Finite temperature QCD sum rules reexamined: [rho], [omega], and A[sub 1] mesons

Technical Report · Wed Jan 01 00:00:00 EST 1992

OSTI ID:6463232

Hatsuda, Tetsuo ^[1]; Koike, Yuji ^[2]; Lee, Su Houng ^[3]

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1. Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory
2. Maryland Univ., College Park, MD (United States). Dept. of Physics
3. Yonsei Univ., Seoul (Korea, Republic of). Dept. of Physics

A new formulation of the 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 [l angle]script-O[r angle][sub T]. Unlike T = 0 case, [l angle]script-O[r angle][sub T] has non-vanishing values for the Lorentz nonscalar operators such as [anti q][gamma][sub [mu]]D[sub nu]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. This method is applied to the light vector mesons ([rho], [omega] and A[sub 1]), and it is found that the change of the four-quark condensate at T [ne] 0 is crucial to cause their mass shift. Associated with the partial restoration of the chiral symmetry, the [rho] and A[sub 1] meson masses obtained by the Borel sum rules decrease as T increases. The [omega] meson mass is rather stable at low T because of its iso-inglet nature. The lepton pair production rate from the hot hadronic medium near the [rho]-resonance is calculated using the result of the sum rules and a considerable spectral change is shown above T = 160 MeV. This has direct relevance to the detection of the lepton pairs in the future projects of the ultra-relativistic heavy ion collisions such as RHIC and LHC.

• Research Organization: Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG06-90ER40561; FG05-87ER40322
• OSTI ID: 6463232
• Report Number(s): DOE/ER/40561-098; ON: DE93011005
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
A1-1270 MESONS
MASS
OMEGA-783 MESONS
QUANTUM CHROMODYNAMICS
SUM RULES
RHO-770 MESONS
DISPERSION RELATIONS
ELECTRON PAIRS
MUONS
OPE MODEL
PAIR PRODUCTION
QUANTUM OPERATORS
TEMPERATURE DEPENDENCE
AXIAL VECTOR MESONS
BOSON-EXCHANGE MODELS
BOSONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FIELD THEORIES
HADRONS
INTERACTIONS
LEPTONS
MATHEMATICAL MODELS
MATHEMATICAL OPERATORS
MESONS
OBE MODEL
PARTICLE MODELS
PARTICLE PRODUCTION
PERIPHERAL MODELS
QUANTUM FIELD THEORY
VECTOR MESONS
662230* - Quantum Chromodynamics- (1992-)
662420 - Properties of Mesons & Meson Resonances- (1992-)