Azimuthal anisotropy of charged hadrons at very high pT in PbPb collisions at 2.76 TeV with CMS

AbstractMeasurements of the azimuthal anisotropy of charged hadrons are presented for PbPb collisions at 2.76 TeV over an extended transverse momentum range up to approximately 60 GeV/c. The data were collected with the CMS detector at the LHC. Utilizing a novel and unique high-pT single-track high-level trigger, the analysis explores the full 2011 PbPb data set corresponding to an integrated luminosity of 150μb−1. Anisotropy parameters (v2,v3 and v4) are extracted by correlating charged tracks with the event plane reconstructed using the energy deposited in the forward calorimeters. The results presented in this talk significantly improve on the statistical precision of previous v2 measurements for pT>12 GeV/c, and explore for the first time the harmonic components of the azimuthal dependence in the very high pT region beyond 20 GeV/c. These new data can impose quantitative constraints on the details of in-medium parton energy loss models, particularly the influence of the path length and the shape of the interaction region

Collective Memory of the 20th Century Russia and Values of Different Generational Groups

Introduction. It is important to consider collective memory from the social constructionism prospective. The present study of collective memory is aimed at identifying the event series that constructs historic memories and determines what is more important to different generational groups of modern society. This paper is the first study on prevailing values in each generational group that characterizes the content of collective memories of the 20th century Russia. Methods. The study employed quantitative and qualitative methods including (a) associative methods, (b) the Schwartz Value Survey, and (c) the questionnaire for comparing Russia of the 20th century and the ‘ideal’ Russia. The study sample consisted of 90 respondents of various ages from different regions of Russia. Results. This section describes the content of group memories about Russia of the 20th century, the specific prevailing group values, and the results of comparing Russia of the 20th century with the ‘ideal’ Russia in three age groups. After analyzing the content of participants’ memories, the authors conclude that various events constitute the content of group memories, reflecting the group specific generational character. In participants’ representations Russia appeared to be both a far from an ideal country and a highly appreciated one. The study revealed that each generational group had its own structure of values. Discussion. The analysis showed that the content of memories about Russia of the 20th century reflected the specific character of relation to the past in the studied groups. The results confirmed the hypothesis about specific group characteristics guiding construction of collective memories of a historical period. This allowed the authors to define collective memory as an essential feature of a social group. The study describes the phenomenon of ‘generational sensitivity’ that manifests itself as hypersensitivity (impressionability) toward past and current events in representatives of different social generational groups

Transformation of mechanisms of the university first-year students’ social adaptation: mathematical analysis tools

The article describes modern approaches to the transformation of the mechanisms of the first-year students’ social adaptation to study at the university, taking into account the requests of students. The theoretical prerequisites of the research are formulated on the basis of the analysis of modern publications of the knowledge-intensive Scopus database of Russian and foreign scientific articles. The theoretical model of transformation of adaptation mechanisms has become the basis of empirical research. The analysis of the process of social adaptation to the training of the modern generation of first-year students was carried out by the survey method using the electronic educational environment of the University of the North Caucasus (Stavropol Krai, Russia). A total of 1,278 people took part in the survey. The results of the study allow us to identify key areas for improving the educational process at the university: the development of alignment programs within the educational program of the level of knowledge in the most significant subject areas (Mathematics, Physics, Chemistry, Social Studies, etc.), entering into the educational rhythm of the university training format, a deeper understanding of the nature of professional activity and the organization of professional socialization. The obtained theoretical conclusions and empirical research data provide an understanding of the transformation of the mechanisms of social adaptation to university education

Inclusive b-hadron production cross section with muons in pp collisions at s√=7TeV

A measurement of the b-hadron production cross section in proton-proton collisions at s√=7TeVs=7TeV is presented. The dataset, corresponding to 85 nb−1, was recorded with the CMS experiment at the LHC using a low-threshold single-muon trigger. Events are selected by the presence of a muon with transverse momentum pμT>6GeVpTμ>6GeV with respect to the beam direction and pseudorapidity |η μ | < 2.1. The transverse momentum of the muon with respect to the closest jet discriminates events containing b hadrons from background. The inclusive b-hadron production cross section is presented as a function of muon transverse momentum and pseudorapidity. The measured total cross section in the kinematic acceptance is σ(pp → b + X → μ + X′) = 1.32 ± 0.01(stat) ± 0.30(syst) ± 0.15(lumi)μb

Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at s√=0.9 and 2.36 TeV

This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP02%282010%29041.Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at s√=0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 ± 0.01 (stat.) ± 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 ± 0.01 (stat.) ± 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between --2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN (ch)/dη|(|η|)<0.5, are 3:48 ± 0:02 (stat.) ± 0.13 (syst.) and 4:47 ± 0:04 (stat.) ± 0.16 (syst.), respectively. The results at 0.9 TeV are in agreement with previous measurements and confirm the expectation of near equal hadron production in p-bar p and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date

Observation of long-range, near-side angular correlations in proton-proton collisions at the LHC

This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP09%282010%29091.Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (η) and azimuthal angle (ϕ). Short-range correlations in Δη, which are studied in minimum bias events, are characterized using a simple “independent cluster” parametrization in order to quantify their strength (cluster size) and their extent in η (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 nb(−1) data set at 7 TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate p T of 1–3 GeV/c, 2.0 < |Δη| < 4.8 and Δϕ ≈ 0. This is the first observation of such a long-range, near-side feature in two-particle correlation functions in pp or pp-bar collisions

Search for heavy quarks decaying into a top quark and a W or Z boson using lepton + jets events in pp collisions at s√=7 TeV

This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP01%282013%29154.Results are presented from a search for the pair-production of heavy quarks, QQ-bar , that decay exclusively into a top quark and a W or Z boson. The search is performed using a sample of proton-proton collisions at s√=7 TeV corresponding to an integrated luminosity of 5.0 fb(−1), collected by the Compact Muon Solenoid experiment. The signal region is defined using a sample of events containing one electron or muon, missing transverse momentum, and at least four jets with large transverse momenta, where one jet is likely to originate from the decay of a bottom quark. No significant excess of events is observed with respect to the standard model expectations. Assuming a strong pair-production mechanism, quark masses below 675 (625) GeV decaying into tW (tZ) are excluded at the 95 % confidence level

Search for supersymmetry in final states with a single lepton, b-quark jets, and missing transverse energy in proton-proton collisions at s√=7 TeV

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.87.052006.A search motivated by supersymmetric models with light top squarks is presented using proton-proton collision data recorded with the CMS detector at a center-of-mass energy of s√=7  TeV during 2011, corresponding to an integrated luminosity of 4.98  fb(−1). The analysis is based on final states with a single lepton, b-quark jets, and missing transverse energy. Standard model yields are predicted from data using two different approaches. The observed event numbers are found to be compatible with these predictions. Results are interpreted in the context of the constrained minimal supersymmetric standard model and of a simplified model with four top quarks in the final state

Evidence for Associated Production of a Single Top Quark and W Boson in pp Collisions at s√=7 TeV

This is the publisher's version, also available electronically from http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.110.022003