Work

Unraveling K ( 1690 ) as a pseudoscalar u d d ¯ s ¯ tetraquark state

Year: 2025

Type: article

Abstract: The recently observed K ( 1690 ) has been identified as a supernumerary pseudoscalar resonance signal in the strange-meson spectrum predicted by quark model calculations. It is the best candidate of a strange cryptoexotic state. In this work, we systematically study the hadron masses of u d d ¯ s ¯ tetraquark states with J P = 0 − in the method of QCD sum rules. For ten interpolating currents, we calculate the correlation functions up to dimension-8 nonperturbative condensates. To calculate the trigluon condensate, we comprehensively consider the contributions from different operators with and without covariant derivatives. The infrared safety can be guaranteed for the completely calculated trigluon condensate by properly addressing the IR divergences in Feynman diagrams. It is demonstrated that the trigluon condensate provides significant contributions to the sum-rule analyses in these light tetraquark systems. Our results support the interpretation of K ( 1690 ) resonance to be a pseudoscalar u d d ¯ s ¯ tetraquark state.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/fv87-6bcr

Authors: Jin-Peng Zhang, Xu-Liang Chen, Zi-Xi Ou-Yang, Xiang Yu, Wei Chen, Jia-Jun Wu

Institutions: Sun Yat-sen University, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Institute of Modern Physics

Language: English

Topic: Quantum Chromodynamics and Particle Interactions

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funder: National Natural Science Foundation of China

Award: G2922008647