Tuesday, March 20, 2012

1203.4106 (Arghya Choudhury et al.)

Many faces of low mass neutralino dark matter in the unconstrained MSSM
and new signals at the LHC
   [PDF]

Arghya Choudhury, Amitava Datta
If all strongly interacting sparticles (the squarks and the gluinos) are heavier than the mass lower limits in the minimal supergravity (mSUGRA) model, obtained by the current LHC experiments, then the existing data allow a variety of electroweak (EW) sectors in the unconstrained MSSM with light sparticles consistent with the WMAP data. Some of them may lie just above the existing lower bounds from LEP and lead to many novel dark matter producing mechanisms not common in mSUGRA. This is illustrated by revisiting the present squark-gluino mass limits obtained in mSUGRA by the ATLAS Collaboration, with an unconstrained EW sector. Using their selection criteria and the corresponding cross section limits, we find at the generator level using Pythia, that the changes in the limits, if any, are by at most 10-12 % in most scenarios. In some cases, however, the relaxation of the gluino mass limits are larger ($\approx 20 %$). If a subset of the strongly interacting sparticles are within the reach of the LHC, then signals sensitive to the EW sector may be obtained. This is illustrated by simulating the blj$\etslash$, $l= e and \mu$, and $b\tau j \etslash$ signals in i) the light stop scenario and ii) the light stop-gluino scenario with various light EW sectors allowed by the WMAP data. Some of more general models may be realized with non-universal scalar and gaugino masses.
View original: http://arxiv.org/abs/1203.4106

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