Gluino mass limits with sbottom NLSP in coannihilation scenarios

In view of the recent interest in the pMSSM with light third generation squarks, we consider a hitherto neglected scenario where the lighter bottom squark ((b) over tilde (1)) is the next lightest supersymmetric particle (NLSP) which co-annihilates with the lightest supersymmetric particle (LSP), the dark matter (DM) candidate. Since the co-annihilation cross section receives contributions from both electroweak and strong vertices, it is relatively large. As a result relatively large NLSP-LSP mass difference (25-35GeV) is consistent with the PLANCK data. This facilitates the LHC signatures of this scenario. We consider several variants of the sbottom NLSP scenario with and without light stops and delineate the parameter space allowed by the PLANCK data. We point out several novel signal (e.g., (t) over tilde (1) -> (b) over tilde W-1) which are not viable in the stop NLSP scenario of DM production. Finally, we consider gluino ((g) over tilde) decays in this scenario and using the current ATLAS data in the jets (with or without b-tagging) + is not an element of(T) channel, obtain new limits in the m((b) over tilde1) - m((g) over tilde) mass plane. We find that for m((b) over tilde1) upto 500GeV, m((g) over tilde) >= 1.1-1.2 TeV in this scenario.