147,361 research outputs found

    The CMB - Contemporary Measurements and Cosmology

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    Since the discovery of the Cosmic Microwave Background (CMB) in 1965, characterization of the CMB anisotropy angular power spectrum has become somewhat of a holy grail for experimental cosmology. Because CMB anisotropy measurements are difficult, the full potential of the CMB is only now being realized. Improvements in experimental techniques and detector technology have yielded an explosion of progress in the past couple of years resulting in the ability to use measurements of the CMB to place meaningful constraints on cosmological parameters. In this review, I discuss the theory behind the CMB but focus primarily on the experiments, reviewing briefly the history of CMB anisotropy measurements and focusing on the recent experiments that have revolutionized this field. Results from these modern experiments are reviewed and the cosmological implications discussed. I conclude with brief comments about the future of CMB physics.Comment: 18 pages including 5 ps figures. GR16 proceedings to appear in World Scientifi

    The influence of strange quarks on QCD phase diagram and chemical freeze-out: Results from the hadron resonance gas model

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    We confront the lattice results on QCD phase diagram for two and three flavors with the hadron resonance gas model. Taking into account the truncations in the Taylor-expansion of energy density ϵ\epsilon done on the lattice at finite chemical potential μ\mu, we find that the hadron resonance gas model under the condition of constant ϵ\epsilon describes very well the lattice phase diagram. We also calculate the chemical freeze-out curve according to the entropy density ss. The ss-values are taken from lattice QCD simulations with two and three flavors. We find that this condition is excellent in reproducing the experimentally estimated parameters of the chemical freeze-out.Comment: 5 pages, 3 figures and 1 table Talk given at VIIIth international conference on ''Strangeness in Quark Matter'' (SQM 2004), Cape Town, South Africa, Sep. 15-20 200

    Conditions driving chemical freeze-out

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    We propose the entropy density as the thermodynamic condition driving best the chemical freeze-out in heavy-ion collisions. Taking its value from lattice calculations at zero chemical potential, we find that it is excellent in reproducing the experimentally estimated freeze-out parameters. The two characteristic endpoints in the freeze-out diagram are reproduced as well.Comment: 8 pages, 5 eps figure

    Entropy for Color Superconductivity in Quark Matter

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    We study a model for color superconductivity with both three colors and massless flavors including quark pairing. By using the Hamiltonian in the color-flavor basis we can calculate the quantum entropy. From this we are able to further investigate the phases of the color superconductor, for which we find a rather sharp transition to color superconductivity above a chemical potential around 290290 MeV.Comment: 10 pages, 2 eps-figure

    Supersymmetric SO(10) Grand Unification at the LHC and Beyond

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    We study models of supersymmetric grand unification based on the SO(10) gauge group. We investigate scenarios of non-universal gaugino masses including models containing a mixture of two representations of hidden sector chiral superfields. We analyse the effect of excluding mu from the fine-tuning measure, and confront the results with low energy constraints, including the Higgs boson mass, dark matter relic density and supersymmetry bounds. We also determine high scale Yukawa coupling ratios and confront the results with theoretical predictions. Finally, we present two additional benchmarks that should be explored at the LHC and future colliders.Comment: Published versio
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