38,340 research outputs found
Thermal field theory derivation of the source term induced by a fast parton from the quark energy-momentum tensor
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 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 . 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
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 GeV is a new scalar
bound state , 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
Using a generalized non-spherical, multi-transonic accretion flow model, we
analytically calculate the normalized QPO frequency
of galactic black hole candidates in terms of dynamical flow variables and
self-consistently study the dependence of on such
variables. Our results are in fairly close agreement with the observed QPO
frequencies of GRS 1915+105. We find that 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
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 () 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
In a class of SUSY SO(10) with
intermediate gauge symmetry, we observe that the
prediction on the unification mass is unaffected by
Planck-scale-induced gravitational and intermediate-scale-threshold effects,
although the intermediate scale 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
GeV and GeV are
permitted in the minimal models. Possibilities of low-mass right-handed gauge
bosons corresponding to 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
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.)
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
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 GeV ("true
vacuum"), and the second Planck scale ("false vacuum") with
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 and radius
We investigated the metric in
the vicinity of the black-hole-hedgehog and estimated its horizon radius:
. 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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