Shear viscosity to entropy density ratio in BUU transport model

Shear viscosity to entropy density ratio in BUU transport model 1 2 first-author 1 corresp Corresponding author. E-mail address: ygma@sinap.ac.cn; dqfang@sinap.ac.cn Corresponding author. E-mail address: ygma@sinap.ac.cn; dqfang@sinap.ac.cn ygma@sinap.ac.cn 1 corresp Corresponding author. E-mail address: ygma@sinap.ac.cn; dqfang@sinap.ac.cn Corresponding author. E-mail address: ygma@sinap.ac.cn; dqfang@sinap.ac.cn ygma@sinap.ac.cn 1 2 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China Graduate School of Chinese Academy of Sciences, Beijing 100080, China Graduate School of Chinese Academy of Sciences, Beijing 100080, China Shear viscosity ( η ) is a basic transport coefficient of the medium. In this work, we calculate shear viscosity to entropy density ratio ( η / S ) of an equilibrated system in intermediate energy heavy ion collisions within the framework of the Boltzmann-Uehling-Uhlenbeck model (BUU) model. After the equilibration of Au + Au system at central collision in a fixed volume is reached, temperature, pressure and energy density are extracted by the phase space information and then η / S is calculated using the Green-Kubo formulas. The results show that η / S drops with the incident energy and its value is not so drastically different from the RHIC results. BUU model Liquid-gas phase transition Shear viscosity Entropy density η / S References Natowitz J B , Wada R , Hagel K , et al . Phys Rev , 2002 , C65 : 034618(1-9) . Phys Rev Pochodzalla J , Möhlenkamp T , Rubehn T , et al . Phys Rev Lett , 1995 , 75 : 1040 - 1043 . Phys Rev Lett Ma Y G , Natowitz J B , Wada R , et al . (NIMROD Collaboration) , Phys Rev , 2005 , C71 : 054606(1-23) . Phys Rev Ma Y G . Phys Rev Lett , 1999 , 83 : 3617 - 3620 . Phys Rev Lett Borderie B , Rivet M F . Prog Part Nucl Phys 2008 , 61 : 551 - 601 . Prog Part Nucl Phys Bonasera A , Bruno M , Dorso C O , et al . Nuovo Cimento , 2000 , 23 : 1 - 101 . Nuovo Cimento Ma Y G , Shen W Q , Nucl Sci Tech , 2004 , 15 : 4 - 29 . Nucl Sci Tech Brown F R , Butler F P , Chen H , et al . Phys Rev Lett , 1990 , 65 : 2491 - 2494 . Phys Rev Lett Arsene I , Bearden I G , Beavis D , et al . Nucl Phys , 2005 , A757 : 1 - 27 . Nucl Phys Back B B , Baker M D , Ballintijn M , et al . (PHOBOS Collaboration) , Nucl Phys , 2005 , A757 : 28 - 183 . Nucl Phys Adams J , Aggarwal M , Ahammed Z ,  et al . (STAR Collaboration) , Nucl Phys , 2005 , A757 : 102 - 183 . Nucl Phys S. Adcox S , Adler S S , Afanasiev S ,  et al . (PHENIX Collaboration) , Nucl Phys , 2005 , A757 : 184 - 284 . Nucl Phys Demir N , Bass S A . Phys Rev Lett , 2009 , 102 : 172302(1-4) . Phys Rev Lett Lacey R , Ajitanand N N , Alexander J M , et al . Phys Rev Lett , 2007 , 98 : 092301(1-4) . Phys Rev Lett Danielewicz P . Phys Lett ., 1984 , B146 : 168 - 175 . Phys Lett Shi L , Danielewicz P . Phys Rev , 2003 , C68 : 064604(1-17) . Phys Rev Pal S . Phys Rev , 2010 , C81 : 051601(R1-R5) . Phys Rev Auerbach N , Shlomo S . Phys Rev Lett , 2009 , 103 : 172501(1-4) . Phys Rev Lett Wong C Y , Tang H K . Phys Rev Lett , 1978 , 40 : 1070 - 1073 . Phys Rev Lett Bertsch G F , Michigan State University Cyclotron Laboratory preprint, MSUCL-544 ( 1985 ). Michigan State University Cyclotron Laboratory preprint, MSUCL-544 Bauer W , Bertsch G F , Cassing W , et al . Phys Rev , 1986 , C34 : 2127 - 2133 . Phys Rev Wuenschel S , Bonasera A , Maya L W , et al . Nucl Phys , 2010 , A843 : 1 - 13 . Nucl Phys Zheng H , Bonasera A . Phys Lett , 2011 , B696 : 178 - 181 . Phys Lett Muronga A . Phys Rev , 2004 , C69 : 04491(1-7) . Phys Rev Baym G , Monien H , Pethick C J , et al . Phys Rev Lett , 1990 , 64 : 1867 - 1870 . Phys Rev Lett Baym G , Heiselberg H . Phys Rev , 1997 , D56 : 5254 - 5259 . Phys Rev Erpenbeck J J . Phys Rev , 1989 , A39 : 4718 - 4731 . Phys Rev Sasaki N , Miyamura O , Muroya S , et al . Europhys Lett , 2001 , 54 : 38 - 44 . Europhys Lett Kubo R . Rep Prog Phys , 1966 , 29 : 255 - 284 . Rep Prog Phys Muronga A . Phys Rev , 2004 , C69 : 044901(1-7) . Phys Rev Konopka J , Graf H , Stöcker H , et al . Phys Rev , 1994 , C50 : 2085 - 2095 . Phys Rev Kovtun P K , Son D T , Starinets A O . Phys Rev Lett , 2005 , 94 : 111601(1-4) . Phys Rev Lett Policastro G , Son D T , Starinets A O . Phys Rev Lett , 2001 , 87 : 081601(1-4) . Phys Rev Lett Song H C , Bass S A , Heinz U , et al . Phys Rev Lett , 2011 , 106 : 192301(1-4) . Phys Rev Lett 10.13538/j.1001-8042/nst.22.235-239 2011-05-07 2011-08-20 2021-01-19 2011 Nuclear Science and Techniques 04 22