Bulk viscosity of a gas of massless pions
In the hadronic phase, the dominant configuration of quantum chromodynamics (QCD) with two flavors of massless quarks is a gas of massless pions. We calculate the bulk viscosity (ζ) using the Boltzmann equation with the kinetic theory generalized to incorporate the trace anomaly. We find that the di...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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American Physical Society
2011
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| Online Access: | http://hdl.handle.net/1721.1/64968 https://orcid.org/0000-0001-5742-3395 |
| _version_ | 1811093486312620032 |
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| author | Chen, Jiunn-Wei Wang, Juven |
| author2 | Massachusetts Institute of Technology. Center for Theoretical Physics |
| author_facet | Massachusetts Institute of Technology. Center for Theoretical Physics Chen, Jiunn-Wei Wang, Juven |
| author_sort | Chen, Jiunn-Wei |
| collection | MIT |
| description | In the hadronic phase, the dominant configuration of quantum chromodynamics (QCD) with two flavors of massless quarks is a gas of massless pions. We calculate the bulk viscosity (ζ) using the Boltzmann equation with the kinetic theory generalized to incorporate the trace anomaly. We find that the dimensionless ratio ζ/s, s being the entropy density, is monotonic increasing below T=120 MeV, where chiral perturbation theory is applicable. This, combined with previous results, shows that ζ/s reaches its maximum near the phase-transition temperature Tc, while η/s, η being the shear viscosity, reaches its minimum near Tc in QCD with massless quarks. |
| first_indexed | 2024-09-23T15:45:19Z |
| format | Article |
| id | mit-1721.1/64968 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:45:19Z |
| publishDate | 2011 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/649682022-09-29T15:57:20Z Bulk viscosity of a gas of massless pions Chen, Jiunn-Wei Wang, Juven Massachusetts Institute of Technology. Center for Theoretical Physics Massachusetts Institute of Technology. Department of Physics Wang, Juven Chen, Jiunn-Wei Wang, Juven In the hadronic phase, the dominant configuration of quantum chromodynamics (QCD) with two flavors of massless quarks is a gas of massless pions. We calculate the bulk viscosity (ζ) using the Boltzmann equation with the kinetic theory generalized to incorporate the trace anomaly. We find that the dimensionless ratio ζ/s, s being the entropy density, is monotonic increasing below T=120 MeV, where chiral perturbation theory is applicable. This, combined with previous results, shows that ζ/s reaches its maximum near the phase-transition temperature Tc, while η/s, η being the shear viscosity, reaches its minimum near Tc in QCD with massless quarks. National Center for Theoretical Sciences (Taiwan) 2011-07-28T15:28:45Z 2011-07-28T15:28:45Z 2009-04 2008-12 Article http://purl.org/eprint/type/JournalArticle 0556-2813 http://hdl.handle.net/1721.1/64968 Chen, Jiunn-Wei, and Juven Wang. “Bulk Viscosity of a Gas of Massless Pions.” Physical Review C 79.4 (2009) : 044913. © 2009 The American Physical Society https://orcid.org/0000-0001-5742-3395 en_US http://dx.doi.org/10.1103/PhysRevC.79.044913 Physical Review C Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Physical Society APS |
| spellingShingle | Chen, Jiunn-Wei Wang, Juven Bulk viscosity of a gas of massless pions |
| title | Bulk viscosity of a gas of massless pions |
| title_full | Bulk viscosity of a gas of massless pions |
| title_fullStr | Bulk viscosity of a gas of massless pions |
| title_full_unstemmed | Bulk viscosity of a gas of massless pions |
| title_short | Bulk viscosity of a gas of massless pions |
| title_sort | bulk viscosity of a gas of massless pions |
| url | http://hdl.handle.net/1721.1/64968 https://orcid.org/0000-0001-5742-3395 |
| work_keys_str_mv | AT chenjiunnwei bulkviscosityofagasofmasslesspions AT wangjuven bulkviscosityofagasofmasslesspions |