Selecting the Optimal LHC Signatures for Distinguishing Models

An algorithm is developed which the goal of producing the most statistically significant signature list for distinguishing between two candidate models given a set of LHC observations.Comment: SUSY09 parallel session proceedin

Higgs Boson Mass Predictions in SUGRA Unification, Recent LHC-7 Results, and Dark Matter

LHC-7 has narrowed down the mass range of the light Higgs boson. This result is consistent with the supergravity unification framework, and the current Higgs boson mass window implies a rather significant loop correction to the tree value pointing to a relatively heavy scalar sparticle spectrum with universal boundary conditions. It is shown that the largest value of the Higgs boson mass is obtained on the Hyperbolic Branch of radiative breaking. The implications of light Higgs boson in the broader mass range of 115 GeV to 131 GeV and a narrower range of 123 GeV to 127 GeV are explored in the context of the discovery of supersymmetry at LHC-7 and for the observation of dark matter in direct detection experiments.Comment: 8 pages, 5 figure

Flavor Changing Heavy Higgs Interactions at the LHC

A general two Higgs doublet model (2HDM) is adopted to study the signature of flavor changing neutral Higgs (FCNH) decay $\phi^0 \to t\bar{c}+\bar{t}c$, where $\phi^0$ could be a CP-even scalar ($H^0$) or a CP-odd pseudoscalar ($A^0$). Measurement of the light 125 GeV neutral Higgs boson ($h^0$) couplings at the Large Hadron Collider (LHC) favor the decoupling limit or the alignment limit of a 2HDM, in which gauge boson and diagonal fermion couplings of $h^0$ approach Standard Model values. In such limit, FCNH couplings of $h^0$ are naturally suppressed by a small mixing parameter $\cos(\beta-\alpha)$, while the off-diagonal couplings of heavier neutral scalars $\phi^0$ are sustained by $\sin(\beta-\alpha) \sim 1$. We study physics background from dominant processes with realistic acceptance cuts and tagging efficiencies. Promising results are found for the LHC running at 13 or 14 TeV collision energies.Comment: 14 pages, 5 figures, to be published in Phys. Lett.

Distinguishing LSP archetypes via gluino pair production at LHC13

The search for supersymmetry at run 1 of the LHC has resulted in gluino mass limits [?] [?] 1.3 TeV for the case [?] [?] [?] and in models with gaugino mass unification. The increased energy and, ultimately, luminosity of LHC13 will explore the range [?] ~ 1.3-2 TeV. We examine how the discovery of SUSY via gluino pair production would unfold via a comparative analysis of three LSP archetype scenarios: (1) mSUGRA/CMSSM model with a binolike LSP, (2) charged SUSY breaking (CSB) with a winolike LSP, and (3) SUSY with radiatively driven naturalness (RNS) and a Higgsino-like LSP. In all three cases we expect heavy-to-very-heavy squarks as suggested by a decoupling solution to the SUSY flavor and CP problems and by the gravitino problem. For all cases, initial SUSY discovery would likely occur in the multi-b-jet + [?] channel. The CSB scenario would be revealed by the presence of highly ionizing, terminating tracks from quasistable charginos. As further data accrue, the RNS scenario with 100–200 GeV Higgsino-like LSPs would be revealed by the buildup of a mass edge/bump in the opposite sign/same flavor dilepton invariant mass which is bounded by the neutralino mass difference. The mSUGRA/CMSSM archetype would contain neither of these features but would be revealed by a buildup of the usual multilepton cascade decay signatures

Studying Gaugino Mass Unification at the LHC

We begin a systematic study of how gaugino mass unification can be probed at the CERN Large Hadron Collider (LHC) in a quasi-model independent manner. As a first step in that direction we focus our attention on the theoretically well-motivated mirage pattern of gaugino masses, a one-parameter family of models of which universal (high scale) gaugino masses are a limiting case. We improve on previous methods to define an analytic expression for the metric on signature space and use it to study one-parameter deviations from universality in the gaugino sector, randomizing over other soft supersymmetry-breaking parameters. We put forward three ensembles of observables targeted at the physics of the gaugino sector, allowing for a determination of this non-universality parameter without reconstructing individual mass eigenvalues or the soft supersymmetry-breaking gaugino masses themselves. In this controlled environment we find that approximately 80% of the supersymmetric parameter space would give rise to a model for which our method will detect non-universality in the gaugino mass sector at the 10% level with an integrated luminosity of order 10 inverse femptobarns. We discuss strategies for improving the method and for adding more realism in dealing with the actual experimental circumstances of the LHC