118627555
Higgs signatures in inverse seesaw model at the LHC
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.
118467851
Displaced Higgs production in type III seesaw
We point out that the type III seesaw mechanism introducing fermion triplets predicts peculiar Higgs boson signatures of displaced vertices with two b jets and one or two charged particles which can be cleanly identified. In a supersymmetric theory, the scalar partner of the fermion triplet contains a neutral dark matter candidate which is almost degenerate with its charged components. A Higgs boson can be produced together with such a dark matter triplet in the cascade decay chain of a strongly produced squark or gluino. When the next lightest supersymmetric particle (NLSP) is bino/wino-like, there appears a Higgs boson associated with two charged tracks of a charged lepton and a heavy charged scalar at a displacement larger than about 1 mm. The corresponding production cross-section is about 0.5 fb for the squark/gluino mass of 1 TeV. In the case of the stau NLSP, it decays mainly to a Higgs boson and a heavy charged scalar whose decay length is larger than 0.1 mm for the stau NLSP mixing with the left-handed stau smaller than 0.3. As this process can have a large cascade production ∼2 pb for the squark/gluino mass ∼1 TeV, one may be able to probe it at the early stage of the LHC experiment.
12790212
Signatures of gaugino mass non-universality in cascade Higgs production at the LHC
Supersymmetric cascades, involving charginos and neutralinos at various stages, contribute in a significant way to Higgs production at the LHC. We explore the nature of such cascades, completely relaxing the universality of the gaugino masses. It is found that the deviation from the scenario with universal gaugino masses would be reflected in the relative production rates for the lightest neutral Higgs and the charged Higgses.
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.
118524249
Unusual Higgs boson signal in R-parity violating nonminimal supersymmetric models at the LHC
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.
16388458
Probing non-universal gaugino masses via Higgs boson production under SUSY cascades at the LHC: a detailed study
Cascade decays of Supersymmetric (SUSY) particles are likely to be prolific sources of Higgs bosons at the Large Hadron Collider (LHC). In this work, we explore, with the help of detailed simulation, the role of non-universal gaugino masses in the production of the Higgs bosons under SUSY cascades. The analysis is carried out by choosing an appropriate set of benchmark points with non-universal gaugino masses in the relevant SUSY parameter space and then contrasting the resulting observations with the corresponding cases having universal relationship among the same. It is shown that even of data at an early phase of the LHC-run with 10 fb−1 one would be able to see, under favourable situations, the imprint of non-universal gaugino masses by reconstructing various Higgs boson resonances and comparing their rates. With increased accumulated luminosities, the indications would naturally become distinct over a larger region of the parameter space.
122875506
Some remarks on nonlocal field theory and space-time quantization
From the point of view that the charge and mass of an electron is of dynamical origin and quantization of charge in units ofe is related to the space-time quantization as developed in an earlier paper, we here show that it is possible to consider that the internal space within the elementary domain of the quantized space-time world is not governed by Lorentz invariance. This helps us to develop a consistent theory of nonlocal fields for extended particles where the infinite mass degeneracy is avoided. Moreover, this ensures the convergence of nonlocal field theories and suggests that massless particles like photons and neutrinos, though they may be taken to be of extended structure, will appear only as point particles in the physical world. In this picture, Lorentz invariance appears to be a consequence of the distribution of matter and energy in the Universe, and this may be taken to be another interpretation of Mach's principle.
119883227
Gravity without metric, torsion, and topological gravity
The role of θ term in gravity without the metric formulation of Capovilla, Jacobson, and Dell has been investigated when the gauge group is taken to be SL(2,C) and it is shown that this corresponds to the introduction of torsion and as such represents the Einstein–Cartan action. Moreover, as this term is related to the chiral anomaly, this helps us to formulate the Einstein–Hilbert gravitational action as a symmetry‐breaking effect in quantum field theory. In view of this one can consider this topological θ term as the fundamental entity. When the chiral nature of matter field is not manifested explicitly, the torsion term effectively gives rise to the cosmological constant. In case there is only the θ term in the action, one can have topological gravity which helps to realize physically Donaldson’s theory of four‐dimensional space–time geometry.
120660249
Lepton-hadron relation and the puzzle of prompt muon production in the forward direction
A series of recently conducted experiments (1-4) have revealed the following important characteristics of the prompt muon production in the forward direction in protonnucleus collisions at high energies: i) the measured V/r: ratio has been, in almost all the cases, of the order of 10 -5. ii) The ratio of prompt positive and negative muons is about 1. iii) The muons are originated in pairs, iv) The V/r: ratio depends on the outgoing-muon momentum, with the direct production rising slowly with increasing transverse momentum (a). We propose to explain here the above-mentioned features of the prompt muon production with the help of a multiple-production model based on a certain kind of lepton-hadron relation. No theoretical model has yet a t tempted-le t alone succeeded--to explain these observations. Side by side, on the basis of the available data there is an important and prospective speculation about the possibilities of copious direct photon production which is supposed to be a possible clue to or a resolution of the afore-mentioned prompt muon puzzle. It has been proposed by FARRAR and ]~RAUTSCHI (5) that all direct leptons not due to vector-meson decay can be at tr ibuted to the decay of virtual photons. Though the detailed behaviour of the y/r: ratio could not be predicted it has been shown there that the expected value of the ratio at large PT is of the order of 10 -1 and falls to 10 -~ at the 1OW-pT region. In case of inclusive production, BEI]~R et al. (e) have, however, reported to the contrary: the ratio (y/r:) is 15 at low PT and falls to zero at high PT.
117842841
Geometry, Topology and Quantization
Preface. 1. Manifold and Differential Forms. 2. Spinor Structure and Twistor Geometry. 3. Quantization. 4. Quantization and Gauge Field. 5. Fermions and Topology. 6. Topological Field Theory. References. Index.
119556027
AREA PRESERVING DIFFEOMORPHISM, QUANTUM GROUP AND BERRY PHASE
We study here the relationship between the area preserving diffeomorphism and quantum group with the deformation of symplectic structure and Berry phase in the Landau problem of 2D electron gas in a magnetic field. It is argued that while the area preserving diffeomorphism leads to the quantization of the symmetry , the deformation of the symplectic structure leads to the quantization of the system having the relation Δp. Δ q=2πnℏ, n being an odd integer giving rise to the Berry phase ei2πμ with n=2μ. A possible link between the deformation parameter q of the deformed algebra with the Berry phase factor arising out of the quantization procedure has been suggested. Finally, the latticization of space associated with the quantum group and its connection with the Zp spin system is discussed.