718 research outputs found

    Evidence for In-Medium Changes of Four-Quark Condensates

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    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

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    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

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    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

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    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

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    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

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    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

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    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

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    "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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