相关论文: GUT's have the ability to defy sphalerons

We propose a new mechanism of leptogenesis in which the asymmetries in lepton numbers are produced through the CP-violating oscillations of ``sterile'' (electroweak singlet) neutrinos. The asymmetry is communicated from singlet neutrinos to…

We consider non-supersymmetric GUT inflation models in which intermediate mass monopoles may survive inflation because of the restricted number of e-foldings experienced by the accompanying symmetry breaking. Thus, an observable flux of…

Recent experimental and theoretical determinations of (g-2)_muon, Omega*h^2 and BF(b->s,gamma) place exceedingly tight constraints on the minimal supergravity (mSUGRA) model. We advocate relaxing the generational universality of mSUGRA, so…

In this work we demonstrate that what was previously considered as different mechanisms of baryon asymmetry generation involving two right-handed Majorana neutrinos with masses far below the GUT scale -- leptogenesis via neutrino…

We show that the Standard Model Lagrangian, including small neutrino masses, has an anomaly-free discrete Z_6 symmetry. This symmetry can emerge naturally from I^{3}_{R}+L_i+L_j-2L_k gauge symmetry (L_i is the i-th lepton number) and ensure…

We address the question whether it is possible in GUTs to obtain R-parity violation with a large ${\Delta L{/}\Delta B}$ hierarchy of strengths so that the proton is stable while phenomenologically interesting $L$-violation is present. We…

We provide an up to date account of progress in understanding the origin of the observed baryon asymmetry of the universe. While our primary goal is to be current, we have attempted to give a pedagogical introduction to the primary areas of…

Grand Unified Theories (GUT) offer an elegant and unified description of electromagnetic, weak and strong interactions at high energy scales. A phenomenological and exciting possibility to grasp GUT is to search for TeV scale observables…

Grand unification of gauge couplings and fermionic representations remains an appealing proposal to explain the seemingly coincidental structure of the Standard Model. However, to realise the Standard Model at low energies, the unified…

A model for GUT baryogenesis, coherent baryogenesis within the framework of supersymmetric SO(10), is considered. In particular, we discuss the Barr-Raby model, where at the end of hybrid infl ation charge asymmetries can be created through…

We investigate possible symmetry properties of the scalar sector of Multi-Higgs-Doublet Models, and, to some extent, the generalization of such models to gauge groups other than $SU(2)_L\times U(1)_Y$. In models where the ${\cal C}$ (charge…

It might be expected that only global symmetries are fundamental symmetries of Nature, whereas local symmetries and associated massless gauge fields could solely emerge due to spontaneous breaking of underlying spacetime symmetries…

We study the effect of integrating out the heavy fields in a supersymmetric GUT which does not contain small mass parameters in the limit of exact supersymmetry. The trilinear ($A$) and bilinear ($B$) coefficients of the supersymmetry…

The possibility to explain the baryon asymmetry in the Universe through the leptogenesis mechanism in the context of Adjoint SU(5) is investigated. In this model the neutrino masses are generated through the Type I and Type III seesaw…

Within the context of traditional logarithmic grand unification at M_GUT = 10^(16) GeV, we show that it is nevertheless possible to observe certain GUT states such as X and Y gauge bosons at lower scales, perhaps even in the TeV range. We…

A generalization of the usual gauge symmetry leads to fourth-order gauge field equations, which imply a new constant force independent of distances. The force associated with the new $U_1$ gauge symmetry is repulsive among baryons. Such a…

In this letter, we quantify the challenge of explaining the baryon asymmetry using initial conditions in a universe that undergoes inflation. Contrary to lore, we find that such an explanation is possible if net $B-L$ number is stored in a…

We explore the possibility that the observed baryon asymmetry of the universe is the result of an earlier phase transition in which an extended gauge sector breaks down into the $SU(3)_C \times SU(2)_L \times U(1)_Y$ of the Standard Model.…

The doublet-triplet splitting problem can be simply solved in product-group GUT models, using a global symmetry that distinguishes the doublets from the triplets. Apart from giving the required mass hierarchy, this ``triplet symmetry'' can…

From a theoretical point of view it is not hard to imagine gaugino masses being much lighter than scalar masses. The dominant contributions to gaugino masses are then their anomaly-mediated values. Given current lower bounds on gauginos,…