Excited and exotic bottomonium spectroscopy from lattice QCD
Sinéad M. Ryan, David J. Wilson
Abstract
A bstract We explore the spectrum of excited and exotic bottomonia using lattice QCD. Highly excited states are identified with masses up to 11,000 MeV, many of which can be grouped into supermultiplets matching those of the quark model while exotic spin-parity-charge-conjugation quantum numbers J PC = 0 + − , 1 − + , 2 + − that cannot be formed from $$ \overline{q}q $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>q</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>q</mml:mi> </mml:math> alone are also identified. Single-meson operator constructions are used that have good J PC in the continuum, these are found to overlap well onto heavy quark states up to J ≤ 4. A continuum J PC is assigned to each level, based on the distribution amongst lattice irreps and dominant operator overlaps. States with a dominant gluonic component are identified and form a hybrid supermultiplet with J PC = (0 , 1 , 2) − + , 1 −− , approximately 1500 MeV above the ground-state η b , similar to previous computations with light, strange and charm quark systems.