Abstract: We study the radiative decay widths of vector quarkonia for the process of and (for principal quantum numbers ) in the framework of Bethe-Salpeter equation under the covariant instantaneous ansatz using a form of BSE. The parameters of the framework were determined by a fit to the mass spectrum of ground states of pseudoscalar and vector quarkonia, such as , , , and . These input parameters so fixed were found to give good agreements with data on mass spectra of ground and excited states of pseudoscalar and vector quarkonia, leptonic decay constants of pseudoscalar and vector quarkonia, two-photon decays, and two-gluon decays of pseudoscalar quarkonia in our recent paper. With these input parameters so fixed, the radiative decay widths of ground and excited states of heavy vector quarkonia ( and ) are calculated and found to be in reasonable agreement with data. PubDate: Tue, 20 Jun 2017 06:32:01 +000
Abstract: We review the realization of Starobinsky-type inflation within induced-gravity supersymmetric (SUSY) and non-SUSY models. In both cases, inflation is in agreement with the current data and can be attained for sub-Planckian values of the inflation. The corresponding effective theories retain perturbative unitarity up to the Planck scale and the inflation mass is predicted to be . The supergravity embedding of these models is achieved by employing two gauge singlet chiral superfields, a superpotential that is uniquely determined by a continuous and a discrete symmetry and several (semi)logarithmic Kähler potentials that respect these symmetries. Checking various functional forms for the noninflation accompanying field in the Kähler potentials, we identify four cases which stabilize it without invoking higher order terms. PubDate: Sun, 18 Jun 2017 08:28:21 +000
Abstract: The present works deals with gravitational collapse of cylindrical viscous heat conducting anisotropic fluid following the work of Misner and Sharp. Using Darmois matching conditions, the dynamical equations are derived and the effects of charge and dissipative quantities over the cylindrical collapse are analyzed. Finally, using the Miller-Israel-Steward causal thermodynamic theory, the transport equation for heat flux is derived and its influence on collapsing system has been studied. PubDate: Wed, 14 Jun 2017 00:00:00 +000
Abstract: We present a gravitational collapse null dust solution of the Einstein field equations. The space-time is regular everywhere except on the symmetry axis where it possesses a naked curvature singularity and admits one parameter isometry group, a generator of axial symmetry along the cylinder which has closed orbits. The space-time admits closed timelike curves (CTCs) which develop at some particular moment in a causally well-behaved manner and may represent a Cosmic Time Machine. The radial geodesics near the singularity and the gravitational lensing (GL) will be discussed. The physical interpretation of this solution, based on the study of the equation of the geodesic deviation, will be presented. It was demonstrated that this solution depends on the local gravitational field consisting of two components with amplitudes and . PubDate: Mon, 12 Jun 2017 00:00:00 +000
Abstract: A simple transformation of field variables eliminates Coulomb forces from the theory of quantum electrodynamics. This suggests that Coulomb forces may be an emergent phenomenon rather than being fundamental. This possibility is investigated in the context of reducible quantum electrodynamics. It is shown that states exist which bind free photon and free electron fields. The binding energy peaks in the long-wavelength limit. This makes it plausible that Coulomb forces result from the interaction of the electron/positron field with long-wavelength transversely polarized photons. PubDate: Tue, 06 Jun 2017 00:00:00 +000
Abstract: We calculate the particle ratios , , and for a strongly interacting hadronic matter using nonlinear Walecka model (NLWM) in relativistic mean field (RMF) approximation. It is found that interactions among hadrons modify and particle ratios, while is found to be insensitive to these interactions. PubDate: Sun, 04 Jun 2017 06:51:38 +000
Abstract: We investigate the possibility of TeV-scale scalars as low energy remnants arising in the nonsupersymmetric grand unification framework where the field content is minimal. We consider a scenario where the gauge symmetry is broken into the gauge symmetry of the Standard Model (SM) through multiple stages of symmetry breaking, and a colored and hypercharged scalar picks a TeV-scale mass in the process. The last stage of the symmetry breaking occurs at the TeV-scale where the left-right symmetry, that is, , is broken into that of the SM by a singlet scalar field of mass TeV, which is a component of an -triplet scalar field, acquiring a TeV-scale vacuum expectation value. For the LHC phenomenology, we consider a scenario where is produced via gluon-gluon fusion through loop interactions with and also decays to a pair of SM gauge bosons through in the loop. We find that the parameter space is heavily constrained from the latest LHC data. We use a multivariate analysis to estimate the LHC discovery reach of into the diphoton channel. PubDate: Tue, 30 May 2017 09:03:57 +000
Abstract: We used a tool of conventional Nikiforov-Uvarov method to determine bound state solutions of Schrodinger equation with quantum interaction potential called Hulthen-Yukawa inversely quadratic potential (HYIQP). We obtained the energy eigenvalues and the total normalized wave function. We employed Hellmann-Feynman Theorem (HFT) to compute expectation values , , , and for four different diatomic molecules: hydrogen molecule (H2), lithium hydride molecule (LiH), hydrogen chloride molecule (HCl), and carbon (II) oxide molecule. The resulting energy equation reduces to three well-known potentials which are as follows: Hulthen potential, Yukawa potential, and inversely quadratic potential. The bound state energies for Hulthen and Yukawa potentials agree with the result reported in existing literature. We obtained the numerical bound state energies of the expectation values by implementing MATLAB algorithm using experimentally determined spectroscopic constant for the different diatomic molecules. We developed mathematica programming to obtain wave function and probability density plots for different orbital angular quantum number. PubDate: Tue, 30 May 2017 00:00:00 +000
Abstract: We review the basic elements of the Minimal Geometric Deformation approach in detail. This method has been successfully used to generate brane-world configurations from general relativistic perfect fluid solutions. PubDate: Thu, 25 May 2017 07:55:51 +000
Abstract: Prediction of production cross section (where ) in proton-proton collisions at TeV is estimated up to next-to-next-to-leading order (NNLO) in perturbative QCD including next-to-leading order (NLO) electroweak (EW) corrections. The total inclusive boson production cross section times leptonic branching ratio, within the invariant mass window GeV, is predicted using NNLO HERAPDF2.0 at NNLO QCD and NLO EW as (PDF) () (scale) (parameterization and model). Theoretical prediction of the fiducial cross section is further computed with the latest modern PDF models (CT14, MMHT2014, NNPDF3.0, HERAPDF2.0, and ABM12) at NNLO for QCD and NLO for EW. The central values of the predictions are based on DYNNLO 1.5 program and the uncertainties are extracted using FEWZ 3.1 program. In addition, the cross section is also calculated as functions of and scales. The choice of and for scale variation uncertainty is further discussed in detail. PubDate: Thu, 25 May 2017 00:00:00 +000
Abstract: Using the experimental data from the ALICE program on the centrality dependence of the transverse momentum () spectra in Pb+Pb collisions at TeV, we show that the double-Tsallis distribution and the generalized Fokker-Planck (FP) solution cannot describe the spectra of pions, kaons, and protons from central to peripheral collisions in the entire region, simultaneously. Hence, a new two-component distribution, which is a hydrodynamic extension of the generalized FP solution accounting for the collective motion effect in heavy-ion collisions, is proposed in order to reproduce all the identified particle spectra. Our results suggest that the particle production dynamics may be different for different particles, especially at very low region. PubDate: Tue, 23 May 2017 07:25:32 +000
Abstract: The transverse momentum distributions of final-state particles are very important for high energy collision physics. In this work, we investigate and meson distributions in the framework of a particle-production source, where Tsallis statistics are consistently incorporated. The results are in good agreement with the experimental data in and -Pb collisions at LHC energies. The temperature of the emission source and the nonequilibrium degree of the collision system are extracted. PubDate: Thu, 18 May 2017 00:00:00 +000
Abstract: In this paper, by analyzing the thermodynamic properties of charged AdS black hole and asymptotically flat space-time charged black hole in the vicinity of the critical point, we establish the correspondence between the thermodynamic parameters of asymptotically flat space-time and nonasymptotically flat space-time, based on the equality of black hole horizon area in the two different types of space-time. The relationship between the cavity radius (which is introduced in the study of asymptotically flat space-time charged black holes) and the cosmological constant (which is introduced in the study of nonasymptotically flat space-time) is determined. The establishment of the correspondence between the thermodynamics parameters in two different types of space-time is beneficial to the mutual promotion of different time-space black hole research, which is helpful to understand the thermodynamics and quantum properties of black hole in space-time. PubDate: Wed, 03 May 2017 00:00:00 +000
Abstract: We consider an extension of the Standard Model (SM) with additional gauge singlets which exhibits a strong first-order phase transition. Due to this first-order phase transition in the early universe gravitational waves are produced. We estimate the contributions such as the sound wave, the bubble wall collision, and the plasma turbulence to the stochastic gravitational wave background, and we find that the strength at the peak frequency is large enough to be detected at future gravitational interferometers such as eLISA. Deviations in the various Higgs boson self-couplings are also evaluated. PubDate: Sun, 30 Apr 2017 07:59:09 +000
Abstract: We study the destruction of heavy quarkonium due to the entropic force in a deformed AdS5 model. The effects of the deformation parameter on the interdistance and the entropic force are investigated. The influence of the deformation parameter on the quarkonium dissociation is analyzed. It is shown that the interdistance increases in the presence of the deformation parameter. In addition, the deformation parameter has the effect of decreasing the entropic force. These results imply that the quarkonium dissociates harder in a deformed AdS background than in a usual AdS background, in agreement with earlier findings. PubDate: Sun, 30 Apr 2017 00:00:00 +000
Abstract: We investigate the entropy product formula for various gravitational instantons. We speculate that due to the mass-independent features of the said instatons they are universal as well as quantized. For isolated Euclidean Schwarzschild black hole, these properties simply fail. PubDate: Sun, 23 Apr 2017 00:00:00 +000
Abstract: For study of quantum self-frictional (SF) relativistic nucleoseed spinor-type tensor (NSST) field theory of nature (SF-NSST atomic-molecular-nuclear and cosmic-universe systems) we use the complete orthogonal basis sets of -component column-matrices type SF -relativistic NSST orbitals (-RNSSTO) and SF -relativistic Slater NSST orbitals (-RSNSSTO) through the -nonrelativistic scalar orbitals (-NSO) and -nonrelativistic Slater type orbitals (-NSTO), respectively. Here or and , are the integer ) or noninteger ) SF quantum numbers, where . We notice that the nonrelativistic -NSO and -NSTO orbitals themselves are obtained from the relativistic -RNSSTO and -RSNSSTO functions for , respectively. The column-matrices-type SF -RNSST harmonics (-RNSSTH) and -modified NSSTH (-MNSSTH) functions for arbitrary spin introduced by the author in the previous papers are also used. The one- and two-center one-range addition theorems for -NSO and noninteger -NSTO orbitals are presented. The quantum SF relativistic nonperturbative theory for -RNSST potentials (-RNSSTP) and their derivatives is also suggested. To study the transportations of mass and momentum in nature the quantum SF relativistic NSST gravitational photon (gph) with is introduced. PubDate: Mon, 03 Apr 2017 09:35:55 +000
Abstract: We study the excited muon production at the FCC-based muon-hadron colliders. We give the excited muon decay widths and production cross-sections. We deal with the process and plot the transverse momentum and normalized pseudorapidity distributions of final state particles to define the kinematical cuts best suited for discovery. By using these cuts, we get the mass limits for excited muons. It is shown that the discovery limits obtained on the mass of are 2.2, 5.8, and 7.5 TeV for muon energies of 63, 750, and 1500 GeV, respectively. PubDate: Thu, 30 Mar 2017 00:00:00 +000
Abstract: We study fermion localization and resonances on a special type of brane-world model supporting brane splitting. In such models one can construct multiwall branes which cause considerable simplification in the field equations. We use a polynomial superpotential to construct this brane. The suitable Yukawa coupling between the background scalar field and the localized fermion is determined. The massive fermion resonance spectrum is obtained. The number of resonances is increased for higher values of Yukawa coupling. PubDate: Sun, 26 Mar 2017 08:06:46 +000
Abstract: Embedding type I seesaw in GUTs, left-right gauge theories, or even in extensions of the SM requires large right-handed neutrino masses making the neutrino mass generation mechanism inaccessible for direct experimental tests. This has been circumvented by introducing additional textures or high degree of fine-tuning in the Dirac neutrino or right-handed neutrino mass matrices. In this work we review another new mechanism that renders type I seesaw vanishing but other seesaw mechanisms dominant. Such mechanisms include extended seesaw, type II, linear, or double seesaw. The linear seesaw, double seesaw, and extended seesaw are directly verifiable at TeV scale. New observable predictions for lepton flavor and lepton number violations by ongoing searches are noted. Type II embedding in (10) also predicts these phenomena in addition to new mechanism for leptogenesis and displaced vertices mediated by gauge singlet fermions. PubDate: Tue, 21 Mar 2017 00:00:00 +000
Abstract: We discuss the modified Maxwell action of a -type Lorentz symmetry breaking theory and present a solution of Maxwell equations derived in the cases of linear and elliptically polarized electromagnetic waves in the vacuum of CPT-even Lorentz violation. We show in this case that the Lorentz violation has the effect of changing the amplitude of one component of the magnetic field, while leaving the electric field unchanged, leading to nonorthogonal propagation of electromagnetic fields and dependence of the eccentricity on -term. Further, we exhibit numerically the consequences of this effect in the cases of linear and elliptical polarization, in particular, the regimes of nonorthogonality of the electromagnetic wave fields and the eccentricity of the elliptical polarization of the magnetic field with dependence on the -term. PubDate: Mon, 20 Mar 2017 00:00:00 +000
Abstract: The cardinal focus of the present review is to explore the role of neutrinos originating from the ultradense core of neutron stars composed of quark gluon plasma in the astrophysical scenario. The collective excitations of the quarks involving the neutrinos through the different kinematical processes have been studied. The cooling of the neutron stars as well as pulsar kicks due to asymmetric neutrino emission has been discussed in detail. Results involving calculation of relevant physical quantities like neutrino mean free path and emissivity have been presented in the framework of non-Fermi liquid behavior as applicable to ultradegenerate plasma. PubDate: Thu, 16 Mar 2017 00:00:00 +000
Abstract: We study the single top and Higgs associated production in the top-Higgs FCNC couplings at the LHeC with the electron beam energy of GeV and GeV and combination of a 7 TeV and 50 TeV proton beam. With the possibility of -beam polarization (, ), we distinct the cut-based method and the multivariate analysis- (MVA-) based method and compare with the current experimental and theoretical limits. It is shown that the branching ratio can be probed to 0.113 (0.093%), 0.071 (0.057%), 0.030 (0.022%), and 0.024 (0.019%) with the cut-based (MVA-based) analysis at (, ) = (7 TeV, 60 GeV), (, ) = (7 TeV, 120 GeV), (, ) = (50 TeV, 60 GeV), and (, ) = (50 TeV, 120 GeV) beam energy and 1 level. With the possibility of -beam polarization, the expected limits can be probed down to 0.090 (0.073%), 0.056 (0.045%), 0.024 (0.018%), and 0.019 (0.015%), respectively. PubDate: Thu, 16 Mar 2017 00:00:00 +000
Abstract: We present an exact treatment of the modulus stabilization condition with the general boundary conditions of the bulk scalar field in the Randall-Sundrum model. We find analytical expressions for the value of the modulus and the mass of the radion. PubDate: Sun, 12 Mar 2017 00:00:00 +000
Abstract: The prompt photon production in hadronic collisions has a long history of providing information on the substructure of hadrons and testing the perturbative techniques of QCD. Some valuable information about the parton densities in the nucleon and nuclei, especially of the gluon, can also be achieved by analysing the measurements of the prompt photon production cross section whether inclusively or in association with heavy quarks or jets. In this work, we present predictions for the inclusive isolated prompt photon production in pp collisions at center-of-mass energy of 13 TeV using various modern PDF sets. The calculations are presented as a function of both photon transverse energy and pseudorapidity for the ATLAS kinematic coverage. We also study in detail the theoretical uncertainty in the cross sections due to the variation of the renormalization, factorization, and fragmentation scales. Moreover, we introduce and calculate the ratios of photon momenta for different rapidity regions and study the impact of various input PDFs on such quantity. PubDate: Sun, 12 Mar 2017 00:00:00 +000
Abstract: We exploit the beauty and strength of the symmetry invariant restrictions on the (anti)chiral superfields to derive the Becchi-Rouet-Stora-Tyutin (BRST), anti-BRST, and (anti-)co-BRST symmetry transformations in the case of a two -dimensional (2) self-dual chiral bosonic field theory within the framework of augmented (anti)chiral superfield formalism. Our 2 ordinary theory is generalized onto a -dimensional supermanifold which is parameterized by the superspace variable , where (with ) are the ordinary 2 bosonic coordinates and () are a pair of Grassmannian variables with their standard relationships: , . We impose the (anti-)BRST and (anti-)co-BRST invariant restrictions on the (anti)chiral superfields (defined on the (anti)chiral -dimensional supersubmanifolds of the above general -dimensional supermanifold) to derive the above nilpotent symmetries. We do not exploit the mathematical strength of the (dual-)horizontality conditions anywhere in our present investigation. We also discuss the properties of nilpotency, absolute anticommutativity, and (anti-)BRST and (anti-)co-BRST symmetry invariance of the Lagrangian density within the framework of our augmented (anti)chiral superfield formalism. Our observation of the absolute anticommutativity property is a completely novel result in view of the fact that we have considered only the (anti)chiral superfields in our present endeavor. PubDate: Tue, 07 Mar 2017 00:00:00 +000
Abstract: We present a cylindrically symmetric, Petrov type D, nonexpanding, shear-free, and vorticity-free solution of Einstein’s field equations. The spacetime is asymptotically flat radially and regular everywhere except on the symmetry axis where it possesses a naked curvature singularity. The energy-momentum tensor of the spacetime is that for an anisotropic fluid which satisfies the different energy conditions. This spacetime is used to generate a rotating spacetime which admits closed timelike curves and may represent a Cosmic Time Machine. PubDate: Mon, 06 Mar 2017 06:41:10 +000
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