scholarly journals Double inclusive small- x gluon production and their azimuthal correlations in a biased ensemble

2020 ◽  
Vol 101 (3) ◽  
Author(s):  
Gary Kapilevich
2018 ◽  
Vol 785 ◽  
pp. 372-380 ◽  
Author(s):  
Alex Kovner ◽  
Vladimir V. Skokov
Keyword(s):  

2016 ◽  
Vol 2016 (12) ◽  
Author(s):  
A. van Hameren ◽  
P. Kotko ◽  
K. Kutak ◽  
C. Marquet ◽  
E. Petreska ◽  
...  

Abstract We study the production of forward di-jets in proton-lead and proton-proton collisions at the Large Hadron Collider. Such configurations, with both jets produced in the forward direction, impose a dilute-dense asymmetry which allows to probe the gluon density of the lead or proton target at small longitudinal momentum fractions. Even though the jet momenta are always much bigger than the saturation scale of the target, Q s, the transverse momentum imbalance of the di-jet system may be either also much larger than Q s, or of the order Q s, implying that the small-x QCD dynamics involved is either linear or non-linear, respectively. The small-x improved TMD factorization framework deals with both situations in the same formalism. In the latter case, which corresponds to nearly back-to-back jets, we find that saturation effects induce a significant suppression of the forward di-jet azimuthal correlations in proton-lead versus proton-proton collisions.


2007 ◽  
Vol 16 (10) ◽  
pp. 3168-3175 ◽  
Author(s):  
◽  
FUQIANG WANG

Mid-rapidity azimuthal correlations probe di-jets originating mainly from gluon-gluon hard-scattering. Measurements of such correlations have revealed significant (gluon-)jet modification in central Au + Au collisions. Azimuthal correlations of hadrons at forward rapidity with a mid-rapidity high-p⊥ hadron, on the other hand, probe asymmetric partonic scatterings involving large- x quarks and small- x gluons. We present preliminary results from STAR on correlations of charged hadrons at forward rapidity in the forward TPCs (2.7 < |η| < 3.9, p⊥ < 2 GeV /c) with high-p⊥ charged hadrons at mid-rapidity from the main TPC (|η| < 1, p⊥ > 3 GeV /c) in pp , d + Au , and Au + Au collisions at [Formula: see text]. The implications of the results for small- x gluon distributions (Color Glass Condensate formation) and the energy loss of quark jets at forward rapidity in nuclear medium are discussed.


2009 ◽  
Author(s):  
Thomas Teubner ◽  
A.D. Martin ◽  
C. Nockles ◽  
M.G. Ryskin ◽  
A.G. Shuvaev
Keyword(s):  

1974 ◽  
Vol 113 (6) ◽  
pp. 360 ◽  
Author(s):  
O.M. Sumbaev ◽  
E.V. Petrovich ◽  
Yu.P. Smirnov ◽  
I.M. Band ◽  
Aleksandr I. Smirnov

1987 ◽  
Vol 02 (04) ◽  
pp. 1369-1387 ◽  
Author(s):  
Wu-Ki Tung

Some non-trivial features of the QCD-improved parton model relevant to applications on heavy particle production and semi-hard (small-x) processes of interest to collider physics are reviewed. The underlying ideas are illustrated by a simple example. Limitations of the naive parton formula as well as first order corrections and subtractions to it are dis-cussed in a quantitative way. The behavior of parton distribution functions at small x and for heavy quarks are discussed. Recent work on possible impact of unconventional small-x behavior of the parton distributions on small-x physics at SSC and Tevatron are summarized. The Drell-Yan process is found to be particularly sensitive to the small x dependence of parton distributions. Measurements of this process at the Tevatron can provide powerful constraints on the expected rates of semi-hard processes at the SSC.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
B. I. Ermolaev ◽  
S. I. Troyan

Abstract We present calculation of FL in the double-logarithmic approximation (DLA) and demonstrate that the synergic effect of the factor 1/x from the $$ {\alpha}_s^2 $$ α s 2 -order and the steep x-dependence of the totally resummed double logarithmic contributions of higher orders ensures the power-like rise of FL at small x and arbitrary Q2.


2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
A. Adler ◽  
J. Adolfsson ◽  
...  

Abstract Systematic studies of charge-dependent two- and three-particle correlations in Pb-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 2.76 and 5.02 TeV used to probe the Chiral Magnetic Effect (CME) are presented. These measurements are performed for charged particles in the pseudorapidity (η) and transverse momentum (pT) ranges |η| < 0.8 and 0.2 < pT< 5 GeV/c. A significant charge-dependent signal that becomes more pronounced for peripheral collisions is reported for the CME-sensitive correlators γ1, 1 = 〈cos(φα + φβ − 2Ψ2)〉 and γ1, − 3 = 〈cos(φα − 3φβ + 2Ψ2)〉. The results are used to estimate the contribution of background effects, associated with local charge conservation coupled to anisotropic flow modulations, to measurements of the CME. A blast-wave parametrisation that incorporates local charge conservation tuned to reproduce the centrality dependent background effects is not able to fully describe the measured γ1,1. Finally, the charge and centrality dependence of mixed-harmonics three-particle correlations, of the form γ1, 2 = 〈cos(φα + 2φβ − 3Ψ3)〉, which are insensitive to the CME signal, verify again that background contributions dominate the measurement of γ1,1.


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