Reconstructing the Chargino System at e+e−e^+e^- Linear Colliders

In most supersymmetric theories charginos, $\tilde{\chi}^\pm_{1,2}$, belong to the class of the lightest supersymmetric particles. The chargino system can be reconstructed completely in $e^+e^-$ collider experiments: $e^+e^-\to\tilde{\chi}_i^+ \tilde{\chi}_j^- [i,j=1,2]$. By measuring the total cross sections and the asymmetries with polarized beams, the chargino masses and the gaugino-higgsino mixing angles of these states can be determined accurately. If only the lightest charginos $\tilde{\chi}_1^\pm$ are kinematically accessible in a first phase of the machine, transverse beam polarization or the measurement of chargino polarization in the final state is needed to determine the mixing angles. From these observables the fundamental SUSY parameters can be derived: the SU(2) gaugino mass $M_2$, the modulus and the cosine of the CP-violating phase of the higgsino mass parameter $\mu$, and $\tan\beta = v_2/v_1$, the ratio of the vacuum expectation values of the two neutral Higgs doublet fields. The remaining two-fold ambiguity of the phase can be resolved by measuring the normal polarization of the charginos. Sum rules of the cross sections can be exploited to investigate the closure of the two-chargino system.Comment: 25 pages, 6 figure

Like Sign Dilepton Signature for R-Parity Violating SUSY Search at the Tevatron Collider

The like sign dileptons provide the most promising signature for superparticle search in a large category of $R$-parity violating SUSY models. We estimate the like sign dilepton signals at the Tevatron collider, predicted by these models, over a wide region of the MSSM parameter space. One expects an unambiguous signal upto a gluino mass of $200 - 300$ GeV ($\geq 500$ GeV) with the present (proposed) accumulated luminosity of $\sim 0.1~(1)~{\rm fb}^{-1}$.Comment: 12 page LaTeX file; 5 figures available upon request from the autho

Using Tau Polarization for Charged Higgs Boson and SUSY Searches at LHC

The $\tau$ polarization can be easily measured at LHC in the 1-prong hadronic $\tau$ decay channel by measuring what fraction of the $\tau$-jet momentum is carried by the charged track. A simple cut requiring this fraction to be >0.8 retains most of the polarization of $\tau=$+1 $\tau$-jet signal while suppressing the polarization of $\tau=$-1 $\tau$-jet background and practically eliminating the fake $\tau$ background. This can be utilized to extract the charged Higgs signal. It can be also utilized to extract the SUSY signal in the stau NLSP region, and in particular the stau co-annihilaton region.Comment: 8 pages, 9 figures; Fig.8 and Fig.9 are replaced, published in "Physics at the Large Hadron Collider", A Platinum Jubilee Special Issue of the Indian National Science Academy, Springer (2009) p 20

Probing Supersymmetry using Event Shape variables at 8 TeV LHC

We have revisited the prospects of Supersymmetry(SUSY) searches at the LHC with 7 TeV energy along with the prediction of the discovery potential at 8 TeV energy assuming an integrated luminosity 5 $fb ^{-1}$ and 20 \invfb with mSUGRA/CMSSM as a model framework. We discuss further optimization of our selection strategy which is based on the hadronic event shape variables. Evaluating the standard model backgrounds and signal rates in detail we predict the discovery reach in the $m_0 - m_{1/2}$ plane for 7 TeV with 5\invfb luminosity. We also present the discovery reach for 8 TeV energy with an integrated luminosity 5\invfb and 20 \invfb. A comparison is made between our results and the exclusion plots obtained by CMS and ATLAS. Finally, discovery reach in the gluino and squark mass plane at the 7 TeV and 8 TeV energy is also presented.Comment: 17 pages, 6 eps figures, 20/fb results and figures added, some references added, version accepted and to be published in Physical Review

Looking for the Charged Higgs Boson

This review article starts with a brief introduction to the charged Higgs boson (H^\pm) in the Minimal Supersymmetric Standard Model (MSSM). It then discusses the prospects of a relatively light H^\pm boson search via top quark decay at Tevatron/LHC, and finally a heavy H^\pm boson search at LHC. The viable channels for H^\pm search are identified in both the cases, with particular emphasis on the H^\pm --> tau + nu decay channel. The effects of NLO QCD correction in the SM as well as the MSSM are discussed briefly.Comment: 17 pages with 8 eps figures, Invited review, Reference adde

Boston Hospitality Review: Winter 2019

TABLE OF CONTENTS: "Training: The Necessity of Error Management Training in the Hospitality Industry" by Priyanko Guchait; "Trends: Green Hotels: An Overview" by Minu Agarwal and Prashant Das; "Tourism: Panacea or peril? The implications of Neolocalism as a more intrusive form of tourism" by Makarand Mody and Kyle Koslowsky; "Restaurants: How Can Single-Unit Restaurants Strive for Powerful Online Presence?" by Leora Lanz and Jenna Berry; "Retention: Why Hoteliers Stay and Go: Future Oriented Thinking" by Sean McGinley; "Service Recovery: Failure is Not Fatal: Actionable Insights on Service Failure and Recovery for the Hospitality Industry" by Lisa C. Wan and Elisa Chan; "Research: A Detailed Study of the Expected and Actual Use of Hotel Amenities" by Chekitan S. Dev and Prateek Kumar

Quantum SUSY signatures in low and high energy processes

In the search for phenomenological evidence of supersymmetry through the indirect method of quantum signatures, it is useful to seek correlations of the non-standard quantum effects in low and high energy proceses, such as those involving on one hand the properties of the B-mesons and on the other hand the physics of the top quark and of the Higgs bosons. There are regions of the MSSM parameter space where the potential quantum SUSY signatures in the two energy regimes are strongly interwoven and therefore the eventual detection of these correlated quantum effects would strongly point towards the existence of underlying supersymmetric dynamics.Comment: 17 pages, LaTeX, 7 figs included with epsfig. Talk at the 5th International Workshop on High Energy Physics Phenomenology (WHEPP-5). To appear in the Proceeding

Lower Bound on the Pseudoscalar Mass in the Minimal Supersymmetric Standard Model

In the Higgs sector of the Minimal Supersymmetric Standard Model, the mass of the pseudoscalar $A$ is an independent parameter together with $\tan \beta \equiv v_2/v_1$. If $m_A$ is small, then the process $e^+ e^- \to h + A$ is kinematically allowed and is suppressed only if $\tan \beta$ is small. On the other hand, the mass of the charged Higgs boson is now near $M_W$, and the decay $t \to b + h^+$ is enhanced if $\tan \beta$ is small. Since the former has not been observed, and the branching fraction of $t \to b + W$ cannot be too small (by comparing the experimentally derived $t \bar t$ cross section from the leptonic channels with the theoretical prediction), we can infer a phenomenological lower bound on $m_A$ of at least 60 GeV for all values of $\tan \beta$.Comment: 11 pages including 2 figs, reference adde