Mass formula

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

Masses of multiquark droplets

Abstract: The mass formulas for finite lumps of strange quark matter with [ital u], [ital d], and [ital s] quarks and nonstrange quark matter consisting of [ital u] and [ital d] quarks are derived in a nonrelativistic potential model. The finite-size effects comprising the surface and curvature were consistently obtained, which shows a converging trend. It is found that there is a good possibility for the formation of metastable strangelets of large mass. The model predicts a low charge to mass ratio as the characteristic signature of strange matter in agreement with the relativistic studies. This study also yields an estimate for the bag energy density [ital B] in terms of the constituent quark mass and the baryon number density.

Baryon resonances and strong QCD

Abstract: Light-baryon resonances (with u,d, and s quarks in the SU(3) classification) fall on Regge trajectories. When their squared masses are plotted against the intrinsic orbital angular momenta {\rm L}, $\Delta^*$'s with even and odd parity can be described by the same Regge trajectory. For a given {\rm L}, nucleon resonances with spin {\rm S}=3/2 are approximately degenerate in mass with $\Delta$ resonances. To which total angular momentum {\rm L} and {\rm S} couple has no significant impact on the baryon mass. Nucleons with spin 1/2 are shifted in mass; the shift is - in units of squared masses - proportional to the component in the wave function which is antisymmetric in spin and flavor. Based on these observations, a new baryon mass formula is proposed which reproduces nearly all known baryon masses. It is shown that the masses are compatible with a quark-diquark picture while the richness of the experimentally known states require three particles to participate in the dynamics. This conflict is resolved by proposing that quarks polarize the QCD condensates and are surrounded by a polarization cloud shielding the color. A new interpretation of constituent quarks as colored quark clusters emerges; their interaction is responsible for the mass spectrum. Fast flavor exchange between the colored quark clusters exhausts the dynamical richness of the three-particle dynamics. The colored-quark-cluster model provides a mechanism in which the linear confinement potential can be traced to the increase of the volume in which the condensates are polarized. The quark-spin magnetic moment induces currents in the polarized condensates which absorb the quark-spin angular momentum: the proton spin is not carried by quark spins. The model provides a new picture of hybrids and glueballs.

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.

New results for the quantum supersymmetric kink

Abstract: We review our work on computations of the quantum corrections to the mass and the central charge of the susy kink. For the mass corrections, we find that the widely used momentum cut-off scheme gives an incorrect result, but we deduce through smoothing of the cut-off an extra term in the mass formula, which produces the correct result. We discover the importance of boundary effects for the mode number cut-off regularization scheme. We introduce the notion of delocalized boundary energy. We discuss two discrete $Z_2$ symmetries and their importance to the mode number approach. For the central charge corrections, we use momentum cut-off regularization with two cut-offs, one for propagators and another for Dirac delta functions. We then compute the quantum anomaly in the central charge, and find that it restores the BPS bound at the one-loop level if the two cut-offs are equal.

A Simple Formula Suggests a Profound Mass Relation between Quarks and Leptons

Abstract: This paper is concerned with a formula for the mass of the neutron. This formula is based on the mass of the proton and the masses of the three heavier leptons: the electron (generation 1), the muon (generation 2) and the tau particle (generation 3). The formula is, at least, accurate to 4 decimal places. Because the mass of the tau particle is poorly known, it is unknown whether this formula is physically correct or it is simply a numeric coincidence. Finally, the formula suggests a deep mass relationship between quarks and leptons.