38,294 research outputs found

    Thermal field theory derivation of the source term induced by a fast parton from the quark energy-momentum tensor

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    I derive the distribution of energy and momentum transmitted from a fast parton to a medium of thermalized quarks, or the source term, in perturbative thermal field theory directly from the quark energy-momentum tensor. The fast parton is coupled to the medium by adding an interaction term to the Lagrangian. The thermal expectation value of the energy-momentum tensor source term is then evaluated using standard Feynman rules at finite temperature. It is found that local excitations, which are important for exciting an observable Mach cone structure, fall sharply as a function of the energy of the fast parton. This may have implications for the trigger pTp_T dependence of measurements of azimuthal dihadron particle correlations in heavy-ion collisions. In particular, a conical emission pattern would be less likely to be observed for increasing trigger pTp_T. I show that the results presented in this paper can be generalized to more realistic modeling of fast parton propagation, such as through a time dependent interaction term, in future studies.Comment: Version as accepted by Physical Review D. New version has several clarifications and added references. 5 pages, 3 figure

    Topological Structure of the Vacuum, Cosmological Constant and Dark Energy

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    In this review we present a theory of cosmological constant and Dark Energy (DE), based on the topological structure of the vacuum. The Multiple Point Principle (MPP) is reviewed. It demonstrates the existence of the two vacua into the SM. The Froggatt-Nielsen's prediction of the top-quark and Higgs masses is given in the assumption that there exist two degenerate vacua in the SM. This prediction was improved by the next order calculations. We also considered B.G. Sidharth's theory of cosmological constant based on the non-commutative geometry of the Planck scale space-time, what gives an extremely small DE density providing the accelerating expansion of the Universe. Theory of two degenerate vacua - the Planck scale phase and Electroweak (EW) phase - also is reviewed, topological defects in these vacua are investigated, also the Compton wavelength phase suggested by B.G. Sidharth was discussed. A general theory of the phase transition and the problem of the vacuum stability in the SM is reviewed. Assuming that the recently discovered at the LHC new resonance with mass mS≃750m_S \simeq 750 GeV is a new scalar SS bound state 6t+6tˉ6t + 6\bar t, earlier predicted by C.D. Froggatt, H.B. Nielsen and L.V. Laperashvili, we try to provide the vacuum stability in the SM and exact accuracy of the MPP.Comment: 37 pages and 7 figures. arXiv admin note: text overlap with arXiv:1601.03231; text overlap with arXiv:1302.2716 by other author

    Role of shocked accretion flows in regulating the QPO of galactic black hole candidates

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    Using a generalized non-spherical, multi-transonic accretion flow model, we analytically calculate the normalized QPO frequency νˉqpo{\bar {\bf {\nu}}}_{qpo} of galactic black hole candidates in terms of dynamical flow variables and self-consistently study the dependence of νˉqpo{\bar {\bf {\nu}}}_{qpo} on such variables. Our results are in fairly close agreement with the observed QPO frequencies of GRS 1915+105. We find that νˉqpo{\bar {\bf {\nu}}}_{qpo} is quite sensitive to various parameters describing the black hole accretion flow containing dissipative and non-dissipative shock waves. Thus the QPO phenomena is, {\it indeed}, regulated by `shocked' black hole accretion, and, for the first time, we establish a definitive connection between the QPO frequency and the properties of advective BH accretion flows. This information may provide the explanation of some important observations of galactic micro quasars.Comment: Final version accepted for publication in the Astrophysical Journal Letters (ApJL). A considerable part of the paper is almost completely re-written, though the results and the final conclussions are the same. One can now ignore the previous version. 8 pages with four black and white figures. For high resolution Fig. 3, please mail the author <[email protected]

    Possible trace of neutrino nonstandard interactions in the supernova

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    Neutrino non-standard interactions (NSI), previously introduced for the sun, are studied in the supernova context. For normal hierarchy the probability for electron neutrinos and antineutrinos at low energy (E≲0.8−0.9MeVE\lesssim 0.8-0.9 MeV) is substantially increased with respect to the non-NSI case and joins its value for inverse hierarchy which is constant with energy. Also for inverse hierarchy the NSI and non-NSI probabilities are the same for each neutrino and antineutrino species. These are the possible visible effects of NSI in the supernova. The decay into antineutrinos, which has been previously shown to be implied by dense matter, cannot be seen experimentally, owing to the smallness of the antineutrino production probability.Comment: 5 pages, 3 eps figures. Acknowledgements include

    Precision and uncertainties in mass scale predictions in SUSY SO(10) with SU(2)_L x SU(2)_R x U(1)_{B-L} x SU(3)_C intermediate breaking

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    In a class of SUSY SO(10) with SU(2)LxSU(2)RxU(1)B−LxSU(3)CSU(2)_L x SU(2)_R x U(1)_{B-L} x SU(3)_C (g2L≠g2R)(g_{2L}\neq g_{2R}) intermediate gauge symmetry, we observe that the prediction on the unification mass (MU)(M_U) is unaffected by Planck-scale-induced gravitational and intermediate-scale-threshold effects, although the intermediate scale (MI)(M_I) itself is subject to such corrections. In particular, without invoking the presence of additional lighter scalar degrees of freedom but including plausible and reasonable threshold effects, we find that interesting solutions for neutrino physics corresponding to MI≃1010−1013M_I\simeq 10^{10}-10^{13} GeV and MU≃(5−6)x1017M_U\simeq (5-6) x 10^{17} GeV are permitted in the minimal models. Possibilities of low-mass right-handed gauge bosons corresponding to MI≃1−10M_I\simeq 1-10 TeV consistent with the CERN-LEP data are pointed out in a number of models when threshold effects are included using effective mass parameters.Comment: 12 pages including 7 tables (Typos corrected as per the published version

    Generalized dual symmetry of nonabelian theories, monopoles and dyons

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    In the present talk we present an investigation of nonabelian SU(N) gauge theories, describing a system of fields with non--dual g and dual \tilde g charges and revealing the generalized dual symmetry. The Zwanziger type action is suggested. The renormalization group equations for pure nonabelian theories, in particular for pure SU(3)\times\widetilde{SU(3)} gauge theory (as an example) are analysed. We consider not only monopoles, but also dyons. The behaviour of the QCD total beta--function is investigated. It was shown that this beta--function is antisymmetric under the interchange \alpha\leftrightarrow\frac 1\alpha (here \alpha\equiv\alpha_s), and has zero ("fixed point") at \alpha = 1. Monopoles, or dyons, are responsible for the phase transition. Considering critical points at \alpha_1\approx 0.4 and \alpha_2\approx 2.5, we give an explanation of the freezing of \alpha_s.Comment: 15 pages, 5 figures, Presented at the 12th Lomonosov Conference on Elementary Particle Physics, Moscow State University, Moscow, 25-31 August, 200

    New Bound States of Top-anti-Top Quarks and T-balls Production at Colliders (Tevatron, LHC, etc.)

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    The present talk is based on the assumption that New Bound States (NBSs) of top-anti-top quarks (named T-balls) exist in the Standard Model (SM): a) there exists the scalar 1S - bound state of 6t+6\bar t - the bound state of 6 top-quarks with their 6 anti-top-quarks; b) the forces which bind these top-quarks are very strong and almost completely compensate the mass of the 12 top-anti-top-quarks forming this bound state; c) such strong forces are produced by the interactions of top-quarks via the virtual exchange of the scalar Higgs bosons having the large value of the top-quark Yukawa coupling constant g_t\simeq 1. Theory also predicts the existence of the NBS 6t + 5\bar t, which is a color triplet and a fermion similar to the t'-quark of the fourth generation. We have also considered "b-replaced" NBSs: n_b b + (6t + 6\bar t - n_b t) and n'_b b + (6t + 5\bar t - n'_b t), etc. We have estimated the masses of the lightest "b-replaced" NBS: M_{NBS}\simeq (300 - 400) GeV, and discussed the larger masses of the NBSs. We have developed a theory of the scalar T-ball's condensate, and predicted the existence of the three SM phases, calculating the top-quark Yukawa coupling constant at the border of two phases (with T-ball's condensate and without it) equal to: g_t \approx 1. The searching for the Higgs boson H and T-balls at the Tevatron and LHC is discussed.Comment: 43 pages, 20 figure

    Gravi-Weak Unification and the Black-Hole-Hedgehog's Solution with Magnetic Field Contribution

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    In the present paper, we investigated the gravitational black-hole-hedgehog's solution with magnetic field contribution in the framework of the f(R)--gravity described by the Gravi-Weak unification model. Assuming the Multiple Point Principle (MPP), we considered the existence of the two degenerate vacua of the Universe: the first Electroweak (EW) vacuum with v1≈246v_1 \approx 246 GeV ("true vacuum"), and the second Planck scale ("false vacuum") with v2∼1018v_2 \sim 10^{18} GeV. In these vacua, we investigated different topological defects. The main aim of this paper is an investigation of the black-hole-hedgehog configurations as defects of the "false vacuum". We have obtained the solution which corresponds to a global monopole, that has been "swallowed" by the black-hole with core mass MBH≈3.65×1018  GeVM_{BH}\approx 3.65\times 10^{18}\,\, {\rm{GeV}} and radius δ≈6⋅10−21GeV−1.\delta \approx 6\cdot 10^{-21} {\rm{GeV}}^{-1}. We investigated the metric in the vicinity of the black-hole-hedgehog and estimated its horizon radius: rh≈1.14δr_h\approx 1.14 \delta. We have considered the phase transition from the "false vacuum" to the "true vacuum" and confirmed the stability of the EW--vacuum.Comment: 22 pages. arXiv admin note: text overlap with arXiv:1703.05594, arXiv:1801.06979, arXiv:1605.01169; text overlap with arXiv:1002.4275 by other author
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