Updated Reach of the CERN LHC and Constraints from Relic Density, b->s gamma and a(mu) in the mSUGRA Model

TL;DR

The paper addresses how far the LHC can probe supersymmetry within the mSUGRA framework, considering cosmological and flavor constraints. It employs detailed collider simulations using ISAJET v7.64 and CMSJET, including new channels with isolated photons and leptonically decaying Z bosons, and scans the $m_0$--$m_{1/2}$ plane across multiple $\tan\beta$ values. Key findings show that the LHC with 100 fb$^{-1}$ can cover the entire stau co-annihilation region and most of the $A/H$ funnel, while the HB/FP region is accessible up to $m_{1/2} \sim 700$ GeV; photonic and Z channels, along with radiative neutralino decays in HB/FP, enhance sensitivity in relevant regions. The results bridge collider reach with cosmological relic density and low-energy constraints (e.g., $BF(b\rightarrow s\gamma)$, $a_\mu$), guiding search strategies and highlighting regions where discovery is most plausible.

Abstract

{We present an updated assessment of the reach of the CERN LHC pp collider for supersymmetric matter in the context of the minimal supergravity (mSUGRA) model. In addition to previously examined channels, we also include signals with an isolated photon or with a leptonically decaying Z boson. For an integrated luminosity of 100 fb^{-1}, values of m_{1/2}\sim 1400 GeV can be probed for small m_0, corresponding to a gluino mass of m_{\tg}\sim 3 TeV. For large m_0, in the hyperbolic branch/focus point region, m_{1/2}\sim 700 GeV can be probed, corresponding to m_{\tg}\sim 1800 GeV. We also map out parameter space regions preferred by the measured values of the dark matter relic density, the b\to sγdecay rate, and the muon anomalous magnetic moment a_μ, and discuss how SUSY might reveal itself in these regions. We find the CERN LHC can probe the entire stau co-annihilation region and also most of the heavy Higgs annihilation funnel allowed by WMAP data, except for some range of large m_0 and m_{1/2} if \tanβ\agt 50.