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Showing papers on "Mass formula published in 2005"


Journal ArticleDOI
TL;DR: In this paper, the Viola-Seaborg formula is used to reproduce the half-life of heavy even-even nuclei within a factor of 1.3 for the superheavy region.
Abstract: The Viola-Seaborg formula is a well-known formula for α-decay half-lives of heavy nuclei. In this work we obtain new parameters of this formula through a least-square fit to even-even nuclei between Z = 84 and Z = 110 with N greater than 126. On average, the formula can reproduce the half-lives of heavy even-even nuclei within a factor of 1.3. The formula with new parameters works well for the superheavy region which is a hot topic of nuclear physics. The numerical results from the formula are compared with those from the cluster model.

64 citations


Journal ArticleDOI
TL;DR: In this paper, the modified Bethe-Weizsacker mass formula with isotonic shifts was used to calculate the nuclear masses of the Neutron and Proton drip lines.
Abstract: Nuclear masses are calculated using the modified Bethe–Weizsacker mass formula in which the isotonic shifts have been incorporated. The results are compared with the improved liquid drop model with isotonic shift. Mass excesses predicted by this method compares well with the microscopic–macroscopic model while being much more simple. The neutron and proton drip lines have been predicted using this modified Bethe–Weizsacker mass formula with isotonic shifts.

62 citations


Journal ArticleDOI
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 for repulsive potential.

38 citations


Journal ArticleDOI
TL;DR: In this article, the average energy of SU(6) multiplet is described using a hypercentral potential containing a linear and a hyper-Coulomb term, which is the same as in this paper.
Abstract: We study the spin- and flavour-dependent SU(6) violations in the baryon spectrum by means of a Gursey-Radicati mass formula. The average energy of each SU(6) multiplet is described using the SU(6)-invariant interaction given by a hypercentral potential containing a linear and a hyper-Coulomb term. We show that the nonstrange- and strange-baryon masses are, in general, fairly well reproduced and moreover that the Gursey-Radicati formula holds in a satisfactory way also for the excited states up to 2 GeV.

37 citations


Journal ArticleDOI
TL;DR: In this article, the spin and flavour-dependent SU(6) violations in the baryon spectrum were studied by means of a Gursey Radicati mass formula. And they were shown that the non strange and strange baryons masses are in general fairly well reproduced and moreover that the Gursey radicati formula holds in a satisfactory way also for the excited states up to 2 GeV.
Abstract: We study the spin- and flavour- dependent SU(6) violations in the baryon spectrum by means of a Gursey Radicati mass formula. The average energy of each SU(6)-multiplet is described using the SU(6) invariant interaction given by a hypercentral potential containing a linear and a hypercoulomb term. We show that the non strange and strange baryon masses are in general fairly well reproduced and moreover that the Gursey Radicati formula holds in a satisfactory way also for the excited states up to 2 GeV. The coefficients of the Gursey Radicati SU(6) breaking part obtained by the fit of the three-quark spectrum can be used to evaluate in first approximation the splitting within multiplets also for exotic baryon systems.

32 citations


Journal ArticleDOI
Chia-Fu Yu1
TL;DR: In this paper, the exact geometric mass formula for superspecial abelian varieties of Hilbert-Blumenthal type was derived and the number of irreducible components of the supersingular locus of some Hilbert-blumenthal varieties in terms of special values of the zeta function was computed.
Abstract: A geometric mass concerning supersingular abelian varieties with real multiplications is formulated and related to an arithmetic mass. We determine the exact geometric mass formula for superspecial abelian varieties of Hilbert-Blumenthal type. As an application, we compute the number of the irreducible components of the supersingular locus of some Hilbert-Blumenthal varieties in terms of special values of the zeta function.

28 citations


Journal ArticleDOI
TL;DR: In this article, Luscher's finite size mass shift formula in a periodic finite volume, involving forward scattering amplitudes in the infinite volume, is revisited for the two stable distinguishable particle system.

24 citations


Posted Content
TL;DR: In this paper, a short historical and bibliographical review of the lepton mass formula of Yoshio Koide is presented, as well as some speculations on its extensions to quark and neutrino masses.
Abstract: We present a short historical and bibliographical review of the lepton mass formula of Yoshio Koide, as well as some speculations on its extensions to quark and neutrino masses, and its possible relations to more recent theoretical developments.

24 citations


Posted Content
TL;DR: Lanczos's fundamental system was put in Lagrangian form and generalized in 1933 by Einstein and Mayer, who used the semivector instead of the quaternion formalism as discussed by the authors.
Abstract: In 1929 Lanczos showed how to derive Dirac's equation from a more fundamental system that predicted that spin 1/2 particles should come in pairs. Today, these pairs can unambiguously be interpreted as isospin doublets. From the same fundamental equation, Lanczos derived also the correct form of the wave equation of massive spin 1 particles that would be rediscovered in 1936 by Proca. Lanczos's fundamental system was put in Lagrangian form and generalized in 1933 by Einstein and Mayer, who used the semivector instead of the quaternion formalism. Although they not did study all possible solutions, Einstein and Mayer showed that the doublets consisted of particles with different mass and charge. In fact, there are two main classes of doublets: proton/neutron and electron/neutrino pairs.

19 citations


Journal ArticleDOI
TL;DR: In this paper, a new form of the binding energy formula of heavy nuclei with Z{>=}90 is proposed where new terms beyond the standard Bethe and Weizsaecker formula are introduced by analytical expressions.
Abstract: A new form of the binding energy formula of heavy nuclei with Z{>=}90 is proposed where new terms beyond the standard Bethe and Weizsaecker formula are introduced by analytical expressions. This can be considered an interesting development of the Bethe and Weizsaecker mass formula for heavy nuclei with Z{>=}90. Two versions of the formulae are presented. The first version of the formula can reproduce the 117 known binding energies of nuclei with Z{>=}90 and N{>=}140 with an average deviation 0.118 MeV. This is the first time that the binding energies of heavy nuclei with Z{>=}90 and N{>=}140 can be calculated very accurately by a formula with only seven parameters. The binding energies, {alpha}-decay energies, and {alpha}-decay half-lives of unknown superheavy nuclei are predicted. The second version of the formula is obtained by fitting the 181 data of nuclei with Z{>=}90 with nine parameters and good agreement with experimental binding energies is also reached for all nuclei with Z{>=}90.

19 citations


Posted Content
TL;DR: In this article, an example of such a mass generation mechanism is proposed, where the origin of the mass spectrum is attributed not to the structure of the Yukawa coupling constants, but to a structure of vacuum expectation values of flavor-triplet scalars under Z_4 \times S_3 symmetries.
Abstract: Why the charged lepton mass formula m_e +m_\mu +m_\tau = {2/3} (\sqrt{m_e}+\sqrt{m_\mu} +\sqrt{m_\tau})^2 is mysterious is reviewed, and guiding principles to solve the mystery are presented. According to the principles, an example of such a mass generation mechanism is proposed, where the origin of the mass spectrum is attributed not to the structure of the Yukawa coupling constants, but to a structure of vacuum expectation values of flavor-triplet scalars under Z_4 \times S_3 symmetries.

Posted Content
TL;DR: In this paper, the spectrum of all known baryons with the mass less than approximately 2000-2200 MeV was reviewed using methods based on the approximate flavor SU(3) symmetry of the strong interaction.
Abstract: We review the spectrum of all baryons with the mass less than approximately 2000-2200 MeV using methods based on the approximate flavor SU(3) symmetry of the strong interaction. The application of the Gell-Mann--Okubo mass formulas and SU(3)-symmetric predictions for two-body hadronic decays allows us to successfully catalogue almost all known baryons in twenty-one SU(3) multiplets. In order to have complete multiplets, we predict the existence of several strange particles, most notably the \Lambda hyperon with J^P=3/2^-, the mass around 1850 MeV, the total width approximately 130 MeV, significant branching into the \Sigma \pi and \Sigma(1385) \pi states and a very small coupling to the N \bar{K} state. Assuming that the antidecuplet exists, we show how a simple scenario, in which the antidecuplet mixes with an octet, allows to understand the pattern of the antidecuplet decays and make predictions for the unmeasured decays.

Journal ArticleDOI
TL;DR: In this paper, the authors give a description of open strings stretched between N parallel D-branes in VSFT and show how higgsing is generated as the branes are displaced: the shift in the mass formula for on-shell states stretched between different branes is due to a twist anomaly.
Abstract: We give a description of open strings stretched between N parallel D-branes in VSFT We show how higgsing is generated as the branes are displaced: the shift in the mass formula for on-shell states stretched between different branes is due to a twist anomaly, a contribution localized at the midpoint

Journal ArticleDOI
TL;DR: In this article, the differences between measured nuclear masses and those calculated using the Finite-Range Droplet Model are analyzed, and it is shown that they have a well defined, clearly correlated oscillatory component as a function of the proton and neutron numbers.
Abstract: Differences between measured nuclear masses and those calculated using the Finite-Range Droplet Model are analyzed. It is shown that they have a well defined, clearly correlated oscillatory component as a function of the proton and neutron numbers. At the same time, they exhibit in their power spectrum the presence of chaos. Comparison with other mass calculations strongly suggest that this chaotic component arises from many body effects not included in the mass formula, and that they do not impose limits in the precision of mass calculations.


Posted Content
TL;DR: In this paper, it was shown that the efficient mass formula for charged leptons in 1992 can be considered as an excellent approximate solution to the mysterious charged-lepton mass equation proposed by Koide in 1981.
Abstract: It is shown that the efficient mass formula we found for charged leptons in 1992 can be considered as an excellent approximate solution to the mysterious charged-lepton mass equation proposed by Koide in 1981.

Journal ArticleDOI
TL;DR: In this paper, the mass, α-decay and spontaneous fission half-life of superheavy elements were studied in macroscopic-microscopic approaches with two different macro-scopic models and the delta-pairing interaction.
Abstract: Masses, α-decay and spontaneous fission half-lives of superheavy elements are studied in macroscopic-microscopic approaches with two different macroscopic models and the delta-pairing interaction. Model mass deviations obtained with different formulae are 0.5-0.8MeV.

Journal ArticleDOI
TL;DR: In this paper, the authors give a description of open strings stretched between N parallel D-branes in VSFT and show how higgsing is generated as the branes are displaced: the shift in the mass formula for onshell states stretched between different branes is due to a twist anomaly, a contribution localized at the midpoint.
Abstract: We give a description of open strings stretched between N parallel D-branes in VSFT. We show how higgsing is generated as the branes are displaced: the shift in the mass formula for on-shell states stretched between different branes is due to a twist anomaly, a contribution localized at the midpoint.

Posted Content
TL;DR: In this paper, a comparison of the predictions of different mass models with experiment on the Tin isotopes is presented, where the difference of the binding energy of various mass models and experimental results with respect to the prediction of the model of Duflo and Zuker is plotted for the chain of isotopes of Sn with neutron number varying between 45 and 110.
Abstract: The general scepticism and loss of faith on the predictive ability of different mass formulae, arising out of the divergence of their predictions in unknown regions taken with respect to a reference mass formula, is successfully dispelled. When the result of relativistic mean field (RMF) theory with a Lagrangian common for all nuclei is taken as reference, the divergence disappears, and clear trend with strong correlation appears restoring our faith in general on the predictions of mass formulae, qualifying them as useful guideline for theoretical and experimental studies of nuclear phenomena. Mass formulae occupy the centre stage in the research in nuclear physics. The first model of the nucleus is a mass formula proposed by Bethe and Weiszackar in mid 1930s, soon after the discovery of the neutron unravelling the composition of the nucleus. It defined some of the key concepts and parameters for the first time for the description of nuclear phenomena, and laid the foundation for their future exploration. Our inability to predict the masses of nuclei starting from first principle, and our present experimental incapability to produce large majority of them in the laboratory, warrants reliable mass formulae of nuclei for understanding many phenomena, most notably, the nucleosynthesis and stellar evolution. Therefore the development of nuclear mass formulae has been all along a core theme of nuclear physics which has implicitly sustained and nourished the research in diverse areas of nuclear structure and nuclear reactions. Over the last 70 years, about a dozen of mass formulae have been proposed. With the advent of heavy-ion reactions, the prospect of the exploration of the "terra incognita" is very much in the realm of possibility. To the already known about 2000 nuclei, another 5000 to 7000 nuclei will be added in future by their synthesis in the laboratory for which unprecedented activity in different laboratories is underway. Therefore the predictive ability of differnt mass formulae is under serious scrutiny. Figure 1 represents an often quoted result (1-3) on the comparison of the predictions of different mass models with experiment on the Tin isotopes. Here the difference of the binding energy of various models and experimental results with respect to the predictions of the model of Duflo and Zuker (4), taken as reference, is plotted for the chain of isotopes of Sn with neutron number varying between 45 and 110. There is unanimity of all the mass models on good agreement with experiment in the known region close to stability, however, the predictions diverge as one moves away to unknown

Journal ArticleDOI
TL;DR: In this paper, the effects of the newly derived microscopic Hartree-Fock-Bogoliubov (HFB) mass formulae on the r-process nucleosynthesis and analyse to what extent a solar-like r -abundance distribution can be obtained.

Journal ArticleDOI
TL;DR: In this article, the r-process that occurs due to the explosion from an inner region of the Fe-core was investigated, and it was shown that the solar R-process abundances are rather well reproduced for a model of 13 M ⊙.

Journal ArticleDOI
TL;DR: Based on an assumed mass formula for the spectrum of the Y=2 pentaquarks, where the chromo-magnetic interaction plays an important role, and identifying the lightest state with the Θ+(1540), the authors predict a spectrum in good agreement with the few I=0 and I=1 candidates proposed in the past.
Abstract: Based on an assumed mass formula for the spectrum of the Y=2 pentaquarks, where the chromo-magnetic interaction plays an important role, and identifying the lightest state with the Θ+(1540), we predict a spectrum in good agreement with the few I=0 and I=1 candidates proposed in the past

Journal ArticleDOI
TL;DR: In this article, the differences between measured nuclear masses and those calculated using the Finite Range Droplet Model are analyzed and it is shown that they have a well defined, clearly correlated oscillatory component as a function of the proton and neutron numbers.
Abstract: Differences between measured nuclear masses and those calculated using the Finite Range Droplet Model are analyzed. It is shown that they have a well defined, clearly correlated oscillatory component as a function of the proton and neutron numbers. At the same time, they exhibit in their power spectrum the presence of chaos. Comparison with other mass calculations strongly suggest that this chaotic component arises from many body effects not included in the mass formula, and that they do not impose limits in the precision of mass calculations.

01 Jan 2005
TL;DR: In this article, a mass formula that generates the mass ratios of the quarks and leptons is described, and the formula succeeds by exploiting a symmetry among the Fibonacci numbers that helps explain why there are no more than three particle families.
Abstract: A mass formula that generates the mass ratios ofthe quarks and leptons is described. The formula succeeds by exploiting a symmetry among the Fibonacci numbers that helps explain why there are no more than three particle families.

Posted Content
TL;DR: Empirical mass formulae for the baryon octet and decuplet are presented in this article, which are functions of one integer variable and charge state of baryons.
Abstract: Empirical mass formulae for the baryon octet and decuplet are presented. These formulae are functions of one integer variable and charge state of the baryons. With an exception of Lambda(1116), the formulae generate masses within 0.1% of the observed masses. The formulae also generate the same electromagnetic mass splittings predicted by SU(6)model. Spin 1/2 octet resonances and its relation to the octet mass formula is described.

Journal ArticleDOI
TL;DR: In this paper, the Hartree-Fock-Bogolyubov framework has been used for the global prediction of atomic masses and its ability to reproduce experimental masses as well as nuclear-matter and giant-resonance properties.
Abstract: We review the latest efforts devoted to the global prediction of atomic masses. Special attention is paid to the new developments made within the Hartree-Fock-Bogolyubov framework. So far, 9 HFB mass tables based on different parametrizations of the effective interactions in the Hartree-Fock and pairing channels have been published. We analyze their ability to reproduce experimental masses as well as nuclear-matter and giant-resonance properties. The possibility to derive within the HFB framework a universal effective interaction that can describe all known properties of the nuclei (including their masses) and of asymmetric nuclear matter is critically discussed.

Journal ArticleDOI
TL;DR: In this article, the arithmetic properties of orders in a quaternion algebra over a dyadic local field were studied, and the mass formula of orders was found in terms of orders.
Abstract: In this paper, we study the arithmetic properties of orders in a quaternion algebra over a dyadic local field and we find the mass formula of orders.

Journal ArticleDOI
TL;DR: In this paper, a typical form of mass formula is re-explained in terms of nuclear structure by considering the T = 0 2n−2p (α-like) correlations as the fundamental concept, instead of the symmetry energy.
Abstract: A typical form of mass formula is re-explained in terms of nuclear structure. For N ≈ Z nuclei, we propose to start with the shell model picture and to consider the T =0 2n−2p (αlike) correlations as the fundamental concept, instead of the symmetry energy. Subsequently, the symmetry energy is described on the basis of the α-like superfluidity caused by the T =0 2n − 2p correlations, in parallel with the pairing energy described on the basis of the pairing superfluidity. This re-explanation gives useful insight for understanding the nuclear mass formula. The origin of the Wigner energy is al so explained in an interacting boson model for the Cooper pairs in the α-like superfluid vacuum. Adding a correction term due to the T =02 n − 2p correlations, which determines the T = 0 base level for nuclear masses, can improve the mass formulas in practice.