36,601 research outputs found

### Comparison of Canonical and Grand Canonical Models for selected multifragmentation data

Calculations for a set of nuclear multifragmentation data are made using a
Canonical and a Grand Canonical Model. The physics assumptions are identical
but the Canonical Model has an exact number of particles, whereas, the Grand
Canonical Model has a varying number of particles, hence, is less exact.
Interesting differences are found.Comment: 12 pages, Revtex, and 3 postscript 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 $m_S \simeq 750$ GeV is a new scalar $S$
bound state $6t + 6\bar t$, 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

### Final-State Interaction as the Origin of the Cronin Effect

Instead of adhering to the usual explanation of the Cronin effect in terms of
the broadening of the parton transverse momentum in the initial state, we show
that the enhancement of hadron production at moderate $p_T$ in d+Au collisions
is due to the recombination of soft and shower partons in the final state. Such
a mechanism can readily explain the decrease of the Cronin effect with
increasing rapidity. Furthermore, the effect should be larger for protons than
for pions.Comment: 4 RevTeX pages including 3 figures and 1 table; Some notational
changes and a corrected referenc

### 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 ($E\lesssim 0.8-0.9 MeV$) 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

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