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Rabindra N. Mohapatra

Publications and source records attributed to Rabindra N. Mohapatra.

115 records · Page 7Linked to original sources
arXiv1996

A Non-supersymmetric Interpretation of the CDF e+e-γγ+ missing E_T Event

The $\eegg$ event reported recently by the CDF Collaboration has been interpreted as a signal of supersymmetry in several recent papers. In this article, we report on an alternative non-supersymmetric interpretation of the event using an extension of the standard model which contains new physics at the electroweak scale that does not effect the existing precision electroweak data. We extend the standard model by including an extra sequential generation of fermions, heavy right-handed neutrinos for all generations and an extra singly charged SU(2)-singlet Higgs boson. We discuss possible ways to discriminate this from the standard supersymemtric interpretations.

hep-ph↗
arXiv1996

A Supersymmetric Solution to CP Problems

We analyze the minimal supersymmetric left-right model with non-re\-nor\-malizable interactions induced by higher scale physics and study its {\it CP} violating properties. We show that it: (i) solves the strong {\it CP} problem; (ii) predicts the neutron electric dipole moment well within experimental limits (thus solving the usual SUSY {\it CP} problem). In addition, it automatically conserves {\it R}-parity. The key points are that the parity symmetry forces the Yukawa couplings to be hermitean, while supersymmetry ensures that the scalar potential has a minimum with real higgs doublet vacuum expectation values. Gluino and B-L gaugino masses are automatically real. The observed {\it CP} violation in the kaon system comes, as in the Standard Model, from the Kobayashi-Maskawa-type phases. These solutions are valid for any value of the right-handed breaking scale $M_R$, as long as the effective theory below $M_R$ has only two Higgs doublets that couple fully to fermions. ({\it i.e.} the theory below $M_R$ is MSSM-like.) The potentially dangerous $SU(2)_L$ gaugino one-loop contributions to $\barΘ$ below $M_R$ can be avoided if the left-right symmetry originates from a unified theory in which the $SU(2)_{L,R}$ gaugino masses are real. As an example, we show how the left-right symmetry can be embedded in an SO(10) theory.

hep-ph↗
arXiv1995

A low $α_s$ and its consequences for unified model building

We review various ways of obtaining consistency between the idea of supersymmetric grand unification and an apparent low value of $α_s \sim 0.112$ indicated by several low energy experiments. We argue that to reconcile the low value of $α_s$ with the predictions of supersymmetric GUTs, we need to go beyond the standard minimal supersymmetric GUT scenario and invoke new physics either at $10^{11}-10^{12}$ GeV, or at the GUT scale.

hep-ph↗
arXiv1995

Neutrinoless Double Beta Decay and Physics Beyond the Standard Model

The various mechanisms for neutrinoless double beta decay in gauge theories are reviewed and the present experimental data is used to set limits on physics scenarios beyond the standard model. The positive indications for nonzero neutrino masses in various experiments such as those involving solar, atmospheric and accelerator neutrinos are discussed and it is pointed out how some neutrino mass textures consistent with all data can be tested by the ongoing double beta decay experiments. Finally, the outlook for observable neutrinoless double beta decay signal in grand unified theories is discussed.

hep-ph↗
arXiv1994

Accomodating Solar and Atmospheric Neutrino Deficits, Hot Dark Matter, and a Double Beta Decay Signal

Neutrino mass explanations of the solar and atmospheric neutrino deficits and a hot dark matter component require one of three patterns of those masses, as already pointed out by us. Recently there have been indications of a non-vanishing amplitude for neutrinoless double beta decay. If this additional hint of neutrino mass is true, it would make even less likely the one unfavored pattern (a sterile neutrino giving warm, rather than hot dark matter), would alter another by making the $ν_e$ a contributor to the hot dark matter, and would make the third ($ν_e$, $ν_μ$, and $ν_τ$ approximately degenerate) much more likely than previously. For this third case we construct a gauge model consistent with other weak interaction data. This model utilizes a more general version of the see-saw mechanism, which is very likely to be the source of neutrino mass, if this degenerate pattern is correct. A new supernova constraint is utilized, and implications and tests of the different mass matrices are noted.

hep-ph↗
arXiv1993

Partial Derivation of Transformation Properties of Quarks and Leptons

Under the assumptions that $SU(3)_c\times U(1)_Y \times G^{\prime}$ with $G^{\prime}$ simple is a local symmetry group at high energies, that color is parity-conserving, and the Y-charges are irreducible, we show that anomaly constraints imply the minimal set of fermions is fifteen in number. Given this minimal set, we further show that $G^{\prime}$ must be $SU(2)$ and the unbroken gauge symmetry is {\it either} color {\it or} the product of color with electric charge.

hep-ph↗