LHC constraints on M 1/2 and m 0 in the semi-constrained NMSSM

Debottam Das,Ana M Teixeira,Ulrich Ellwanger

doi:10.1007/jhep04(2013)117

Abstract

Abstract Constraints from searches for squarks and gluinos at the LHC at $ \sqrt{s}=8 $ TeV are applied to the parameter space of the NMSSM with universal squark/slepton and gaugino masses at the GUT scale, but allowing for non-universal soft Higgs mass parameters (the sNMSSM). We confine ourselves to regions of the parameter space compatible with a 125 GeV Higgs boson with diphoton signal rates at least as large as the Standard Model ones, and a dark matter candidate compatible with WMAP and XENON100 constraints. Following the simulation of numerous points in the m 0 − M 1/2 plane, we compare the constraints on the sNMSSM from 3-5 jets + missing E T channels as well as from multijet + missing E T channels with the corresponding cMSSM constraints. Due to the longer squark decay cascades, lower bounds on M 1/2 are alleviated by up to 50 GeV. For heavy squarks at large m 0, the dominant constraints originate from multijet + missing E T channels due to gluino decays via stop pairs.

Highlights

The MSSM is not the only possible supersymmetric extension of the SM
After simulation of a variety of points in the m0 − M1/2 plane in the semi-constrained Next-toMinimal Supersymmetric Standard Model (NMSSM) and application of the cuts, we require that accepted points give a number of signal events below the 95% confidence level (CL) upper limit in each search channel, ± the uncertainty as determined above
We have verified that a statistical combination of the limits in the various channels is not required since, whenever the number of signal events for a given point is close to the 95% CL upper limit for one of the channels listed in table 1, the number of signal events lies far below the 95% CL upper limit in all other channels

Summary

Introduction

The MSSM is not the only possible supersymmetric extension of the SM. The simplest supersymmetric extension of the Standard Model with a scale invariant superpotential, i.e. where the soft SUSY breaking terms are the only dimensionful parameters, is the Next-toMinimal Supersymmetric Standard Model (NMSSM) [33]. In table 1 we summarise the cuts corresponding to the search channels which lead to the most stringent constraints in the m0 − M1/2 plane in the semi-constrained NMSSM (depending on m0 and M1/2), and the 95% confidence level (CL) upper limits (UL) on the number NSE of signal events beyond the expected background in the corresponding channels, for an integrated luminosity of 5.8 fb−1.

Results

Conclusion