1,294 research outputs found
TMD parton densities in associated real and virtual photon and jet production at LHC
We study the associated production of real (isolated) or virtual photons
(with their subsequent leptonic decay) and hadronic jets in proton-proton
collisions at the LHC using the -factorization approach of QCD. The
consideration is based on the off-shell quark-gluon QCD Compton scattering
subprocesses. In the case of virtual photon production, the contributions from
Z boson exchange as well as gamma*-Z interference with the full spin
correlations are included. The transverse momentum dependent (TMD) quark and
gluon densities in a proton are determined from the Kimber-Martin-Ryskin
prescription or Catani-Ciafoloni-Fiorani-Marchesini (CCFM) equation. In the
latter, we restricted to the case where the gluon-to-quark splitting occurs at
the last evolution step and calculate the sea quark density as a convolution of
the CCFM-evolved gluon distribution and the TMD gluon-to-quark splitting
function. Our numerical predictions are compared with the recent experimental
data taken by the ATLAS Collaboration. We discuss the theoretical uncertainties
of our calculations and argue that further studies are capable of constraining
the TMD parton densities in a proton.Comment: 11 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1402.549
Duality symmetry of BFKL equation: reggeized gluons vs color dipoles
We show that the duality symmetry of the BFKL equation can be interpreted as
a symmetry under rotation of the BFKL Kernel in the transverse space from
s-channel (color dipole model) to t-channel (reggeized gluon formulation). We
argue that the duality symmetry holds also in the non-forward case due to a
very special structure of the non-forward BFKL Kernel, which can be written as
a sum of three forward BFKL Kernels. The duality symmetry is established by
identifying the dual coordinates with the transverse coordinates of a
non-diagonal dipole scattered off the target.Comment: 13 pages, 5 figure
On the possibility to detect the Higgs decay in the associated production at the LHC
We investigate the possibility to detect the scalar Higgs boson decay in the associated and production at the LHC using the
-factorization QCD approach. Our consideration is based on the off-shell
(i.e. depending on the transverse momenta of initial quarks and gluons)
production amplitudes of ,
and partonic subprocesses supplemented with the
Catani-Ciafoloni-Fiorani-Marchesini (CCFM) dynamics of parton densities in a
proton. We argue that the signal could be observed at large
transverse momenta near Higgs boson peak despite the overwhelming QCD
background, and point out an important role of angular correlations between the
produced boson and -quarks.Comment: 11 pages, 6 figure
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