Hyperfine splittings in the $b\bar{b}$ system

Abstract

Recent measurements of the ${\eta }_b(1S)$, the ground state of the $b\bar{b}$ system, show the splitting between it and the $\Up(1S)$ to be 69.5$\pm$3.2 MeV, considerably larger than lattice QCD and potential model predictions, including recent calculations published by us. The models are unable to incorporate such a large hyperfine splitting within the context of a consistent description of the energy spectrum and decays. We demonstrate that in our model, which incorporates a relativistic kinetic energy term, a linear confining term including its scalar-exchange relativistic corrections, and the complete one-loop QCD short distance potential, such a consistent description, including the measured hyperfine splitting, can be obtained by not softening the delta function terms in the hyperfine potential. We calculate the hyperfine splitting to be 67.5 MeV.

5 pages, 3 tables, text revisions

References in corpus (7)

• Potential model calculations and predictions for heavy quarkonium
• Quarkonium mass splittings in three-flavor lattice QCD
• Bottomonium spectrum at order v^6 from domain-wall lattice QCD: precise results for hyperfine splittings
• Measurement of the eta_b(1S) mass and the branching fraction for Upsilon(3S) --> gamma eta_b(1S)
• Bottomonium spectroscopy with mixing of eta_b states and a light CP-odd Higgs
• The bottomonium spectrum from lattice QCD with 2+1 flavors of domain wall fermions
• The Hyperfine Splittings in Bottomonium and the $B_q(q=n,s,c)$ Mesons

Cited by in corpus (12)

• Higher mass bottomonia
• $Q\bar{Q}$ ($Q\in \{b,c\}$) spectroscopy using Cornell potential
• Leptonic and Digamma decay Properties of S-wave quarkonia states
• Status of quarkonia - like negative and positive parity states in a relativistic confinement scheme
• $B_c$ meson spectroscopy motivated by general features of pNRQCD
• Chi_b(3P) splitting predictions in potential models
• Hyperfine splitting and the experimental candidates for η_b(2S)
• Bottomonium spectroscopy motivated by general features of pNRQCD
• Unified covariant treatment of hyperfine splitting for heavy and light mesons
• Relativistic two fermion treatment of hyperfine transitions
• Relativistic two-body calculation of $b\bar{b}$-mesons radiative decays
• Spin splitting spectroscopy of heavy quark anti quark systems