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Title: The small-x gluon distribution in centrality biased pA and pp collisions

Journal Article · · Nuclear Physics. A
 [1];  [2];  [3]
  1. Baruch College, New York, NY (United States); The City Univ. of New York, New York, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. The City Univ. of New York, New York, NY (United States)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
+ Show Author Affiliations

Here, the nuclear modification factor RpA(pT) provides information on the small- x gluon distribution of a nucleus at hadron colliders. Several experiments have recently measured the nuclear modification factor not only in minimum bias but also for central pA collisions. In this paper we analyze the bias on the configurations of soft gluon fields introduced by a centrality selection via the number of hard particles. Such bias can be viewed as reweighting of configurations of small- x gluons. We find that the biased nuclear modification factor QpA(pT) for central collisions is above RpA(pT) for minimum bias events, and that it may redevelop a “Cronin peak” even at small x . The magnitude of the peak is predicted to increase approximately like 1/A⊥ν, ν~0.6±0.1 , if one is able to select more compact configurations of the projectile proton where its gluons occupy a smaller transverse area A⊥. We predict an enhanced Qpp(pT)–1~1/(pT2)ν and a Cronin peak even for central pp collisions.

Research Organization:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP); RIKEN
Grant/Contract Number:
SC0012704
OSTI ID:
1434787
Report Number(s):
BNL-203571-2018-JAAM; TRN: US1802397
Journal Information:
Nuclear Physics. A, Vol. 974, Issue C; ISSN 0375-9474
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 8 works
Citation information provided by
Web of Science

References (50)

Cronin effect and high- p T suppression in pA collisions journal November 2003
Cronin effect and high- suppression in the nuclear gluon distribution at small x journal September 2004
Parton saturation and Npart scaling of semi-hard processes in QCD journal May 2003
Energy Dependence of the Cronin Effect from Nonlinear QCD Evolution journal February 2004
The energy dependence of the saturation momentum journal September 2002
Asymptotic freedom in parton language journal August 1977
Hard processes in quantum chromodynamics journal February 1980
Transverse Momentum Distribution and Nuclear Modification Factor of Charged Particles in p + Pb Collisions at s N N = 5.02     TeV journal February 2013
Nuclear effects on the transverse momentum spectra of charged particles in pPb collisions at $$\sqrt{s_{_\mathrm {NN}}} =5.02$$ s NN = 5.02 $$\,\text {TeV}$$ TeV journal May 2015
Transverse momentum, rapidity, and centrality dependence of inclusive charged-particle production in s NN = 5.02   TeV p + Pb collisions measured by the ATLAS experiment journal December 2016
QCD saturation at the LHC: Comparisons of models to p+p and A+A data and predictions for p+Pb collisions journal March 2012
Erratum to “QCD saturation at the LHC: Comparisons of models to p + p and A + A data and predictions for p + Pb collisions” [Phys. Lett. B 710 (1) (2012) 125] journal January 2013
CGC predictions for p+Pb collisions at the LHC journal January 2013
Triumvirate of running couplings in small-x evolution journal March 2007
Quark contribution to the small- x evolution of color dipole journal January 2007
Next-to-leading order evolution of color dipoles journal January 2008
PREDICTIONS FOR p+ Pb COLLISIONS AT $\sqrt{s_{_{\it NN}}} = 5$ journal April 2013
Predictions for p+Pb Collisions at sNN = 5TeV: Comparison with Data journal September 2016
Evolution of the Nuclear Modification Factors with Rapidity and Centrality in d + A u Collisions at N N S = 200     G e V journal December 2004
Centrality dependence of particle production in p − Pb collisions at s NN = 5.02 TeV journal June 2015
Fluctuating Glasma Initial Conditions and Flow in Heavy Ion Collisions journal June 2012
Event-by-event gluon multiplicity, energy density, and eccentricities in ultrarelativistic heavy-ion collisions journal September 2012
Event-by-Event Anisotropic Flow in Heavy-ion Collisions from Combined Yang-Mills and Viscous Fluid Dynamics journal January 2013
Gluon production in current-nucleus and nucleon-nucleus collisions in a quasi-classical approximation journal September 1998
How protons shatter colored glass journal March 2002
High energy pA collisions in the color glass condensate approach I: gluon production and the Cronin effect journal October 2004
Odd azimuthal anisotropy of the Glasma for pA scattering journal March 2017
A Gaussian effective theory for gluon saturation journal August 2003
New scaling in high energy DIS journal August 2001
Geometric scaling above the saturation scale journal October 2002
Geometric scaling violations in the central rapidity region of collisions at RHIC journal May 2006
Fluctuations of the gluon distribution from the small- x effective action journal September 2017
Anisotropy of the semiclassical gluon field of a large nucleus at high energy journal April 2015
Computing quark and gluon distribution functions for very large nuclei journal March 1994
Gluon distribution functions for very large nuclei at small transverse momentum journal April 1994
Non-Abelian Weizsäcker-Williams field and a two-dimensional effective color charge density for a very large nucleus journal November 1996
Operator expansion for high-energy scattering journal March 1996
Effective field theory for the small-x evolution journal October 2001
The BFKL equation from the Wilson renormalization group journal October 1997
Nonlinear gluon evolution in the color glass condensate: I journal September 2001
Saturation and universality in QCD at small x journal June 2001
The renormalization group equation for the color glass condensate journal June 2001
A simple derivation of the JIMWLK equation journal December 2001
Nonlinear gluon evolution in the color glass condensate: II journal May 2002
Unitarity at small Bjorken x journal June 2002
Non linear gluon evolution in path-integral form journal January 2003
Exclusive diffractive processes at HERA within the dipole picture journal October 2006
Dijet production as a centrality trigger for pp collisions at CERN LHC journal June 2004
Angular and long Range Rapidity Correlations in Particle Production at high Energy journal January 2013
Collectivity in Small Collision Systems: An Initial-State Perspective journal January 2016

Cited By (2)

Event engineering studies for heavy flavor production and hadronization in high multiplicity hadron-hadron and hadron-nucleus collisions journal October 2018
Measuring the Weizsäcker-Williams distribution of linearly polarized gluons at an electron-ion collider through dijet azimuthal asymmetries journal January 2019

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Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
Cronin peak
Saturation
CGC
Small x
pA collisions