arXiv subjects

M. Chabab

Publications and source records attributed to M. Chabab.

At least 127 records · Page 7Linked to original sources

arXiv2015

Closed analytical solutions of the d-dimensional Schrödinger equation with deformed Woods-Saxon potential plus double ring-shaped potential

By employing the Pekeris approximation, the D-dimensional Schrödinger equation is solved for the nuclear deformed Woods-Saxon potential plus double ring-shaped potential within the framework of the Asymptotic Iteration Method (AIM). The energy eingenvalues are given in a closed form and the corresponding normalized eigenfunctions are obtained in terms of hypergeometric functions. Our general results reproduce many predictions obtained in the literature, using the Nikiforov-Uvarov method (NU) and the Improved Quantization Rule approach, particulary those derived by considering Woods-Saxon potential without deformation and/or without ring shape interaction.

nucl-th↗

arXiv2015

Vibrational and rotational excited states within Bohr Hamiltonian with deformation-dependent mass formalism

In a recent work (Phys.Rev.C84, 044321, 2011) M.J. Ermamatov and P.R. Fraser have studied rotational and vibrational excited states of axially symmetric nuclei within the Bohr Hamiltonian with different mass parameters. However, the energy formula that the authors have used contains some inaccuracies. So, the numerical results they obtained seem to be controversial. In this paper, we revisit all calculations related to this problem and determine the appropriate formula for the energy spectrum. Moreover, in order to improve such calculations, we reconsider this problem within the framework of the deformation dependent mass formalism. Also, unlike the work of Bonatsos et al. (Phys.Rev.C83, 044321, 2011) where the mass parameter has not been considered, we will show the importance of this parameter and its effect on numerical predictions.

nucl-th↗

arXiv2015

Bohr Hamiltonian with Hulth?en plus Ring shaped potential for triaxial nuclei

In this paper, we solve the eigenvalues and eigenvectors problem with Bohr collective Hamil- tonian for triaxial nuclei. The ? beta part of the collective potential is taken to be equal to Hulth?en potential while the gamma part is defined by a new generalized potential obtained from a ring shaped one. Analytical expressions for spectra and wave functions are derived by means of a recent version of the asymptotic iteration method and the usual approximations. The calculated energies and B(E2) transition rates are compared with experimental data and the available theoretical results in the literature.

nucl-th↗

arXiv2015

Closed analytical solutions of Bohr Hamiltonian with Manning-Rosen potential model

In the present work, we have obtained closed analytical expressions for eigenvalues and eigenfunctions of the Bohr Hamiltonian with the Manning-Rosen potential for γ-unstable nuclei as well as exactly separable rotational ones with γ=0. Some heavy nuclei with known \b{eta} and γ bandheads have been fitted by using two parameters in the ν-unstable case and three parameters in the axially symmetric prolate deformed one. A good agreement with experimental data has been achieved.

nucl-th↗

arXiv2015

On Thermodynamics of AdS Black Holes in M-Theory

Motivated by a recent work on asymptotically AdS_4 black holes in M-theory, we investigate the thermodynamics and thermodynamical geometry of AdS black holes from M2 and M5-branes. Concretely, we consider AdS black holes in AdS_{p+2}\times S^{11-p-2}, where p=2,5 by interpreting the number of M2 (and M5-branes) as a thermodynamical variable. We study the corresponding phase transition to examine their stabilities by calculating and discussing various thermodynamical quantities including the chemical potential. Then, we compute the thermodynamical curvatures from the Quevedo metric for M2 and M5-branes geometries to reconsider the stability of such black objects. The Quevedo metric singularities recover similar stability results provided by the phase transition program.

hep-th↗

arXiv2015

On Hawking Radiation of 3D Rotating Hairy Black Holes

We study the Hawking radiation of 3D rotating hairy black holes. More concretely, we compute the transition probability of a bosonic and fermionic particle in such backgrounds. Thew, we show that the transition probability is independent of the nature of the particle. It is observed that the charge of the scalar hair B and the rotation parameter a control such a probability.

hep-th↗

arXiv2015

Ehrenfest Scheme of Higher Dimensional Topological AdS Black Holes in The Third Order Lovelock-Born-Infeld Gravity

Interpreting the cosmological constant as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume, we reconsider the investigation of P-V critical behaviors of (1+n)-dimensional topological AdS black holes in Lovelock-Born-Infeld gravity. In particular, we give an explicit expression of the universal number χ=\frac{P_c v_c}{T_c} in terms of the space dimension $n$. Then, we examine the phase transitions at the critical points of such topological black holes for 6 \leq n \leq 11 as required by the physical condition of the thermodynamical quantities. More precisely, the Ehrenfest equations have been checked revealing that the black hole system undergoes a second phase transition at the critical points.

hep-th↗

arXiv2015

On Heat Properties of AdS Black Holes in Higher Dimensions

We investigate the heat properties of AdS Black Holes in higher dimensions. We consider the study of the corresponding thermodynamical properties including the heat capacity explored in the determination of the black hole stability. In particular, we compute the heat latent. To overcome the instability problem, the Maxwell construction, in the (T,S)-plane, is elaborated. This method is used to modify the the Hawking-Page phase structure by removing the negative heat capacity regions. Then, we discuss the thermodynamic cycle and the heat engines using the way based on the extraction of the work from a black hole solution.

hep-th↗

arXiv2015

Exact solutions of Deformed Schrodinger Equation with a class of non central physical potentials

In this paper we present exact solutions of Schrodinger equation (SE) for a class of non central physical potentials within the formalism of position-dependent effective mass. The energy eigenvalues and eigenfunctions of the bound-states for the Schrodinger equation are obtained analytically by means of asymptotic iteration method (AIM) and easily calculated through a new generalized decomposition of the effective potential allowing easy separation of the coordinates. Our results are in excellent agreement with other works in the literature.

math-ph↗

arXiv2015

Maxwell's equal-area law for Gauss-Bonnet Anti-de Sitter black holes

Interpreting the cosmological constant Λas a thermodynamic pressure and its conjugate quantity as a thermodynamic volume, we study the Maxwell's equal area law of higher dimensional Gauss-Bonnet-AdS black holes in extended phase space. These black hole solutions critically behave like Van der Waals systems. It has been realized that below the critical temperature T_c the stable equilibrium is violated. We show through calculations that the critical behaviors for the uncharged black holes only appear in d=5. For the charged case, we analyse solutions in d = 5 and d = 6 separately and find that, up to some constrains, the critical behaviors only appear in the spherical topology. Using the Maxwell's construction, we also find the isobar line for which the liquid-gas-like phases coexist.

hep-th↗

arXiv2014

Statistical Physics of 3D Hairy Black Holes

We investigate the statistical behaviors of 3D hairy black holes in the presence of a scalar field. The present study is made in terms of two relevant parameters: rotation parameter a and B parameter related to the scalar field. More precisely, we compute various statistical quantities including the partition function for non-charged and charged black hole solutions. Using a partition function calculation, we show that the probability is independent of a and B parameters.

hep-th↗

arXiv2014

Critical Behaviors of 3D Black Holes with a Scalar Hair

The principal focus of the present work concerns the critical behaviors of a class of three dimensional black holes with a scalar field hair. Since the cosmological constant is viewed as a thermodynamic pressure and its conjugate quantity as a volume, we examine such properties in terms of two parameters B and a. The latters are related to the scalar field and the angular momentum respectively. In particular, we give the equation of state predicting a critical universal number depending on the (B,a) moduli space. In the vanishing limit of the B parameter, we recover the usual perfect gas behavior appearing in the case of the non rotating BTZ black hole. We point out that in a generic region of the (B,a) moduli space, the model behaves like a Van der Waals system.

hep-th↗

arXiv2014

Degenerate Higgs bosons decays to ${γγ}$ and ${Zγ}$ in the type II Seesaw Model

Using the most recent results of CMS and ATLAS, we study the Higgs decays to $γγ$ and $Zγ$ in the scenario where the two CP even Higgs predicted by the type II seesaw model (HTM) are close to mass degenerate with a mass near $125$ GeV. We analyse the effects of the Higgs potential parameters constrained by the full set of perturbative unitarity, boundedness from below (BFB) as well as from precision electroweak measurements on these decay modes. Our analysis demonstrates that the observed excess in the diphoton Higgs decay channel can be interpreted in our scenario within a delineated region controlled by $λ_{1}$ and $λ_{4}$ coupling. We also find a deviation in the Higgs decay to $Zγ$ with respect to the Standard Model prediction and the largest enhancement is found for a ratio $R_{Zγ}$ of the order $1.6$. Furthermore we show that consistency with current ATLAS data on the diphoton decay channel favours a light doubly charged Higgs with mass in the range $92 - 180$~GeV. Finally, we find that the $γγ$ and $Z γ$ Higgs decay modes are generally correlated and the magnitude of correlation is sensitive to the sign of the $λ_{1}$ parameter.

hep-ph↗

arXiv2014

On Thermodynamics of 2d Black Holes in Brane Inflationary Potentials

Inspired from the inflation brane world cosmology, we study the thermodynamics of a black hole solution in two dimensional dilaton gravity with an arctangent potential background. We first derive the two dimensional black hole geometry, then we examine its asymptotic behaviors. More precisely, we find that such behaviors exhibit properties appearing in some known cases including the Anti de Sitter and the Schwarzchild black holes. Using the complex path method, we compute the Hawking radiation. The entropy function can be related to the value of the potential at the horizon.

hep-th↗

arXiv2013

On Thermodynamical Behaviors of Kerr-Newman AdS Black Holes

We reconsider the study of critical behaviors of Kerr-Newman AdS black holes in four dimensions. The study is made in terms of the moduli space parameterized by the charge Q and the rotation parameter a, relating the mass M of the black hole and its angular momentum J via the relation a=J/M. Specifically, we discuss such thermodynamical behaviors in the presence of a positive cosmological constant considered as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume. The equation of state for a charged RN-AdS black hole predicts a critical universal number depending on the (Q,a) moduli space. In the vanishing limit of the a parameter, this prediction recovers the usual universal number in four dimensions. Then, we find the bounded regions of the moduli space allowing the consistency of the model with real thermodynamical variables.

hep-th↗

arXiv2012

On Thermodynamics of AdS Black Holes in Arbitrary Dimensions

Considering the cosmological constant $Λ$ as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume as proposed in Kubiznak and Mann (2012), we discuss the critical behavior of charged AdS black hole in arbitrary dimensions $d$. In particular, we present a comparative study in terms of the spacetime dimension $d$ and the displacement of critical points controlling the transition between the small and the large black holes. Such behaviors vary nicely in terms of $d$. Among our result in this context consists in showing that the equation of state for a charged RN-AdS black hole predicts an universal number given by $\frac{2d-5}{4d-8}$. The three dimensional solution is also discussed.

hep-th↗

arXiv2012

Analytic l-state solutions of the Klein-Gordon equation for q-deformed Woods-Saxon plus generalized ring shape potential

The analytical expressions for the eigenvalues and eigenvectors of the Klein-Gordon equation for q-deformed Woods-Saxon plus new generalized ring shape potential are derived within the asymptotic iteration method. The obtained eigenvalues are given in a closed form and the corresponding normalized eigenvectors, for any l, are formulated in terms of the generalized Jacobi polynomials for the radial part of the Klein-Gordon equation and associated Legendre polynomials for its angular one. When the shape deformation is canceled, we recover the same solutions previously obtained by the Nikiforov-Uvarov method for the standard spherical Woods-Saxon potential. It is also shown that, from the obtained results, we can derive the solutions of this problem for Hulthen potential.

quant-ph↗

arXiv2012

h γγCoupling in Higgs Triplet Model

We investigate Higgs boson decay into two photons in the type-II seesaw model. The rate of $h\to γγ$ gets suppressed/enhanced in this model compared to the Standard Model (SM) due to the presence of the singly and doubly charged Higgs $H^\pm$ and $H^{\pm\pm}$.

hep-ph↗