120089980
ELECTROMAGNETIC MASS DIFFERENCES.
Abstract In Cottingham's approach to electromagnetic masses ( δm ) one encounters the problem of unknown subtractions in the fixed mass dispersion relations for the virtual Compton scattering amplitude. We avoid this problem and express δm in terms of measurable quantities, assuming knowledge of light-cone singularities of the electro-magnetic current commutator.
121043964
INELASTIC e--p SCATTERING DATA AND A NEW PARTON MODEL.
116971806
Problems in electromagnetic mass-difference calculations.
119713326
Nature of the scale-invariance breaking term in inelastic e-p scattering from DGS representation
Abstract Using the DGS representation and the scaling phenomena we suggest that the nature of the scale breaking term of νW 2 in inelastic e-p scattering, should be of the form G 2 (ω)M 2 Q 2 . Using Regge theory it is then predicted that G 2 ( ω ) would be a constant for large ω , and is estimated to be approximately −0.06. These predictions, in particular the constancy of the slopes for νW 2 versus 1 Q 2 plots for large ω ( ω >8), compare very well with the recent experimental data. Similar results for W 1 ( ν , Q 2 ) are also discussed.
119974277
Inelastic-Compton-Scattering Inequalities in the Quark-Parton Model
120289082
NOTE ON THE MOST PROBABLE NUMBER OF PARTONS IN PARTON MODELS.
46702702
A possible explanation of low energy γ-ray excess from galactic centre and Fermi bubble by a Dark Matter model with two real scalars
We promote the idea of multi-component Dark Matter (DM) to explain results from both direct and indirect detection experiments. In these models as contribution of each DM candidate to relic abundance is summed up to meet WMAP/Planck measurements of Ω{sub DM}, these candidates have larger annihilation cross-sections compared to the single-component DM models. We illustrate this fact by introducing an extra scalar to the popular single real scalar DM model. We also present detailed calculations for the vacuum stability bounds, perturbative unitarity and triviality constraints on this model. As direct detection experimental results still show some conflict, we kept our options open, discussing different scenarios with different DM mass zones. In the framework of our model we make an interesting observation: the existing direct detection experiments like CDMS II, CoGeNT, CRESST II, XENON 100 or LUX together with the observation of excess low energy γ-ray from galactic centre and Fermi bubble by Fermi Gamma-ray Space Telescope (FGST) already have the capability to distinguish between different DM halo profiles.
2568474
Late-time acceleration in a slow-moving Galileon field
�� 2M2 � ;� � ;� respects the Galileon symmetry in curved spacetime. We carry out detailed investigations of the underlying dynamics of this Lagrangian with an Einstein-Hilbert term and a potential. We demonstrate that the model can give rise to a viable ghost-free late-time acceleration of the universe. Furthermore, we study the cosmological perturbation of the model and see that the model gives different big bang nucleosynthesis constraints at early times. We also carry out the observational analysis of the model and use observational data from growth, type Ia supernovae data, baryon acoustic oscillations, and the cosmic microwave background to constrain the parameters of the theory. From cosmological observations (1-4) it is evident that our Universe is currently undergoing an accelerated ex- pansion. The theoretical understanding of the nature of cosmic repulsion is a challenge for the cosmologist and the particle physicist today. A variety of approaches have been studied to address this problem, but to date there is still no definite answer. According to the standard ap- proach, the late-time acceleration can be accounted for by supplementing the energy-momentum tensor by an exotic fluid component with large negative pressure dubbed dark energy (5-12), which constitutes about three quarters of the total cosmic budget of the Universe (13). The simplest candidate for dark energy which is consistent with the observations is provided by a cosmological con- stant � . However, there are various serious theoretical problems associated to it, namely, the fine-tuning and the coincidence problems. An interesting alternative to a cosmological constant is provided by the scalar fields. The cosmological dynamics of a variety of scalar field models has been studied in the literature (7). Though these models do not address the cosmological constant problem, they can give late-time cosmic acceleration and can also provide a viable cosmo- logical dynamics at early epochs. Scalar field models with generic features like the trackers are capable of alleviating the fine-tuning and coincidence problems. At present, these scalar field models are absolutely consistent with the observations but, at the same time, a large number of these models are also permitted. One must therefore rely on future data which should allow one to narrow down the class of permissible scalar field dark energy models.
16035264
Probing deviations from tribimaximal mixing through ultrahigh energy neutrino signals
We investigate deviation from the tribimaximal mixing in the case of ultrahigh energy neutrino using the ICECUBE detector. We consider the ratio of the number of muon tracks to the shower generated due to eletrons and hadrons. Our analysis shows that for tribimaximal mixing the ratio comes out around 4.05. Keeping {theta}{sub 12} and {theta}{sub 23} fixed at tribimaximal value, we have varied the angle {theta}{sub 13}=3 deg. , 6 deg. , 9 deg. and the value of the ratio gradually decreases. The variation of ratio lies within 8% to 18% from the tribimaximal mixing value and it is very difficult to detect such a small variation by the ICECUBE detector.