Mass formula

About: Mass formula is a research topic. Over the lifetime, 1248 publications have been published within this topic receiving 22043 citations.

Opposite charged two-body system of identical counterrotating black holes

Abstract: A four-parametric exact solution describing a two-body system of identical Kerr-Newman counterrotating black holes endowed with opposite electric/magnetic charges is presented. The axis conditions are solved in order to really describe two black holes separated by a massless strut. Moreover, the explicit form of the horizon half length parameter $\ensuremath{\sigma}$ in terms of physical Komar parameters, i.e., Komar's mass $M$, electric charge ${Q}_{E}$, angular momentum $J$, and a coordinate distance $R$ is derived. Additionally, magnetic charges ${Q}_{B}$ arise from the rotation of electrically charged black holes. As a consequence, in order to account for the contribution to the mass of the magnetic charge, the usual Smarr mass formula should be generalized, as it is proposed by A. Tomimatsu, Prog. Theor. Phys. 72, 73 (1984).

Determination of the effective atomic and mass numbers for mixture and compound materials in high energy photon interactions

Abstract: In consideration the radiological properties of materials and studying the scattering processes in atomic and nuclear physics, the effective atomic and mass numbers is widely employed. These numbers have been calculated for any mixed or composite materials in interaction with high energy photons (Linac in radiation therapy). A pair equation in terms of these numbers is obtained. The first equation has been derived from the conservation of mass energy law and the second by minimizing the binding energy from the semiempirical mass formula (Myers and Swiatecki formula) that gives a relation between atomic and mass numbers for stable nuclei approximately. By these equations one can obtain the effective atomic and mass numbers for any compound or mixed materials uniquely. These numbers are calculated for some materials and compared with the other studies.

Thermodynamics and phase transition in rotational Kiselev black hole

Abstract: In this paper, we investigate the thermodynamic properties of rotational Kiselev black holes (KBH). Specifically, we use the first-order approximation of the event horizon (EH) to calculate thermodynamic properties for general equations of state ω. These thermodynamic properties include areas, entropies, horizon radii, surface gravities, surface temperatures, Komar energies and irreducible masses at the Cauchy horizon (CH) and EH. We study the products of these thermodynamic quantities, we find that these products are determined by the equation of state ω and strength parameter α. In the case of the quintessence matter (ω = −2/3), radiation (ω = 1/3) and dust (ω = 0), we discuss their properties in detail. We also generalize the Smarr mass formula and Christodoulou–Ruffini mass formula to rotational KBH. Finally, we study the phase transition and thermodynamic geometry for rotational KBH with radiation (ω = 1/3). Through analysis, we find that this phase transition is a second-order phase transition. Furthermore, we also obtain the scalar curvature in the thermodynamic geometry framework, indicating that the radiation matter may change the phase transition condition and properties for Kerr black hole.

Extrapolation of a self-consistent energy density mass formula to the superheavy region and to the neutron drip line

Abstract: The previously developed energy density mass formula is extrapolated to the superheavy region and to the neutron drip line. Fission barriers,α-decay andβ-decay energies of isotones withN=184 are computed and half-lives are estimated by using simple corrections to the half-lives obtained by Fiset and Nix. According to the assumption made to extrapolate the pairing parameters, the most stable nucleus atN=184 is found to be either184X 110 294 with a half-life of 67 years, or184 108 292 with a half-life of 13 years. The position of the neutron drip line for 8≦Z≦44 is also studied and compared to the predictions of other mass formulae. Important differences are found, particularly for the influence of the shell effects in this region.

Charm and bottom baryon masses in the combined 1/N{sub c} and 1/m{sub Q} expansion versus the quark model

Abstract: A good agreement between a flux tube-based quark model of light baryons (strange and nonstrange) and the 1/N{sub c} expansion mass formula has been found in previous studies In the present work a larger connection is established between the quark model and the 1/N{sub c} and 1/m{sub Q} expansion method by extending the previous procedure to baryons made of one heavy and two light quarks The compatibility between both approaches is shown to hold in this sector too