Showing papers on "Mass formula published in 1978"
TL;DR: In this paper, a large number of different Hartree-Fock effective interactions were considered and it was shown that the M -coefficient of the droplet-model part of the mass formula is close to zero.
46 citations
TL;DR: A six-parameter energy density functional is used to calculate self-consistently the binding energies of spherical nuclei in this article, which has a better precision than other mass formulae with a similar number of parameters.
32 citations
TL;DR: In this article, it was shown that Gardner's and Levkovskii's empirical formulas for 14-MeV neutron cross sections can be mainly equivalent to the following approximation subject to modifications from direct interaction: T is the nuclear temperature given by 10/A1/2 and Vp′ is Dostrovsky's value of the effective Coulomb barrier.
Abstract: Levkovskii's and Gardner's empirical formulas for 14 MeV neutron (n,p) cross sections can be shown to be mainly equivalent to the following approximation: subject to modifications from direct interaction. Here T is the nuclear temperature, given by 10/A1/2 and Vp′ is Dostrovsky's value of the effective Coulomb barrier. Qnp′ is the effective Q value calculated using the mass formula in which B and Z0/A are shell-independent parameters.
27 citations
TL;DR: In this paper, Hartree-Fock calculations on semi-infinite nuclear matter have been performed for effective interactions that have finite range and also contain a spin-orbit component, and the value a sf = 20.1 MeV for the surface coefficient of the mass formula.
26 citations
01 Sep 1978
TL;DR: In this article, the Qβ-value of 144,145Ba,144,145,147La, 145,147,148Ce and148Pr has been measured using mass-separated sources produced at the on-line mass separator LOHENGRIN.
Abstract: TheQβ-value of144,145Ba,144,145,147La,145,147,148Ce and148Pr has been measured using mass-separated sources produced at the on-line mass separator LOHENGRIN. The experimental values are compared with mass formula predictions.
20 citations
01 Mar 1978
TL;DR: In this article, a subshellclosure effect for the neutron numberN=56 and proton numberZ=38 is shown to exist, taking also into account earlier results, and the experimental values are compared with mass formula predictions.
Abstract: TheQβ-values of85, 86Se,90Br,93Kr,103Nb and103Tc were measured using massseparated sources produced at the on-line mass separator LOHENGRIN. The experimental values are compared with mass formula predictions. Taking also into account earlier results, a subshell-closure effect for the neutron numberN=56 and proton numberZ=38 is shown to exist.
15 citations
TL;DR: In this article, a variational technique for describing the bulk properties of neutron and nuclear matter is extended to the case of a nucleon fluid with arbitrary proton to neutron ratio.
Abstract: A lowest-order constrained variational technique previously used by the authors to describe the bulk properties of neutron and nuclear matter is extended to the case of a nucleon fluid with arbitrary proton to neutron ratio. Calculations with the Reid soft-core potential are performed and a value of the symmetry coefficient in the semi-empirical mass formula is obtained. Inclusion of the saturating effect of the Delta (1236) described by Green and collaborators is shown to improve this value.
13 citations
TL;DR: In this paper, the authors show in the leading order of the 1/N expansion that different results on the fermion mass as a function of the coupling constant are obtained depending on various ways of renormalizing the gap equation for the dynamically generated mass.
Abstract: In the Gross-Neveu model in 2 space-time dimensions, fermion masses are generated dynamically for any positive value of the renormalized coupling constant. We show in the leading order of the 1/N expansion that different results on the fermion mass as a function of the coupling constant are obtained depending on various ways of renormalizing the gap equation for the dynamically generated mass. One of the most reasonable renormalization procedures provides the mass equation in Abarbanel's self-consistent ..beta..-function method. We find that the dimensional transmutation of Coleman and Weinberg is possible at the infrared-stable zero found by Abarbanel.
12 citations
TL;DR: In this article, an approximate method based on the Strutinsky prescription with a modified smoothing method was used to extend the energy density mass formula to deformed nuclei, without too long numerical calculations.
11 citations
TL;DR: In this paper, the energy density mass formula is extrapolated to the superheavy region and to the neutron drip line, and the most stable nucleus at N =184 is found to be either184X¯¯¯¯ 110 294 with a half-life of 67 years, or184====== 108 292 with a 14-year half life.
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.
10 citations
TL;DR: In this article, an extended partially conserved axial-vector current (EPCAC) hypothesis is used to obtain the chiral SU(3) x SU (3) -symmetry-breaking corrections to Dashen mass formula.
Abstract: The recently proposed extended partially conserved axial-vector current (EPCAC) hypothesis is used in order to obtain the chiral-SU(3) x SU(3) -symmetry-breaking corrections to (a) the Dashen mass formula, (b) the soft-meson theorem relevant to the eta ..-->.. 3..pi.. decay, and (c) the ..delta..I = 1 baryon mass differences. It is found that the EPCAC hypothesis together with current algebra and an epsilon/sub 3/u/sub 3/ term in the chiral Hamiltonian provides a working explanation for the eta ..-->.. 3..pi.. puzzle in the framework of the (3,3*) + (3*,3) model.
TL;DR: In this paper, a hadronic mass formula of the Gell-Mann-Okubo type is derived for an isolated black gheon. But this formula is not applicable to the case of a scalar field equation.
Abstract: The basic forces of nature, mediated by spin-one and spin-two particles, are unified within a geometrical gauge theory. Gravity, electromagnetism, and strong forces are described by two nonsymmetric fields g/sub munu/ and s/sub munu/. Field equations are derived from a variational principle. The field equations possess an exact (classical) nonsingular solution that corresponds to a geometrical object called a gheon (gravitational-hadronic-electromagnetic entity). Space inside a gheon is Euclidean four-dimensional and a gheon can have event horizons. The gheons describe hadrons and at the classical level permanently confine quarks. The event horizons trap normal hadrons and can also radiate them, producing a thermal hadronic spectrum. There exists a limit in which the field equations reduce to Einstein-Maxwell equations. In this limit, the gheons shrink to point singularities. By matching the boundary conditions of the solutions of a scalar field equation on the surface of a gheon, a discrete mass spectrum for a scalar particle is obtained. A hadronic mass formula of the Gell-Mann--Okubo type is derived for an isolated black gheon.
TL;DR: In this paper, the mass formula for the axion system is analyzed taking into account instanton effects, and it is argued that small-size instantons serve as an independent source of axion's mass.
Abstract: The mass formula for the ..pi.., eta, A (axion) system is analyzed taking into account explicit instanton effects. It is argued that small-size instantons serve as an independent source for the axion's mass which may render the axion more massive than the mixing the bare axion with ..pi.. an eta.
TL;DR: In this article, the relativistic quark model of hadrons was proposed and the matrix elements for the above processes were calculated directly by considering appropriately Lorentz-boosted hadronic states.
Abstract: Radiative decays of mesons, both $V\ensuremath{\rightarrow}P\ensuremath{\gamma}$ and $P\ensuremath{\rightarrow}V\ensuremath{\gamma}$, are calculated in a relativistic quark model of hadrons proposed earlier by one of the authors. The matrix elements for the above processes are calculated directly by considering appropriately Lorentz-boosted hadronic states. The electromagnetic current operator in terms of the appropriately Lorentz-boosted quark field operators are utilized. Only the wave functions of hadrons enter the picture. No vector dominance is assumed. Mixing angles of mesons are taken from quadratic mass formula in SU(3). Thus with no adjustable free parameters or concepts, there is reasonable agreement with experimental results.
TL;DR: In this paper, the mass, mass splittings and other properties of the ϒ(9.4 GeV) particle and related mesons were discussed in terms of mass formula based on the observation that the excitatation spectra of spin triplet mesons are roughly independent of meson masses.
TL;DR: The Christodoulou-Ruffini mass formula of a black hole also holds true in case of the charged Kerr-Tomimatsu-Sato family of fields with arbitrary odd δ.
TL;DR: In this paper, a semi-empirical mass formula for all medium and heavy nuclei has been used to analyze experimental results of mass measurements for both medium and light nuclei.
Abstract: Experimental results of mass measurements for all medium and heavy nuclei have been analyzed using a semiempirical mass formula. The analysis indicates the existence of a universal dependence on the neutron number for the shell-effects term in the neutron separation energies, and the existence of a similar universal dependence on the proton number for the shell-effects term in proton separation energies.
TL;DR: New fits to experimental data seem to point in the direction of an A~ resonance which is both wider and at a higher mass than previously thought (~-a), although one can still find experiments giving a lower mass (4-6) as discussed by the authors.
Abstract: New fits to experimental data seem to point in the direction of an A~ resonance which is both wider and at an higher mass than previously thought (~-a) (although one can still find experiments giving a lower mass (4-6)). At the same time new evidence appeared for the existence of the 9'(1250) (7) not far in mass from the A I. The question now is how these new facts fit in a chiral-symmetry scheme which seemed to work well for the restricted p-Al-~: system when it looked as if m2 -- 2m~ (s,~) A1~'(1250) together with pql600) are, in the quark model, radial excitations of ~(770). Many more (or an infinite number) of these radial excitations could in principle exist. A~ and 7: could also have their radial excitations even when none of them are known at the present time (~0).
TL;DR: In this paper, the OZI rule and the FWR rule are unified into a selection rule (covalence rule), which forbids not only baryoniums to decay into the conventional mesons but also meson decay between three different kinds of baryons.
Abstract: Mass formula of hadrons is given for their topological structure of the junction type. The result agrees with recent candidates for baryonium. By noticing the topological structure, the OZI rule and the FWR rule are unified into a selection rule (covalence rule). This rule forbids not only baryoniums to decay into the conventional mesons but also meson decay between three different kinds of baryoniums, which may be favorable to explain narrowness of rather many baryonium candidates. The covalence rule is uniquely interpreted by fission of oriented strings connecting constituents (quark and junction). The world of hadrons is characterized by a stepwise coupling, from the conventional baryons to baryoniums, and baryoniums to the higher unconventional hadrons.
TL;DR: A general mass formula for all observed hadron multiplets was derived in this article, which involves, besides hypercharge and charm, the second-order Casimir operator of the subgroup SU¯¯¯¯3, as well as that of some other subgroup named¯¯¯¯ �₷Ⴗ€ 0.
Abstract: A general mass formula is derived for all observedSU
4 hadron multiplets. The formula involves, besides hypercharge and charm, the second-order Casimir operator of the subgroupSU
3, as well as that of some other subgroup named
$$\widetilde{SU}_3 $$
. The classification of hadrons according to the decompositionSU
4⊃
$$\widetilde{SU}_3 $$
is also given.
TL;DR: In this paper, a nuclear mass formula was derived using a few extremely reasonable assumptions within an independent particle model with residual interactions, and the parameters in the mass formula were determined by a least square fit to the experimental energies.
Abstract: A nuclear mass formula is derived using a few extremely reasonable assumptions within an independent particle model with residual interactions. The parameters in the mass formula are determined by a least square fit to the experimental energies. The mass formula is further used to study Garvey-Kelson and Franzini-Radicati mass relationships.
TL;DR: In this paper, it was shown that the η′ is close to an SU(3) singlet and has an equal amount of strange and non-strange quarks just as required by the quadratic version of the Gell-Mann-Okubo mass formula.