Resonances from a hadronic fireball

Abstract

Abstract. Production of φ(1020), Λ * (1520) and K * (892) resonances at the final stage of a heavy-ion collision is considered. It is shown that original momentum distributions and abundance of resonances formed during the process of heavy ion collision may differ significantly from their measured spectra and yields. Reconstruction probability of resonances decaying inside the fireball can be strongly suppressed because of interactions of their hadronic decay products in the fireball medium. We investigate dependence of the degree of the suppression on the fireball size, dynamics, and the resonance decay width in medium. Quantitative results are presented for lead-lead collisions at 158 GeV SPS beam energy.

Equation of state for hot and dense matter: model with scaled hadron masses and couplings

“…As follows from the π − atomic data, one needs a slight π − energy shift upward, ∼ 10 ÷ 30 MeV for N = Z at the saturation density n B = n 0 , cf. [53]. The value of the pion Σ-term estimated from scattering data is rather small: Σ πN ≃ 30 ÷45 MeV.…”

“…that solves the pole problem. To reproduce (50) in the range 0 < 1 − η ω < ∼ 0.15 it is sufficient to take 10 terms in (53). Certainly we could introduce other parameterizations for the scaling functions.…”

“…However we will use advantages of the KVOR model have been demonstrated in [4,12] in application to cold nucleon matter. Therefore we use the choice (49), (53).…”

A Search for a Mixed Quark-Hadron Phase of QCD Matter

“…The main difference comes from the very low mass used for in-medium nucleon at the normal nuclear density and T = 0, M * N = 0.6M N . In this case the coefficient C 4 ahead the highest sigma-meson interaction term C 4 σ 4 turns out to be negative and, therefore, such a system should be unstable [14]. If the bag constant increases, the transition boundary moves to higher values.…”

“…A more realistic description of the hadronic phase, which takes into account the density dependence of hadron masses and coupling constants [14], was used for the results presented in Fig.4. The general trend of curves is quite similar to that in Fig.3 but now the values of transition densities are higher though the same bag constant B 1/4 =187 MeV was used in both the calculations [12,14]. The main difference comes from the very low mass used for in-medium nucleon at the normal nuclear density and T = 0, M * N = 0.6M N .…”