Abstract
Using the QCD operator product expansion, we derive the real part of the transverse and longitudinal vector-vector correlation function with the quantum numbers of the ρ and ω mesons to leading order in density and three-momentum (q2) for ω2 → -∞. The operator product expansion provides, through the Borel transformed energy dispersion relation, a model independent constraint for the momentum dependence of the vector-meson spectral density in nuclear matter. Existing model calculations for the dispersion effect of the ρ, where the vector-meson nucleon scattering amplitude is obtained by resonance saturation in the s-channel, in general violate this constraint. We trace this to an inconsistent choice for the form factor of the ΔNρ vertex. With a consistent choice, where both the form factor and the coupling constant are obtained from the Bonn potential, the contribution of the Δ is substantially reduced and we find good agreement with the constraint equation. We briefly comment on the implications of our result for attempts to interpret the enhancement of low-mass dileptons in heavy-ion collisions.
| Original language | English |
|---|---|
| Pages (from-to) | 91-111 |
| Number of pages | 21 |
| Journal | Nuclear Physics A |
| Volume | 653 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1999 Jun 28 |
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All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
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Constraints on vector mesons with finite momentum in nuclear matter. / Friman, Bengt; Lee, Su Houng; Kim, Hungchong.
In: Nuclear Physics A, Vol. 653, No. 1, 28.06.1999, p. 91-111.Research output: Contribution to journal › Article
TY - JOUR
T1 - Constraints on vector mesons with finite momentum in nuclear matter
AU - Friman, Bengt
AU - Lee, Su Houng
AU - Kim, Hungchong
PY - 1999/6/28
Y1 - 1999/6/28
N2 - Using the QCD operator product expansion, we derive the real part of the transverse and longitudinal vector-vector correlation function with the quantum numbers of the ρ and ω mesons to leading order in density and three-momentum (q2) for ω2 → -∞. The operator product expansion provides, through the Borel transformed energy dispersion relation, a model independent constraint for the momentum dependence of the vector-meson spectral density in nuclear matter. Existing model calculations for the dispersion effect of the ρ, where the vector-meson nucleon scattering amplitude is obtained by resonance saturation in the s-channel, in general violate this constraint. We trace this to an inconsistent choice for the form factor of the ΔNρ vertex. With a consistent choice, where both the form factor and the coupling constant are obtained from the Bonn potential, the contribution of the Δ is substantially reduced and we find good agreement with the constraint equation. We briefly comment on the implications of our result for attempts to interpret the enhancement of low-mass dileptons in heavy-ion collisions.
AB - Using the QCD operator product expansion, we derive the real part of the transverse and longitudinal vector-vector correlation function with the quantum numbers of the ρ and ω mesons to leading order in density and three-momentum (q2) for ω2 → -∞. The operator product expansion provides, through the Borel transformed energy dispersion relation, a model independent constraint for the momentum dependence of the vector-meson spectral density in nuclear matter. Existing model calculations for the dispersion effect of the ρ, where the vector-meson nucleon scattering amplitude is obtained by resonance saturation in the s-channel, in general violate this constraint. We trace this to an inconsistent choice for the form factor of the ΔNρ vertex. With a consistent choice, where both the form factor and the coupling constant are obtained from the Bonn potential, the contribution of the Δ is substantially reduced and we find good agreement with the constraint equation. We briefly comment on the implications of our result for attempts to interpret the enhancement of low-mass dileptons in heavy-ion collisions.
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U2 - 10.1016/S0375-9474(99)00171-2
DO - 10.1016/S0375-9474(99)00171-2
M3 - Article
AN - SCOPUS:0033612489
VL - 653
SP - 91
EP - 111
JO - Nuclear Physics A
JF - Nuclear Physics A
SN - 0375-9474
IS - 1
ER -