Identification of theta

Abstract

By incorporating a soft form factor, we show that {theta}({ital f}{sub 2}(1720)) has flavor-independent decays to {ital K{bar K}}, {eta}{eta}, and {pi}{pi}. The same form factor is needed to understand the suppression of {theta} in {ital K}{sup {minus}}p{r arrow}{Lambda}K{sub S}{sup 0}K{sub S}{sup 0} as well as its emergence in the central productions of {pi}{ital p}{r arrow}{pi}({ital K}{sup +}K{sup {minus}})p and {ital pp}{r arrow}{ital p}({ital K}{sup +}K{sup {minus}})p. This flavor-symmetric feature of {theta} is further enhanced by comparing {ital f}{sub 2}{sup {prime}}(1525) and {theta} in {ital J}/{psi} decays to {gamma}{ital K{bar K}}, {omega}{ital K{bar K}}, and {phi}{ital K{bar K}}. The absence of {theta} in {gamma}{gamma}{r arrow}{ital K}{sub {ital S}}{sup 0}K{sub S}{sup 0} and {ital K}{sup {minus}}p{r arrow}{Lambda}K{sub S}{sup 0}K{sub S}{sup 0} leads us to conclude that the quark content in {theta} is very low. With {theta} shown to be a flavor singlet and void of quarks, we believe that {theta} could indeed be a tensor glueball, subject to the verification of the soft form factor.