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Title: Interplay of soft and hard processes and hadron p{sub T} spectra in pA and AA collisions

Abstract

Motivated by a schematic model of multiple parton scattering within the Glauber formalism, the transverse momentum spectra in pA and AA collisions are analyzed in terms of a nuclear modification factor with respect to pp collisions. The existing data at the CERN Super Proton Synchrotron energies are shown to be consistent with the picture of Glauber multiple scattering in which the interplay between soft and hard processes and the effect of absorptive processes lead to nontrivial nuclear modification of the particle spectra. Relative to the additive model of incoherent hard scattering, the spectra are enhanced at large p{sub T} (hard) by multiple scattering while suppressed at low p{sub T} (soft) by absorptive correction with the transition occurring at around a scale p{sub 0}{approx}1-2 GeV/c that separates soft and hard processes. Around the same scale, the p{sub T} spectra in pp collisions also change from an exponential form at low p{sub T} to a power-law behavior at high p{sub T}. At very large p{sub T}>>p{sub 0}, the nuclear enhancement is shown to decrease as 1/p{sub T}{sup 2}. Implications of these nuclear effects on the study of jet quenching, parton thermalization, and collective radial flow in high-energy AA collisions are discussed.

Authors:
;
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory
Sponsoring Org.:
(US)
OSTI Identifier:
40277087
Report Number(s):
LBNL-47702
Journal ID: ISSN 0556-2813; TRN: US0109646
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Journal Article
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 64; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevC.64.034901; Othernumber: PRVCAN000064000003034901000001; 003109PRC; PBD: Sep 2001; Journal ID: ISSN 0556-2813
Publisher:
The American Physical Society
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ADDITIVES; CERN; HADRONS; MODIFICATIONS; MULTIPLE SCATTERING; PARTONS; PROTONS; QUENCHING; SCATTERING; SPECTRA; SYNCHROTRONS; THERMALIZATION; TRANSVERSE MOMENTUM

Citation Formats

Wang, Enke, and Wang, Xin-Nian. Interplay of soft and hard processes and hadron p{sub T} spectra in pA and AA collisions. United States: N. p., 2001. Web. doi:10.1103/PhysRevC.64.034901.
Wang, Enke, & Wang, Xin-Nian. Interplay of soft and hard processes and hadron p{sub T} spectra in pA and AA collisions. United States. https://doi.org/10.1103/PhysRevC.64.034901
Wang, Enke, and Wang, Xin-Nian. Sat . "Interplay of soft and hard processes and hadron p{sub T} spectra in pA and AA collisions". United States. https://doi.org/10.1103/PhysRevC.64.034901.
@article{osti_40277087,
title = {Interplay of soft and hard processes and hadron p{sub T} spectra in pA and AA collisions},
author = {Wang, Enke and Wang, Xin-Nian},
abstractNote = {Motivated by a schematic model of multiple parton scattering within the Glauber formalism, the transverse momentum spectra in pA and AA collisions are analyzed in terms of a nuclear modification factor with respect to pp collisions. The existing data at the CERN Super Proton Synchrotron energies are shown to be consistent with the picture of Glauber multiple scattering in which the interplay between soft and hard processes and the effect of absorptive processes lead to nontrivial nuclear modification of the particle spectra. Relative to the additive model of incoherent hard scattering, the spectra are enhanced at large p{sub T} (hard) by multiple scattering while suppressed at low p{sub T} (soft) by absorptive correction with the transition occurring at around a scale p{sub 0}{approx}1-2 GeV/c that separates soft and hard processes. Around the same scale, the p{sub T} spectra in pp collisions also change from an exponential form at low p{sub T} to a power-law behavior at high p{sub T}. At very large p{sub T}>>p{sub 0}, the nuclear enhancement is shown to decrease as 1/p{sub T}{sup 2}. Implications of these nuclear effects on the study of jet quenching, parton thermalization, and collective radial flow in high-energy AA collisions are discussed.},
doi = {10.1103/PhysRevC.64.034901},
url = {https://www.osti.gov/biblio/40277087}, journal = {Physical Review C},
issn = {0556-2813},
number = 3,
volume = 64,
place = {United States},
year = {2001},
month = {9}
}