2008/07/18 by Swarup Kumar Majee, Majee, Swarup Kumar
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.48550/arxiv.0807.2872
Ph.D. thesis submitted to the University of Calcutta. 123 pages latex, special style file is included
arxiv created 2008/07/18 · openalex publication_date 2008/07/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Some new physics beyond the Standard Model of particle physics, like Supersymmetry, Extra-dimensions etc., and their effect on the nature of different standard model phenomena are explored in this thesis. We discuss the power law scaling of the gauge, Yuakawa and quartic scalar couplings in the Universal Extra-Dimensional scenario assuming compactification on an S1/Z2 orbifold. We get a low unification scale around 30 TeV for a radius R ∼ 1 TeV-1. We show that the effect of one (two) extra-dimension(s) will allow to relax the upper limit on the mass of the lightest CP-even neutral Higgs in the minimal supersymmetric standard model upto around 200 GeV (300 GeV). We obtain a low intermediate scale (MR), a desirable feature to accommodate leptogenesis, within minimal supersymmetric SO(10) Grand Unified Theory with the help of any one of three options -- threshold corrections, non-renormalizable operators or presence of additional light Higgs multiplets. In the triplet Higgs scalar model irrespective of these corrections, from the perturbitivity requirement, we find a lower bound MR > 109 GeV. On the other hand remaining in the standard quark model we estimate the pentaquark mass after taking care of the colour-spin symmetry properties for the triquark (qq q) state.