Parameterization of deformed nuclei for Glauber modeling in relativistic heavy ion collisions

Journal Article · Thu Oct 01 00:00:00 EDT 2015 · Physics Letters B

DOI:https://doi.org/10.1016/j.physletb.2015.07.078· OSTI ID:1209169

Shou, Q. Y.; Ma, Y. G.; Sorensen, P.; Tang, A. H.; Videbæk, F.; Wang, H.

In this study, the density distributions of large nuclei are typically modeled with a Woods–Saxon distribution characterized by a radius R₀ and skin depth a. Deformation parameters β are then introduced to describe non-spherical nuclei using an expansion in spherical harmonics R₀(1+β₂Y₂⁰+β₄Y₄⁰). But when a nucleus is non-spherical, the R₀ and a inferred from electron scattering experiments that integrate over all nuclear orientations cannot be used directly as the parameters in the Woods–Saxon distribution. In addition, the β₂ values typically derived from the reduced electric quadrupole transition probability B(E2)↑ are not directly related to the β₂ values used in the spherical harmonic expansion. B(E2)↑ is more accurately related to the intrinsic quadrupole moment Q₀ than to β₂. One can however calculate Q₀ for a given β₂ and then derive B(E2)↑ from Q₀. In this paper we calculate and tabulate the R₀, a , and β₂ values that when used in a Woods–Saxon distribution, will give results consistent with electron scattering data. We then present calculations of the second and third harmonic participant eccentricity (ε₂ and ε₃) with the new and old parameters. We demonstrate that ε₃ is particularly sensitive to a and argue that using the incorrect value of a has important implications for the extraction of viscosity to entropy ratio (η/s) from the QGP created in Heavy Ion collisions.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC02-98-CH10886; 2014CB845401; SC00112704
• OSTI ID: 1209169
• Alternate ID(s): OSTI ID: 1235887
• Report Number(s): BNL-111725-2016-JA; S0370269315005985; PII: S0370269315005985
• Journal Information: Physics Letters B, Journal Name: Physics Letters B Vol. 749 Journal Issue: C; ISSN 0370-2693
• Publisher: Elsevier
• Country of Publication: Netherlands
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
Relativistic Heavy Ion Collider