Advances in High Energy Physics
[SJR: 1.334] [H-I: 12] [16 followers] Follow
Open Access journal
ISSN (Print) 1687-7357 - ISSN (Online) 1687-7365
Published by Hindawi [360 journals]
- Analysis of Decay in Scalar Leptoquark Model
Abstract: We analyze the baryonic semilepton decay in the scalar leptoquark models with and states, respectively. We also discuss the effects of these two NP models on some physical observables. For some measured observables, like the differential decay width, the longitudinal polarization of the dilepton system, the lepton-side forward-backward asymmetry, and the baryon-side forward-backward asymmetry, we find that the prediction values of SM are consistent with the current data in most ranges, where the prediction values of these two NP models can also keep consistent with the current data with . However, in some ranges, the prediction values of SM are difficult to meet the current data, but the contributions of these two NP models can meet them or keep close to them. For the double-lepton polarization asymmetries, , , , and are sensitive to the scalar leptoquark model but not to . However, , , , and are not sensitive to these two NP models.
PubDate: Thu, 18 Aug 2016 10:39:25 +000
- Self-Dual Configurations in a Generalized Abelian Chern-Simons-Higgs Model
with Explicit Breaking of the Lorentz Covariance
Abstract: We have studied the existence of self-dual solitonic solutions in a generalization of the Abelian Chern-Simons-Higgs model. Such a generalization introduces two different nonnegative functions, and , which split the kinetic term of the Higgs field, , breaking explicitly the Lorentz covariance. We have shown that a clean implementation of the Bogomolnyi procedure only can be implemented whether with . The self-dual or Bogomolnyi equations produce an infinity number of soliton solutions by choosing conveniently the generalizing function which must be able to provide a finite magnetic field. Also, we have shown that by properly choosing the generalizing functions it is possible to reproduce the Bogomolnyi equations of the Abelian Maxwell-Higgs and Chern-Simons-Higgs models. Finally, some new self-dual -vortex solutions have been analyzed from both theoretical and numerical point of view.
PubDate: Thu, 18 Aug 2016 08:32:43 +000
- Study of Void Probability Scaling of Singly Charged Particles Produced in
Ultrarelativistic Nuclear Collision in Fractal Scenario
Abstract: We study the fractality of void probability distribution measured in -Ag/Br interaction at an incident energy of 200 GeV per nucleon. A radically different and rigorous method called Visibility Graph analysis is used. This method is shown to reveal a strong scaling character of void probability distribution in all pseudorapidity regions. The scaling exponent, called the Power of the Scale-Freeness in Visibility Graph (PSVG), a quantitative parameter related to Hurst exponent, is strongly found to be dependent on the rapidity window size.
PubDate: Thu, 18 Aug 2016 08:29:28 +000
- Quantum-Corrected Two-Dimensional Horava-Lifshitz Black Hole Entropy
Abstract: We focus on the Hamilton-Jacobi method to determine several thermodynamic quantities such as temperature, entropy, and specific heat of two-dimensional Horava-Lifshitz black holes by using the generalized uncertainty principles (GUP). We also address the product of horizons, mainly concerning the event, Cauchy, and cosmological and virtual horizons.
PubDate: Thu, 18 Aug 2016 07:49:50 +000
- Tachyon Warm Intermediate and Logamediate Inflation in the Brane World
Model in the Light of Planck Data
Abstract: Tachyon inflationary universe model on the brane in the context of warm inflation is studied. In slow-roll approximation and in longitudinal gauge, we find the primordial perturbation spectrums for this scenario. We also present the general expressions of the tensor-scalar ratio, scalar spectral index, and its running. We develop our model by using exponential potential; the characteristics of this model are calculated in great detail. We also study our model in the context of intermediate (where scale factor expands as ) and logamediate (where the scale factor expands as ) models of inflation. In these two sectors, dissipative parameter is considered as a constant parameter and a function of tachyon field. Our model is compatible with observational data. The parameters of the model are restricted by Planck data.
PubDate: Mon, 15 Aug 2016 15:53:00 +000
- Fermions Tunneling from Higher-Dimensional Reissner-Nordström Black
Hole: Semiclassical and Beyond Semiclassical Approximation
Abstract: Based on semiclassical tunneling method, we focus on charged fermions tunneling from higher-dimensional Reissner-Nordström black hole. We first simplify the Dirac equation by semiclassical approximation, and then a semiclassical Hamilton-Jacobi equation is obtained. Using the Hamilton-Jacobi equation, we study the Hawking temperature and fermions tunneling rate at the event horizon of the higher-dimensional Reissner-Nordström black hole space-time. Finally, the correct entropy is calculation by the method beyond semiclassical approximation.
PubDate: Sun, 14 Aug 2016 11:43:52 +000
- Generalized Solutions of the Dirac Equation, Bosons, and Beta Decay
Abstract: We study the Hagen-Hurley equations describing spin 1 particles. We split these equations, in the interacting case, into two Dirac equations with nonstandard solutions. It is argued that these solutions describe decay of a virtual boson in beta decay.
PubDate: Wed, 10 Aug 2016 11:50:26 +000
- Matter Localization on Brane-Worlds Generated by Deformed Defects
Abstract: Localization and mass spectrum of bosonic and fermionic matter fields of some novel families of asymmetric thick brane configurations generated by deformed defects are investigated. The localization profiles of spin 0, spin 1/2, and spin 1 bulk fields are identified for novel matter field potentials supported by thick branes with internal structures. The condition for localization is constrained by the brane thickness of each model such that thickest branes strongly induce matter localization. The bulk mass terms for both fermion and boson fields are included in the global action as to produce some imprints on mass-independent potentials of the Kaluza-Klein modes associated with the corresponding Schrödinger equations. In particular, for spin 1/2 fermions, a complete analytical profile of localization is obtained for the four classes of superpotentials here discussed. Regarding the localization of fermion fields, our overall conclusion indicates that thick branes produce a left-right asymmetric chiral localization of spin 1/2 particles.
PubDate: Sun, 07 Aug 2016 08:58:08 +000
- The Effects of Minimal Length, Maximal Momentum, and Minimal Momentum in
Abstract: The modified entropic force law is studied by using a new kind of generalized uncertainty principle which contains a minimal length, a minimal momentum, and a maximal momentum. Firstly, the quantum corrections to the thermodynamics of a black hole are investigated. Then, according to Verlinde’s theory, the generalized uncertainty principle (GUP) corrected entropic force is obtained. The result shows that the GUP corrected entropic force is related not only to the properties of the black holes but also to the Planck length and the dimensionless constants and . Moreover, based on the GUP corrected entropic force, we also derive the modified Einstein’s field equation (EFE) and the modified Friedmann equation.
PubDate: Wed, 03 Aug 2016 07:00:38 +000
- Thermodynamics of Acoustic Black Holes in Two Dimensions
Abstract: It is well-known that the thermal Hawking-like radiation can be emitted from the acoustic horizon, but the thermodynamic-like understanding for acoustic black holes was rarely made. In this paper, we will show that the kinematic connection can lead to the dynamic connection at the horizon between the fluid and gravitational models in two dimensions, which implies that there exists the thermodynamic-like description for acoustic black holes. Then, we discuss the first law of thermodynamics for the acoustic black hole via an intriguing connection between the gravitational-like dynamics of the acoustic horizon and thermodynamics. We obtain a universal form for the entropy of acoustic black holes, which has an interpretation similar to the entropic gravity. We also discuss the specific heat and find that the derivative of the velocity of background fluid can be regarded as a novel acoustic analogue of the two-dimensional dilaton potential, which interprets why the two-dimensional fluid dynamics can be connected to the gravitational dynamics but it is difficult for four-dimensional case. In particular, when a constraint is added for the fluid, the analogue of a Schwarzschild black hole can be realized.
PubDate: Mon, 01 Aug 2016 09:53:59 +000
- Unified Treatment of a Class of Spherically Symmetric Potentials:
Abstract: We investigate the Schrödinger equation for a class of spherically symmetric potentials in a simple and unified manner using the Lie algebraic approach within the framework of quasi-exact solvability. We illustrate that all models give rise to the same basic differential equation, which is expressible as an element of the universal enveloping algebra of . Then, we obtain the general exact solutions of the problem by employing the representation theory of Lie algebra.
PubDate: Sun, 31 Jul 2016 14:31:07 +000
- Stability of the Regular Hayward Thin-Shell Wormholes
Abstract: The aim of this paper is to construct regular Hayward thin-shell wormholes and analyze their stability. We adopt Israel formalism to calculate surface stresses of the shell and check the null and weak energy conditions for the constructed wormholes. It is found that the stress-energy tensor components violate the null and weak energy conditions leading to the presence of exotic matter at the throat. We analyze the attractive and repulsive characteristics of wormholes corresponding to and , respectively. We also explore stability conditions for the existence of traversable thin-shell wormholes with arbitrarily small amount of fluid describing cosmic expansion. We find that the space-time has nonphysical regions which give rise to event horizon for and the wormhole becomes nontraversable producing a black hole. The nonphysical region in the wormhole configuration decreases gradually and vanishes for the Hayward parameter . It is concluded that the Hayward and Van der Waals quintessence parameters increase the stability of thin-shell wormholes.
PubDate: Sun, 31 Jul 2016 08:43:23 +000
- Spontaneous Symmetry Breaking in 5D Conformally Invariant Gravity
Abstract: We explore the possibility of the spontaneous symmetry breaking in 5D conformally invariant gravity, whose action consists of a scalar field nonminimally coupled to the curvature with its potential. Performing dimensional reduction via ADM decomposition, we find that the model allows an exact solution giving rise to the 4D Minkowski vacuum. Exploiting the conformal invariance with Gaussian warp factor, we show that it also admits a solution which implements the spontaneous breaking of conformal symmetry. We investigate its stability by performing the tensor perturbation and find the resulting system is described by the conformal quantum mechanics. Possible applications to the spontaneous symmetry breaking of time-translational symmetry along the dynamical fifth direction and the brane-world scenario are discussed.
PubDate: Wed, 27 Jul 2016 07:44:34 +000
- Analysis of the Intermediate-State Contributions to Neutrinoless Double
Abstract: A comprehensive analysis of the structure of the nuclear matrix elements (NMEs) of neutrinoless double beta-minus () decays to the ground and first excited states is performed in terms of the contributing multipole states in the intermediate nuclei of transitions. We concentrate on the transitions mediated by the light (l-NMEs) Majorana neutrinos. As nuclear model we use the proton-neutron quasiparticle random-phase approximation (pnQRPA) with a realistic two-nucleon interaction based on the Bonn one-boson-exchange matrix. In the computations we include the appropriate short-range correlations, nucleon form factors, and higher-order nucleonic weak currents and restore the isospin symmetry by the isoscalar-isovector decomposition of the particle-particle proton-neutron interaction parameter .
PubDate: Tue, 26 Jul 2016 07:04:01 +000
- Calculating Masses of Pentaquarks Composed of Baryons and Mesons
Abstract: We consider an exotic baryon (pentaquark) as a bound state of two-body systems composed of a baryon (nucleon) and a meson. We used a baryon-meson picture to reduce a complicated five-body problem to simple two-body problems. The homogeneous Lippmann-Schwinger integral equation is solved in configuration space by using one-pion exchange potential. We calculate the masses of pentaquarks and .
PubDate: Mon, 25 Jul 2016 11:29:16 +000
- Thermodynamic Product Relations for Generalized Regular Black Hole
Abstract: We derive thermodynamic product relations for four-parametric regular black hole (BH) solutions of the Einstein equations coupled with a nonlinear electrodynamics source. The four parameters can be described by the mass (), charge (), dipole moment (), and quadrupole moment (), respectively. We study its complete thermodynamics. We compute different thermodynamic products, that is, area product, BH temperature product, specific heat product, and Komar energy product, respectively. Furthermore, we show some complicated function of horizon areas that is indeed mass-independent and could turn out to be universal.
PubDate: Mon, 25 Jul 2016 06:32:01 +000
- High Order QCD Predictions for Inclusive Production of Bosons in
Collisions at TeV
Abstract: Predictions of fiducial cross sections, differential cross sections, and lepton charge asymmetry are presented for the production of bosons with leptonic decay up to next-to-next-to-leading order (NNLO) in perturbative QCD. Differential cross sections of bosons and boson lepton charge asymmetry are computed as a function of lepton pseudorapidity for a defined fiducial region in collisions at TeV. Numerical results of fiducial cross section predictions are presented with the latest modern PDF models at next-to-leading order (NLO) and NNLO. It is found that the CT14 and NNPDF 3.0 predictions with NNLO QCD corrections are about 4% higher than the NLO CT14 and NNPDF 3.0 predictions while MMHT 2014 predictions with NLO QCD corrections are smaller than its NNLO QCD predictions by approximately 6%. In addition, the NNLO QCD corrections reduce the scale variation uncertainty on the cross section by a factor of 3.5. The prediction of central values and considered uncertainties are obtained using FEWZ 3.1 program.
PubDate: Tue, 19 Jul 2016 12:12:03 +000
- Solution of Deformed Einstein Equations and Quantum Black Holes
Abstract: Recently, one- and two-parameter deformed Einstein equations have been studied for extremal quantum black holes which have been proposed to obey deformed statistics by Strominger. In this study, we give a deeper insight into the deformed Einstein equations and consider the solutions of these equations for the extremal quantum black holes. We then represent the implications of the solutions, such that the deformation parameters lead the charged black holes to have a smaller mass than the usual Reissner-Nordström black holes. This reduction in mass of a usual black hole can be considered as a transition from classical to quantum black hole regime.
PubDate: Mon, 18 Jul 2016 16:32:02 +000
- On the UV Dimensions of Loop Quantum Gravity
Abstract: Planck-scale dynamical dimensional reduction is attracting more and more interest in the quantum-gravity literature since it seems to be a model independent effect. However, different studies base their results on different concepts of space-time dimensionality. Most of them rely on the spectral dimension; others refer to the Hausdorff dimension; and, very recently, the thermal dimension has also been introduced. We here show that all these distinct definitions of dimension give the same outcome in the case of the effective regime of Loop Quantum Gravity (LQG). This is achieved by deriving a modified dispersion relation from the hypersurface-deformation algebra with quantum corrections. Moreover, we also observe that the number of UV dimensions can be used to constrain the ambiguities in the choice of these LQG-based modifications of the Dirac space-time algebra. In this regard, introducing the polymerization of connections, that is, , we find that the leading quantum correction gives . This result may indicate that the running to the expected value of two dimensions is ongoing, but it has not been completed yet. Finding at ultrashort distances would require going beyond the effective approach we here present.
PubDate: Mon, 18 Jul 2016 14:24:40 +000
- Charged Massive Particle’s Tunneling from Charged Nonrotating
Abstract: In the tunneling framework of Hawking radiation, charged massive particle’s tunneling in charged nonrotating TeV-scale black hole is investigated. To this end, we consider natural cutoffs as a minimal length, a minimal momentum, and a maximal momentum through a generalized uncertainty principle. We focus on the role played by these natural cutoffs on the luminosity of charged nonrotating microblack hole by taking into account the full implications of energy and charge conservation as well as the backscattered radiation.
PubDate: Sun, 17 Jul 2016 14:19:38 +000
- Production of in Radiative Decays
Abstract: We investigate the production of in the process , where is assumed to be the counterpart of in the bottomonium sector as molecular state. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate their production ratios. Our results have shown that the production ratios for are orders of with reasonable cutoff parameter range . The sizeable production ratios may be accessible at the future experiments like forthcoming BelleII, which will provide important clues to the inner structures of the exotic state .
PubDate: Thu, 14 Jul 2016 16:00:57 +000
- Lepton Pair Čerenkov Radiation Emitted by Tachyonic Neutrinos:
Lorentz-Covariant Approach and IceCube Data
Abstract: Current experiments do not exclude the possibility that one or more neutrinos are very slightly superluminal or that they have a very small tachyonic mass. Important bounds on the size of a hypothetical tachyonic neutrino mass term are set by lepton pair Čerenkov radiation (LPCR), that is, by the decay channel , which proceeds via a virtual boson. Here, we use a Lorentz-invariant dispersion relation which leads to very tight constraints on the tachyonic mass of neutrinos; we also calculate decay and energy loss rates. A possible cutoff seen in the IceCube neutrino spectrum for PeV, due to the potential onset of LPCR, is discussed.
PubDate: Thu, 14 Jul 2016 09:57:30 +000
- Lorentz Invariance Violation and Modified Hawking Fermions Tunneling
Abstract: Recently the modified Dirac equation with Lorentz invariance violation has been proposed, which would be helpful to resolve some issues in quantum gravity theory and high energy physics. In this paper, the modified Dirac equation has been generalized in curved spacetime, and then fermion tunneling of black holes is researched under this correctional Dirac field theory. We also use semiclassical approximation method to get correctional Hamilton-Jacobi equation, so that the correctional Hawking temperature and correctional black hole’s entropy are derived.
PubDate: Tue, 12 Jul 2016 12:16:28 +000
- Do Small-Mass Neutrinos Participate in Gauge Transformations'
Abstract: Neutrino oscillation experiments presently suggest that neutrinos have a small but finite mass. If neutrinos have mass, there should be a Lorentz frame in which they can be brought to rest. This paper discusses how Wigner’s little groups can be used to distinguish between massive and massless particles. We derive a representation of the group which separates out the two sets of spinors: one set is gauge dependent and the other set is gauge invariant and represents polarized neutrinos. We show that a similar calculation can be done for the Dirac equation. In the large-momentum/zero-mass limit, the Dirac spinors can be separated into large and small components. The large components are gauge invariant, while the small components are not. These small components represent spin- non-zero-mass particles. If we renormalize the large components, these gauge invariant spinors represent the polarization of neutrinos. Massive neutrinos cannot be invariant under gauge transformations.
PubDate: Tue, 12 Jul 2016 07:34:32 +000
- Self-Regular Black Holes Quantized by means of an Analogue to Hydrogen
Abstract: We suggest a quantum black hole model that is based on an analogue to hydrogen atoms. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of nonextreme black holes are given by the probability densities of excited states with no angular momenta. Such an analogue is inclined to adopt quantization of black hole horizons. In this way, the total mass of black holes is quantized. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.
PubDate: Mon, 04 Jul 2016 11:26:01 +000
- On the Study of Oscillons in Scalar Field Theories: A New Approach
Abstract: We study configurations in one-dimensional scalar field theory, which are time-dependent, localized in space, and extremely long-lived, called oscillons. How the action of changing the minimum value of the field configuration representing the oscillon affects its behavior is investigated. We find that one of the consequences of this procedure is the appearance of a pair of oscillon-like structures presenting different amplitudes and frequencies of oscillation. We also compare our analytical results to numerical ones, showing excellent agreement.
PubDate: Thu, 30 Jun 2016 15:21:52 +000
- Effects of the FCNC Couplings in Production of New Heavy Quarks within
Models at the LHC
Abstract: We study the flavor changing neutral current couplings of new heavy quarks through the models at the LHC. We calculate the cross sections for the signal and the corresponding standard model background processes. Considering the present limits on the mass of new heavy quarks and the boson, we performed an analysis to investigate the parameter space (mixing and mass) through different models. For FCNC mixing parameter and the mass GeV and new heavy quark mass GeV at the LHC with TeV, we find the cross section for single production of new heavy quarks associated with top quarks as fb, fb, fb, and fb within the , , , and models, respectively. It is shown that the sensitivity would benefit from the flavor tagging.
PubDate: Thu, 30 Jun 2016 11:13:03 +000
- On a Neutral Particle with a Magnetic Quadrupole Moment in a Uniform
Effective Magnetic Field
Abstract: Quantum effects on a Landau-type system associated with a moving atom with a magnetic quadrupole moment subject to confining potentials are analysed. It is shown that the spectrum of energy of the Landau-type system can be modified, where the degeneracy of the energy levels can be broken. In three particular cases, it is shown that the analogue of the cyclotron frequency is modified, and the possible values of this angular frequency of the system are determined by the quantum numbers associated with the radial modes and the angular momentum and by the parameters associated with confining potentials in order that bound states solutions can be achieved.
PubDate: Tue, 28 Jun 2016 12:20:43 +000
- Comment on “Does the Equivalence between Gravitational Mass and
Energy Survive for a Composite Quantum Body?”
Abstract: Lebed has given an argument that when a hydrogen atom is transported slowly to a different gravitational potential, it has a certain probability of emitting a photon. He proposes a space-based experiment to detect this effect. I show here that his arguments also imply the existence of nuclear excitations, as well as an effect due to the earth’s motion in the sun’s potential. This is not consistent with previous results from underground radiation detectors. It is also in conflict with astronomical observations.
PubDate: Tue, 28 Jun 2016 06:31:17 +000
- Decays with Perturbative QCD Approach
Abstract: Besides the traditional strong and electromagnetic decay modes, meson can also decay through the weak interactions within the standard model of elementary particle. With anticipation of copious data samples at the running LHC and coming SuperKEKB experiments, the two-body nonleptonic bottom-changing decays () are investigated with perturbative QCD approach firstly. The absolute branching ratios for and decays are estimated to reach up to about and , respectively, which might possibly be measured by the future experiments.
PubDate: Tue, 21 Jun 2016 08:55:15 +000