Using a sample of 122×106 Υ(3S) events recorded with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the hb(1P) spin-singlet partner of the P-wave χbJ(1P) states in the sequential decay Υ(3S)→π0hb(1P), hb(1P)→γηb(1S). We observe an excess of events above background in the distribution of the recoil mass against the π0 at mass 9902±4(stat)±2(syst) MeV/c2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.1σ, including systematic uncertainties. We obtain the value (4.3±1.1(stat)±0.9(syst))×10-4 for the product branching fraction B(Υ(3S)→π0hb)×B(hb→γηb).
Evidence for the hb(1P) meson in the decay Υ(3S)→π0hb(1P).
BIASINI, Maurizio;PACETTI, Simone;PERUZZI, Ida Marena
2011
Abstract
Using a sample of 122×106 Υ(3S) events recorded with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the hb(1P) spin-singlet partner of the P-wave χbJ(1P) states in the sequential decay Υ(3S)→π0hb(1P), hb(1P)→γηb(1S). We observe an excess of events above background in the distribution of the recoil mass against the π0 at mass 9902±4(stat)±2(syst) MeV/c2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.1σ, including systematic uncertainties. We obtain the value (4.3±1.1(stat)±0.9(syst))×10-4 for the product branching fraction B(Υ(3S)→π0hb)×B(hb→γηb).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.