Details

Autor(en) / Beteiligte

• Tamponi, U

Titel

First Observation of the Hadronic Transition [Upsilon](4S) arrow right [eta]hb(1P) and New Measurement of the hb(1P) and [eta]b(1S) Parameters

Ist Teil von

• Physical review letters, 2015-10, Vol.115 (14)

Erscheinungsjahr

2015

Link zum Volltext

Quelle

PROLA - Physical Review Online Archive

Beschreibungen/Notizen

• Using a sample of 771.6x106 [Upsilon][Upsilon](4S) decays collected by the Belle experiment at the KEKB e+e-collider, we observe, for the first time, the transition [Upsilon](4S) arrow right [eta]hb(1P) with the branching fraction B[[Upsilon](4S) arrow right [eta]hb(1P)]=(2.18+ or -0.11+ or -0.18)x10-3 and we measure the hb(1P) mass Mhb(1P)= (9899.3+ or -0.4+ or -1.0) MeV/c2, corresponding to the hyperfine (HF) splitting Delta MHF(1P)= (0.6+ or -0.4+ or -1.0) MeV/c2. Using the transition hb(1P) arrow right gamma [eta]b(1S), we measure the nb(1S) mass M[eta]b(1S)= (9400.7+ or -1.7+ or -1.6) MeV/c2, corresponding to Delta MHF(1S)=(59.6+ or -1.7+ or -1.6) MeV/c2, the [eta]b(1S) width [Gamma][eta]b(1S)=(8-5+6+ or -5) MeV/c2 and the branching fraction B[hb(1P) arrow right gamma [eta]b(1S)]=(56+ or -8+ or -4)%.