36,486 research outputs found
The 24-Cell and Calabi-Yau Threefolds with Hodge Numbers (1,1)
Calabi-Yau threefolds with h^11(X)=h^21(X)=1 are constructed as free
quotients of a hypersurface in the ambient toric variety defined by the
24-cell. Their fundamental groups are SL(2,3), a semidirect product of Z_3 and
Z_8, and Z_3 x Q_8.Comment: 22 pages, 3 figures, 3 table
Production of Strange Clusters and Strange Matter in Nucleus-Nucleus Collisions at the AGS
Production probabilities for strange clusters and strange matter in Au+Au
collisions at AGS energy are obtained in the thermal fireball model. The only
parameters of the model, the baryon chemical potential and temperature, were
determined from a description of the rather complete set of hadron yields from
Si+nucleus collisions at the AGS. For the production of light nuclear fragments
and strange clusters the results are similar to recent coalescence model
calculations. Strange matter production with baryon number larger than 10 is
predicted to be much smaller than any current experimental sensitivities.Comment: 9 Pages (no figures
Probing the Phase Boundary between Hadronic Matter and the Quark-Gluon-Plasma in Relativistic Heavy Ion Collisions
We discuss recent data on particle production with emphasis on the degree of
thermal and chemical equilibration achieved. The data are interpreted in terms
of a resonance gas model. The phase boundary constructed between the resonance
gas and the quark-gluon plasma is shown to be very close to the deduced
parameters characterizing the hadronic fireball at freeze-out.Comment: 7 pages, latex, 6 figures, 1 table submitted to Nuclear Physics A,
dedicated to Gerry Brown in honor of his 70th birthda
Charmonium Production from the Secondary Collisions at LHC Energy
We consider the charmonium production in thermalized hadronic medium created
in ultrarelativistic heavy ion collisions at LHC energy.
The calculations for the secondary and production by annihilation are performed within a kinetic model taking into account the
space-time evolution of a longitudinally and transversely expanding medium. We
show that the secondary charmonium production appears almost entirely during
the mixed phase and it is very sensitive to the charmonium dissociation cross
section with co-moving hadrons. Within the most likely scenario for the
dissociation cross section of the mesons their regeneration in the
hadronic medium will be negligible. The secondary production of mesons
however, due to their large cross section above the threshold, can
substantially exceed the primary yield.Comment: ps file 11
On Charm Production near the Phase Boundary
We discuss aspects of the statistical hadronization model for the production
of mesons with open and hidden charm in ultra-relativistic nuclear collisions.
Emphasis is placed on what can be inferred from the dependence of the yield of
charmonia on the number of participants in the collisions.Comment: Invited Paper, NAN Conference, Darmstadt, Oct. 2000, final version,
expanded discussion on results at collider energies, Nucl. Phys. A. (in
print). Dedicated to Achim Richter in honor of his 60th birthda
Statistical hadronization of charm at SPS, RHIC and LHC
We study the production of charmonia and charmed hadrons for nucleus-nucleus
collisions at SPS, RHIC, and LHC energies within the framework of the
statistical hadronization model. Results from this model are compared to the
observed centrality dependence of J/psi production at SPS energy. We further
provide predictions for the centrality dependence of the production of open and
hidden charm mesons at RHIC and LHC.Comment: Contribution to Quark Matter 2002, 4 pages, 3 figures; revised
version including charmed hyperons (omitted in v1
coupling constant in light cone QCD sum rules
We employ the light cone QCD sum rules to calculate coupling
constant by studying the two point correlation function between the vacuum and
the pion state. Our result is consistent with the traditional QCD sum rules
calculations and it is in agreement with the experimental value.Comment: 8 pages, latex, 2 figure
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