1,900 research outputs found
Differential cross sections for top pair production at the LHC
We present results of phenomenological studies for top-quark pair production
at the LHC at the center of mass energy TeV. The transverse
momentum and rapidity distributions for final-state top quarks are calculated
in perturbative QCD at approximate next-to-next-to-leading order by using methods of threshold resummation beyond the leading
logarithmic accuracy. The theoretical predictions are obtained by using the
computer code \textsc{DiffTop} and are compared to recent measurements by the
ATLAS and CMS collaborations. \textsc{Difftop} can be employed in the general
case of heavy-quark pair production at hadron-hadron colliders and provides a
basis for applications in QCD analyses for parton distribution functions
determination.Comment: 6 pages, 2 figures, Conference proceedings for DIS2014, XXII
International Workshop on Deep-Inelastic Scattering and Related Subjects, 28
April - 2 May 2014, Warsaw, Poland, and ICHEP 2014, 37 International
Conference on High Energy Physics, 2-9 July 2014, Valencia, Spai
Top-quark production at the LHC: differential cross section and phenomenological applications
We discuss top-quark pair production at hadron colliders and review available
calculations of differential top-pair production cross section in perturbative
QCD at approximate next-to-next-to-leading order (NNLO) within the threshold
resummation formalism. These calculations are implemented into an open source
program under development. We present phenomenological studies at the LHC that
include transverse momentum and rapidity distribution of the top quarks at a
center-of-mass energy of 7 TeV. Preliminary results obtained with this program
are in very good agreement with the recent LHC measurements.Comment: 5 pages, 2 Figures, conference proceeding, DIS2013: XXI International
Workshop on Deep-Inelastic Scattering and Related Subjects 22-26 April 2013,
Marseilles, Franc
Top-quark pair production at hadron colliders: differential cross section and phenomenological applications with DiffTop
The results of phenomenological studies of top-quark pair production in
proton-proton collisions are presented. Differential cross sections are
calculated in perturbative QCD at approximate next-to-next-to-leading order
by using methods of threshold resummation beyond the
leading logarithmic accuracy. Predictions for the single-particle inclusive
kinematics are presented for transverse momentum and rapidity distributions of
final-state top quarks. Uncertainties related to the description of proton
structure, top-quark mass and strong coupling constant are investigated in
detail. The results are compared to the recent measurements by the ATLAS and
CMS collaborations at the LHC at the center of mass energy of 7 TeV. The
calculation presented here is implemented in the computer code \textsc{Difftop}
and can be applied to the general case of heavy-quark pair production at
hadron-hadron colliders. For the first time, a fit of parton distribution
functions at NNLO is performed by using the differential cross sections of
top-quark pair production together with other data sets. The impact of the
top-pair production on the precision of the gluon distribution at high scales
is illustrated.Comment: 30 pages, 12 figures, 2 tables, regular article. Version accepted for
a publication on JHE
Single-differential top quark pair production cross sections with running mass schemes at NLO
Single-differential cross section predictions for top quark pair production
are presented at next-to-leading order, using running top quark mass
renormalization schemes. The evolution of the mass of the top quark is
performed in the MSR scheme for
renormalization scales below the top quark mass
, and in the
scheme for scales
above. In particular, the implementation of a mass renormalization scale
independent of the strong coupling renormalization scale and factorization
scale in quantum chromodynamics allows investigating independent dynamical
scale variations. Furthermore, the first theoretically consistent extraction of
the top quark MSR mass from experimental data is presented.Comment: To appear in the Proceedings of the 41st International Conference on
High Energy physics - ICHEP2022, Bologna, Italy, 6-13 July, 202
DIS structure functions and the double-spin asymmetry in rho(0) electroproduction within a Regge approach
The proton, neutron and deuteron structure functions F2(x,Q2) and g1(x,Q2), measured at intermediate Q2, are analyzed within a Regge approach. This analysis serves to fix the parameters of this scheme which are then used to calculate, in a unified Regge approach, the properties of ρ0 meson electroproduction on the proton and the deuteron. In this way, the double-spin asymmetry observed at HERMES in ρ0 electroproduction on the proton, can be related to the anomalous behavior of the flavor-singlet part of the spin-dependent structure function g1(x,Q2) at small x
Differential cross sections for top pair production at the LHC
We present results of phenomenological studies for top-quark pair production at the LHC at the center of mass energy √S = 7 TeV. The transverse momentum and rapidity distributions for final- state top quarks are calculated in perturbative QCD at approximate next-to-next-to-leading order O( α4 s ) by using methods of threshold resummation beyond the leading logarithmic accuracy. The theoretical predictions are obtained by using the computer code DIFFTOP and are compared to recent measurements by the ATLAS and CMS collaborations. DIFFTOP can be employed in the general case of heavy-quark pair production at hadron-hadron colliders and provides a basis for applications in QCD analyses for parton distribution functions determination
Impact of heavy-flavour production cross sections measured by the LHCb experiment on parton distribution functions at low x
The impact of recent measurements of heavy-flavour production in deep
inelastic scattering and in collisions on parton distribution
functions is studied in a QCD analysis in the fixed-flavour number scheme at
next-to-leading order. Differential cross sections of charm- and beauty-hadron
production measured by LHCb are used together with inclusive and heavy-flavour
production cross sections in deep inelastic scattering at HERA. The
heavy-flavour data of the LHCb experiment impose additional constraints on the
gluon and the sea-quark distributions at low partonic fractions of the
proton momentum, down to . This kinematic range is
currently not covered by other experimental data in perturbative QCD fits
Pengembangan media pembelajaran berbasis ICT: konsep dan aplikasi pada pembelajaran Pendidikan Agama Islam
Dunia pendidikan sudah saatnya dapat memetik manfaat dari perkembangan teknologi informatika yang begitu pesat. Mungkin sudah bukan zamannya pendidik menyampaikan materi secara oral mulai awal sampai akhir pembelajaran, di samping melelahkan juga akan membosankan peserta didik. Ada beberapa media pembelajaran yang dapat difungsikan misalnya, media visual, media audio visual, media komputer, media berbasis internet, dan lain-lain. Buku ini berbicara tentang Pengembangan Media Pembelajaran berbasis ICT, Kajian dan Aplikasi pada pembelajaran Pendidikan Agama Islam. Dalam buku ini dipaparkan berbagai macam media pembelajaran, fungsi, kelebihan dan kekurangannya. Juga disajikan cara memanfaatkan media internet untuk mengembangkan materi Pendidikan Agama Islam. Dengan demikian, pendidik dapat memilah dan memilih media yang tepat untuknya, sekaligus pendidik dapat berinovasi serta mengembangkan pembelajaran yang kreatif dan inovatif
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