Dimuon production m p-U, O-U and S-U collisions has been studied at 200 GeV/N. It is observed that 〈 p T 〉 and 〈 p 2 T 〉 of the J / Ψ transverse momentum distributions increase with the transverse energy of the ion induced reactions. Such a marked behaviour is not seen for muon pairs of the continuum.
No description provided.
No description provided.
No description provided.
None
No description provided.
No description provided.
No description provided.
We present preliminary results on the measurement of a variety of exclusive hadron interactions at center of mass scattering angles of 90°. Data are also presented which show the relative transparency of nuclei to πp and pp elastic scattering in this kinematic range.
No description provided.
No description provided.
No description provided.
The two-spin parameter A LL in inclusive π 0 productionby longitudinally-polarized protons and antiprotons on a longitudinally-polarized proton target has been measured at the 200 GeV Fermilab spin physics facility, for π 0 's at x F =0 with 1⩽ p t ⩽3 GeV/ c . The results exclude, at the 95% confidence level, values of A LL (pp) > 0.1 and < − 0.1 for π 0 's produced by protons, and values of A LL ( p p) > 0.1 and < −0.2 for incident antiprotons. The relevance of A LL (pp) for the gluon spin density is discussed. The data are in good agreement with “conventional”, small or zero, gluon polarization.
No description provided.
Parity nonconservation in proton-proton scattering has been studied by measuring the angle-integrated longitudinal analyzing power A z . We found A z (13.6 MeV)=(−1.5±0.5)×10 −7 . The error includes uncertainties due to statistics and corrections, as well as upper limits on systematic effects. The experimental result is discussed with respect to recent theoretical calculations.
No description provided.
Using the CUSB-II detector at CESR we have measured the B ∗ cross section in the energy range from s = 10.61–10.65 GeV and 10.70 GeV to be 0.16±0.03 nb and 0.33±0.13 nb respectively. The photon energy for B ∗ →Bγ decays is measured to be 45.4±0.8 MeV, in agreement with our earlier determination. The implication of this measurement for future B factories is discussed.
Errors include systematic uncertainties.
The scaled factorial moments, F q and fractal moments, G q have been measured and their power law variation as a function of size of the pseudorapidity interval has been studied in the central region of the pseudorapidity distribution of the produced charged particles in quasi-central and central collisions of 16 O + Ag Br at 2.1 GeV c per nucleon and 24 Mg + Ag Br at 4.5 GeV c per nucleon. The smooth spectral function f ( α q ), characterizing the fluctuation in the pseudorapidity distribution and the generalised dimensions D q have been derived from G q moments. The analyses reveal a self-similarity in multiparticle production in nucleus-nucleus interactions at an incident momentum of a few GeV/ c per nucleon. Interesting observations can be very effective in establishing multifractality in multiparticle production at this energy range.
No description provided.
No description provided.
Low mass muon pair production at high P T and low X F studied in pU, OU and SU 200 GeV per nucleon react ions. When energy density or projectile mass are increased, φ production is enhanced as compared with the yield of muon pairs in the mass continuum (1.7< M μμ < 2.4 GeV/ c 2 ), whereas the production of ω and ϱ, experimentally unresolved, remains approximately constant. This φ enhancement is in agreement with predictions based on quark-gluon plasma formation and, together with the previously reported J/Ψ suppression, puts severe constraints on a purely hadronic description of nucleus-nucleus collisions.
The cross sections are parametrized as A**POWER.
We report a search for the production of light quark vector bosons in hadron-nucleus collisions at 100 GeV bombarding energy. We find surprisingly few of these resonances produced. The lack of these particles is though to be due to the absorption by the many modestly energetic nucleons and the few anti-nucleons in the final state.
No description provided.
No description provided.
No description provided.
None
No description provided.
CONTINUUM MUONS ORIGINATE MAINLY FROM VECTOR MESON DECAYS, SEMI-LEPTONIC DECAYS OF D DBAR PAIRS AND FROM DRELL-YAN MECHANISM.
No description provided.
Forum