Search for light gravitinos in events with photons and missing transverse momentum at HERA

Abstract

A search for gravitinos produced in $e\pmp$ collisions is performed using the H1 detector at HERA. The data were taken at a centre-of-mass energy of 319 GeV and correspond to an integrated luminosity of 64.3 pb$^{-1}$ for $e^+p$ collisions and 13.5 pb$^{-1} for e$^-p$ collisions. If $R$-parity is not conserved, the $t$-channel exchange of a selectron can produce a neutralino, which, in models where the gravitino is the lightest supersymmetric particle, subsequently decays into a photon and a light gravitino. The resulting event signature, which involves an isolated photon, a jet and missing transverse energy, is analysed for the first time at HERA. No deviation from the Standard Model is found. Exclusion limits on the cross section and on $R$-parity-violating Yukawa couplings are derived in a Gauge Mediated Supersymmetry Breaking scenario. The results are independent of the squark sector. Neutralinos and supersymmetric partners of the left-handed electron with masses up to 112 GeV and 164 GeV, respectively, can be ruled out at the 95\% confidence level for $R$-parity-violating couplings $\lambda^{\prime}$ equal to 1, in some parts of the parameter space of the considered model

Search for new physics in events with photons, jets, and missing transverse energy in pp collisions at $ \sqrt{s}=7 $ TeV

“…Previous searches for gauge-mediated SUSY breaking were performed by the ATLAS experiment with 36 pb −1 [15], 1.1 fb −1 [16], and 4.8 fb −1 [17] of pp collision data, by CMS with 36 pb −1 [18], as well as by experiments at the Tevatron [19,20], LEP [21][22][23][24], and HERA [25].…”

Review of searches for rare processes and physics beyond the Standard Model at HERA

“…A search for R p / resonant single neutralino production via t-channel selectron exchange, e ± q →χ 0 1 q ′ is performed by H1 using their HERA I data set taken at √ s = 319 GeV, corresponding to an integrated luminosity of 64.3 pb −1 for e + p collisions and 13.5 pb −1 for e − p collisions [274]. It is assumed that theχ 0 1 is the NLSP and that the decayχ 0 1 → γG occurs with an unobservably small lifetime and dominates over R p / neutralino decays.…”

Search forZγevents with large missing transverse energy inpp¯collisions ats=Abazov1, Abbott2, Acharya3 et al. 2012Phys. Rev. DSelf Cite7010View full textAdd to dashboardCite

“…The CDF, D0, ATLAS, CMS, and H1 Collaborations have all searched for GMSB neutralinosχ 0 1 in the γG+γG (and single γG) final state, assuming that theχ 0 1 is the NLSP and decays promptly producing a photon [3][4][5]. In this Letter, we present the first search for the ZG + γG final state.…”