1,722,733 research outputs found
Single Top Quark in the SM and Beyond
No full textThe prospects of single top quark physics at colliders of the TeV energy scale are discussed. Single top quark study allows a direct measurement of the vertex and a precise probing physics beyond the Standard Model in various scenarios.The prospects of single top quark physics at colliders of the TeV energy scale are discussed. Single top quark study allows a direct measurement of the vertex and a precise probing physics beyond the Standard Model in various scenarios
Single top quark tW+X production at the CERN LHC: a closer look
No full textWe have reexamined the tW+X single top-quark production process which is important at the LHC contrary to the Tevatron. The special attention was paid to the treatment of the 2->2[Wt] process and the part of it's next-to-leading correction: 2->3[Wtb] process. We show that 2->3[Wtb] process has to be correctly taken into account with a proper subtraction of the top pair contribution and that it has qualitatively different kinematical distributions from the 2->2[Wt] process. We present the total cross section of the tW+X production to be about 62 pb at QCD scale be taken as a top quark mass, suggest the method of combining Wt and Wtb processes with gauge invariant subtraction of the tt-bar part which allows to reproduce correct kinematical properties and perform a proper event simulation of the tW+X process in the whole kinematical region.We have reexamined the tW+X single top-quark production process which is important at the LHC contrary to the Tevatron. The special attention was paid to the treatment of the 2->2[Wt] process and the part of it's next-to-leading correction: 2->3[Wtb] process. We show that 2->3[Wtb] process has to be correctly taken into account with a proper subtraction of the top pair contribution and that it has qualitatively different kinematical distributions from the 2->2[Wt] process. We present the total cross section of the tW+X production to be about 62 pb at QCD scale be taken as a top quark mass, suggest the method of combining Wt and Wtb processes with gauge invariant subtraction of the tt-bar part which allows to reproduce correct kinematical properties and perform a proper event simulation of the tW+X process in the whole kinematical region
Azimuthal anisotropy of charged particles with transverse momentum up to 100 GeV/c in PbPb collisions at √sNN = 5.02 TeV
No full textThe Fourier coefficients v2 and v3 characterizing the anisotropy of the azimuthal distribution of charged particles produced in PbPb collisions at sNN=5.02TeV are measured with data collected by the CMS experiment. The measurements cover a broad transverse momentum range, 1<pT<100GeV/c. The analysis focuses on the pT>10GeV/c range, where anisotropic azimuthal distributions should reflect the path-length dependence of parton energy loss in the created medium. Results are presented in several bins of PbPb collision centrality, spanning the 60% most central events. The v2 coefficient is measured with the scalar product and the multiparticle cumulant methods, which have different sensitivities to initial-state fluctuations. The values from both methods remain positive up to pT∼60–80GeV/c, in all examined centrality classes. The v3 coefficient, only measured with the scalar product method, tends to zero for pT≳20GeV/c. Comparisons between theoretical calculations and data provide new constraints on the path-length dependence of parton energy loss in heavy ion collisions and highlight the importance of the initial-state fluctuations
CompHEP - PYTHIA interface: integrated package for the collision events generation based on exact matrix elements
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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