Rohini M. Godbole

SUSY Les Houches accord: interfacing SUSY spectrum calculators, decay packages, and event generators

An accord specifying a unique set of conventions for supersymmetric extensions of the Standard Model together with generic file structures for 1) supersymmetric model specifications and input parameters, 2) electroweak scale supersymmetric mass and coupling spectra, and 3) decay tables is presented, to provide a universal interface between spectrum calculation programs, decay packages, and high energy physics event generators.

Theory and Phenomenology of Sparticles: An Account of Four-Dimensional N=1 Supersymmetry in High Energy Physics

Introduction and Overview: Supersymmetry: Why and How Supersymmetry Formalism: Preliminaries Algebraic Aspects Free Superfields in Superspace Interacting Superfields Superspace Perturbation Theory and Supergraphs General Aspects of Supersymmetry Breaking Supersymmetry Phenomenology: Basic Structure of the MSSM Soft Supersymmetry Breaking in the MSSM Higgs Bosons in the MSSM Evolution from Very High Energies Gravity Mediated Supersymmetry Breaking Gauge Mediated Supersymmetry Breaking Beyond the MSSM Supersymmetry at Colliders Supersymmetric Cosmology Conclusion: Wish List, Roadmap and Fine Tuning.

Benchmark scenarios for the NMSSM

We discuss constrained and semi--constrained versions of the next--to--minimal supersymmetric extension of the Standard Model (NMSSM) in which a singlet Higgs superfield is added to the two doublet superfields that are present in the minimal extension (MSSM). This leads to a richer Higgs and neutralino spectrum and allows for many interesting phenomena that are not present in the MSSM. In particular, light Higgs particles are still allowed by current constraints and could appear as decay products of the heavier Higgs states, rendering their search rather difficult at the LHC. We propose benchmark scenarios which address the new phenomenological features, consistent with present constraints from colliders and with the dark matter relic density, and with (semi--)universal soft terms at the GUT scale. We present the corresponding spectra for the Higgs particles, their couplings to gauge bosons and fermions and their most important decay branching ratios. A brief survey of the search strategies for these states at the LHC is given.

Aspects of CP violation in the HZZ coupling at the LHC

We examine the CP-conserving (CPC) and CP-violating (CPV) effects of a general HZZ coupling through a study of the process H → ZZ (�) → l + l l ′ + l ′ at the LHC. We construct asymmetries that directly probe these couplings. Further, we present complete analytical formulae for the angular distributions of the decay leptons and for some of the asymmetries. Using these we have been able to identify new observables which can provide enhanced sensitivity to the CPV HZZ coupling. We also explore probing CP violation through shapes of distributions in different kinematic variables, which can be used for Higgs bosons with mH < 2 mZ.

Charge and Color Breaking Constraints in MSSM after the Higgs Discovery at LHC

A bstractWe revisit the constraints on the parameter space of the Minimal Supersymmetric Standard Model (MSSM), from charge and color breaking minima in the light of information on the Higgs from the LHC so far. We study the behavior of the scalar potential keeping two light sfermion fields along with the Higgs in the pMSSM framework and analyze the stability of the vacuum. We find that for lightest stops ≲ 1 TeV and small μ ≲ 500 GeV, the absolute stability of the potential can be attained only for

Survey of vector-like fermion extensions of the Standard Model and their phenomenological implications

\left| {{X_t}} \right|\lesssim \sqrt{{6{m_{{\widetilde{t}1}}}{m_{{\widetilde{t}2}}}}}

Lepton distribution as a probe of new physics in production and decay of the t quark and its polarization

. The bounds become stronger for larger values of the μ parameter. Note that this is approximately the value of Xt which maximizes the Higgs mass. Our bounds on the low scale MSSM parameters are more stringent than those reported earlier in literature. We reanalyze the stau sector as well, keeping both staus. We study the connections between the observed Higgs rates and vacuum (meta)stability. We show how a precision study of the ratio of signal strengths, (μγγ/μZZ) can shed further light.

The Photon Collider at Tesla

A bstractWith the renewed interest in vector-like fermion extensions of the Standard Model, we present here a study of multiple vector-like theories and their phenomenological implications. Our focus is mostly on minimal flavor conserving theories that couple the vector-like fermions to the SM gauge fields and mix only weakly with SM fermions so as to avoid flavor problems. We present calculations for precision electroweak and vector-like state decays, which are needed to investigate compatibility with currently known data. We investigate the impact of vector-like fermions on Higgs boson production and decay, including loop contributions, in a wide variety of vector-like extensions and their parameter spaces.

Determining the CP properties of the Higgs boson

We investigate the possibility of studying new physics in various processes of t-quark production using kinematical distributions of the secondary lepton coming from the decay of t quarks. We show that the angular distribution of the secondary lepton is insensitive to the anomalous tbW vertex and hence is a pure probe of new physics in a generic process of t-quark production. The energy distribution of the lepton is distinctly affected by anomalous tbW couplings and can be used to analyze them independent of the production process of t quarks. The effects of t polarization on the distributions of the decay lepton are demonstrated for top-pair production process at a

Future collider signatures of the possible 750 GeV state

\gamma \gamma