skip to main content

DOE PAGESDOE PAGES

Title: Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow

In this paper, we compute the momentum diffusion coefficients of heavy quarks, κ and κ , in a strong magnetic field B along the directions parallel and perpendicular to B, respectively, at the leading order in QCD coupling constant α s. We consider a regime relevant for the relativistic heavy ion collisions, α seB << T 2 << eB, so that thermal excitations of light quarks are restricted to the lowest Landau level (LLL) states. In the vanishing light-quark mass limit, we find κ LO ∝ α 2 sTeB in the leading order that arises from screened Coulomb scatterings with (1+1)-dimensional LLL quarks, while κ gets no contribution from the scatterings with LLL quarks due to kinematic restrictions. We show that the first nonzero leading order contributions to κ LO come from the two separate effects: 1) the screened Coulomb scatterings with thermal gluons, and 2) a finite light-quark mass m q. The former leads to κ LO,gluon ∝ α 2 sT 3 and the latter to κ LO,massive ∝ α sseB) 1/2m 2 q. Based on our results, we propose a new scenario for the large value of heavy-quark elliptic flow observedmore » in RHIC and LHC. Namely, when κ >> κ , an anisotropy in drag forces gives rise to a sizable amount of the heavy-quark elliptic flow even if heavy quarks do not fully belong to an ellipsoidally expanding background fluid.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. The Univ. of Tokyo, Tokyo (Japan)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States); Nishina Center, RIKEN, Saitama (Japan)
  3. Univ. of Illinois, Chicago, IL (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
  4. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
BNL-112136-2016-JA
Journal ID: ISSN 2470-0010; PRVDAQ; R&D Project: PO-3
Grant/Contract Number:
SC00112704; SC0012704
Type:
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 93; Journal Issue: 7; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Riken BNL Research Center
OSTI Identifier:
1254122
Alternate Identifier(s):
OSTI ID: 1248250

Fukushima, Kenji, Hattori, Koichi, Yee, Ho -Ung, and Yin, Yi. Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow. United States: N. p., Web. doi:10.1103/PhysRevD.93.074028.
Fukushima, Kenji, Hattori, Koichi, Yee, Ho -Ung, & Yin, Yi. Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow. United States. doi:10.1103/PhysRevD.93.074028.
Fukushima, Kenji, Hattori, Koichi, Yee, Ho -Ung, and Yin, Yi. 2016. "Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow". United States. doi:10.1103/PhysRevD.93.074028. https://www.osti.gov/servlets/purl/1254122.
@article{osti_1254122,
title = {Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow},
author = {Fukushima, Kenji and Hattori, Koichi and Yee, Ho -Ung and Yin, Yi},
abstractNote = {In this paper, we compute the momentum diffusion coefficients of heavy quarks, κ∥ and κ⊥, in a strong magnetic field B along the directions parallel and perpendicular to B, respectively, at the leading order in QCD coupling constant αs. We consider a regime relevant for the relativistic heavy ion collisions, αseB << T2 << eB, so that thermal excitations of light quarks are restricted to the lowest Landau level (LLL) states. In the vanishing light-quark mass limit, we find κLO⊥ ∝ α2sTeB in the leading order that arises from screened Coulomb scatterings with (1+1)-dimensional LLL quarks, while κ∥ gets no contribution from the scatterings with LLL quarks due to kinematic restrictions. We show that the first nonzero leading order contributions to κLO∥ come from the two separate effects: 1) the screened Coulomb scatterings with thermal gluons, and 2) a finite light-quark mass mq. The former leads to κLO,gluon∥ ∝ α2sT3 and the latter to κLO,massive∥ ∝ αs(αseB)1/2m2q. Based on our results, we propose a new scenario for the large value of heavy-quark elliptic flow observed in RHIC and LHC. Namely, when κ⊥ >> κ∥, an anisotropy in drag forces gives rise to a sizable amount of the heavy-quark elliptic flow even if heavy quarks do not fully belong to an ellipsoidally expanding background fluid.},
doi = {10.1103/PhysRevD.93.074028},
journal = {Physical Review D},
number = 7,
volume = 93,
place = {United States},
year = {2016},
month = {4}
}