Abstract: Employing a pseudo-orthonormal coordinate-free approach, the solutions to the Klein–Gordon and Dirac equations for particles in Melvin spacetime are derived in terms of Heun’s biconfluent functions. PubDate: Mon, 11 Jun 2018 08:36:56 +000

Abstract: We study the modification of thermodynamic properties of Schwarzschild and Reissner-Nordström black hole in the framework of generalized uncertainty principle with correction terms up to fourth order in momentum uncertainty. The mass-temperature relation and the heat capacity for these black holes have been investigated. These have been used to obtain the critical and remnant masses. The entropy expression using this generalized uncertainty principle reveals the area law up to leading order logarithmic corrections and subleading corrections of the form . The mass output and radiation rate using Stefan-Boltzmann law have been computed which show deviations from the standard case and the case with the simplest form for the generalized uncertainty principle. PubDate: Thu, 07 Jun 2018 00:00:00 +000

Abstract: The Schrödinger equation where is rewritten as a more popular form of a second order differential equation by taking a similarity transformation with . The Schrödinger invariant can be calculated directly by the Schwarzian derivative and the invariant of the differential equation . We find an important relation for a moving particle as and thus explain the reason why the Schrödinger invariant keeps constant. As an illustration, we take the typical Heun’s differential equation as an object to construct a class of soluble potentials and generalize the previous results by taking different transformation as before. We get a more general solution through integrating directly and it includes all possibilities for those parameters. Some particular cases are discussed in detail. The results are also compared with those obtained by Bose, Lemieux, Batic, Ishkhanyan, and their coworkers. It should be recognized that a subtle and different choice of the transformation also related to will lead to difficult connections to the results obtained from other different approaches. PubDate: Sun, 03 Jun 2018 00:00:00 +000

Abstract: The relativistic quantum decay laws of moving unstable particles are analyzed for a general class of mass distribution densities which behave as power laws near the (nonvanishing) lower bound of the mass spectrum. The survival probability , the instantaneous mass , and the instantaneous decay rate of the moving unstable particle are evaluated over short and long times for an arbitrary value of the (constant) linear momentum. The ultrarelativistic and nonrelativistic limits are studied. Over long times, the survival probability is approximately related to the survival probability at rest by a scaling law. The scaling law can be interpreted as the effect of the relativistic time dilation if the asymptotic value of the instantaneous mass is considered as the effective mass of the unstable particle over long times. The effective mass has magnitude at rest and moves with linear momentum or, equivalently, with constant velocity . The instantaneous decay rate is approximately independent of the linear momentum , over long times, and, consequently, is approximately invariant by changing reference frame. PubDate: Tue, 29 May 2018 10:11:17 +000

Abstract: The energy eigenvalues with any states and mass of heavy quark-antiquark system (quarkonium) are obtained by using Asymptotic Iteration Method in the view of nonrelativistic quantum chromodynamics, in which the quarks are considered as spinless for easiness and are bounded by Cornell potential. A semianalytical formula for energy eigenvalues and mass is achieved via the method in scope of the perturbation theory. The accuracy of this formula is checked by comparing the eigenvalues with the ones numerically obtained in this study and with exact ones in literature. Furthermore, semianalytical formula is applied to c, b, and c meson systems for comparing the masses with the experimental data. PubDate: Tue, 29 May 2018 06:50:46 +000

Abstract: Lorentz and CPT symmetries may be violated in new physics that emerges at very high energy scale, that is, at the Planck scale. The differential cross section of the Möller scattering due to Lorentz violation at finite temperature is calculated. Lorentz-violating effects emerge from an interaction vertex due to a CPT-odd nonminimal coupling in the covariant derivative. The finite temperature effects are determined using the Thermo Field Dynamics (TFD) formalism. PubDate: Thu, 24 May 2018 08:24:12 +000

Abstract: We propose in this paper a new regularization, where integer-order differential operators are replaced by fractional-order operators. Regularization for quantum field theories based on application of the Riesz fractional derivatives of noninteger orders is suggested. The regularized loop integrals depend on parameter that is the order of the fractional derivative. The regularization procedure is demonstrated for scalar massless fields in -theory on -dimensional pseudo-Euclidean space-time. PubDate: Wed, 23 May 2018 07:54:59 +000

Abstract: The present paper aims to complete an earlier paper where the acoustic world was introduced. This is accomplished by analyzing the interactions which occur between the inhomogeneities of the acoustic medium, which are induced by the acoustic vibrations travelling in the medium. When a wave packet travels in a medium, the medium becomes inhomogeneous. The spherical wave packet behaves like an acoustic spherical lens for the acoustic plane waves. According to the principle of causality, there is an interaction between the wave and plane wave packet. In specific conditions, the wave packet behaves as an acoustic black hole. PubDate: Wed, 23 May 2018 07:42:48 +000

Abstract: The discovery of neutrino masses has raised the importance of studies in the context of neutrinoless double beta decay (), which constitutes a landmark for lepton number violation (LNV). The standard interpretation is that the light massive neutrinos that we observed oscillating in terrestrial experiments mediate double beta decay. In the minimal 3-3-1 model (3-3-1M), object of our study, there is an additional contribution that stems from the mixing between a new charged vector boson, , and the Standard Model boson. Even after setting this mixing to be very small, we show that tight constraints arise from the nonobservation of . Indeed, we derive bounds on the mass of the gauge boson that might exceed those from collider probes and most importantly push the scale of symmetry breaking beyond its validity, leading to an exclusion bound for the minimal 3-3-1 model. PubDate: Wed, 23 May 2018 06:41:51 +000

Abstract: The fermionic Green’s functions of QCD exhibit an unexpected property of effective locality, which appears to be exact, involving no approximation. This property is nonperturbative, resulting from a full integration of the elementary gluonic degrees of freedom of QCD. Recalling, correcting, and extending the derivations of effective locality, focus is put on the way nonabelian gauge invariance gets realized in the fermionic nonperturbative regime of QCD. PubDate: Tue, 22 May 2018 07:36:57 +000

Abstract: We solve the -dimensional Schrödinger equation with hyperbolic Pöschl-Teller potential plus a generalized ring-shaped potential. After the separation of variable in the hyperspherical coordinate, we used Nikiforov-Uvarov (NU) method to solve the resulting radial equation and obtain explicitly the energy level and the corresponding wave function in closed form. The solutions to the energy eigenvalues and the corresponding wave functions are obtained using the NU method as well. PubDate: Tue, 22 May 2018 00:00:00 +000

Abstract: An effective approach is presented to produce Schrödinger-like equation for the spinor components from Dirac equation. Considering electrostatic potential as a constant value yields a second-order differential equation that is comparable with the well-known solvable models in the nonrelativistic quantum mechanics for the certain bound state energy spectrum and the well-known potentials. By this comparison, the gauge field potential and the relativistic energy can be written by the nonrelativistic models and the spinors will be related to the orthogonal polynomials. It has also shown that the upper spinors wave functions based on the orthogonal polynomials can be given in terms of the Rodrigues representations. Association with the Rodrigues representations of orthogonal polynomials has also been investigated in the lower spinor components, since they are related to the upper spinor components according to first-order differential equation that is attained from Dirac equation. PubDate: Sun, 20 May 2018 09:07:57 +000

Abstract: The entropic force attracts a lot of interest for its multifunctional properties. For instance, Einstein’s field equation, Newton’s law of gravitation, and the Friedmann equation can be derived from the entropic force. In this paper, utilizing a new kind of rainbow gravity model that was proposed by Magueijo and Smolin, we explore the quantum gravity corrections to the entropic force. First, we derive the modified thermodynamics of a rainbow black hole via its surface gravity. Then, according to Verlinde’s theory, the quantum corrections to the entropic force are obtained. The result shows that the modified entropic force is related not only to the properties of the black hole but also to the Planck length and the rainbow parameter . Furthermore, based on the rainbow gravity corrected entropic force, the modified Einstein field equation and the modified Friedmann equation are also derived. PubDate: Tue, 15 May 2018 00:00:00 +000

Abstract: We have studied that the implication of a large value of the effective Majorana neutrino mass in case of neutrino mass matrices has either two equal elements and one zero element (popularly known as hybrid texture) or two equal cofactors and one zero minor (popularly known as inverse hybrid texture) in the flavor basis. In each of these cases, four out of sixty phenomenologically possible patterns predict near maximal atmospheric neutrino mixing angle in the limit of large effective Majorana neutrino mass. This feature remains irrespective of the experimental data on solar and reactor mixing angles. In addition, we have also performed the comparative study of all the viable cases of hybrid and inverse hybrid textures at 3 CL. PubDate: Mon, 14 May 2018 00:00:00 +000

Abstract: We study the identified particle ratios produced at mid-rapidity () in heavy-ion collisions, along with their correlations with the collision energy. We employ our earlier proposed unified statistical thermal freeze-out model (USTFM), which incorporates the effects of both longitudinal and transverse hydrodynamic flow in the hot hadronic system. A fair agreement seen between the experimental data and our model results confirms that the particle production in these collisions is of statistical nature. The variation of the chemical freeze-out temperature and the baryon chemical potential with respect to collision energies is studied. The chemical freeze-out temperature is found to be almost constant beyond the RHIC energy and is found to be close to the QCD predicted phase-transition temperature suggesting that the chemical freeze-out occurs soon after the hadronization takes place. The vanishing value of chemical potential at LHC indicates very high degree of nuclear transparency in the collision. PubDate: Sun, 13 May 2018 09:38:19 +000

Abstract: The potential of the process in the first stage of CLIC considering center-of-mass energy of 380 GeV and assuming the baseline integrated luminosity of 500 is examined to probe CP-conserving dimension-six operators in a model-independent Standard Model effective field theory framework. In the analysis, a detailed fast simulation on signal processes and dominant backgrounds is performed including parton showering with PYTHIA and detector simulation based on ILD type detector with DELPHES in MadGraph. The obtained best limits on ,, and are , , and , respectively. PubDate: Sun, 13 May 2018 00:00:00 +000

Abstract: The strong coupling constants of newly observed baryons with spins and decaying into are estimated within light cone QCD sum rules. The calculations are performed within two different scenarios on quantum numbers of baryons: (a) all newly observed baryons are negative parity baryons; that is, the ,,, and have quantum numbers and states, respectively; (b) the states and have quantum numbers and , while the states and have the quantum numbers and , respectively. By using the obtained results on the coupling constants, we calculate the decay widths of the corresponding decay. The results on decay widths are compared with the experimental data of LHC Collaboration. We found out that the predictions on decay widths within these scenarios are considerably different from the experimental data; that is, both considered scenarios are ruled out. PubDate: Thu, 10 May 2018 00:00:00 +000

Abstract: A brief review is given of the current state of the problem of neutrino pair emission through neutral weak currents caused by the Cooper pairs breaking and formation (PBF) in superfluid baryon matter at thermal equilibrium. The cases of singlet-state pairing with isotropic superfluid gap and spin-triplet pairing with an anisotropic gap are analyzed with allowance for the anomalous weak interactions caused by superfluidity. It is shown that taking into account the anomalous weak interactions in both the vector and axial channels is very important for a correct description of neutrino energy losses through the PBF processes. The anomalous contributions lead to an almost complete suppression of the PBF neutrino emission in spin-singlet superfluids and strong reduction of the PBF neutrino losses in the spin-triplet superfluid neutron matter, which considerably slows down the cooling rate of neutron stars with superfluid cores. PubDate: Thu, 10 May 2018 00:00:00 +000

Abstract: The cross section of has been measured by BESIII and Belle experiments. Fit to the line shape, the resonant structures are evident. The parameters for the three resonant structures are MeV/, MeV; MeV/, MeV; and MeV/, MeV, where the first uncertainties are statistical and the second are systematic. We attribute the three structures to ,, and states. The branching fractions and are given. If is taken as state, the branching fraction is also given. Combining all parameters obtained from different decays, we give average parameters for , which are MeV/, MeV. PubDate: Wed, 09 May 2018 10:07:46 +000

Abstract: Coulomb effects on charged pion transverse momentum spectra measured in Au+Au collisions at RHIC-BES energies are investigated. From these spectra the ratios as a function of transverse momentum are obtained and used to extract the “Coulomb kick”, (a momentum change due to the Coulomb interaction), and initial pion ratio for three different collision energies and various centrality classes. The Coulomb kick shows a decrease with the increase of beam energy and a clear centrality dependence, with larger values for the most central collisions. The results are connected with the kinetic freeze-out dynamics. PubDate: Wed, 09 May 2018 09:22:04 +000

Abstract: We investigate the quantum vacuum and find that the fluctuations can lead to the inhomogeneous quantum vacuum. We find that the vacuum fluctuations can significantly influence the cosmological inhomogeneity, which is different from what was previously expected. By introducing the modified Green’s function, we reach a new inflationary scenario which can explain why the Universe is still expanding without slowing down. We also calculate the tunneling amplitude of the Universe based on the inhomogeneous vacuum. We find that the inhomogeneity can lead to the penetration of the Universe over the potential barrier faster than previously thought. PubDate: Tue, 08 May 2018 00:00:00 +000

Abstract: The Standard Model problems lead to the new theories of extra dimensions: Randall-Sundrum model, Arkani-Hamed-Dimopoulos-Dvali model, and model. In the framework of these models, with the help of computer program Pythia8.2, the production cross sections for Kaluza-Klein particles at various energies at the LHC were calculated. The generation of monojet events from scalar graviton emission was considered for number of extra dimensions (, 4, and 6) for the energy at the LHC 14 TeV. The graviton production processes through the gluon-gluon, quark-gluon, and quark-quark fusion processes are also studied and some periodicity was found in the behavior of the graviton mass spectrum. Production cross sections multiplied by branching fractions were calculated for the massive graviton, G, within Randall-Sundrum scenario and the most probable processes of graviton decay at 13 TeV, 14 TeV, and 100 TeV were counted. PubDate: Mon, 30 Apr 2018 07:21:46 +000

Abstract: In the global framework of quantum theory, the individual quantum systems seem clearly separated into two families with the respective manifestly Hermitian and hiddenly Hermitian operators of their Hamiltonian. In the light of certain preliminary studies, these two families seem to have an empty overlap. In this paper, we will show that whenever the interaction potentials are chosen to be weakly nonlocal, the separation of the two families may disappear. The overlaps alias interfaces between the Hermitian and non-Hermitian descriptions of a unitarily evolving quantum system in question may become nonempty. This assertion will be illustrated via a few analytically solvable elementary models. PubDate: Tue, 24 Apr 2018 09:17:48 +000

Abstract: We have studied the existence of self-dual effective compact and true compacton configurations in Abelian Higgs models with generalized dynamics. We have named an effective compact solution the one whose profile behavior is very similar to the one of a compacton structure but still preserves a tail in its asymptotic decay. In particular, we have investigated the electrically neutral configurations of the Maxwell-Higgs and Born-Infeld-Higgs models and the electrically charged ones of the Chern-Simons-Higgs and Maxwell-Chern-Simons-Higgs models. The generalization of the kinetic terms is performed by means of dielectric functions in gauge and Higgs sectors. The implementation of the BPS formalism without the need to use a specific Ansatz has led us to the explicit determination for the dielectric function associated with the Higgs sector to be proportional to ,. Consequently, the followed procedure allows us to determine explicitly new families of self-dual potential for every model. We have also observed that, for sufficiently large values of , every model supports effective compact vortices. The true compacton solutions arising for are analytical. Therefore, these new self-dual structures enhance the space of BPS solutions of the Abelian Higgs models and they probably will imply interesting applications in physics and mathematics. PubDate: Tue, 24 Apr 2018 08:27:38 +000

Abstract: The analytical solutions to a double ring-shaped Coulomb potential (RSCP) are presented. The visualizations of the space probability distribution (SPD) are illustrated for the two- (contour) and three-dimensional (isosurface) cases. The quantum numbers are mainly relevant for those quasi-quantum numbers via the double RSCP parameter . The SPDs are of circular ring shape in spherical coordinates. The properties for the relative probability values (RPVs) are also discussed. For example, when we consider the special case , the SPD moves towards two poles of -axis when increases. Finally, we discuss the different cases for the potential parameter , which is taken as negative and positive values for . Compared with the particular case , the SPDs are shrunk for , while they are spread out for . PubDate: Tue, 24 Apr 2018 06:45:26 +000

Abstract: Azimuthal distributions of radial velocities of charged hadrons produced in nucleus-nucleus collisions are compared with the corresponding azimuthal distribution of charged hadron multiplicity in the framework of a multiphase transport (AMPT) model at two different collision energies. The mean radial velocity seems to be a good probe for studying radial expansion. While the anisotropic parts of the distributions indicate a kind of collective nature in the radial expansion of the intermediate “fireball,” their isotropic parts characterize a thermal motion. The present investigation is carried out keeping the upcoming Compressed Baryonic Matter (CBM) experiment to be held at the Facility for Antiproton and Ion Research (FAIR) in mind. As far as high-energy heavy-ion interactions are concerned, CBM will supplement the Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) experiments. In this context our simulation results at high baryochemical potential would be interesting, when scrutinized from the perspective of an almost baryon-free environment achieved at RHIC and LHC. PubDate: Sun, 22 Apr 2018 00:00:00 +000

Abstract: We suggest using Einstein’s static universe metric for the metastable state after reheating, instead of the Friedman-Robertson-Walker spacetime. In this case, strong static gravitational potential leads to the effective reduction of the Higgs vacuum expectation value, which is found to be compatible with the Standard Model first-order electroweak phase transition conditions. Gravity could also increase the CP-violating effects for particles that cross the new phase bubble walls and thus is able to lead to the successful electroweak baryogenesis scenario. PubDate: Thu, 19 Apr 2018 00:00:00 +000

Abstract: In Poincaré-Wigner-Dirac theory of relativistic interactions, boosts are dynamical. This means that, just like time translations, boost transformations have a nontrivial effect on internal variables of interacting systems. In this respect, boosts are different from space translations and rotations, whose actions are always universal, trivial, and interaction-independent. Applying this theory to unstable particles viewed from a moving reference frame, we prove that the decay probability cannot be invariant with respect to boosts. Different moving observers may see different internal compositions of the same unstable particle. Unfortunately, this effect is too small to be noticeable in modern experiments. PubDate: Thu, 19 Apr 2018 00:00:00 +000

Abstract: The existence of the tiny neutrino mass and the flavor mixing can be naturally explained by type I Seesaw model which is probably the simplest extension of the Standard Model (SM) using Majorana type SM gauge singlet heavy Right Handed Neutrinos (RHNs). If the RHNs are around the Electroweak- (EW-) scale having sizable mixings with the SM light neutrinos, they can be produced at the high energy colliders such as Large Hadron Collider (LHC) and future 100 TeV proton-proton (pp) collider through the characteristic signatures with the same-sign dilepton introducing lepton number violations (LNV). On the other hand Seesaw models, namely, inverse Seesaw, with small LNV parameter can accommodate EW-scale pseudo-Dirac neutrinos with sizable mixings with SM light neutrinos while satisfying the neutrino oscillation data. Due to the smallness of the LNV parameter of such models, the “smoking-gun” signature of same-sign dilepton is suppressed where the RHNs in the model will be manifested at the LHC and future 100 TeV pp collider dominantly through the Lepton number conserving (LNC) trilepton final state with Missing Transverse Energy (MET). Studying various production channels of such RHNs, we give an updated upper bound on the mixing parameters of the light-heavy neutrinos at the 13 TeV LHC and future 100 TeV pp collider. PubDate: Thu, 19 Apr 2018 00:00:00 +000