Mass formula

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

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.

Scalar Solitons in Non(anti)commutative Superspace

Abstract: We study solitonic solutions of a deformed Wess-Zumino model in 2 dimensions, corresponding to a deformation of the usual ${\cal N}=1,D=2$ superspace to the one with non-anticommuting odd supercoordinates. The deformation turns out to add a kinetic term for the auxiliary field besides the known $F^{3}$ term coming from the deformation of the cubic superpotential. Both these modifications are proportional to the effective deformation parameter $\lambda \equiv \det C$, where $C$ denotes the non-anticommutativity matrix. We find a modified ``orbit'' equation which on the EOM relates the auxiliary and the scalar components of the scalar superfield as a first order correction to the usual relation in terms of the small parameter $\lambda $. Subsequently, we obtain the modified form of the first order BPS equation for the scalar field and find its solution to first order in $\lambda $. Issues such as modification of the BPS mass formula and a non-linear realization of the ${\cal N}=1$ supersymmetry are discussed.

Lambda hyperonic effect on the normal drip lines

Abstract: A generalized mass formula is used to calculate the neutron and proton drip lines of normal and lambda hypernuclei treating non-strange and strange nuclei on the same footing. Calculations suggest the existence of several bound hypernuclei whose normal cores are unbound. Addition of Λ or ΛΛ hyperon(s) to a normal nucleus is found to cause non-uniform shifts of the neutron and proton drip lines from their conventional limits making existance of a few exotic hypernuclei beyond the normal drip lines possible.

Group schemes and local densities of quadratic lattices in residue characteristic 2

Abstract: The celebrated Smith–Minkowski–Siegel mass formula expresses the mass of a quadratic lattice .