quarks. Using data collected by the CMS experiment at the LHC in 2015-2016, corresponding to an integrated luminosity of 38.2 fb^{-1}, reconstructed particles are clustered into two large jets of similar mass, each consistent with four-parton substructure.
View Article and Find Full Text PDFPhys Rev Lett
October 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
This Letter presents the observation of the rare Z boson decay Z→ψℓ^{+}ℓ^{-}. Here, ψ represents contributions from direct J/ψ and ψ(2S)→J/ψX, ℓ^{+}ℓ^{-} is a pair of electrons or muons, and the J/ψ meson is detected via its decay to μ^{+}μ^{-}. The sample of proton-proton collision data, collected by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV, corresponds to an integrated luminosity of 35.
View Article and Find Full Text PDFPhys Rev Lett
September 2018
University of Wisconsin-Madison, Madison, Wisconsin, Wisconsin, USA.
The observation of the standard model (SM) Higgs boson decay to a pair of bottom quarks is presented. The main contribution to this result is from processes in which Higgs bosons are produced in association with a W or Z boson (VH), and are searched for in final states including 0, 1, or 2 charged leptons and two identified bottom quark jets. The results from the measurement of these processes in a data sample recorded by the CMS experiment in 2017, comprising 41.
View Article and Find Full Text PDFPhys Rev Lett
August 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
The χ_{b1}(3P) and χ_{b2}(3P) states are observed through their ϒ(3S)γ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. The data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0 fb^{-1}.
View Article and Find Full Text PDFPhys Rev Lett
August 2018
University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
The elliptic azimuthal anisotropy coefficient (v_{2}) is measured for charm (D^{0}) and strange (K_{S}^{0}, Λ, Ξ^{-}, and Ω^{-}) hadrons, using a data sample of p+Pb collisions collected by the CMS experiment, at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=8.16 TeV. A significant positive v_{2} signal from long-range azimuthal correlations is observed for all particle species in high-multiplicity p+Pb collisions.
View Article and Find Full Text PDFPhys Rev Lett
August 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
The pseudorapidity distributions of dijets as functions of their average transverse momentum (p_{T}^{ave}) are measured in proton-lead (pPb) and proton-proton (pp) collisions. The data samples were collected by the CMS experiment at the CERN LHC, at a nucleon-nucleon center-of-mass energy of 5.02 TeV.
View Article and Find Full Text PDFSci Rep
July 2018
Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, Korea.
In this work, the mechanical characteristics of high-entropy alloy CoCrFeMnNi with low-stacking fault energy processed by cryogenic and room temperature high-pressure torsion (HPT) were studied. X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses were performed to identify the phase and microstructure variation and the mechanical properties characterized by Vickers hardness measurements and tensile testing. Cryogenic HPT was found to result in a lower mechanical strength of alloy CoCrFeMnNi than room temperature HPT.
View Article and Find Full Text PDFMaterials (Basel)
July 2018
International Scientific and Educational Laboratory of Radiation Physics, Belgorod State National Research University, Belgorod 308015, Russia.
Experiments on acceleration of electrons and production of X-ray radiation with use of ceramic piezoelectric transformers installed in vacuum are described and analyzed. The piezoelectric transformer operates at resonance frequency. Electrons are accelerated from the high-voltage electrode of the ceramic piezoelectric transformer toward the grounded target, where they emit bremsstrahlung and characteristic X-ray radiation in the target material.
View Article and Find Full Text PDFA search for physics beyond the standard model in events with one or more high-momentum Higgs bosons, H, decaying to pairs of b quarks in association with missing transverse momentum is presented. The data, corresponding to an integrated luminosity of 35.9 fb^{-1}, were collected with the CMS detector at the LHC in proton-proton collisions at the center-of-mass energy sqrt[s]=13 TeV.
View Article and Find Full Text PDFPhys Rev Lett
June 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
The observation of Higgs boson production in association with a top quark-antiquark pair is reported, based on a combined analysis of proton-proton collision data at center-of-mass energies of sqrt[s]=7, 8, and 13 TeV, corresponding to integrated luminosities of up to 5.1, 19.7, and 35.
View Article and Find Full Text PDFPhys Rev Lett
June 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
A search for a heavy neutral lepton N of Majorana nature decaying into a W boson and a charged lepton is performed using the CMS detector at the LHC. The targeted signature consists of three prompt charged leptons in any flavor combination of electrons and muons. The data were collected in proton-proton collisions at a center-of-mass energy of 13 TeV, with an integrated luminosity of 35.
View Article and Find Full Text PDFJ Phys Condens Matter
July 2018
National Science Center 'Kharkov Institute of Physics and Technology', 1, Akademicheskaya St., Kharkov, 61108, Ukraine. Kharkov National University, 4, Svobody Sq., Kharkov, 61077, Ukraine.
The two-temperature model (2TM) introduced by Kaganov, Lifshitz, and Tanatarov is widely used to describe the energy relaxation in the electron-phonon system of a metallic film. At the same time, the accuracy of the description of the electron-phonon system in terms of the 2TM, i.e.
View Article and Find Full Text PDFPhys Rev Lett
May 2018
University of Wisconsin-Madison, Madison, Wisconsin, USA.
A search for narrow resonances decaying to bottom quark-antiquark pairs is presented, using a data sample of proton-proton collisions at sqrt[s]=8 TeV corresponding to an integrated luminosity of 19.7 fb^{-1}. The search is extended to masses lower than those reached in typical searches for resonances decaying into jet pairs at the LHC, by taking advantage of triggers that identify jets originating from bottom quarks.
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