117394387
Half orbital angular momentum and Lorentz invariance in an anisotropic space
The possible existence of half orbital angular momentum is studied in the context of an anisotropic microlocal space--time. It is shown that through l = 1/2 poses serious problems in an isotropic space, that is acceptable in an anisotropic space and is of relevance in determining the internal symmetry of hadrons. A crucial feature of l = 1/2 in such a space is that l/sub z/ is a conserved quantity and though L/sup 2/ is not a good operator, J/sup 2/ = (L+1/2/sup a/)/sup 2/ is an 0(3) invariant where -1/2(a x r) = ..mu.. is the measure of anisotropy given by the commutation of linear momentum components. It is pointed out that when the angular momentum operator is modified so that we have a 'conserved angular momentum' in this space, the system resembles the motion of a charged particle in the field of a magnetic monopole or a top motion. An oscillator representation of this formalism has been develo
118949681
QUANTUM HALL SKYRMIONS IN THE FRAMEWORK OF O(4) NONLINEAR SIGMA MODEL
A new framework for quantum Hall skyrmions in O(4) nonlinear sigma model is studied here. The size and energy of the skyrmions are determined incorporating the quartic stability term in the Lagrangian. Moreover, the introduction of a θ-term determines the spin and statistics of these skyrmions.
122012618
EQUIVALENCE OF STOCHASTIC, KLAUDER AND GEOMETRIC QUANTIZATION
The relativistic generalization of stochastic quantization helps us to introduce a stochastic-phase-space formulation when a relativistic quantum particle appears as a stochastically extended one. The nonrelativistic quantum mechanics is obtained in the sharp point limit. This also helps us to introduce a gauge-theoretical extension of a relativistic quantum particle when for a fermion the group structure of the gauge field is SU(2). The sharp point limit is obtained when we have a minimal contribution of the residual gauge field retained in the limiting procedure. This is shown to be equivalent to the geometrical approach to the phase-space quantization introduced by Klauder if it is interpreted in terms of a universal magnetic field acting on a free particle moving in a higher-dimensional configuration space when quantization corresponds to freezing the particle to its first Landau level. The geometric quantization then appears as a natural consequence of these two formalisms, since the Hermitian line bundle introduced there finds a physical meaning in terms of the inherent gauge field in stochastic-phase-space formulation or in the interaction with the magnetic field in Klauder quantization.
120179043
Random fields, ising model and bosson-fermion phase transition
SummaryIt is here shown that when the stochastic quantization procedure is introduced to a massive Thirring fermion where the latter is described as a bound state of massless oscillators interacting through a gradient term in a linear chain, we find that a boson-fermion phase transition occurs at a critical temperatureT =Tc, and atT >Tc supersymmetry is restored. In this scheme supersymmetry is broken by the generation of mass which arises due to the presence of the gradient term.
122412315
EXTENDED CONFORMAL GROUP, SUPERSYMMETRY, AND GEOMETRICAL PROPERTIES OF HADRONS
We have studied the interrelation among conformal symmetry, internal symmetry and super-symmetry and have shown that extended conformal group which includes, apart from conformal transformation, space, time and conformal reflection can give rise to internal symmetry algebra as well as supersymmetry algebra. To achieve this result, we have dealt with conformal spinors which are taken to be the constituents of the hadrons and these split into two Cartan semispinors or Dirac spinors in the Minkowski space, giving rise to the particle and antiparticle configurations. Supersymmetry is broken here just by the mass term and as such no massless hadron can exist in nature. The internal symmetry arises from the discrete symmetry of reflection. The most significant feature of this formalism is that the symmetry structure helps us to explain the meson-baryon mass difference in an elegant way and the role of fictitious superpartners is completely avoided. Again, any baryon number nonconserving process like proton decay is found to be forbidden by the Lorentz invariance. Finally, it is noted that though the discrete symmetry of reflection is taken to be the origin of the internal symmetry, topological nontrivial structures like strings do not appear here and this also avoids the possibility of the nonconservation of global charge.
122007745
Stochastic field theory at finite temperature, supersymmetry, and witten index
Finite temperature supersymmetry is studied here from the point of view of stochastic field theory and the formalism of thermofield dynamics. It is shown that the Witten index can take only the values 1 and ½ in this formalism. It is pointed out that when at a critical temperature T c , below which supersymmetry is spontaneously broken, the zero energy mode is given by a thermal doublet of opposite statistics when the index is 1. However, when the index is ½, the zero energy mode is given by a thermal doublet of the same fermionic statistics.
121486698
Working group report: Physics at the Large Hadron Collider
Abstract.This is a summary of the activities of the Physics at the LHC working group in the XIth Workshop on High Energy Physics Phenomenology (WHEPP-XI) held at the Physical Research Laboratory, Ahmedabad, India in January 2010. We discuss the activities of each sub-working group on physics issues at colliders such as Tevatron and Large Hadron Collider (LHC). The main issues discussed involve (1) results on W mass measurement and associated QCD uncertainties, (2) an attempt to understand the asymmetry measured at Tevatron in the top quark production, and (3) phenomenology of warped space dimension model.
118190750
Production of two higgses at the Large Hadron Collider in CP-violating MSSM
A bstractProduction of two Higgs bosons is studied in a CP violating supersymmetric scenario at the Large Hadron Collider with Ecm = 14 TeV. There exists a region where a very light Higgs ≲ 50 GeV could not be probed by LEP experiment. This leads to so called ’LEP hole’ region. Recently LHC found a Higgs boson around ~ 125 GeV, which severely constrains the possibility of having lighter Higgs bosons, which cannot be detected, i.e., buried Higgs, in this model. We investigate the possibility of buried Higgs bosons along with the direct and indirect bounds coming from LEP, LHC and other experiments. In particular we take into account the constraints from EDM and from B-observables. We analyse first the case where a Higgs boson mass is around 125 GeV and the other two Higgs masses are below 100 GeV and not observed so far. In the second case the lightest Higgs boson mass is around 125 GeV and the other two are decoupled. We analyse the production of two Higgses and their decay modes leading to various final states for these benchmark points. We perform a collider simulation with PYTHIA and Fastjet where we consider all the major backgrounds. Among the final states we have analysed, we find that 2b + 2τ is promising and the signal significance is 5σ at an integrated luminosity ≲ 10 fb−1. For some benchmark points it is also possible to observe the light Higgs mass peak. We also explore the leptonic final state which could be instrumental in the precision measurement of a very light Higgs.
119292092
Boosted top quarks in supersymmetric cascade decays at the LHC
At the LHC, a generic supersymmetric cascade can be a source of top quark. Specifically third generation squarks and gluino are the major sources of top quark which could also be boosted. In this article, we have shown that jet substructure algorithm can be very useful in identifying such boosted top quarks in the cascade. We take inclusive three jets plus zero lepton plus missing energy final state and try to reconstruct at least one hadronically decaying top quark by using top tagging techniques which has good prospect at the LHC.
118308113
Higgs production in CP-violating supersymmetric cascade decays: probing the ‘open hole’ at the Large Hadron Collider
A benchmark CP-violating supersymmetric scenario (known as ‘CPX-scenario’ in the literature) is studied in the context of the Large Hadron Collider (LHC). It is shown that the LHC, with low to moderate accumulated luminosity, will be able to probe the existing ‘hole’ in the $ {m_{{h_1}}} $-tan β plane, which cannot be ruled out by the LEP data. We explore the parameter space with cascade decay of third generation squarks and gluino with CP-violating decay branching fractions. We propose a multi-channel analysis to probe this parameter space some of which are background free at an integrated luminosity of 5-10 fb−1. Specially, multi-lepton final states (3l, 4l and like sign di-lepton) are almost background free and have 5σ reach for the corresponding signals with very early data of LHC for both 14 TeV and 7 TeV center of mass energy.
15787893
Associated Higgs production in CP-violating supersymmetry: Probing the 'open hole' at the large hadron collider
A benchmark CP-violating supersymmetric scenario (known in the literature as 'CPX-scenario') is studied in the context of the Large Hadron Collider (LHC). It is shown that the LHC, with low to moderate accumulated luminosity, will be able to probe the existing 'hole' in the m{sub h{sub 1}}-tan{beta} plane, which cannot be ruled out by the Large Electron Positron Collider data. This can be done through associated production of Higgs bosons with top quark and top squark pairs leading to the signal dilepton+ {<=}5 jets (including 3b-jets)+missing p{sub T}. Efficient discrimination of such a CP-violating supersymmetric scenario from other contending ones is also possible at the LHC with a moderate volume of data.