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${{\mathit \eta}_{{b}}{(2S)}}$ MASS

INSPIRE   PDGID:

M200M

VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT $9999.0$ $\pm3.5$ ${}^{+2.8}_{-1.9}$ 26k 1 MIZUK 2012 BELL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ + hadrons • • We do not use the following data for averages, fits, limits, etc. • • $9974.6$ $\pm2.3$ $\pm2.1$ $11$ $\pm4$ 2, 3, 4 DOBBS 2012 ${{\mathit \Upsilon}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}$ hadrons 1  Assuming ${\Gamma}_{{\mathit \eta}_{{b}}{(2S)}}$ = 4.9 MeV. Not independent of the corresponding mass difference measurement. 2  SANDILYA 2013 (Belle Collab.) search for such a state reconstructed in the same 26 exclusive hadronic final states as DOBBS 2012 using a sample of ($157.8$ $\pm3.6$) $ \times 10^{6}{{\mathit \Upsilon}{(2S)}}$ decays or about 17 times larger and find no evidence for a signal. Their 90$\%$ C.L. upper limit on the branching fraction B( ${{\mathit \Upsilon}{(2S)}}$ $\rightarrow$ ${{\mathit \eta}_{{b}}{(2S)}}{{\mathit \gamma}}$ ) ${\times }$ $\sum_{i}$B( ${{\mathit \eta}_{{b}}{(2S)}}$ $\rightarrow$ ${{\mathit X}_{{i}}}$ ) $<$ $4.9 \times 10^{-6}$, summed over the exclusive hadronic final states ${{\mathit X}_{{i}}}$, is an order of magnitude smaller than that reported by DOBBS 2012 . 3  Obtained by analyzing CLEO III data but not authored by the CLEO Collaboration. 4  Assuming ${\Gamma}_{{\mathit \eta}_{{b}}{(2S)}}$ = 5 MeV. Not independent of the corresponding mass difference measurement.

References:

DOBBS 2012 PRL 109 082001 Observation of the ${{\mathit \eta}_{{b}}{(2S)}}$ Meson in ${{\mathit \Upsilon}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{b}}{(2S)}}$ , ${{\mathit \eta}_{{b}}{(2S)}}$ $\rightarrow$ Hadrons and Confirmation of the ${{\mathit \eta}_{{b}}{(1S)}}$ Meson MIZUK 2012 PRL 109 232002 Evidence for the ${{\mathit \eta}_{{b}}{(2S)}}$ and Observation of ${{\mathit h}_{{b}}{(1P)}}$ $\rightarrow$ ${{\mathit \eta}_{{b}}{(1S)}}{{\mathit \gamma}}$ and ${{\mathit h}_{{b}}{(2P)}}$ $\rightarrow$ ${{\mathit \eta}_{{b}}{(1S)}}{{\mathit \gamma}}$