arXiv subjects

Wei-Yang Lai

Publications and source records attributed to Wei-Yang Lai.

2 recordsLinked to original sources

arXiv2026

Probing Excited $q\bar{q}$ Mesons via QCD Sum Rules

We present a systematic study of the masses of light excited $q\bar{q}$ mesons using QCD sum rules at next-to-leading order (NLO). To probe excited states, we construct several interpolating currents with covariant derivatives inserted. The calculation is carried out up to dimension-8 condensates, including NLO perturbative and $m\langle\bar{q}q\rangle$ corrections. Employing Gaussian sum rules, we obtain several $J^P=2^\pm$ nonets with masses that agree well with experiments. Several $J=0,1$ states compatible with experiments are also obtained using both Gaussian and Laplace sum rules. In particular, the $J^{PC}=2^{++}$ current couples to two distinct $2^{++}$ resonances. This work demonstrates the efficacy of operators with covariant derivatives for studying excited hadrons.

hep-ph↗

arXiv2026

NLO QCD sum rules analysis of $1^{-+}$ tetraquark states

We present a next-to-leading order QCD sum rule analysis of $J^{PC}=1^{-+}$ light tetraquark states. By investigating various compact tetraquark and molecular configurations, we determine the mass spectrum of these states. Our calculations exclude the possibility that $π_{1}(1400)$ is a tetraquark or hybrid-tetraquark mixture. This suggests that it may not exist, which is consistent with recent experimental results. In contrast, we obtained multiple $1^{-+}$ states around $2.0\,\text{GeV}$ that match well with $π_{1}(2015)$, which makes us confident that $π_{1}(2015)$ is a tetraquark candidate. As for $π_{1}(1600)$, our results indicate that the tetraquark currents tend to couple to heavier states, reducing the possibility of it being a tetraquark, while earlier studies suggested the opposite.

hep-ph↗