Mass formula

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

Magnetic Resonances and the Positron Peak in Heavy-Ion Collisions

Abstract: In this lecture I discuss the possibility of magnetic dipole resonaces in the e+e--system just above the two-body threshold. Wong and Becker1have recently applied this idea in order to explain the positron peak observed in heavy-ion collisions2. Can the e+e--system form a magnetic resonance with mass around M≅3m and a width of about τ~10-18sec.? I shall examine the assumptions underlying this model more precisely, the nature of the neglected terms, a simple derivation and interpretation of the mass formula and the possibility of other higher mass sharp resonances in the (e+e-)-system.

Quark masses using Barut-like mass formula

Abstract: An extension of Barut's (1979) lepton mass formula to quark masses, using lepton-quark symmetry is applied to obtain the masses of the third and fourth generation quarks. The t-quark mass is found to be quite a bit smaller than present estimates.

Gauge field theory of quantum and the mass empirical formulas of lepton and quarks

Abstract: In this paper, we discuss the mathematical relation determined by the basic physical constant between three types of quarks and the masses of leptons with charges in detail. First, by further theoretical analysis, we wonderfully see that the result got from the mass empirical formula of quark and charged lepton is identical with the data received by theoretical estimating from the gauge field theory. Second, we also gladly see that the result got from quark and lepton (with charges) mass empirical formula is completely accordant with experiment data. These mass formulas reveal the essential relation between m e, m μ, m τ and m q. At the same time, the empirical formula may also derive the mass formula of neutrinos. As to the mass of neutrinos, at present we only know the square difference of its mass, and so this is meaningful to theoretically estimating the mass.

Investigation of three-body forces from atomic mass data

Abstract: Although two-nucleon (NN) interactions successfully explain many aspects of nuclear structure, recent studies are pointing to the important role of three-body (3N) forces in the predictions of neutron-rich nuclei and in the evolution of shell structure [1], in particular from an ab-initio point of view. The aim of this work is to investigate whether we can describe atomic masses using valence-shell corrections that include both NN and 3N forces in the mass formulae. The focus lies on pinpointing indications of NN and 3N forces in the residuals of the mass formulae fits from the standpoint of their dependence on the valence particles (or holes). Starting from the Bethe–Weizsacker formula, an investigation on the effects of NN and 3N forces by performing local fits to the experimental mass compilation AME2016 [2,3], was made. By introducing inert cores and a valence-configuration space, a search to identify hints of NN and 3N forces was conducted mainly around the traditional magic numbers 8, 20, 28, 50, 82 and 126 of neutrons and/(or) protons. Additionally, a modified Bethe–Weizsacker mass formula was employed to estimate its ability to better fit the doubly magic nuclei. The results show that the addition of the suggested terms of NN and 3N to the mass formulae are applicable to describe the trend observed around the doubly magic nuclei for some atomic mass regions. Although this is a fact, we cannot directly claim that these expressions correspond to the NN and 3N body forces. Moreover, a shell correction [4] was employed to extend the Bethe–Weizsacker mass formula. The results obtained from a fit using this modified formula show an agreement between the valence-shell corrections of the present investigation and the suggested ones, in the description of the parabolic-like behavior of the residuals between two doubly magic nuclei.

Nuclear matter and surface clustering

Abstract: We demonstrate that the binding energy per nucleon of symmetric nuclear matter (SNM) (with Coulomb interaction switched off and N = Z) in the limit of zero density approaches to its value, uv, at the saturation density, where uv is the volume term of the Weizsacker mass formula. This phenomenon is a direct result of the clustering of nuclei in the low density region of nuclear matter. We study the implications of this result on the properties of nuclei. We also study the properties of asymmetric nuclear matter. Because of clustering a provocative interpretation of the equation of state of asymmetric nuclear matter emerges which is at considerable variance at low densities with hitherto all the previous calculations. For nuclei, as a framework, an extended version of Thomas-Fermi theory is invoked. Calculations are performed for 2149 nuclei with N, Z ≥ 8. The present scheme leads to a forceful interpretation of the low density asymmetry energy data of Natowitz et al. [1].