### Abstract

A new formulation of QCD sum rules at finite temperature (T) is developed. Because of the factorization in the operator product expansion, all the soft dynamics including the effect of finite T in the hadronic phase is taken into account in the thermal average of local operators 〈¢O〉_{T}. Unlike for the T = 0 case, 〈¢O〉_{T} has non-vanishing values for the Lorentz non-scalar operators such as vγ_{μ}D_{v}q. On the basis of the observation that the finite-temperature medium can be well approximated by a dilute (non-interacting) pion gas at low T, one can make a sensible estimate of the T-dependence of various condensates, where the current algebra and the experimental information of the pion structure functions turn out to be a useful guide. We applied this method to the light vector mesons (ρ{variant}, ω and A_{1}) and found that the change of the four-quark condensate at T ≠ 0 is crucial to the change of meson properties. The lepton pair production rate from the hot hadronic medium near the ρ{variant}-resonance is calculated using the result of the sum rules. This has direct relevance to the detection of the lepton pairs in future projects of the ultra-relativistic heavy-ion collisions such as RHIC and LHC.

Original language | English |
---|---|

Pages (from-to) | 221-264 |

Number of pages | 44 |

Journal | Nuclear Physics, Section B |

Volume | 394 |

Issue number | 1 |

DOIs | |

Publication status | Published - 1993 Apr 5 |

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### All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics

### Cite this

_{1}mesons.

*Nuclear Physics, Section B*,

*394*(1), 221-264. https://doi.org/10.1016/0550-3213(93)90107-Z

}

_{1}mesons',

*Nuclear Physics, Section B*, vol. 394, no. 1, pp. 221-264. https://doi.org/10.1016/0550-3213(93)90107-Z

**Finite-temperature QCD sum rules reexamined : ρ{variant}, ω and A _{1} mesons.** / Hatsuda, Tetsuo; Koike, Yuji; Lee, Su Houng.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Finite-temperature QCD sum rules reexamined

T2 - ρ{variant}, ω and A1 mesons

AU - Hatsuda, Tetsuo

AU - Koike, Yuji

AU - Lee, Su Houng

PY - 1993/4/5

Y1 - 1993/4/5

N2 - A new formulation of QCD sum rules at finite temperature (T) is developed. Because of the factorization in the operator product expansion, all the soft dynamics including the effect of finite T in the hadronic phase is taken into account in the thermal average of local operators 〈¢O〉T. Unlike for the T = 0 case, 〈¢O〉T has non-vanishing values for the Lorentz non-scalar operators such as vγμDvq. On the basis of the observation that the finite-temperature medium can be well approximated by a dilute (non-interacting) pion gas at low T, one can make a sensible estimate of the T-dependence of various condensates, where the current algebra and the experimental information of the pion structure functions turn out to be a useful guide. We applied this method to the light vector mesons (ρ{variant}, ω and A1) and found that the change of the four-quark condensate at T ≠ 0 is crucial to the change of meson properties. The lepton pair production rate from the hot hadronic medium near the ρ{variant}-resonance is calculated using the result of the sum rules. This has direct relevance to the detection of the lepton pairs in future projects of the ultra-relativistic heavy-ion collisions such as RHIC and LHC.

AB - A new formulation of QCD sum rules at finite temperature (T) is developed. Because of the factorization in the operator product expansion, all the soft dynamics including the effect of finite T in the hadronic phase is taken into account in the thermal average of local operators 〈¢O〉T. Unlike for the T = 0 case, 〈¢O〉T has non-vanishing values for the Lorentz non-scalar operators such as vγμDvq. On the basis of the observation that the finite-temperature medium can be well approximated by a dilute (non-interacting) pion gas at low T, one can make a sensible estimate of the T-dependence of various condensates, where the current algebra and the experimental information of the pion structure functions turn out to be a useful guide. We applied this method to the light vector mesons (ρ{variant}, ω and A1) and found that the change of the four-quark condensate at T ≠ 0 is crucial to the change of meson properties. The lepton pair production rate from the hot hadronic medium near the ρ{variant}-resonance is calculated using the result of the sum rules. This has direct relevance to the detection of the lepton pairs in future projects of the ultra-relativistic heavy-ion collisions such as RHIC and LHC.

UR - http://www.scopus.com/inward/record.url?scp=11544373273&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=11544373273&partnerID=8YFLogxK

U2 - 10.1016/0550-3213(93)90107-Z

DO - 10.1016/0550-3213(93)90107-Z

M3 - Article

VL - 394

SP - 221

EP - 264

JO - Nuclear Physics B

JF - Nuclear Physics B

SN - 0550-3213

IS - 1

ER -

_{1}mesons. Nuclear Physics, Section B. 1993 Apr 5;394(1):221-264. https://doi.org/10.1016/0550-3213(93)90107-Z