Search

If the new boson lying in the narrow mass range between 122 and 127 GeV is confirmed to be a Higgs boson, then stability of the electroweak vacuum in a minimal model with a universal extra dimension (mUED) will require a much lower cutoff for the theory than has been envisaged earlier. We show that this low cutoff leads to important changes in much of the minimal model with a universal extra dimension phenomenology studied till now. In particular, prospects for LHC searches for n=1 states are rather limited, while resonant n=2 states may go completely undetected. Prospects for detection at high energy e+e- colliders are less affected. [ABSTRACT FROM AUTHOR]

We study the allowed parameter space of the constrained minimal supersymmetric Standard Model (cMSSM) in the light of direct searches, constraints from S-physics (including the recent measurement of the branching ratio for Bs → μ+μ- and the dark matter relic density. For low or moderate values of tan/?, the strongest constraints are those imposed by direct searches, and therefore, large areas of the parameter space are still allowed. In the large tanβ limit, however, the 5-physics constraints are more restrictive, effectively forcing the squark and gluino masses to lie close to or above a TeV. A light Higgs boson could dramatically change the allowed parameter space, but we need to know its mass precisely for this to be effective. We emphasize that it is still too early to write off the cMSSM, even in the large tanβ limit. Finally we explore strategies to extend the LHC search for cMSSM signals beyond the present reach of the ATLAS and CMS Collaborations. [ABSTRACT FROM AUTHOR]

Observation of some low-energy processes in the flavor physics regime may require the existence of supersymmetry with two relatively large R-parity-violating couplings of the λ'-type, together with reasonably light superparticles. At the LHC, such interactions would be expected to give rise to clear signals with convenient leptonic triggers, including some multileptons of the same sign. We undertake a detailed investigation of these signals taking care to correlate with low-energy requirements and taking proper account of the standard model backgrounds as well as the R-parity-conserving sector of the supersymmetric model. We find clear indications that R-parity violation as envisaged in this scenario can be detected at the LHC--even, perhaps, in the early runs. [ABSTRACT FROM AUTHOR]

We make a careful analysis of W±γ production at the LHC, identifying the W± through leptonic decays, with a view to exploring the sensitivity of the machine to anomalous CP-conserving WWγ interactions. All the available kinematic variables are used, but we find that the most useful one is the opening angle in the transverse plane between the decay products of the W±. It is shown that even a simple-minded analysis using this variable can lead to a much greater sensitivity at the LHC than the current constraints on the relevant parameters. [ABSTRACT FROM AUTHOR]

Nonobservation of superpartners of the Standard Model particles at the early runs of the LHC provide strong motivation for introducing an R-symmetric minimal supersymmetric Standard Model. This model also comes with a pair of extra scalars which couple only to superpartners at the tree level. We demonstrate that in the case when the U(1)R symmetry is mildly broken one of these scalars develops all the properties necessary to explain the 750 GeV diphoton resonance recently observed at the LHC, as well as the nonobservation of associated signals in other channels. Some confirmatory tests in the upcoming LHC runs are proposed. [ABSTRACT FROM AUTHOR]

The CP-violating version of the Minimal Supersymmetric Standard Model is an example of a model where experimental data do not preclude the presence of light Higgs bosons in the range around 10-110 GeV. Such light Higgs bosons, decaying almost wholly to b... pairs, may be copiously produced at the LHC but would remain inaccessible to conventional Higgs searches because of intractable QCD backgrounds. We demonstrate that a significant number of these light Higgs bosons would be boosted strongly enough for the pair of daughter b-jet pairs to appear as a single 'fat' jet with substructure. Tagging such jets could extend the discovery potential at the LHC into the hitherto-inaccessible region for light Higgs bosons. [ABSTRACT FROM AUTHOR]

The recent Belle and BABAR measurements of the branching ratio of B+→τ+ντ indicate a significant deviation from the standard model prediction. We demonstrate that this measurement has a serious impact on models with minimal flavor violation involving a charged Higgs boson, ruling out a large portion of the currently allowed parameter space. In the constrained minimal supersymmetric standard model, this creates a tension between the measurements of B+→τ+ντ and the anomalous magnetic moment of the muon, unless tanβ is small, μ>0, and A0 takes a large negative value. In fact, a very small region of the parameter space of this model, with small values of m0 and m1/2, survives all the constraints at 95% C.L. It is remarkable that this specific region is still consistent with the lightest supersymmetric particle as the dark matter. Moreover, it predicts observable supersymmetric signals in the early runs of the LHC, even perhaps at 7 TeV. We also show that a consistent explanation for the deviation of the B+→τ+ντ branching ratio from the standard model can be achieved in a nonuniversal Higgs-mass model, which could also predict early signals of supersymmetry at the LHC. [ABSTRACT FROM AUTHOR]