### Abstract

Lattice calculations of the QCD trace anomaly at temperatures T<160 MeV have been shown to match hadron resonance gas model calculations, which include an exponentially rising hadron mass spectrum. In this paper we perform a more detailed comparison of the model calculations to lattice data that confirms the need for an exponentially increasing density of hadronic states. Also, we find that the lattice data is compatible with a hadron density of states that goes as ρ(m)∼m^{-}aexp(m/T_{H}) at large m with a>5/2 (where T_{H}∼167 MeV). With this specific subleading contribution to the density of states, heavy resonances are most likely to undergo two-body decay (instead of multiparticle decay), which facilitates their inclusion into hadron transport codes. Moreover, estimates for the shear viscosity and the shear relaxation time coefficient of the hadron resonance model computed within the excluded volume approximation suggest that these transport coefficients are sensitive to the parameters that define the hadron mass spectrum.

Original language | English (US) |
---|---|

Article number | 024913 |

Journal | Physical Review C - Nuclear Physics |

Volume | 86 |

Issue number | 2 |

DOIs | |

State | Published - Aug 27 2012 |

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### All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics

### Cite this

*Physical Review C - Nuclear Physics*,

*86*(2), [024913]. https://doi.org/10.1103/PhysRevC.86.024913

}

*Physical Review C - Nuclear Physics*, vol. 86, no. 2, 024913. https://doi.org/10.1103/PhysRevC.86.024913

**Hadron mass spectrum and the shear viscosity to entropy density ratio of hot hadronic matter.** / Noronha-Hostler, Jacquelyn; Noronha, Jorge; Greiner, Carsten.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Hadron mass spectrum and the shear viscosity to entropy density ratio of hot hadronic matter

AU - Noronha-Hostler, Jacquelyn

AU - Noronha, Jorge

AU - Greiner, Carsten

PY - 2012/8/27

Y1 - 2012/8/27

N2 - Lattice calculations of the QCD trace anomaly at temperatures T<160 MeV have been shown to match hadron resonance gas model calculations, which include an exponentially rising hadron mass spectrum. In this paper we perform a more detailed comparison of the model calculations to lattice data that confirms the need for an exponentially increasing density of hadronic states. Also, we find that the lattice data is compatible with a hadron density of states that goes as ρ(m)∼m-aexp(m/TH) at large m with a>5/2 (where TH∼167 MeV). With this specific subleading contribution to the density of states, heavy resonances are most likely to undergo two-body decay (instead of multiparticle decay), which facilitates their inclusion into hadron transport codes. Moreover, estimates for the shear viscosity and the shear relaxation time coefficient of the hadron resonance model computed within the excluded volume approximation suggest that these transport coefficients are sensitive to the parameters that define the hadron mass spectrum.

AB - Lattice calculations of the QCD trace anomaly at temperatures T<160 MeV have been shown to match hadron resonance gas model calculations, which include an exponentially rising hadron mass spectrum. In this paper we perform a more detailed comparison of the model calculations to lattice data that confirms the need for an exponentially increasing density of hadronic states. Also, we find that the lattice data is compatible with a hadron density of states that goes as ρ(m)∼m-aexp(m/TH) at large m with a>5/2 (where TH∼167 MeV). With this specific subleading contribution to the density of states, heavy resonances are most likely to undergo two-body decay (instead of multiparticle decay), which facilitates their inclusion into hadron transport codes. Moreover, estimates for the shear viscosity and the shear relaxation time coefficient of the hadron resonance model computed within the excluded volume approximation suggest that these transport coefficients are sensitive to the parameters that define the hadron mass spectrum.

UR - http://www.scopus.com/inward/record.url?scp=84865588670&partnerID=8YFLogxK

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U2 - 10.1103/PhysRevC.86.024913

DO - 10.1103/PhysRevC.86.024913

M3 - Article

AN - SCOPUS:84865588670

VL - 86

JO - Physical Review C - Nuclear Physics

JF - Physical Review C - Nuclear Physics

SN - 0556-2813

IS - 2

M1 - 024913

ER -