10,868 research outputs found
Resolution of Cosmological Singularity and a Plausible Mechanism of the Big Bang
The initial cosmological singularity in the framework of the general theory
of relativity is resolved by introducing the effect of the uncertainty
principle of quantum theory without violating conventional laws of physics. A
plausible account of the mechanism of the big bang, analogous to that of a
nuclear explosion, is given and the currently accepted Planck temperature of
about 10^(32)K at the beginning of the big bang is predicted.
Subj-class: cosmology: theory-pre-big bang; mechanism of the big bang.Comment: 5 pages, LaTex, Talk given at INPC 2001. To be published by the
American Institute of Physics in the Proceedings of the International Nuclear
Physics Conference that took place at the University of California campus in
Berkeley, California on July 30-August 3,200
Big Bang Nucleosynthesis and the Missing Hydrogen Mass in the Universe
It is proposed that when the era of the big-bang nucleosynthesis ended,
almost all of the 75 percent of the observed total baryonic matter remained in
the form of hydrogen and continued to exist in the form of protons and
electrons. They are present today as baryonic dark matter in the form of
intergalactic hydrogen plasma. To test our hypothesis we have investigated the
effects of Thomson scattering by free electrons on the reported dimming of Type
Ia supernovae. The quantitative results of our calculation suggest that the
dimming of these supernovae, which are dimmer than expected and hence more
distant than predicted by Hubble expansion, is a result of Thomson scattering
without cosmic acceleration.Comment: A typographical error in equation (7) page 3 has been correcte
Unparticle physics in diphoton production at the CERN LHC
We have considered the di-photon production with unparticle at LHC. The
contributions of spin-0 and spin-2 unparticle to the di-photon production are
studied in the invariant mass and other kinematical distributions, along with
their dependencies on the model dependent parameters. The signal corresponding
to the unparticle is significant for moderate coupling constant values.Comment: 17 pages, 15 eps figure
Unparticle physics in top pair signals at the LHC and ILC
We study the effects of unparticle physics in the pair productions of top
quarks at the LHC and ILC. By considering vector, tensor and scalar unparticle
operators, as appropriate, we compute the total cross sections for pair
production processes depending on scale dimension d_{\U}. We find that the
existence of unparticles would lead to measurable enhancements on the SM
predictions at the LHC. In the case of ILC this may become two orders of
magnitude larger than that of SM, for smaller values of d_\U, a very striking
signal for unparticles.Comment: 19 pages, 9 figures, analysis for ILC has been adde
Unitarity constraints on the stabilized Randall-Sundrum scenario
Recently proposed stabilization mechanism of the Randall-Sundrum metric gives
rise to a scalar radion, which couples universally to matter with a weak
interaction ( TeV) scale. Demanding that gauge boson scattering as
described by the effective low enerrgy theory be unitary upto a given scale
leads to significant constraints on the mass of such a radion.Comment: 10 page Latex 2e file including 4 postscript figures. Accepted in
Journal of Physics
Fractal Inspired Models of Quark and Gluon Distributions and Longitudinal Structure Function FL(x, Q2) at small x
In recent years, Fractal Inspired Models of quark and gluon densities at
small x have been proposed. In this paper, we investigate longitudinal
structure function F-L (x, Q2) within this approach. We make predictions using
the QCD based approximate relation between the longitudinal structure function
and the gluon density. As the Altarelli-Martinelli equation for the
longitudinal structure function cannot be applied to Model I due to the
presence of a singularity in the Bjorken x-space we consider Model II only. The
qualitative feature of the prediction of Model II is found to be compatible
with the QCD expectation.Comment: 11 pages, 4 figures, Accepted for publication on 10-07-2010 in Indian
Journal of Physic
CP violation at colliders
The prospects of experimental detection of violation at and
colliders are reviewed. After a general discussion on the
quantities which can measure violation and on the implications of the
theorem, various possibilities of measuring violation arising
outside the standard model are taken up. violation in leptonic processes,
especially polarization effects in are discussed
next. violation in and production and decay is
also described. (Based on talk presented at the WHEPP3, Madras, January 1994).Comment: 20 pages, latex, no figures (only revision is the comment that the
article is based on a talk presented at WHEPP3, Madras, January 1994
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