Measurement of Pion Enhancement at Low Transverse Momentum and of the Delta-Resonance Abundance in Si-Nucleus Collisions at AGS Energy

We present measurements of the pion transverse momentum (p_t) spectra in central Si-nucleus collisions in the rapidity range 2.0<y<5.0 for p_t down to and including p_t=0. The data exhibit an enhanced pion yield at low p_t compared to what is expected for a purely thermal spectral shape. This enhancement is used to determine the Delta-resonance abundance at freeze-out. The results are consistent with a direct measurement of the Delta-resonance yield by reconstruction of proton-pion pairs and imply a temperature of the system at freeze-out close to 140 MeV.Comment: 12 pages + 4 figures (uuencoded at end-of-file

Hadron yields and spectra in Au+Au collisions at the AGS

Inclusive double differential multiplicities and rapidity density distributions of hadrons are presented for 10.8 A GeV/c Au+Au collisions as measured at the AGS by the E877 collaboration. The results indicate that large amounts of stopping and collective transverse flow effects are present. The data are also compared to the results from the lighter Si+Al system.Comment: 12 pages, latex, 10 figures, submitted to Nuclear Physics A (Quark Matter 1996 Proceedings

Measurement of the B0s lifetime and study of B0s-B0s oscillations using Dsℓ events

Lifetime and oscillations of B0s mesons have been studied in events with a large transverse momentum lepton and a Ds of opposite electric charge in the same hemisphere, selected from about, 3.6 million hadronic Z0 decays accumulated by DELPHI between 1992 and 1995. The B0s lifetime and the fractional width difference between the two physical B0s states have been found to be: τB0s = (1.42+0.14-0.13(stat.) ± 0.03(syst.)) ps ΔΓB0s/ΓB0s &amp;lt; 0.46 at the 95% C.L. In the latter result it has been assumed that τB0s = τB0d. Using the same sample, a limit on the mass difference between the physical B0s states has been set: ΔmB0s &amp;gt; 7.4 ps-1 at the 95% C.L. with a corresponding sensitivity equal to 8.1 ps-1

Searches for neutral Higgs bosons in e+e- collisions around √s = 189 GeV

Searches for neutral Higgs bosons in the Standard Model and the MSSM have been performed using data collected by the DELPHI experiment at a centre-of-mass energy of 188.7 GeV, corresponding to an integrated luminosity of 158 pb-1. These analyses are used, in combination with our results from lower energies, to set new 95% confidence level lower mass bounds on the Standard Model Higgs boson (94.6 GeV/c2) and on the lightest neutral scalar (82.6 GeV/c2) and neutral pseudoscalar (84.1 GeV/c2) Higgs bosons in a representative scan of the MSSM parameters. The results are also interpreted in the framework of a general two-Higgs doublet model