Heavy-quark pair production in polarized photon-photon collisions at next-to-leading order: Fully integrated total cross sections

2009 ◽  
Vol 79 (11) ◽  
Author(s):  
B. A. Kniehl ◽  
A. V. Kotikov ◽  
Z. V. Merebashvili ◽  
O. L. Veretin
Keyword(s):  
Pair Production ◽  
Heavy Quark ◽  
Cross Sections ◽  
Leading Order ◽  
Total Cross Sections ◽  
Fully Integrated ◽  
Heavy Quark Pair

scholarly journals Dielectron Production in Proton–Proton Collisions at √s=7 TeV with ALICE

Proceedings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 24
Author(s):  
Sebastian Scheid
Keyword(s):  
Cross Sections ◽  
Mass Range ◽  
Heavy Ion ◽  
Event Generator ◽  
Leading Order ◽  
Proton Proton ◽  
Total Cross Sections ◽  
Proton Collisions ◽  
Ion Collisions ◽  
Proton Proton Collisions

The ALICE Collaboration measured dielectron production as a function of the invariant mass ( m ee ), the pair transverse momentum ( p T , ee ) and the pair distance of closest approach ( DCA ee ) in pp collisions at s = 7 TeV. Prompt and non-prompt dielectron sources can be separated with the DCA ee , which will give the opportunity in heavy-ion collisions to identify thermal radiation from the medium in the intermediate-mass range dominated by contributions from open-charm and beauty hadron decays. The charm and beauty total cross sections are extracted from the data by fitting the spectra with two different MC generators, i.e., PYTHIA a leading order event generator and POWHEG a next-to-leading order event generator. Significant model dependences are observed, reflecting the sensitivity of this measurement to the heavy-flavour production mechanisms.

scholarly journals How to measure the linear polarization of gluons in unpolarized proton using the heavy-quark pair production

2019 ◽  
Vol 204 ◽  
pp. 02006 ◽  
Author(s):  
N. Ya. Ivanov ◽  
A. V. Efremov ◽  
O. V. Teryaev
Keyword(s):  
Pair Production ◽  
Heavy Quark ◽  
Linear Polarization ◽  
Heavy Quark Production ◽  
Production Plane ◽  
Linearly Polarized ◽  
Quark Production ◽  
Mulders Function ◽  
Heavy Quark Pair ◽  
Azimuthal Asymmetries

In recent papers [1, 2], two new ways have been proposed to probe the linear polarization of gluons in unpolarized proton: using the azimuthal asymmetries and Callan-Gross ratio in heavy-quark pair leptoproduction, lN → l′QQ̅X. In this talk, we discuss in details the sensitivity of the QCD predictions for the azimuthal cos φ and cos 2φ asymmetries to the contribution of linearly polarized gluons inside unpolarized proton, where the azimuth φ is the angle between the lepton scattering plane (l, l′) and the heavy quark production plane (N, Q). Our analysis shows that the azimuthal distributions under consideration vary from 0 to 1 depending on the value of the gluonic counterpart of the Boer- Mulders function, $h_{1}^{ \bot g}$. We conclude that the cos φ and cos 2φ asymmetries in heavy-quark pair production in DIS processes are predicted to be large in wide kinematic ranges and sensitive to the contribution of linearly polarized gluons.

scholarly journals Exclusive heavy quark-pair production in ultraperipheral collisions

2019 ◽  
Vol 99 (3) ◽  
Author(s):  
Mateus Reinke Pelicer ◽  
Emmanuel Gräve de Oliveira ◽  
Roman Pasechnik
Keyword(s):  
Pair Production ◽  
Heavy Quark ◽  
Heavy Quark Pair

scholarly journals The two-loop soft function for heavy quark pair production at future linear colliders

2015 ◽  
Vol 92 (4) ◽  
Author(s):  
Andreas von Manteuffel ◽  
Robert M. Schabinger ◽  
Hua Xing Zhu
Keyword(s):  
Pair Production ◽  
Heavy Quark ◽  
Soft Function ◽  
Linear Colliders ◽  
Heavy Quark Pair

scholarly journals Low transverse momentum heavy quark pair production to probe gluon tomography

2013 ◽  
Vol 727 (4-5) ◽  
pp. 474-479 ◽  
Author(s):  
Ruilin Zhu ◽  
Peng Sun ◽  
Feng Yuan
Keyword(s):  
Transverse Momentum ◽  
Pair Production ◽  
Heavy Quark ◽  
Heavy Quark Pair

scholarly journals SCALING IN γ*p TOTAL CROSS-SECTIONS, SATURATION AND THE GLUON DENSITY

2001 ◽  
Vol 16 (28) ◽  
pp. 1829-1839 ◽  
Author(s):  
DIETER SCHILDKNECHT ◽  
BERND SURROW ◽  
MIKHAIL TENTYUKOV
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Gluon Density ◽  
Hera Data ◽  
Leading Order ◽  
Total Cross Sections ◽  
Vector Dominance ◽  
Color Dipole ◽  
Dipole Picture ◽  
Increasing Function

Including the new HERA data, the γ*p total cross-section is analyzed in the generalized vector dominance/color-dipole picture (GVD/CDP) that contains scaling in [Formula: see text], where Λ2(W2) is an increasing function of W2. At any Q2, for W2→∞, the cross-sections for virtual and real photons become identical, σγ*p (W2,Q2)/σγp (W2)→ 1. The gluon density deduced from the color-dipole cross-section fulfills the leading order DGLAP relationship. Evolution à la DGLAP breaks down for η≲0.1.

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