Broken R-parity in the sky and at the LHC

Abstract

Supersymmetric extensions of the Standard Model with small R-parity and lepton number violating couplings are naturally consistent with primordial nucleosynthesis, thermal leptogenesis and gravitino dark matter. We consider supergravity models with universal boundary conditions at the grand unification scale, and scalar τ -lepton or binolike neutralino as next-to-lightest superparticle (NLSP). Recent Fermi-LAT data on the isotropic diffuse gamma-ray flux yield a lower bound on the gravitino lifetime. Comparing two-body gravitino and neutralino decays we find a lower bound on a neutralino NLSP decay length, cτ χ 0 1 > ∼ 30 cm. Together with gravitino and neutralino masses one obtains a microscopic determination of the Planck mass. For a τ -NLSP there exists no modelindependent lower bound on the decay length. Here the strongest bound comes from the requirement that the cosmological baryon asymmetry is not washed out, which yields cτ e τ 1 > ∼ 4 mm. However, without fine-tuning of parameters, one finds much larger decay lengths. For typical masses, m 3/2 ∼ 100 GeV and m NLSP ∼ 150 GeV, the discovery of a photon line with an intensity close to the Fermi-LAT limit would imply a decay length cτ NLSP of several hundred meters, which can be measured at the LHC.

Dark matter production in the early Universe: Beyond the thermal WIMP paradigm

“…For the broken R-parity case, the neutralino NLSP [436,437] and the stop NLSP [438] cases were studied in the search for a gravitino DM signal at LHC.…”

Gravitino dark matter and neutrino masses with bilinearR-parity violation

“…Indeed monochromatic photons of ∼ GeV energies are generally not expected to be produced by conventional astrophysical processes. For this reason, the detection of gamma-ray lines would be a striking signature of dark matter processes, pointing either to annihilations [44][45][46][47][48][49][50] or to decays of dark matter particles [51][52][53][54][55][56]. Search of gamma-ray lines have been recently performed using the data of the Fermi-LAT satellite [14,15].…”

The International Linear Collider Technical Design Report - Volume 2: Physics

“…Bilinear R-parity violation (bRPV) has phenomenological motivations in neutrino mixing [126] as well as in leptogenesis [127,128]. In this case, the characteristic decayχ 0 1 → W ± l ∓ will lead to background-free signatures at the ILC, possibly with a detectable lifetime of theχ 0 1 depending on the strength of the RPV couplings.…”