Constraints on vector mesons with finite momentum in nuclear matter
✍ Scribed by Bengt Friman; Su Houng Lee; Hungchong Kim
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 934 KB
- Volume
- 653
- Category
- Article
- ISSN
- 0375-9474
No coin nor oath required. For personal study only.
✦ Synopsis
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/9 and ~o mesons to leading order in density and three-momentum (q2) for w 2 --o -oo. 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 p, 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 ANp vertex. With a consistent choice, where both the form factor and the coupling constant are obtained from the Bonn potential, the contribution of the A 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.