ar X iv : n uc l - th / 9 31 10 23 v 1 2 4 N ov 1 99 3 Dilepton production from virtual bremsstrahlung induced by proton capture

ar X iv : n uc l - th / 9 31 00 28 v 1 2 1 O ct 1 99 3 An antiproton - proton partial - wave analysis

ar X iv : n uc l - th / 9 61 10 37 v 1 1 8 N ov 1 99 6 Dilepton production in proton - nucleus and nucleus - nucleus collisions at SPS energies

Dilepton production in proton-and nucleus-induced reactions is studied in relativistic transport model using initial conditions determined by the string dynamics from RQMD. It is found that both the CERES and HELIOS-3 data for dilepton spectra in proton-nucleus reactions can be well described by the 'conventional' mechanism of Dalitz decay and direct vector meson decay. However, to provide a qu...

ar X iv : n uc l - th / 9 90 71 18 v 1 3 0 Ju l 1 99 9 Transport calculation of dilepton production at ultrarelativistic energies

Dilepton spectra are calculated within the microscopic transport model UrQMD and compared to data from the CERES experiment. The invariant mass spectra in the mass region between 300 and 600 MeV depend strongly on the mass dependence of the ρ meson decay width which is not sufficiently determined by the Vector Meson Dominance (VMD) model. A consistent explanation of both the recent Pb+Au data a...

ar X iv : n uc l - th / 9 71 10 28 v 1 1 4 N ov 1 99 7 A clue to the mechanism of Λ K + production in pp - reactions ∗

ar X iv : n uc l - th / 9 71 10 49 v 1 2 5 N ov 1 99 7 π + Emission from Hypernuclei and the Weak ∆

Low energy π emission in hypernuclear weak decays is related to ∆I = 3/2 part of nonmesonic weak decays according to the soft pion theorem. We show that neither meson exchange pictures nor virtual Σ excitation can solve the π emission puzzle. On the other hand, the direct quark mechanism gives the ratio R(π/π : S-wave, soft pion) ≈ 1/4 for 4ΛHe and 5ΛHe. ∗email: [email protected]