8-13 August 2011
Rhode Island Convention Center
US/Eastern timezone

First observation of the h_b(1P) and h_b(2P) bottomonium states

Aug 12, 2011, 8:50 AM
552 A (Rhode Island Convention Center)

552 A

Rhode Island Convention Center

Parallel contribution Hadron Spectroscopy Hadron Spectroscopy


Dr David Asner (Pacific Northwest National Laboratory)


We report the observation of the h_b(1P) and h_b(1P)p spin-singlet bottomonium states produced in the reaction e^+e^-\to h_b(1P)n\pi^+\pi^- with significances of 5.5\,\sigma and 11.2\,\sigma, respectively. We find that M[h_b(1P)]=(9898.25\pm 1.06^{+1.03}_{-1.07})\,\mathrm{MeV}/c^2 and M[h_b(1P)p]=(10259.76\pm0.64^{+1.43}_{-1.03})\,\mathrm{MeV}/c^2, which correspond to measurements of the P-wave hyperfine splittings \Delta M_{ m HF}=(1.62\pm1.52)\,\mathrm{MeV}/c^2 and (0.48^{+1.57}_{-1.22})\,\mathrm{MeV}/c^2, respectively. We also report measurements of the cross sections for e^+e^-\to h_b(1P)n\pi^+\pi^- relative to the cross section for the e^+e^-\to\Upsilon(2S)\pi^+\pi^- reaction. These results are obtained from a 121.4\,{\rm fb}^{-1} data sample collected with the Belle detector near the \Upsilon(5S) resonance at the KEKB asymmetric-energy e^+e^- collider.

Primary author

Dr David Asner (Pacific Northwest National Laboratory)

Presentation materials