Heavy squarks at the LHC

Abstract

The LHC, with its seven-fold increase in energy over the Tevatron, is capable of probing regions of SUSY parameter space exhibiting qualitatively new collider phenomenology. Here we investigate one such region in which first generation squarks are very heavy compared to the other superpartners. We find that the production of these squarks, which is dominantly associative, only becomes rate-limited at ${m_{\tilde{q}}} \gtrsim 4(5)\;{\text{TeV}}$ for $\mathcal{L}\sim 10\left( {100} \right)\;{\text{f}}{{\text{b}}^{ - 1}}$. However, discovery of this scenario is complicated because heavy squarks decay primarily into a jet and boosted gluino, yielding a dijet-like topology with missing energy (MET) pointing along the direction of the second hardest jet. The result is that many signal events are removed by standard jet/MET anti-alignment cuts designed to guard against jet mismeasurement errors. We suggest replacing these anti-alignment cuts with a measurement of jet substructure that can significantly extend the reach of this channel while still removing much of the background. We study a selection of benchmark points in detail, demonstrating that ${m_{\tilde{q}}} = 4(5) \ {\rm TeV}$ first generation squarks can be discovered at the LHC with $\mathcal{L}\sim 10\left( {100} \right)\;{\text{f}}{{\text{b}}^{ - 1}}$.