Tetraquark mixing framework for isoscalar resonances in light mesons

Precision spectroscopy in light isovector , isoscalar and hybrid mesons

We discuss all-to-all propagators in the context of high statistical precision determinations of the isovector and isoscalar meson spectrum. In particular we look at the method of Ref. [2] that incorporates the low-lying eigenmodes and variance-reduced stochastic estimation. We find significant low-lying eigenmode dependence of mass determinations, with the number of required modes varying with...

Isoscalar Resonances with J

Tetraquark mesons in large-N quantum chromodynamics.

It is argued that exotic mesons consisting of two quarks and two antiquarks are not ruled out in quantum chromodynamics with a large number N of colors, as generally thought. Tetraquarks of one class are typically long-lived, with decay rates proportional to 1/N.

Isoscalar-isovector mass splittings in excited mesons.

Mass splittings between the isovector and isoscalar members of meson nonets arise in part from hadronic loop diagrams which violate the Okubo-ZweigIizuka rule. Using a model for these loop processes which works qualitatively well in the established nonets, I tabulate predictions for the splittings and associated isoscalar mixing angles in the remaining nonets below about 2.5 GeV, and explain so...

Determining the Gluonic Content of Isoscalar Mesons

We develop tools to determine the gluonic content of a resonance of known mass, width and J from its branching fraction in radiative quarkonium decays and production cross section in γγ collisions. We test the procedures by applying them to known qq̄ mesons, then analyze four leading glueball candidates. We identify inconsistencies in data for J/ψ → γf0(1500) and J/ψ → γfJ(1710) whose resolution...