718 research outputs found
Evidence for In-Medium Changes of Four-Quark Condensates
Utilizing the QCD sum rule approach to the behavior of the omega meson in
nuclear matter we derive evidence for in-medium changes of particular
four-quark condensates from the recent CB-TAPS experiment for the reaction
gamma + A -> A' + omega (-> pi0 gamma) with A = Nb and LH2.Comment: Submitted to Phys. Rev. Lett., 4 page
QCD sum rules for D and B mesons in nuclear matter
QCD sum rules for D and B mesons embedded in cold nuclear matter are
evaluated. We quantify the mass splitting of D - D-bar and B - B-bar mesons as
a function of the nuclear matter density; extrapolated to saturation density it
is in the order of 60 and 130 MeV driven essentially by the condensates
, and . The genuine chiral
condensate , amplified by heavy-quark masses, enters the Borel
transformed sum rules for the mass splitting beyond linear density dependence.
Including strange quark condensates reveals a umerically smaller and opposite
effect for the Ds - Ds-bar mass splitting.Comment: 16 pages, 8 figures, to be published; a broader range of condensate
values is discussed (v2
Statistical-Thermal Model Calculations using THERMUS
Selected results obtained using THERMUS, a newly-developed
statistical-thermal model analysis package, are presented.Comment: Contributed to 8th International Conference on Strangeness in Quark
Matter, Cape Town, South Africa, 15-20 September 200
Chiral QCD sum rules for open charm mesons
QCD sum rules for chiral partners in the open-charm meson sector are
presented at nonzero baryon net density or temperature. We focus on the
differences between pseudo-scalar and scalar as well as vector and axial-vector
D mesons and derive the corresponding Weinberg type sum rules. This allows for
the identification of such QCD condensates which drive the non-degeneracy of
chiral partners in lowest order of the strong coupling alpha_s and which
therefore may serve as "order parameters" for chiral restoration (or elements
thereof).Comment: 24 pages, 4 figure
Towards strangeness saturation in central heavy-ion collisions at high energies
Analyses of the centrality binned identified hadron multiplicities at SPS and
RHIC within the statistical-thermal model point to strangeness saturation with
increasing centrality and energy.Comment: 4 pages, 2 figures. Presented at the 16th International Conference on
Ultra-Relativistic Nucleus-Nucleus Collisions, Nantes, France, 18-24 July,
200
Towards strangeness saturation in central heavy-ion collisions at high energies
It is now well established that particle abundances can be described by statistical-thermal models. In such a way, a large number of observables can be reproduced with a small number of parameters, namely the temperature, baryo-chemical potential and a factor measuring the degree of strangeness saturation. Here we focus on the centrality dependence of the hadron multiplicities and adjust the thermal parameters so as to reproduce the experimental data
Estimates of production rates of SUSY particles in ultra-relativistic heavy-ion collisions
We estimate the production rates of supersymmetric particles in central
heavy-ion collisions at LHC. The parton cascade model is used to seek for
possible collective phenomena which enlarge the production probability of very
heavy particles. Even if there is some indication of such cooperative effects,
higher energy and higher luminosity of proton beams at LHC disfavor heavy-ion
reactions in the search for supersymmetric particles.Comment: 19 pages including 10 EPS figure
The European Union's idea of gender equality and its support among citizens of 27 European countries
"This article first describes the European Union’s idea of gender equality and its im-plementation into European policies. The second section analyses the extent to which citizens of different European countries support the idea of gender equality. The em-pirical basis for our analysis is the “Eurobarometer 63.1” from 2005. The descriptive findings show that while a majority of European citizens support the idea of gender equality, there are substantial differences between individual countries. In the third section we explain these differences by referring to the country’s level of moderniza-tion and degree of politically institutionalised gender equality, as well as the respon-dents’ religious orientation and level of education, among other factors." [author's abstract
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