Flavour structure of R-violating neutralino decays at the LHC

Abstract

Abstract:We study signatures of R-parity violation in the production of supersymmetric particles at the LHC, and the subsequent decay of the lightest neutralino being the end product of a supersymmetric cascade decay. In doing so, we pay particular attention to the possible flavour structure of the operators, and how one may discriminate between different possibilities. A neutralino LSP would couple to all quarks and leptons and a comparative study of its decays provides an optimal channel for the simultaneous study of all 45 R-violating operators. By studying the expected signals from all these operators, we demonstrate the ability to understand whether more than one coupling dominates, and to map the experimental signatures to operator hierarchies that can then be compared against theoretical models of flavour. Detailed comparisons with backgrounds, including those from MSSM cascade decays are made, using the PYTHIA event simulator.

R-parity violating chargino decays at the LHC

“…As in the case of neutralino decays discussed in [61], there are also interesting features in the di-lepton invariant mass distributions. The advantage with di-lepton distributions is that we can employ same-sign subtraction to practically remove the combinatorial background and hence reveal features otherwise invisible.…”

“…6 We use the single dominant coupling approximation. 7 As the search for RPV decays of charginos is similar to the corresponding decays of neutralinos, we refer to [61] for details on the analysis. Here we will mostly focus on the differences that appear when charginos are involved.…”

3.5 keV x-ray line from decaying gravitino dark matter

“…For LHC studies of all possible decay topologies, see Ref. [40]. If the gravitino decay is due to a tau loop, the LHC phenomenology of decaying neutralinos is promising; the final state will consist of multiple leptons and missing transverse energy, and although many of the leptons will be taus this would be clearly detectable if the neutralino production (either direct or through decay) is large enough.…”

Supersymmetry with trilinear R-parity violation at the LHC

“…(1.1) do allow for a large variety of exotic phenomena, like single sparticle production [3], direct decay of squarks and sleptons as well as charged particles as end stages of cascade decays (possible since the end stage is no longer expected to be dark matter), it is likely that pair-production still dominates and that the produced particles cascade down to the neutralino which is the lightest sparticle apart from the gravitino [4].…”

“…The study discussed here [4] is based on Monte Carlo studies of neutralino decays through all 45 operators using the Monte Carlo generator PYTHIA 8 [5].…”