QCD sum rule study on excited light meson operators

TL;DR

This paper uses QCD sum rules to analyze excited light meson operators with derivatives, calculating their decay constants and predicting properties of new excited meson states.

Contribution

It systematically constructs and analyzes twelve excited light meson operators, providing new insights into their decay constants and meson state predictions.

Findings

Support for the $a_2(1320)$, $f_2(1270)$, $f_2^\'(1525)$, and $K_2^*(1430)$ as a flavor nonet.

Predicted masses and decay constants for several excited meson states.

Numerical analysis of ten excited light meson operators.

Abstract

We apply the QCD sum rule method to systematically study excited light meson operators and calculate their decay constants. These operators are constructed by explicitly adding one covariant derivative to the quark-antiquark pair. In total, twelve such operators are constructed, among which ten are subjected to detailed numerical analyses. The considered quark contents include $\bar{q}q$, $\bar{q}s$, and $\bar{s}s$ ($q = u/d$), allowing the formation of various $SU(3)$ flavor nonets. For instance, our results support the interpretation that the $a_2(1320)$, $f_2(1270)$, $f_2^\prime(1525)$, and $K_2^*(1430)$ constitute a flavor nonet with quantum numbers $J^{P(C)} = 2^{+(+)}$. In addition, we predict several excited meson states, whose masses and decay constants are determined using the QCD sum rule method.