18,397 research outputs found

    Isothermal method for volume determination

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    Isothermal volume measurements for weight computation on monkey

    Kˉ∗\bar K^* meson in dense matter

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    We study the properties of Kˉ∗\bar K^* mesons in nuclear matter using a unitary approach in coupled channels within the framework of the local hidden gauge formalism and incorporating the Kˉπ\bar K \pi decay channel in matter. The in-medium Kˉ∗N\bar K^* N interaction accounts for Pauli blocking effects and incorporates the Kˉ∗\bar K^* self-energy in a self-consistent manner. We also obtain the Kˉ∗\bar K^* (off-shell) spectral function and analyze its behaviour at finite density and momentum. At normal nuclear matter density, the Kˉ∗\bar K^* meson feels a moderately attractive potential while the Kˉ∗\bar K^* width becomes five times larger than in free space. We estimate the transparency ratio of the γA→K+K∗−A′\gamma A \to K^+ K^{* -} A^\prime reaction, which we propose as a feasible scenario at present facilities to detect the changes of the properties of the Kˉ∗\bar K^* meson in the nuclear medium.Comment: 26 pages, 9 figures, one new section added, version published in Phys. ReV. C, http://link.aps.org/doi/10.1103/PhysRevC.82.04521

    Vevacious: A Tool For Finding The Global Minima Of One-Loop Effective Potentials With Many Scalars

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    Several extensions of the Standard Model of particle physics contain additional scalars implying a more complex scalar potential compared to that of the Standard Model. In general these potentials allow for charge and/or color breaking minima besides the desired one with correctly broken SU(2)_L times U(1)_Y . Even if one assumes that a metastable local minimum is realized, one has to ensure that its lifetime exceeds that of our universe. We introduce a new program called Vevacious which takes a generic expression for a one-loop effective potential energy function and finds all the tree-level extrema, which are then used as the starting points for gradient-based minimization of the one-loop effective potential. The tunneling time from a given input vacuum to the deepest minimum, if different from the input vacuum, can be calculated. The parameter points are given as files in the SLHA format (though is not restricted to supersymmetric models), and new model files can be easily generated automatically by the Mathematica package SARAH. This code uses HOM4PS2 to find all the minima of the tree-level potential, PyMinuit to follow gradients to the minima of the one-loop potential, and CosmoTransitions to calculate tunneling times.Comment: 44 pages, 1 figure, manual for publicly available software, v2 corresponds to version accepted for publication in EPJC [clearer explanation of scale dependence and region of validity, explicit mention that SLHA files should have blocks matching those expected by model files, updated references

    A new interpretation for the Ds2∗(2573)D^*_{s2}(2573) and the prediction of novel exotic charmed mesons

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    In this manuscript we study the vector - vector interaction within the hidden gauge formalism in a coupled channel unitary approach. In the sector C=1,S=1,J=2C=1,S=1,J=2 we get a pole in the T-matrix around 25722572 MeV that we identify with the Ds2∗(2573)D^*_{s2}(2573), coupling strongly to the D∗K∗D^*K^*(Ds∗ϕD^*_s\phi(ω\omega)) channels. In addition we obtain resonances in other exotic sectors which have not been studied before such as C=1,S=−1C=1,S=-1, C=2,S=0C=2,S=0 and C=2,S=1C=2,S=1. This 'flavor-exotic' states are interpreted as D∗K∗ˉD^*\bar{K^*}, D∗D∗D^*D^* and Ds∗D∗D^*_sD^* molecular states but have not been observed yet. In total we obtain nine states with different spin, isospin, charm and strangeness of non C=0,S=0C=0,S=0 and C=1,S=0C=1,S=0 character, which have been reported before
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