QUANTUM SPACE-TIME, QUANTUM GRAVITY AND TORSION

title: Stochastic field theory at finite temperature, supersymmetry, and witten index
abstract: 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.

title: Random fields, ising model and bosson-fermion phase transition
abstract: 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.

title: EQUIVALENCE OF STOCHASTIC, KLAUDER AND GEOMETRIC QUANTIZATION
abstract: 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.

title: EXTENDED CONFORMAL GROUP, SUPERSYMMETRY, AND GEOMETRICAL PROPERTIES OF HADRONS
abstract: 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.

title: QUANTUM HALL SKYRMIONS IN THE FRAMEWORK OF O(4) NONLINEAR SIGMA MODEL
abstract: 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.

title: Probing Higgs bosons via the type III seesaw mechanism at the LHC
abstract: We show that the type III seesaw mechanism opens up a promising possibility of searching the Higgs boson in the $b \bar b$ channel through the Higgs production associated with a charged lepton coming from the decay of the triplet seesaw particle. In particular we look for the $2b$ signals with trileptons or same-sign dileptons to construct the Higgs and the triplet fermion mass and calculate the reach with the integrated luminosity of 10 fb$^{-1}$ at the 14 TeV LHC.

title: Higgs signatures in inverse seesaw model at the LHC
abstract: A bstractIn the inverse seesaw mechanism where the spontaneously broken B-L symmetry induces tiny B-L violating Majorana masses for right-handed neutrinos, non-standard Higgs signatures can arise due to a possible Higgs doublet and singlet mixing and/or Higgs boson decays to a left- and right-handed neutrino. This leads to a remarkable feature of hadronically quiet di-lepton final states which can exhibit, in particular, lepton flavour violating signatures coming from flavour-dependent neutrino Yukawa couplings. In this process, one lepton coming from the right-handed decay could be soft enough can be missed by the trigger level cuts of CMS and ATLAS for the di-lepton plus missing energy signature. The prospects of such a signature are investigated for 8 TeV and 14 TeV center of mass energy of the LHC, taking the maximum value of the allowed neutrino Yukawa coupling and the right-handed neutrino mass of 100 GeV. A PYTHIA level simulation shows that the integrated luminosity of 10-20/fb and 1.6/fb for 8 TeV is required to observe the inclusive leptonic and lepton flavour violating signatures, respectively. For 14 TeV, the reach is more and a larger parameter space of the inverse seesaw model can be probed.

title: Clan structure and intermittency in proton-nucleus interactions at high energy
abstract: In this paper we examine the similarity between clan structure and self-similar cascading in high energy proton-nucleus interactions at 70 GeV/c in emulsion. The investigation shows that the negative bionomial fitting parameterk can be used for the evaluation of factorial moments in intermittency studies and that these exhibit similar behaviour with those derived from nonstatistical procedure. The results of our study signify compatibility between clan cascading and self-similar cascading in soft hadroization processes.

title: Higgs production in CP-violating supersymmetric cascade decays: probing the ‘open hole’ at the Large Hadron Collider
abstract: 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.

title: Unusual Higgs boson signal in R-parity violating nonminimal supersymmetric models at the LHC
abstract: We predict an unconventional background free signal of the Higgs boson in $R$-parity violating nonminimal supersymmetric models at the Large Hadron Collider (LHC). The signal comprises dilepton plus four hadronic jets and two large displaced vertices. The displaced leptons and jets are coming from the decay of the lightest supersymmetric particle (LSP), which is predominantly a gauge-singlet neutrino. A pair of such LSPs can couple to a Higgs boson, created via gluon fusion. We have analyzed two cases - one corresponding to the tree-level Higgs boson mass and another with the one-loop corrected mass of the Higgs boson. A reliable Higgs mass reconstruction using this signal can lead to discovery at the LHC with center-of-mass energy $\sqrt{s}=14~\rm{TeV}$ and 5 fb$^{-1}$ of integrated luminosity $(\mathcal{L})$. Even at $\sqrt{s}=7~\rm{TeV}$ and $\mathcal{L}$ = 5 fb$^{-1}$, a reasonable number of events are expected. Besides, mass reconstruction of a gauge-singlet LSP can provide an estimate of the seesaw scale.