Showing papers on "Mass formula published in 2021"

Ultra-spinning Chow’s black holes in six-dimensional gauged supergravity and their properties

Abstract: By taking the ultra-spinning limit as a simple solution-generating trick, a novel class of ultra-spinning charged black hole solutions has been constructed from Chow’s rotating charged black hole with two equal-charge parameters in six-dimensional $$ \mathcal{N} $$ = 4 gauged supergravity theory. We investigate their thermodynamical properties and then demonstrate that all thermodynamical quantities completely obey both the differential first law and the Bekenstein-Smarr mass formula. For the six-dimensional ultra-spinning Chow’s black hole with only one rotation parameter, we show that it does not always obey the reverse isoperimetric inequality, thus it can be either sub-entropic or super-entropic, depending upon the ranges of the mass parameter and especially the charge parameter. This property is obviously different from that of the six-dimensional singly-rotating Kerr-AdS super-entropic black hole, which always strictly violates the RII. For the six-dimensional doubly-rotating Chow’s black hole but ultra-spinning only along one spatial axis, we point out that it may also obey or violate the RII, and can be either super-entropic or sub-entropic in general.

Isobaric Multiplet Mass Equation for $A \le 71$ Revisited

Abstract: Accurate mass determination of short-lived nuclides by Penning-trap spectrometers and progress in the spectroscopy of proton-rich nuclei have triggered renewed interest in the isobaric multiplet mass equation (IMME). The energy levels of the members of $T=1/2, 1, 3/2,$ and 2 multiplets and the coefficients of the IMME are tabulated for $A\le 71$. The new compilation is based on the most recent mass evaluation (AME2011) and it includes the experimental results on energies of the states evaluated up to end of 2011. Taking into account the error bars, a significant deviation from the quadratic form of the IMME for the $A=9, 35$ quartets and the $A=32$ quintet is observed.

Improved macroscopic microscopic mass formula

Abstract: A nuclear mass formula based on the macroscopic microscopic approach is proposed, in which the number of model parameters is reduced compared with other macroscopic microscopic models. The root mean square (RMS) deviation with respect to 2314 training sets (measured nuclear masses) is reduced to 0.447 MeV, and the calculated value of each nucleus is no more than 0.8% different from the experimental value. The single and two nucleon separation energies and the shell gaps are calculated to test the model. The shell corrections and double magic number of superheavy nuclei are also analyzed.

Chiral excitations of open-beauty systems

Abstract: We study the scattering of open-beauty mesons and Goldstone bosons as predicted by the chiral SU(3) Lagrangian. The impact of subleading-order chiral interactions to systems with ${J}^{P}={0}^{+}$ and ${J}^{P}={1}^{+}$ quantum numbers is worked out. We estimate the relevant low-energy coefficients from the open-charm sector, for which their values have been determined previously from sets of QCD lattice data. The leading-order heavy-quark symmetry-breaking effects are estimated by matching the $B$-meson ground-state chiral mass formula to the mass formula from the heavy-quark effective theory. We make refined predictions for the flavor antitriplet and sextet resonances that are generated dynamically by coupled-channel interactions.

Effect of large light-heavy neutrino mixing and natural type-II seesaw dominance to lepton flavor violation and neutrinoless double beta decay

Abstract: We derive the lower bound on the absolute scale of lightest neutrino mass for normal hierarchy and inverted hierarchy pattern of light neutrinos by studying the new physics contributions to charged lepton flavour violations in the framework of a TeV scale left-right symmetric model. In the model, the fermion sector comprises the usual quarks and leptons plus a fermion singlet per generation and the scalar sector consists of isospin doublets, triplets and a bidoublet. The framework allows large light-heavy neutrino mixing where the light neutrino mass formula is governed by a natural type-II seesaw mechanism, unlike the generic type-II seesaw dominance which assumes suppressed light-heavy neutrino mixing. We demonstrate how sizeable loop-induced contribution to light neutrino mass is kept under control such that the light neutrino mass formula is dominantly explained by the type-II seesaw mechanism. We examine the heavy neutrino contributions with large light-heavy neutrino mixing to charged lepton flavour violating processes like $\mu \to e \gamma$, $\mu \to 3 e$ and $\mu \to e$ conversion inside a nucleus. We present a complementary study between neutrinoless double beta decay and charged lepton flavour violation taking into account single beta decay bound, double beta decay bound and cosmology bounds on the sum of light neutrino masses.

A very special case of Siegel's mass formula and Hecke operators

Abstract: We make use of Hecke operators and arithmetic of imaginary quadratic fields to derive an explicit version of a special case of Siegel's mass formula.

Phenomenological mass model for exotic hadrons and predictions for masses of non-strange dibaryons as hexaquarks

Abstract: We investigate the mass spectra of exotic hadrons known as hexaquarks in the form of dibaryons. We use a phenomenological model based on an extended version of the Gursey-Radicati mass formula for hadrons to include non-charmed baryons, charmed baryons, and non-strange dibaryons to be able to predict masses of potential dibaryon states. We perform six numerical fits of this model to input data for three different sets of masses of baryons and dibaryons. We find that the model can fit some of the data sets well, especially the sets including charmed baryons and non-strange dibaryons, and observe that the predicted mass of one of the dibaryons is close to the measured mass of the observed hexaquark candidate $d^*(2380)$ reported by the WASA-at-COSY experiment. The predicted mass of the deuteron is slightly larger than its measured mass. Finally, for the data sets including charmed baryon and non-strange dibaryon masses, we find that the predicted masses of potential dibaryon states are all in the range from 1900 MeV to 3500 MeV.

Genus of vertex algebras and mass formula

Abstract: We introduce the notion of a genus and its mass for vertex algebras. For lattice vertex algebras, their genera are the same as those of lattices, which play an important role in the classification of lattices. We derive a formula relating the mass for vertex algebras to that for lattices, and then give a new characterization of some holomorphic vertex operator algebras.

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.

The Eventuality of Equating Energy and Mass - Laws and Theories: Physics

Abstract: Einstein's famous equation, , revolutionized the theory of physics and introduced new perspectives to the study of energy and mass. However, a close consideration of its principles raises essential concerns on the equitability of mass and energy as well as other phenomena like the speed of light. The unavoidable scientific claim of this paper is that the total energy of matter depends on its internal and external energies, which are accounted for by kinetic and potential energies. In the current work, thought experiments reveal important additions to this idea regarding the apparent effects of external energy on the nature of matter and particles. This paper employs detailed thought experiments and theoretical discussions to identify and address several notable inconsistencies related to the energy and mass equation based on previous works in physics. The relative external energy of an object will be influenced by the position of the observer. The outcomes of the experiments presented herein also provide key insights into the constancy of the internal energy of all matter and particles. Generally, this paper provides an important basis for analyzing the theory underlying the physics of energy and mass, addressing questionable ideas that are common but poorly substantiated and providing a new understanding of the nature of mass and energy that lays the foundations for further research in this area by projecting the difference between them.

Mass measurements of $^{60-63}$Ga reduce X-ray burst model uncertainties and extend the evaluated $\mathbf{T=1}$ isobaric multiplet mass equation

Abstract: We report precision mass measurements of neutron-deficient gallium isotopes approaching the proton drip line. The measurements of $^{60-63}$Ga performed with TITAN's multiple-reflection time-of-flight mass spectrometer provide a more than threefold improvement over the current literature mass uncertainty of $^{61}$Ga and mark the first direct mass measurement of $^{60}$Ga. The improved precision of the $^{61}$Ga mass has important implications for the astrophysical rp-process, as it constrains essential reaction Q-values near the $^{60}$Zn waiting point. Based on calculations with a one-zone model, we demonstrate the impact of the improved mass data on prediction uncertainties of X-ray burst models. The first-time measurement of the $^{60}$Ga ground-state mass establishes the proton-bound nature of this nuclide; thus, constraining the location of the proton drip line along this isotopic chain. Including the measured mass of $^{60}$Ga enables us to extend the evaluated $T=1$ isobaric multiplet mass equation up to $A=60$.

Heavy Baryons in Holographic QCD Using Higher Dimensional Degrees of Freedom

Abstract: In these proceedings, we discuss baryon properties in holographic QCD. First, we propose a method of introducing a heavy flavor into the Sakai–Sugimoto model by regarding the gauge field of the extra dimension as a heavy meson. Using the Forgacs–Manton method, we obtain an action consisting of light and heavy mesons. By performing collective coordinate quantization for the instanton of the light meson fields, we derive the mass formula of heavy baryons. Then, we investigate the decay properties of the Roper resonance using the Sakai–Sugimoto model.

Ultra-spinning Chow's black holes in six-dimensional gauged supergravity and their properties

Abstract: By taking the ultra-spinning limit as a simple solution-generating trick, a novel class of ultra-spinning charged black hole solutions has been constructed from Chow's rotating charged black hole with two equal-charge parameters in six-dimensional $\mathcal{N} = 4$ gauged supergravity theory. We investigate their thermodynamical properties and then demonstrate that all thermodynamical quantities completely obey both the differential first law and the Bekenstein-Smarr mass formula. For the six-dimensional ultra-spinning Chow's black hole with only one rotation parameter, we show that it does not always obey the reverse isoperimetric inequality, thus it can be either sub-entropic or super-entropic, depending upon the ranges of the mass parameter and especially the charge parameter. This property is obviously different from that of the six-dimensional singly-rotating Kerr-AdS super-entropic black hole, which always strictly violates the RII. For the six-dimensional doubly-rotating Chow's black hole but ultra-spinning only along one spatial axis, we point out that it may also obey or violate the RII, and can be either super-entropic or sub-entropic in general.