Spin effects in heavy hybrid mesons on an anisotropic lattice

被引：31

作者：

Drummond, IT ^{[1
]}

Goodman, NA ^{[1
]}

Horgan, RR ^{[1
]}

Shanahan, HP ^{[1
]}

Storoni, LC ^{[1
]}

机构：

[1] DAMTP, Cambridge CB3 9EW, England

来源：

PHYSICS LETTERS B | 2000年 / 478卷 / 1-3期

关键词：

lattice; Gauge; anisotropic; QCD;

D O I：

10.1016/S0370-2693(00)00225-2

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present a quenched calculation of lowest bottomonium hybrid states on an anisotropic lattice with Landau mean-link tadpole improvement, using the improved NRQCD Hamiltonian. We investigate the quark-spin s = 0,1 sectors which contain both the non-exotic 1(--) and the exotic 1(-+), and demonstrate their degeneracy in the case of the lowest order Hamiltonian. Both states are found at around 1.6 GeV above the T ground state. We examine the spin-splitting for several hybrid states (1(--), 1(-+), 0(-+), 2(-+)) which is due to the -c(1)sigma.B/(2)m(b) term in the NRQCD Hamiltonian, all other terms having negligible effect. The spin splittings are well resolved outside errors and are surprisingly large. We investigate their dependence on c(1) for several values of c(1). We calculate one contribution to these splittings using the Born-Oppenheimer picture for hybrids and show that the observed size of the effect is plausibly explained by mixing with hybrid states with more than one constituent gluon. (C) 2000 Elsevier Science B.V. All rights reserved.

引用

页码：151 / 160

页数：10

共 9 条

[1] Quark action for very coarse lattices [J].