Dynamical R-parity violations from exotic instantons

TL;DR

This paper demonstrates how exotic instantons in D-brane models can dynamically break R-parity, generating specific superpotential terms with significant implications for particle physics and cosmology.

Contribution

It introduces a calculable mechanism for R-parity violation via exotic instantons in string-inspired models, avoiding proton decay and enabling selective violation.

Findings

Exotic instantons generate R-parity violating terms in MSSM-like models.

R-parity violation can be selective, affecting leptons or baryons without destabilizing the proton.

Implications include effects on neutrino physics, neutron-antineutron oscillations, EDMs, dark matter, and collider signals.

Abstract

We show how R-parity can be dynamically broken by non-perturbative quantum gravity effects. In particular, in D-brane models, Exotic instantons provide a simple and calculable mechanism for the generation of R-parity violating bilinear, trilinear and higher order superpotential terms. We show examples of MSSM-like D-brane models, in which one Exotic Instanton induces only one term among the possible R-parity violating superpotentials. Naturally, the idea can be generalized for other gauge groups. As a consequence, a dynamical violation of R-parity does not necessarily destabilize the proton, i.e. a strong fine tuning is naturally avoided, in our case. For example, a Lepton violating superpotential term can be generated without generating Baryon violating terms, and viceversa. This has strong implications in phenomenology: neutrino, neutron-antineutron, electric dipole moments, dark matter and LHC physics.