155,145 research outputs found
QCD CORRECTIONS TO THE H+ -->t anti-b decay within the minimal supersymmetric standard model
I present the results of the QCD corrections to the H+ --> t anti-b decay
within the minimal supersymmetric standard model, if gluinos and scalar quarks
are taken within the relevant loop diagram. I include the mixing of the scalar
partners of the left- and right-handed top quark, which is proportional to the
top quark mass. The standard corrections via gluons and quarks are about +8%
for a charged Higgs mass of 300 GeV and about -11% for a Higgs mass of 800 GeV.
I show that the standard corrections are diminished or enhanced by a
non-negligible amount for certain values of the supersymmetric parameter space.
I also obtain sign changes.Comment: UQAM-PHE-94/03, 5 pages, plain tex, 5 figures not included, available
under request via mail or fa
Primordial hadrosynthesis in the Little Bang
The present status of soft hadron production in high energy heavy-ion
collisions is summarized. In spite of strong evidence for extensive dynamical
evolution and collective expansion of the fireball before freeze-out I argue
that its chemical composition is hardly changed by hadronic final state
interactions. The measured hadron yields thus reflect the primordial conditions
at hadronization. The observed production pattern is consistent with
statistical hadronization at the Hagedorn temperature from a state of
uncorrelated, color deconfined quarks and antiquarks, but requires non-trivial
chemical evolution of the fireball in a prehadronic (presumably QGP) stage
before hadron formation.Comment: 10 pages LaTeX, including 5 figures. Invited overview talk given at
Quark Matter '99, Torino, Italy, May 10-15, 1999. To appear in Nucl. Phys.
Inhomogeneous condensates in the parity doublet model
Within the parity doublet model coupled to the linear sigma model including
vector mesons it is possible to describe vacuum properties of the low energy
mesons and to achieve nuclear saturation at nonzero density. Motivated by
recent studies we investigate the emergence of inhomogeneous condensation in
the parity doublet model. As a first step the chiral density wave (CDW) is con-
sidered, which allows for a straightforward investigation of inhomogeneous
condensation. As a result it is still possible to have a homogeneous ground
state of nuclear matter, but at larger baryon chemical potential the CDW is
favored with respect to the homogeneous phase.Comment: 7 pages, 4 figure
Strange and Multi-Strange Particle Production in P+P Collisions at =200 Gev in Star
We present measurements of the transverse momentum spectra for K0s, Lambda,
Xi and their antiparticles in p+p collisions at GeV. The
extracted mid-rapidity yields and are in agreement with previous
experiments while they have smaller statistical errors. We compare
the measured particle spectra and values to predictions from the PYTHIA
leading order pQCD model (v6.221) and see significant disagreements with the
default settings. Finally we compare the spectra to the latest calculations
from NLO pQCD and see a good agreement for the K0s, but large discrepancies
Lambda.Comment: 4 pages, Proceedings for the 40th Rencontres de Moriond (QCD), La
Thuile, March 200
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