深度束缚双重重四夸克的格点预测

Lattice Prediction for Deeply Bound Doubly Heavy Tetraquarks.

作者信息

Francis A, Hudspith R J, Lewis R, Maltman K

机构信息

Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada.

Department of Mathematics and Statistics, York University, Toronto, Ontario M3J 1P3, Canada.

出版信息

Phys Rev Lett. 2017 Apr 7;118(14):142001. doi: 10.1103/PhysRevLett.118.142001. Epub 2017 Apr 5.

DOI:10.1103/PhysRevLett.118.142001

PMID:28430484

Abstract

We investigate the possibility of qq^{'}b[over ¯]b[over ¯] tetraquark bound states using n_{f}=2+1 lattice QCD ensembles with pion masses ≃164, 299, and 415 MeV. Motivated by observations from heavy baryon phenomenology, we consider two lattice interpolating operators, both of which are expected to couple efficiently to tetraquark states: one with a diquark-antidiquark and one with a meson-meson structure. Using nonrelativistic QCD to simulate the bottom quarks, we study the udb[over ¯]b[over ¯], ℓsb[over ¯]b[over ¯] channels with ℓ=u, d, and find unambiguous signals for strong-interaction-stable J^{P}=1^{+} tetraquarks. These states are found to lie 189(10) and 98(7) MeV below the corresponding free two-meson thresholds.

摘要

我们使用具有约164、299和415 MeV 介子质量的 (n_f = 2 + 1) 格点量子色动力学系综，研究 (qq^{'}b\overline{b}) 四夸克束缚态的可能性。受重子现象学观测结果的启发，我们考虑两个格点内插算符，预计它们都能有效地与四夸克态耦合：一个具有双夸克 - 反双夸克结构，另一个具有介子 - 介子结构。使用非相对论量子色动力学来模拟底夸克，我们研究了 (ud\overline{b}\overline{b})、(\ell s\overline{b}\overline{b}) 通道（其中 (\ell = u, d)），并发现了强相互作用稳定的 (J^{P}=1^{+}) 四夸克的明确信号。发现这些态位于相应的自由双介子阈值以下189(10) 和98(7) MeV 处。