Showing papers on "Mass formula published in 2006"
TL;DR: In this paper, a new parametrization for the phenomenological nuclear level density taking account of the shell and pairing energies of the recent nuclear mass formula of Koura, Tachibana, Uno, and Yamada (KTUY05) a is proposed.
Abstract: A new parametrization for the phenomenological nuclear level density taking account of the shell and pairing energies of the recent nuclear mass formula of Koura, Tachibana, Uno, and Yamada (KTUY05) a is proposed. Such a level density formula is often required to calculate nuclear reaction cross sections for nuclei off-stability, especially for fission systems and astrophysical applications. With the phenomenological level density formula of Gilbert-Cameron with the energy dependent level density parameter of Ignatyuk, a smooth dependence of the asymptotic level density parameter a* on the mass number is obtained. At low energies, systematics for the constant temperature model are also derived by connecting the Fermi gas level density and the discrete level information available for more than 1,000 nuclei. Some comparisons with the discrete level data and the microscopic model are made to validate our approach, and it is concluded that the parametrization obtained can be used for nuclear reaction calculat...
51 citations
TL;DR: In this paper, a simultaneous description of nonstrange nuclei and hypernuclei is provided by a single mass formula inspired by the spin-flavour SU(6) symmetry breaking.
Abstract: A simultaneous description of non-strange nuclei and hypernuclei is provided by a single mass formula inspired by the spin–flavour SU(6) symmetry breaking. This formula is used to estimate the hyperon binding energies of lambda, double lambda, sigma, cascade and theta hypernuclei. The results are found to be in good agreement with the available experimental data on 'bound' nuclei and relativistic as well as quark mean-field calculations. This mass formula is useful to estimate binding energies over a wide range of masses including the light mass nuclei. It is not applicable to a repulsive potential.
45 citations
TL;DR: In this paper, the coefficients of different combinations of terms of the liquid drop model have been determined by a least square fitting procedure to the experimental atomic masses, and the nuclear masses can also be reproduced using a Coulomb radius taking into account the increase of the ratio R{sub 0}/A{sup 1/3} with increasing mass.
Abstract: The coefficients of different combinations of terms of the liquid drop model have been determined by a least square fitting procedure to the experimental atomic masses. The nuclear masses can also be reproduced using a Coulomb radius taking into account the increase of the ratio R{sub 0}/A{sup 1/3} with increasing mass, the fitted surface energy coefficient remaining around 18 MeV.
33 citations
TL;DR: In this article, the chiral soliton model has been used to describe the differences in the masses of isotopes with atomic numbers between ∼10 and ∼30 in terms of the Weizsacker-Bethe-Bacher mass formula.
Abstract: The differences in the masses of isotopes with atomic numbers between ∼10 and ∼30 can be described within the chiral soliton model in satisfactory agreement with data. The rescaling of the model is necessary for this purpose—a decrease in the Skyrme constant by ∼30%, providing the “nuclear variant” of the model. The asymmetric term in the Weizsacker-Bethe-Bacher mass formula for nuclei can be obtained as the isospin-dependent quantum correction to the nucleus energy. Some predictions of the binding energies of neutron-rich isotopes are made in this way from, e.g., 16Be, 19B to 31Ne or 32Na. The neutron-rich nuclides with high values of isospin are unstable relative to decay owing to strong interactions. The SK4 (Skyrme) variant of the model, as well as the SK6 variant (sixth-order term in the derivatives of the chiral field in the Lagrangian as soliton stabilizer), is considered; the rational-map approximation is used to describe multi-Skyrmions.
21 citations
TL;DR: In this paper, the authors derived the mass formula for elementary particles; m k ǫ = m 0 k ( ϕ ) λ k( ϕ) δ k (ǫ ) using the perturbation method and E -infinity theory.
Abstract: With the use of the perturbation method and E -infinity theory, we have derived the mass formula for elementary particles; m k = m 0 k ( ϕ ) λ k ( ϕ ) δ k ( ϕ ). By using this formula, we have calculated the mass of quarks, leptons and weak bosons on the basis of subquark model, and obtained the nice agreement with experiments. We have shown that the hierarchy structure of leptons is reduced to the mass formula obtained in this paper. We have also given some discussions on the related problems, such as the sum rules and the mass of Higgs bosons.
17 citations
TL;DR: In this paper, the mass of octet baryons and nonet mesons has been derived using the E-infinity theory and quantum mechanics and obtained nice agreement with experiments.
Abstract: With the use of quantum mechanics and E-infinity theory, we have derived the mass formula for elementary particles; mk = m0k(ϕ)λk(ϕ)δk(ϕ). By using this formula, we have calculated the mass of octet baryons and nonet mesons on the basis of quark model, and obtained the nice agreement with experiments. We have shown that the multiplet structure of baryons and mesons is reduced to the mass formula obtained in this paper. We have also given several discussions on the related problems of hadron masses, such as the sum rules and the mass of heavier hadrons.
12 citations
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01 Jan 2006
TL;DR: In this article, the symmetries of a cube are exploited to economically generate the masses and charges of the quarks and leptons of the cube and the mass formula employed succeeds in part by exploiting the first six Fibonacci numbers.
Abstract: The symmetries of a cube are exploited to economically generate the masses and charges of the quarks and leptons. The mass formula employed succeeds in part by exploiting the first six Fibonacci numbers.
7 citations
TL;DR: In this article, it was shown that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} {approx}> 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula.
Abstract: Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} {approx}> 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T {approx}< {Lambda}{sub QCD}.
5 citations
TL;DR: In this article, the authors used the mass formula of E -infinity theory to estimate the mass of the Higgs boson using the masses of the electro-weak bosons as reference masses.
Abstract: The aim of the present work is to estimate the value of the mass of the Higgs boson using the mass formula of E -infinity theory. We use the masses of the electro-weak bosons ( W ± , Z 0 ) as reference masses. The calculations show that the estimated masses of the Higgs bosons ( H ± , H 0 ) are very close to those found earlier by some authors.
4 citations
23 Mar 2006
TL;DR: In this paper, the nature of the symmetry and Wigner energy in the nuclear mass formula is studied and it is shown that their effects are intertwined and that one term cannot be reliably determined without knowledge of the other.
Abstract: The nature of the symmetry and Wigner energy in the nuclear mass formula is studied. It is shown that their effects are intertwined and that one term cannot be reliably determined without knowledge of the other. This leads to considerable uncertainty in the value for the symmetry energy that should be adopted in nuclear matter.
3 citations
Posted Content•
TL;DR: In this paper, a new option of parameter constraint is described for the recently proposed neutrino mass formula involving primarily three free parameters, which implies the vanishing of a part of mass formula for the lowest mass neutrinos, the part which may -in an intuitive model - be identified with its formal "intrinsic selfenergy".
Abstract: A new option of parameter constraint is described for the recently proposed neutrino mass formula involving primarily three free parameters. The option implies the vanishing of a part of mass formula for the lowest mass neutrino, the part which may - in an intuitive model - be identified with its formal "intrinsic selfenergy". However, its actual mass induced then by another part of mass formula is considerable. In this option, our neutrino mass formula predicts all three neutrino masses as m_1 \sim 2.5 x 10^{-3} eV, m_2 \sim 9.3 x 10^{-3} eV and m_3 \sim 5.0 x 10^{-2} eV, when two experimental estimates \Delta m^2_{21} \sim 8.0 x 10^{-5} eV^2 and \Delta m^2_{32} \sim 2.4 x 10^{-3} eV^2 are applied as an input.
TL;DR: In this article, the authors define the genus of a g-maximal lattice with respect to φ by m(L) = k ∑ √ k √ n.
Abstract: Introduction. Let V be an n-dimensional row vector space over a totally real algebraic number field F , and let φ be a totally positive definite symmetric matrix with entries in F . Put φ[x] = xφ · tx for x ∈ V . By a gmaximal lattice L with respect to φ, we understand a g-lattice L in V which is maximal among g-lattices on which the values φ[x] are contained in g. Here g is the ring of integers of F . Put Gφ = {α ∈ GLn(F ) | αφ · tα = φ} and let {Li}i=1 be representatives of classes in the genus of L with respect to Gφ. Then we define the mass of the genus of a g-maximal lattice L with respect to φ by m(L) = k ∑
Journal Article•
TL;DR: In this article, the problem of predicting neutrino masses was considered and an eigenvalue equation for the three charged lepton masses was derived, which removed one degree of freedom from the leptons and obtained information about the other degrees of freedom.
Abstract: Written in the above manner, this relation removes one degree of freedom from the three charged lepton masses. In this paper, we will first derive this relation as an eigenvalue equation, then obtain information about the other degrees of freedom, and finally speculatively apply the same techniques to the problem of predicting the neutrino masses. If we suppose that the leptons are composite particles made up of colorless combinations of colored subparticles or preons, we expect that the three colors must be treated equally, and therefore a natural form for a matrix operator that can cross generation boundaries is the circulant : Γ(A,B,C) = A B C C A B B C A . (2)
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TL;DR: In this paper, the authors developed an approach to calculate the mass spectra of elementary particles within the framework of the resonance theory of the elementary particles as de Broglie waves.
Abstract: The purpose of present paper is to develop the approach to calculation of the mass spectra of elementary particles within the framework of the resonance theory of elementary particles as de Broglie waves
TL;DR: In this paper, an approximate expression for the energy per nucleon in asymmetric nuclear matter is derived through a combination of two procedures, one used for symmetric nuclear matters and the other for spin-polarized liquid 3 He with spin polarization replaced by isospin polarization.
Abstract: Asymmetric nuclear matter at zero temperature is studied using a variational method which is an extension of the methods used by the present authors previously for simpler systems. An approximate expression for the energy per nucleon in asymmetric nuclear matter is derived through a combination of two procedures, one used for symmetric nuclear matter and the other for spin-polarized liquid 3 He with spin polarization replaced by isospin polarization. The approximate expression for the energy is obtained as a functional of various spin-isospin-dependent radial distribution functions, tensor distribution functions, and spin-orbit distribution functions. The Euler-Lagrange equations are derived to minimize this approximate expression for the energy; they consist of 16 coupled integrodifferential equations for various distribution functions. These equations were solved numerically for several values of the nucleon number density p and for many degrees of asymmetry ξ [ ζ = (ρ n -ρ p )/ρ, where ρ n (ρ p ) is the neutron (proton) number density]. Unexpectedly, we find that the energies at a fixed density cannot be represented by a power series in ζ 2 . A new energy term, e 1 (ζ 2 + ζ 2 0 ) 1/2 , where ζ0 is a small number and e1 is a positive coefficient, is proposed. It is shown that if the power series is supplemented with this new term, it reproduces the energies obtained by variational calculations very accurately. This new term is studied in relation to cluster formation in nuclear matter, and some mention is made of a possible similar term in the mass formula for finite nuclei.
TL;DR: In this article, the SU(3) mass formula was introduced and a brief history of the discovery of the mass formula and a few remarks on the inequality of partial decay rates of particles and their antiparticles were made.
Abstract: We give a brief history of the discovery of the SU(3) mass formula and offer a few remarks on the inequality of partial decay rates of particles and their antiparticles.
TL;DR: The spectrum of the Kaluza-Klein (KK) spectrum of N = 1 supersymmetric gauge theory compactified on a circle was investigated in this article, where the authors derived the exact mass formula of KK modes using Seiberg-Witten theory.
Abstract: We investigate the Kaluza-Klein (KK) spectrum of N=1 supersymmetric gauge theory compactified on a circle. We concentrate on a model with the gauge group SU(2) and four massless matter fields in the fundamental representation. We derive the exact mass formula of KK modes using Seiberg-Witten theory. From the mass formula and the D3-brane probe realization, we determine the spectrum of the KK modes of the matter fields and gauge fields. We find that the lightest KK state of the gauge fields is stable in the entire vacuum moduli space, while the lightest KK state of the matter fields decays more readily than other KK states in one region of the moduli space. This region becomes small as we decrease the five-dimensional gauge coupling constant g 5 , and vanishes in the limit g 5 → 0. This result continuously connects the known KK spectrum in the weak coupling limit and that in the strong coupling limit.
TL;DR: In this article, a modified Bethe-Weizsacker mass formula (BWMH) was proposed to describe the normal and hypernuclei on the same footing.
Abstract: Simultaneous description of ordinary and hypernuclei masses by a single mass formula has been a great challenge in nuclear physics. Hyperon-separation energies of about forty Lambda($\Lambda$), three Lambda-Lambda($\Lambda\Lambda$), one Sigma($\Sigma$) and seven Cascade($\Xi$) hypernuclei have been experimentally found. Many of these nuclei are of light masses. We prescribe a new mass formula, called BWMH, which describes the normal and hypernuclei on the same footing. It is based on the modified-Bethe-Weizs\"acker mass formula (BWM). BWM is basically an extension of the Bethe-Weizs\"acker mass formula (BW) for light nuclei. The parameters of BWM were optimized by fitting about 3000 normal nuclei available recently. The original Bethe-Weizs\"acker mass formula (BW) was designed for medium and heavy mass nuclei and it fails for light nuclei. Two earlier works on hypernuclei based on this BW show some limitations. The BWMH gives improved agreement with the experimental data for the line of stability, one-neutron separation energy versus neutron number spectra of normal nuclei, and the hyperon-separation energies from hypernuclei. The drip lines are modified for addition of a $\Lambda$ hyperon in a normal nucleus.
TL;DR: In this paper, the mass splittings of the baryons belonging to the $[{\bf 70,1^-]$-plet are derived by using a simple group theoretical approach to the matrix elements of the mass formula.
Abstract: The mass splittings of the baryons belonging to the $[{\bf 70},1^-]$-plet are derived by using a simple group theoretical approach to the matrix elements of the mass formula. The basic conclusion is that the first order correction to the baryon masses is of order $1/N_c$ instead of order $N^0_c$, as previously found. The conceptual difference between the ground state and the excited states is therefore removed.