Advances in High Energy Physics
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The latest articles from Hindawi Publishing Corporation
© 2014 , Hindawi Publishing Corporation . All rights reserved.

Emission of Protons and Charged Pions in p + Cu and p + Pb Collisions at 3, 8, and 15 GeV/c
Sun, 20 Jul 2014 06:28:10 +0000
http://www.hindawi.com/journals/ahep/2014/675192/
We present an analysis of proton and charged pion transverse momentum spectra of and reactions at 3, 8, and 15 GeV/c in the framework of a multisource thermal model. The spectra are compared closely with the experimental data of HARPCDP at all angular intervals. The result shows that the widths of the particle distributions in both and collisions decrease with increasing the angle for the same incident momentum.
J. H. Kang, Y. C. Qian, B. C. Li, and S. W. Wu
Copyright © 2014 J. H. Kang et al. All rights reserved.

Common Behaviors of SpinorType Instantons in 2D Thirring and 4D Gursey Fermionic Models
Thu, 17 Jul 2014 10:07:40 +0000
http://www.hindawi.com/journals/ahep/2014/148375/
We investigate two examples of conformal invariant pure spinor fermionic models, which admit particlelike solutions of the classical field equations. For different dimensions and quantum spinor numbers, the vector field visualizations of the models are constructed to provide a better understanding of the spinortype instanton dynamics in phase space. The hierarchical cluster analysis method investigations of the models are also presented. Finally, the autocorrelation and power spectrum graphs of models are constructed and frequencies of motions are defined.
Fatma Aydogmus and Eren Tosyali
Copyright © 2014 Fatma Aydogmus and Eren Tosyali. All rights reserved.

On Finite Interquark Potential in Driven by a Minimal Length
Thu, 17 Jul 2014 00:00:00 +0000
http://www.hindawi.com/journals/ahep/2014/142373/
We address the effect of a quantum gravity induced minimal length on a physical observable for threedimensional YangMills. Our calculation is done within stationary perturbation theory. Interestingly enough, we find an ultraviolet finite interaction energy, which contains a regularized logarithmic function and a linear confining potential. This result highlights the role played by the new quantum of length in our discussion.
Patricio Gaete
Copyright © 2014 Patricio Gaete. All rights reserved.

Gaseous Detector with SubkeV Threshold to Study Neutrino Scattering at Low Recoil Energies
Tue, 15 Jul 2014 12:27:49 +0000
http://www.hindawi.com/journals/ahep/2014/147046/
Gaseous detector with a subkeV electron equivalent threshold is a very perspective tool for the precision measurement of the neutrino magnetic moment and for observing coherent scattering of neutrinos on nuclei. The progress in the development of low noise electronics makes it possible to register the rare events at the threshold less than 100 eV. The construction of the gaseous detector is given and the typical pulses with amplitudes of a few eV observed on a bench scale installation are presented. The possible implications for future experiments are discussed.
A. V. Kopylov, I. V. Orekhov, V. V. Petukhov, and A. E. Solomatin
Copyright © 2014 A. V. Kopylov et al. All rights reserved.

Scattering and Bound States of DuffinKemmerPetiau Particles for Parameter Hyperbolic PöschlTeller Potential
Mon, 14 Jul 2014 12:11:09 +0000
http://www.hindawi.com/journals/ahep/2014/840907/
The DuffinKemmerPetiau (DKP) equation in the presence of a scalar potential is solved in one spatial dimension for the vector parameter Hyperbolic PöschlTeller (HPT) potential. In obtaining complete solutions we used the weak interaction approach and took the scalar and vector potentials in a correlated form. By looking at the asymptotic behaviors of the solutions, we identify the bound and scattering states. We calculate transmission () and reflection () probability densities and analyze their dependence on the potential shape parameters. Also we investigate the dependence of energy eigenvalues of the bound states on the potential shape parameters.
Hilmi Yanar, Ali Havare, and Kenan Sogut
Copyright © 2014 Hilmi Yanar et al. All rights reserved.

Theory of NeutrinoAtom Collisions: The History, Present Status, and BSM Physics
Thu, 10 Jul 2014 08:42:21 +0000
http://www.hindawi.com/journals/ahep/2014/569409/
An overview of the current theoretical studies on neutrinoatom scattering processes is presented. The ionization channel of these processes, which is studied in experiments searching for neutrino magnetic moments, is brought into focus. Recent developments in the theory of atomic ionization by impact of reactor antineutrinos are discussed. It is shown that the stepping approximation is well applicable for the data analysis practically down to the ionization threshold.
Konstantin A. Kouzakov and Alexander I. Studenikin
Copyright © 2014 Konstantin A. Kouzakov and Alexander I. Studenikin. All rights reserved.

Dirac Particle for the Position Dependent Mass in the Generalized Asymmetric WoodsSaxon Potential
Thu, 10 Jul 2014 00:00:00 +0000
http://www.hindawi.com/journals/ahep/2014/973847/
The onedimensional Dirac equation with position dependent mass in the generalized asymmetric WoodsSaxon potential is solved in terms of the hypergeometric functions. The transmission and reflection coefficients are obtained by considering the onedimensional electric current density for the Dirac particle and the equation describing the bound states is found by utilizing the continuity conditions of the obtained wave function. Also, by using the generalized asymmetric WoodsSaxon potential solutions, the scattering states are found out without making calculation for the WoodsSaxon, Hulthen, cusp potentials, and so forth, which are derived from the generalized asymmetric WoodsSaxon potential and the conditions describing transmission resonances and supercriticality are achieved. At the same time, the data obtained in this work are compared with the results achieved in earlier studies and are observed to be consistent.
Soner Alpdoğan and Ali Havare
Copyright © 2014 Soner Alpdoğan and Ali Havare. All rights reserved.

Chemical Potentials of Quarks Extracted from Particle Transverse Momentum Distributions in Heavy Ion Collisions at RHIC Energies
Tue, 08 Jul 2014 09:18:48 +0000
http://www.hindawi.com/journals/ahep/2014/742193/
In the framework of a multisource thermal model, the transverse momentum distributions of charged particles produced in nucleusnucleus (AA) and deuteronnucleus (dA) collisions at relativistic heavy ion collider (RHIC) energies are investigated by a twocomponent revised Boltzmann distribution. The calculated results are in agreement with the PHENIX experimental data. It is found that the source temperature increases obviously with increase of the particle mass and incident energy, but it does not show an obvious change with the collision centrality. Then, the values of chemical potentials for up, down, and strange quarks can be obtained from the antiparticle to particle yield ratios in a wide transverse momentum range. The relationship between the chemical potentials of quarks and the transverse momentum with different centralities is investigated, too.
Hong Zhao and FuHu Liu
Copyright © 2014 Hong Zhao and FuHu Liu. All rights reserved.

Transverse Momentum and Pseudorapidity Distributions of Charged Particles and Spatial Shapes of Interacting Events in PbPb Collisions at 2.76 TeV
Mon, 07 Jul 2014 07:51:29 +0000
http://www.hindawi.com/journals/ahep/2014/725739/
The transverse momentum and pseudorapidity distributions of charged
particles produced in PbPb collisions with different centrality intervals at centerofmass
energy per nucleon pair TeV have been analyzed by using the improved
multisource thermal model in which the whole interacting system and then the sources
are described by the Tsallis statistics. The modelling results are in agreement with experimental data of the ALICE Collaboration. The rapidity distributions of charged particles are obtained according to the extracted parameter values. The shapes of interacting
events (the dispersion plots of charged particles) are given in the momentum, rapidity,
velocity, and coordinate spaces. Meanwhile, the event shapes in different spaces consisted
by different transverse quantities and longitudinal quantities are presented.
FuHu Liu, YaQin Gao, Tian Tian, and BaoChun Li
Copyright © 2014 FuHu Liu et al. All rights reserved.

Eta Prime Gluonic Contribution to the Nucleon SelfEnergy in an Effective Theory
Mon, 07 Jul 2014 00:00:00 +0000
http://www.hindawi.com/journals/ahep/2014/841703/
We estimate a possible gluonic contribution to the selfenergy of a nucleon in an effective theory. The couplings of the topological charge density to nucleons give rise to OZI violating nucleon interactions. The oneloop selfenergy of nucleon arising due to these interactions is studied using a heavy baryon chiral perturbation theory. The divergences have been removed using appropriate form factors. The nontrivial structure of the QCD vacuum has also been taken into account. The numerical results are sensitive to the choice of the regulator to a nonnegligible extent. We get the total contribution to the nucleon mass coming from its interaction with the topological charge density % of the nucleon mass.
A. Upadhyay and J. P. Singh
Copyright © 2014 A. Upadhyay and J. P. Singh. All rights reserved.

Analytical BPS MaxwellHiggs Vortices
Wed, 02 Jul 2014 09:31:45 +0000
http://www.hindawi.com/journals/ahep/2014/210929/
We have established a prescription for the calculation of analytical vortex solutions in the context of generalized MaxwellHiggs models whose overall dynamics is controlled by two positive functions of the scalar field, namely, and . We have also determined a natural constraint between these functions and the Higgs potential , allowing the existence of axially symmetric Bogomol'nyiPrasadSommerfield (BPS) solutions possessing finite energy. Furthermore, when the generalizing functions are chosen suitably, the nonstandard BPS equations can be solved exactly. We have studied some examples, comparing them with the usual AbrikosovNielsenOlesen (ANO) solution. The overall conclusion is that the analytical selfdual vortices are wellbehaved in all relevant sectors, strongly supporting the consistency of the respective generalized models. In particular, our results mimic wellknown properties of the usual (numerical) configurations, as localized energy density, while contributing to the understanding of topological solitons and their description by means of analytical methods.
R. Casana, M. M. Ferreira Jr., E. da Hora, and C. dos Santos
Copyright © 2014 R. Casana et al. All rights reserved.

Anomalous Couplings in Collision at the LHC
Wed, 02 Jul 2014 08:35:50 +0000
http://www.hindawi.com/journals/ahep/2014/935840/
We have examined the constraints on the anomalous couplings through the process at the LHC by considering four forward detector acceptances: , , , and , where with and the energies of the photon and of the incoming proton, respectively. The sensitivity bounds on the anomalous couplings have been obtained at the 95% confidence level in a model independent effective Lagrangian approach. We have found that the bounds on these couplings can be highly improved compared to current experimental bounds.
M. Köksal and S. C. İnan
Copyright © 2014 M. Köksal and S. C. İnan. All rights reserved.

Exact Solutions of the Dirac Hamiltonian on the Sphere under Hyperbolic Magnetic Fields
Tue, 01 Jul 2014 11:44:53 +0000
http://www.hindawi.com/journals/ahep/2014/186425/
Twodimensional massless Dirac Hamiltonian under the influence of hyperbolic magnetic fields is mentioned in curved space. Using a spherical surface parameterization, the Dirac operator on the sphere is presented and the system is given as two supersymmetric partner Hamiltonians which coincides with the position dependent mass Hamiltonians. We introduce two ansatzes for the component of the vector potential to acquire effective solvable models, which are RosenMorse II potential and the model given Midya and Roy, whose bound states are Jacobi type polynomials, and we adapt our work to these special models under some parameter restrictions. The energy spectrum and the eigenvectors are found for RosenMorse II potential. On the other hand, complete solutions are given for the second system. The vector and the effective potentials with their eigenvalues are sketched for each system.
Özlem Yeşiltaş
Copyright © 2014 Özlem Yeşiltaş. All rights reserved.

Astronomical Signatures of Dark Matter
Thu, 26 Jun 2014 00:00:00 +0000
http://www.hindawi.com/journals/ahep/2014/878203/
Several independent astronomical observations in different wavelength bands reveal the existence of much larger quantities of matter than what we would deduce from assuming a solar mass to light ratio. They are very high velocities of individual galaxies within clusters of galaxies, higher than expected rotation rates of stars in the outer regions of galaxies, 21 cm line studies indicative of increasing mass to light ratios with radius in the halos of spiral galaxies, hot gaseous Xray emitting halos around many elliptical galaxies, and clusters of galaxies requiring a much larger component of unseen mass for the hot gas to be bound. The level of gravitational attraction needed for the spatial distribution of galaxies to evolve from the small perturbations implied by the very slightly anisotropic cosmic microwave background radiation to its current weblike configuration requires much more mass than is observed across the entire electromagnetic spectrum. Distorted shapes of galaxies and other features created by gravitational lensing in the images of many astronomical objects require an amount of dark matter consistent with other estimates. The unambiguous detection of dark matter and more recently evidence for dark energy has positioned astronomy at the frontier of fundamental physics as it was in the 17th century.
Paul Gorenstein and Wallace Tucker
Copyright © 2014 Paul Gorenstein and Wallace Tucker. All rights reserved.

The Annual Modulation Signature for Dark Matter: DAMA/LIBRAPhase1 Results and Perspectives
Tue, 24 Jun 2014 00:00:00 +0000
http://www.hindawi.com/journals/ahep/2014/605659/
The results obtained with the total exposure of 1.04 ton × yr collected by DAMA/LIBRAphase1 deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. during 7 annual cycles are summarized. The DAMA/LIBRAphase1 and the former DAMA/NaI data (cumulative exposure 1.33 ton × yr, corresponding to 14 annual cycles) give evidence at 9.3 σ C.L. for the presence of Dark Matter (DM) particles in the galactic halo, on the basis of the exploited model independent DM annual modulation signature by using highly radiopure NaI(Tl) target. The modulation amplitude of the singlehit events in the (2–6) keV energy interval is cpd/kg/keV; the measured phase is days and the measured period is yr; values are in a good well in agreement with those expected for DM particles. No systematic or side reactions able to mimic the exploited DM signature have been found or suggested by anyone over more than a decade. Some of the perspectives of the presently running DAMA/LIBRAphase2 are outlined.
Rita Bernabei, Pierluigi Belli, Fabio Cappella, Vincenzo Caracciolo, Simone Castellano, Riccardo Cerulli, Chang Jang Dai, Annelisa d’Angelo, Silio d’Angelo, Alessandro Di Marco, H. L. He, Antonella Incicchitti, H. H. Kuang, X. H. Ma, Francesco Montecchia, X. D. Sheng, Rui Guang Wang, and ZiPiao Ye
Copyright © 2014 Rita Bernabei et al. All rights reserved.

Experimental Tests of Quantum Gravity and Exotic Quantum Field Theory Effects
Mon, 23 Jun 2014 12:16:27 +0000
http://www.hindawi.com/journals/ahep/2014/192712/
Emil T. Akhmedov, Stephen Minter, Piero Nicolini, and Douglas Singleton
Copyright © 2014 Emil T. Akhmedov et al. All rights reserved.

Remarks on the SpinOne DuffinKemmerPetiau Equation in the Presence of Nonminimal Vector Interactions in Dimensions
Thu, 19 Jun 2014 12:47:50 +0000
http://www.hindawi.com/journals/ahep/2014/784072/
We point out a misleading treatment in the recent literature regarding analytical solutions for nonminimal vector interaction for spinone particles in the context of the DuffinKemmerPetiau (DKP) formalism. In those papers, the authors use improperly the nonminimal vector interaction endangering in their main conclusions. We present a few properties of the nonminimal vector interactions and also present the correct equations to this problem. We show that the solution can be easily found by solving Schrödingerlike equations. As an application of this procedure, we consider spinone particles in presence of a nonminimal vector linear potential.
L. B. Castro and L. P. de Oliveira
Copyright © 2014 L. B. Castro and L. P. de Oliveira. All rights reserved.

Nuclear Stopping in Central Au+Au Collisions at RHIC Energies
Tue, 17 Jun 2014 09:02:29 +0000
http://www.hindawi.com/journals/ahep/2014/946934/
Nuclear stopping in central Au+Au collisions at relativistic heavyion collider (RHIC) energies is studied in the framework of a cascade mode and the modified ultrarelativistic quantum molecular dynamics (UrQMD) transport model. In the modified mode, the mean field potentials of both formed and “preformed” hadrons (from string fragmentation) are considered. It is found that the nuclear stopping is increasingly influenced by the meanfield potentials in the projectile and target regions with the increase of the reaction energy. In the central region, the calculations of the cascade model considering the modifying factor can describe the experimental data of the PHOBOS collaboration.
Ying Yuan and Nana Guan
Copyright © 2014 Ying Yuan and Nana Guan. All rights reserved.

Neutrinos as Probes of Lorentz Invariance
Mon, 16 Jun 2014 06:29:53 +0000
http://www.hindawi.com/journals/ahep/2014/962410/
Neutrinos can be used to search for deviations from exact Lorentz invariance. The worldwide experimental program in neutrino physics makes these particles a remarkable tool to search for a variety of signals that could reveal minute relativity violations. This paper reviews the generic experimental signatures of the breakdown of Lorentz symmetry in the neutrino sector.
Jorge S. Díaz
Copyright © 2014 Jorge S. Díaz. All rights reserved.

Constraints on Heavy Neutrino and SUSY Parameters Derived from the Study of Neutrinoless Double Beta Decay
Mon, 16 Jun 2014 00:00:00 +0000
http://www.hindawi.com/journals/ahep/2014/724315/
New constraints on the lepton number violating (LNV) parameters are derived from the analysis of the neutrinoless double beta () decay in the hypothesis that this process would occur through the exchange of heavy neutrinos and/or SUSY particles. For derivation, we use new values of both phase space factors (PSFs) and nuclear matrix elements (NMEs) calculated with numerical codes developed recently, as well as the most recent experimental lifetimes. The NMEs are computed with a shell model (ShM) code for , , and nuclei, while at present similar ShM results are available only for the first nucleus. We compare our results with similar ones from literature, obtained with ShM, QRPA, and IBM2 methods, and conclude that more results are needed for a relevant analysis on the validity of NMEs associated with these decay mechanisms.
Andrei Neacsu and Sabin Stoica
Copyright © 2014 Andrei Neacsu and Sabin Stoica. All rights reserved.

Searches for Dark Matter with Superheated Liquid Techniques
Thu, 12 Jun 2014 00:00:00 +0000
http://www.hindawi.com/journals/ahep/2014/387493/
This is a short review of the detectors based on the superheated liquid techniques, including continuously sensitive bubble chambers, superheated droplet detectors (SDD) and Geysers.
A. Pullia
Copyright © 2014 A. Pullia. All rights reserved.

A Note on Asymmetric Thick Branes
Wed, 11 Jun 2014 12:42:06 +0000
http://www.hindawi.com/journals/ahep/2014/276729/
We study asymmetric thick braneworld scenarios, generated after adding a constant to the superpotential associated with the scalar field. We study in particular models with odd and even polynomial superpotentials, and we show that asymmetric brane can be generated irrespective of the potential being symmetric or asymmetric. We study in addition the nonpolynomial sineGordon like model, also constructed with the inclusion of a constant in the standard superpotential, and we investigate gravitational stability of the asymmetric brane. The results suggest robustness of the new braneworld scenarios and add further possibilities of the construction of asymmetric branes.
D. Bazeia, R. Menezes, and R. da Rocha
Copyright © 2014 D. Bazeia et al. All rights reserved.

Physics of Quark Gluon Plasma: An Update and the Status Report
Mon, 09 Jun 2014 06:26:11 +0000
http://www.hindawi.com/journals/ahep/2014/825041/
Jan E. Alam, Edward SarkisyanGrinbaum, and Subrata Bhattacharyya
Copyright © 2014 Jan E. Alam et al. All rights reserved.

Influence of Neutral Currents on Electron and Gamma Polarizations in the Process
Thu, 05 Jun 2014 07:36:23 +0000
http://www.hindawi.com/journals/ahep/2014/217389/
The differential cross section of electron inelastic scattering by nuclei followed by γ radiation is calculated using the multipole decomposition of the hadronic currents and by taking into account the longitudinal polarization of the initial electron and the circular polarization of the γ radiation. We performed the analysis of the angular and energy dependence of the degree of electron and photon polarization which can yield information on values of weak neutral currents parameters.
N. V. Samsonenko, Adamou Ousmane Manga, Almoustapha Aboubacar, and Aboubacar Moussa
Copyright © 2014 N. V. Samsonenko et al. All rights reserved.

Dark Atoms and Dark Radiation
Wed, 04 Jun 2014 09:25:18 +0000
http://www.hindawi.com/journals/ahep/2014/913856/
Maxim Khlopov, Konstantin Belotsky, JeanRené Cudell, and Chris Kouvaris
Copyright © 2014 Maxim Khlopov et al. All rights reserved.

Dynamics of Interacting Tachyonic Teleparallel Dark Energy
Tue, 03 Jun 2014 12:37:15 +0000
http://www.hindawi.com/journals/ahep/2014/631630/
We consider a tachyon scalar field which is nonminimally coupled to gravity in the framework of teleparallel gravity. We analyze the phasespace of the model, known as tachyonic teleparallel dark energy, in the presence of an interaction between dark energy and background matter. We find that although there exist some latetime accelerated attractor solutions, there is no scaling attractor. So, unfortunately interacting tachyonic teleparallel dark energy cannot alleviate the coincidence problem.
Ali Banijamali
Copyright © 2014 Ali Banijamali. All rights reserved.

Black Holes Physics
Wed, 28 May 2014 12:00:51 +0000
http://www.hindawi.com/journals/ahep/2014/453586/
Xiaoxiong Zeng, Christian Corda, and Deyou Chen
Copyright © 2014 Xiaoxiong Zeng et al. All rights reserved.

Constraints on Light Neutrino Parameters Derived from the Study of Neutrinoless Double Beta Decay
Wed, 28 May 2014 11:00:15 +0000
http://www.hindawi.com/journals/ahep/2014/745082/
The study of the neutrinoless double beta decay mode can provide us with important information on the neutrino properties, particularly on the electron neutrino absolute mass. In this work we revise the present constraints on the neutrino mass parameters derived from the decay analysis of the experimentally interesting nuclei. We use the latest results for the phase space factors (PSFs) and nuclear matrix elements (NMEs), as well as for the experimental lifetime limits. For the PSFs we use values computed with an improved method reported very recently. For the NMEs we use values chosen from the literature on a casebycase basis, taking advantage of the consensus reached by the community on several nuclear ingredients used in their calculation. Thus, we try to restrict the range of spread of the NME values calculated with different methods and, hence, to reduce the uncertainty in deriving limits for the Majorana neutrino mass parameter. Our results may be useful to have an updated image on the present neutrino mass sensitivities associated with measurements for different isotopes and to better estimate the range of values of the neutrino masses that can be explored in the future double beta decay (DBD) experiments.
Sabin Stoica and Andrei Neacsu
Copyright © 2014 Sabin Stoica and Andrei Neacsu. All rights reserved.

Anomalous Factors for Charged Leptons in a Fractional CoarseGrained Approach
Sun, 25 May 2014 12:54:31 +0000
http://www.hindawi.com/journals/ahep/2014/572180/
We here propose to extend the concept of helicity to include it in a fractional scenario and we write down the left and the righthanded Weyl equations from first principles in this extended framework. Next, by coupling the different fractional
Weyl sectors by means of a mass parameter, we arrive at the fractional version of Dirac's equation which, whenever coupled
to an external electromagnetic field and reduced to the nonrelativistic regime, yields a fractional Paulitype equation.
From the latter, we are able to present an explicit expression for the gyromagnetic ratio of charged fermions in terms of
the fractionality parameter. We then focus our efforts to relate the coarsegrained property of spacetime to fractionality
and to the () anomalies of the different leptonic species.
J. Weberszpil and J. A. HelayëlNeto
Copyright © 2014 J. Weberszpil and J. A. HelayëlNeto. All rights reserved.

Study of and Decays via QCD Sum Rules
Sun, 25 May 2014 12:16:41 +0000
http://www.hindawi.com/journals/ahep/2014/432903/
We present the calculation of the form factor of the and decays in the frame work of QCD sum rules. We also find branching ratio = which is in agreement with the experimental data. Furthermore, we estimate the MeV, where experimental bound for full width of is MeV.
V. Bashiry
Copyright © 2014 V. Bashiry. All rights reserved.