Observation of the eta_b(1S) in Y(3S)-> gamma eta_b and bottomonium physics at BaBar

by Claudia Patrignani (University and INFN Genova)

Tuesday Sep 16, 2008, 4:30 PM → 5:30 PM Europe/Zurich

Main Auditorium** (CERN)

We report the observation of the bottomonium ground state, eta_b(1S), based on a study of the inclusive photon spectrum of (109±1) millions Upsilon(3S) recorded at the Upsilon(3S) energy with the BABAR detector at the PEP-II B factory at SLAC. The hyperfine Upsilon(1S)-eta_b(1S) mass splitting, a key ingredient in many theoretical calculations, is 71.4 {+2.3} {-3.1} (stat) ± 2.7(syst) MeV/c2. The precision of our measurement will allow, among others, a more precise determination of the lattice spacing and new precision determinations of alpha_s. Other results on bottomonium physics from BABAR will also be presented.

Poster EPPPSeminar16092008.pdf

Slides patrignani-CERN.pdf