Slepton searches in the trilinear RPV SUSY scenarios at the HL-LHC and HE-LHC

In this work we have studied a multi-lepton final state arising from sneutrino and left-handed slepton production at the high luminosity and high energy LHC in the context of R-parity violating supersymmetry when only the lepton number violating $\lambda_{121}$ and/or $\lambda_{122}$ couplings are non-zero. We have taken into account both pair production and associated production of the three generations of left-handed sleptons and sneutrinos, which are assumed to be mass degenerate. The lightest supersymmetric particle is assumed to be bino and it decays via the R-parity violating couplings into light leptons and neutrinos. Our final state has a large lepton multiplicity, $N_{l}\geq 4~(l=e,~\mu)$. We perform both cut-based and machine learning based analyses for comparison. We present our results in the bino-slepton/sneutrino mass plane in terms of exclusion and discovery reach at the LHC. Following our analysis, the slepton mass can be discovered upto $\sim$ 1.54 TeV and excluded upto $\sim$ 1.87 TeV at the high luminosity LHC while these ranges go upto $\sim$ 2.46 TeV and $\sim$ 3.06 TeV respectively at the high energy LHC.Comment: 15 pages, 7 figures, 5 Table

Status of R-parity violating SUSY

In this article, we discuss various phenomenological implications of possible R-parity violating (RPV) supersymmetric scenarios. In this context, the implications of both bilinear and trilinear RPV terms are reviewed from the viewpoint of neutrino physics, anomalous muon magnetic moment, different flavor observables, and collider physics. Apart from discussing the distinctive phenomenological implications of the RPV scenarios, we also survey the updated results from different studies to highlight the present status of the RPV couplings.Comment: 43 pages, 20 figures, invited short review on RPV SUSY published in EPJS

Dark matter and collider signals in supersymmetric U(1)' models with nonuniversal Z ' couplings

We analyze supersymmetric models augmented by an extra U(1) gauge group. To avoid anomalies in these models without introducing exotics, we allow for family-dependent U(1)' charges, and choose a simple form for these, dependent on one U(1)' charge parameter only. With this choice, Z' decays into ditaus but not dileptons, weakening considerably the constraints on its mass. In the supersymmetric sector, the effect is to lower the singlino mass, allowing it to be the dark matter candidate. We investigate the dark matter constraints and collider implications of such models, with mostly singlinos, mostly Higgsinos, or a mixture of the two as the lightest supersymmetric particles. In these scenarios, Z' decays significantly into chargino or neutralino pairs, and thus indirectly into final state leptons. We devise benchmarks which, with adequate cuts, can yield signals visible at the high-luminosity LHC.Peer reviewe

Lepton flavor violating Higgs boson decay at e(+)e(-) colliders

We estimate the smallest branching ratio for the Higgs decay channel h -> mu tau, which can be probed at an e(+)e(-) collider, and compare it with the projected reach at the high-luminosity run of the LHC. Using a model-independent approach, Higgs production is considered in two separate cases. In the first case, hWW and hZZ couplings are allowed to be scaled by a factor allowed by the latest experimental limits on hWW and hZZ couplings. In the second case, we have introduced higher-dimensional effective operators for these interaction vertices. Keeping BR(h -> mu tau) as a purely phenomenological quantity, we find that this branching ratio can be probed down to approximate to 2.69 x 10(-3) and approximate to 5.83 x 10(-4), respectively, at the 250 GeV and 1000 GeV runs of an e(+)e(-) collider.Peer reviewe

Search for a compressed supersymmetric spectrum with a light Gravitino

Presence of the light gravitino as dark matter candidate in a supersymmetric (SUSY) model opens up interesting collider signatures consisting of one or more hard photons together with multiple jets and missing transverse energy from the cascade decay. We investigate such signals at the 13 TeV LHC in presence of compressed SUSY spectra, consistent with the Higgs mass as well as collider and dark matter constraints. We analyse and compare the discovery potential in different benchmark scenarios consisting of both compressed and uncompressed SUSY spectra, considering different levels of compression and intermediate decay modes. Our conclusion is that compressed spectra upto 2.5 TeV are likely to be probed even before the high luminosity run of LHC. Kinematic variables are also suggested, which offer distinction between compressed and uncompressed spectra yielding similar event rates for photons + multi-jets + $E\!\!\!\!/_T$.Comment: 32 pages, 7 figures, 4 tables. Published in JHEP, minor modifications in text and few references adde

Probing the NMSSM via Higgs boson signatures from stop cascade decays at the LHC

Higgs signatures from the cascade decays of light stops are an interesting possibility in the next to minimal supersymmetric standard model (NMSSM). We investigate the potential reach of the light stop mass at the 13 TeV run of the LHC by means of five NMSSM benchmark points where this signature is dominant. These benchmark points are compatible with current Higgs coupling measurements, LHC constraints, dark matter relic density and direct detection constraints. We consider single and di-lepton search strategies, as well as the jet-substructure technique to reconstruct the Higgs bosons. We find that one can probe stop masses up to 1.2 TeV with 300 $\rm fb^{-1}$ luminosity via the di-lepton channel, while with the jet-substructure method, stop masses up to 1 TeV can be probed with 300 $\rm fb^{-1}$ luminosity. We also investigate the possibility of the appearance of multiple Higgs peaks over the background in the fat-jet mass distribution, and conclude that such a possibility is viable only at the high luminosity run of 13 TeV LHC.Comment: 20 pages, 5 figures; Two figures updated, typos corrected. Matched with the published versio