1,319 research outputs found
Statistical Model Predictions for Pb-Pb Collisions at LHC
The systematics of Statistical Model parameters extracted from heavy-ion
collisions at lower energies are exploited to extrapolate in the LHC regime.
Predictions of various particle ratios are presented and particle production in
central Pb-Pb collisions at LHC is discussed in the context of the Statistical
Model. The sensitivity of several ratios on the temperature and the baryon
chemical potential is studied in detail, and some of them, which are
particularly appropriate to determine the chemical freeze-out point
experimentally, are indicated. The impact of feed-down contributions from
resonances, especially to light hadrons, is illustrated.Comment: 5 pages, 2 figures, 1 table, SQM 2006 conference proceedings,
accepted for publication in J. Phys.
Statistical Model and the mesonic-baryonic transition region
The statistical model assuming chemical equilibriumand local strangeness
conservation describes most of the observed features of strange particle
production from SIS up to RHIC. Deviations are found as the maximum in the
measured K+/pi+ ratio is much sharper than in the model calculations. At the
incident energy of the maximum, the statistical model shows that freeze out
changes regime from one being dominated by baryons at the lower energies toward
one being dominated by mesons. It will be shown how deviations from the usual
freeze-out curve influence the various particle ratios. Furthermore, other
observables exhibit also changes just in this energy regime.Comment: 9 pages, 7 figures, CPOD conference proceeding
Alien Registration- Wheaton, James H. (Milo, Piscataquis County)
https://digitalmaine.com/alien_docs/8356/thumbnail.jp
Statistical Model Predictions for p+p and Pb+Pb Collisions at LHC
Particle production in p+p and central Pb+Pb collisions at LHC is discussed
in the context of the statistical thermal model. For heavy-ion collisions,
predictions of various particle ratios are presented. The sensitivity of
several ratios on the temperature and the baryon chemical potential is studied
in detail, and some of them, which are particularly appropriate to determine
the chemical freeze-out point experimentally, are indicated. Considering
elementary interactions on the other hand, we focus on strangeness production
and its possible suppression. Extrapolating the thermal parameters to LHC
energy, we present predictions of the statistical model for particle yields in
p+p collisions. We quantify the strangeness suppression by the correlation
volume parameter and discuss its influence on particle production. We propose
observables that can provide deeper insight into the mechanism of strangeness
production and suppression at LHC.Comment: 7 pages, 5 figures, conference contribution to "International school
of nuclear physics", Erice, Sicily, 16 - 24 September 2008; Progress in
Particle and Nuclear Physics, 2009, in pres
Transition from Baryon- to Meson-Dominated Freeze Out -- Early Decoupling around 30 A GeV?
The recently discovered sharp peak in the excitation function of the K+/pi+
ratio around 30 A GeV in relativistic heavy-ion collisions is discussed in the
framework of the Statistical Model. In this model, the freeze-out of an ideal
hadron gas changes from a situation where baryons dominate to one with mainly
mesons. This transition occurs at a temperature T = 140 MeV and baryon chemical
potential mu(B) = 410 MeV corresponding to an energy of sqrt(s) = 8.2 GeV. The
calculated maximum in the K+/pi+ ratio is, however, much less pronounced than
the one observed by the NA49 Collaboration. The smooth increase of the K-/pi-
ratio with incident energy and the shape of the excitation functions of the
Lambda/pi+, Xi-/pi+ and Omega/pi ratios all exhibiting maxima at different
incident energies, is consistent with the presently available experimental
data. The measured K+/pi+ ratio exceeds the calculated one just at the incident
energy when the freeze-out condition is changing.
We speculate that at this point freeze-out might occur in a modified way. We
discuss a scenario of an early freeze-out which indeed increases K+/pi+ ratio
while most other particle ratios remain essentially unchanged. Such an early
freeze-out is supported by results from HBT studies.Comment: 8 pages, 5 figures, SQM2006 conference, Los Angeles, March 200
Development of ductile claddings for dispersion-strengthened nickel-base alloys Final report
Development of ductile oxidation-resistant cladding alloys for thoria dispersion, strengthened nickel and nickel-chromiu
Statistical Model Predictions for Particle Ratios at sqrt(s_NN) = 5.5 TeV
Particle production in central Pb-Pb collisions at LHC is discussed in the
context of the Statistical Model. Predictions of various particle ratios are
presented with the corresponding choice of model parameters made according to
the systematics extracted from heavy-ion collisions at lower energies. The
sensitivity of several ratios on the temperature and the baryon chemical
potential is studied in detail, and some of them, which are particularly
appropriate to determine the chemical freeze-out point experimentally, are
indicated. We show that the anti-p / p ratio is most suitable to determine the
baryon chemical potential while the Omega / K and Omega / pi ratios are best to
determine the temperature at chemical freeze-out.Comment: Submitted to Phys. Rev. C, 7 pages, 4 figure
Seeding mixtures for hay, pasture and silage
"For best results from pasture and hay crops, keep seeding mixtures simple. Grasses and legumes that are sown in combination should be similar in palatability, maturity patterns and growing vigor. Because of the differences between grasses, it is recommended that each mixture contain only one grass and one or two legumes. For example, seeding tall fescue and orchardgrass in the same mixture results in spotty grazing and wasted forage because of the differences in palatability."--First page.H.N. Wheaton and Jimmy C. Henning (Department of Agronomy, College of Agriculture)RevisedL 9/87/10
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