Advances in High Energy Physics
[SJR: 0.892] [H-I: 19] [16 followers] Follow
Open Access journal
ISSN (Print) 1687-7357 - ISSN (Online) 1687-7365
Published by Hindawi [334 journals]
- A New Method for Obtaining the Baryons Mass under the Killingbeck Plus
Isotonic Oscillator Potentials
Abstract: The spectrum of ground state and excited baryons (N, Δ, Λ, Σ, , and Ω particles) has been investigated by using nonrelativistic quantum mechanics under the Killingbeck plus isotonic oscillator potentials. Using the Jacobi coordinates, anzast method, and generalized Gürsey Radicati (GR) mass formula the three-body-wave equation is solved to calculate the different states of the considered baryons. A comparison between our calculations and the available experimental data shows that the position of the Roper resonances of the nucleon, the ground states, and the excited multiplets up to three GeV are in general well reproduced. Also one can conclude that the interaction between the quark constituents of baryon resonances could be described adequately by using the combination of Killingbeck and isotonic oscillator potentials form.
PubDate: Thu, 22 Sep 2016 13:09:40 +000
- Thermodynamic Partition Function from Quantum Theory for Black Hole
Horizons in Loop Quantum Gravity
Abstract: We establish the link between the thermodynamics and the quantum theory of black hole horizons through the construction of the thermodynamic partition function, partly based on some physically plausible arguments, by beginning from the description of quantum states of the horizon, considering loop quantum gravity (LQG) as the underlying theory. Although the effective “thermalized” form of the partition function has been previously used in the literature to study the effect of thermal fluctuations of the black hole horizon, nonetheless the direct link to any existing quantum theory (which is here taken to be LQG), especially a derivation of the partition function from the quantum states of the horizon, appears to be hitherto absent. This work is an attempt to bridge this small, but essential, gap that appears to be present between the existing literature of quantum theory and thermodynamics of black holes. Furthermore, it may be emphasized that this work is only concerned with the metric independent approaches to black hole thermodynamics.
PubDate: Wed, 21 Sep 2016 14:12:15 +000
- Review of Anisotropic Flow Correlations in Ultrarelativistic Heavy-Ion
Abstract: Anisotropic flow phenomena are a key probe of the existence of Quark-Gluon Plasma. Several new observables associated with correlations between anisotropic flow harmonics are developed, which are expected to be sensitive to the initial fluctuations and transport properties of the created matter in heavy-ion collisions. I review recent developments of correlations of anisotropic flow harmonics. The experimental measurements, together with the comparisons to theoretical model calculations, open up new opportunities of exploring novel QCD dynamics in heavy-ion collisions.
PubDate: Tue, 20 Sep 2016 13:33:14 +000
- An Experimental Review on Elliptic Flow of Strange and Multistrange
Hadrons in Relativistic Heavy Ion Collisions
Abstract: Strange hadrons, especially multistrange hadrons, are good probes for the early partonic stage of heavy ion collisions due to their small hadronic cross sections. In this paper, I give a brief review on the elliptic flow measurements of strange and multistrange hadrons in relativistic heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC).
PubDate: Mon, 19 Sep 2016 13:06:49 +000
- Relativistic Energy Analysis of Five-Dimensional q-Deformed Radial
Rosen-Morse Potential Combined with q-Deformed Trigonometric Scarf
Noncentral Potential Using Asymptotic Iteration Method
Abstract: We study the exact solution of Dirac equation in the hyperspherical coordinate under influence of separable -deformed quantum potentials. The -deformed hyperbolic Rosen-Morse potential is perturbed by -deformed noncentral trigonometric Scarf potentials, where all of them can be solved by using Asymptotic Iteration Method (AIM). This work is limited to spin symmetry case. The relativistic energy equation and orbital quantum number equation have been obtained using Asymptotic Iteration Method. The upper radial wave function equations and angular wave function equations are also obtained by using this method. The relativistic energy levels are numerically calculated using Matlab, and the increase of radial quantum number causes the increase of bound state relativistic energy level in both dimensions and . The bound state relativistic energy level decreases with increasing of both deformation parameter and orbital quantum number .
PubDate: Thu, 15 Sep 2016 16:09:18 +000
- Holographic Schwinger Effect in a Confining D3-Brane Background with
Abstract: Using the AdS/CFT correspondence, we investigate the Schwinger effect in a confining D3-brane background with chemical potential. The potential between a test particle pair on the D3-brane in an external electric field is obtained. The critical field in this case is calculated. Also, we apply numerical method to evaluate the production rate for various cases. The results imply that the presence of chemical potential tends to suppress the pair production effect.
PubDate: Thu, 15 Sep 2016 07:35:41 +000
- Dynamics of an Anisotropic Universe in Theory
Abstract: Dynamics of an anisotropic universe is studied in gravity using a rescaled functional , where is the Ricci Scalar and is the trace of energy-momentum tensor. Three models have been constructed assuming a power law expansion of the universe. Physical features of the models are discussed. The model parameters are constrained from a dimensional analysis. It is found from the work that the anisotropic Bianchi type () model in the modified gravity generally favours a quintessence phase when the parameter is either or . We may not get viable models in conformity with the present day observation for .
PubDate: Wed, 14 Sep 2016 12:07:13 +000
- Large Rapidity Gap Method to Select Soft Diffraction Dissociation at the
Abstract: In proton-proton (pp) collisions, any process involves exchanging the vacuum quantum numbers is known as diffractive process. A diffractive process with no large is called soft diffractive process. The diffractive processes are important for understanding nonperturbative QCD effects and they also constitute a significant fraction of the total pp cross section. The diffractive events are typically characterized by a region of the detector without particles, known as a rapidity gap. In order to observe diffractive events in this way, we consider the pseudorapidity acceptance in the forward region of the ATLAS and CMS detectors at the Large Hadron Collider (LHC) and discuss the methods to select soft diffractive dissociation for pp collisions at TeV. It is shown that, in the limited detector rapidity acceptance, it is possible to select diffractive dissociation events by requiring a rapidity gap in the event; however, without using forward detectors, it seems not possible to fully separate single and double diffractive dissociation events. The Zero Degree Calorimeters can be used to distinguish the type of the diffractive processes up to a certain extent.
PubDate: Thu, 08 Sep 2016 17:58:44 +000
- Spectra and Elliptic Flow of (Multi)Strange Hadrons at RHIC and LHC within
Viscous Hydrodynamics + Hadron Cascade Hybrid Model
Abstract: Using the ()-dimensional ultrarelativistic viscous hydrodynamics + hadron cascade, VISHNU, hybrid model, we study the -spectra and elliptic flow of , , and in Au + Au collisions at = 200 GeV and in Pb + Pb collisions at = 2.76 TeV. Comparing our model results with the data measurements, we find that the VISHNU model gives good descriptions of the measurements of these strange and multistrange hadrons at several centrality classes at RHIC and LHC. Mass ordering of elliptic flow among , , , , , and are further investigated and discussed at the two collision systems. We find that, at both RHIC and LHC, mass ordering among , , , and is fairly reproduced within the VISHNU hybrid model, and more improvements are needed to be implemented for well describing mass ordering among , , and .
PubDate: Wed, 07 Sep 2016 11:45:15 +000
- Charged Particles Multiplicity and Scaling Violation of Fragmentation
Functions in Electron-Positron Annihilation
Abstract: By the use of data from the annihilation process of electron-positron in AMY detector at 60 GeV center of mass energy, charged particles multiplicity distribution is obtained and fitted with the KNO scaling. Then, momentum spectra of charged particles and momentum distribution with respect to the jet axis are obtained, and the results are compared to the different models of QCD; also, the distribution of fragmentation functions and scaling violations are studied. It is being expected that the scaling violations of the fragmentation functions of gluon jets are stronger than the quark ones. One of the reasons for such case is that splitting function of quarks is larger than splitting function of gluon.
PubDate: Mon, 05 Sep 2016 16:21:54 +000
- Investigation of Free Particle Propagator with Generalized Uncertainty
Abstract: We consider the Schrödinger equation with a generalized uncertainty principle for a free particle. We then transform the problem into a second-order ordinary differential equation and thereby obtain the corresponding propagator. The result of ordinary quantum mechanics is recovered for vanishing minimal length parameter.
PubDate: Thu, 01 Sep 2016 16:04:17 +000
- Israel-Stewart Approach to Viscous Dissipative Extended Holographic Ricci
Dark Energy Dominated Universe
Abstract: This paper reports a study on the truncated Israel-Stewart formalism for bulk viscosity using the extended holographic Ricci dark energy (EHRDE). Under the consideration that the universe is dominated by EHRDE, the evolution equation for the bulk viscous pressure in the framework of the truncated Israel-Stewart theory has been taken as , where is the relaxation time and is the bulk viscosity coefficient. Considering effective pressure as a sum of thermodynamic pressure of EHRDE and bulk viscous pressure, it has been observed that under the influence of bulk viscosity the EoS parameter is behaving like phantom, that is, . It has been observed that the magnitude of the effective pressure is decaying with time. We also investigated the case for a specific choice of scale factor; namely, . For this choice we have observed that a transition from quintessence to phantom is possible for the equation of state parameter. However, the CDM phase is not attainable by the state-finder trajectories for this choice. Finally it has been observed that in both of the cases the generalized second law of thermodynamics is valid for the viscous EHRDE dominated universe enveloped by the apparent horizon.
PubDate: Thu, 01 Sep 2016 13:29:34 +000
- Gravity’s Rainbow and Its Einstein Counterpart
Abstract: Motivated by UV completion of general relativity with a modification of a geometry at high energy scale, it is expected to have an energy dependent geometry. In this paper, we introduce charged black hole solutions with power Maxwell invariant source in the context of gravity’s rainbow. In addition, we investigate two classes of gravity’s rainbow solutions. At first, we study energy dependent gravity without energy-momentum tensor, and then we obtain gravity’s rainbow in the presence of conformally invariant Maxwell source. We study geometrical properties of the mentioned solutions and compare their results. We also give some related comments regarding thermodynamical behavior of the obtained solutions and discuss thermal stability of the solutions.
PubDate: Wed, 31 Aug 2016 13:01:06 +000
- 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