Observation of Zb(10610) and Zb(10650) Decaying to B Mesons

We report the analysis of the three-body e+e-→BB¯π±, BB¯*π±, and B*B¯*π± processes, including the first observations of the Zb±(10610)→[BB¯*+c.c.]± and Zb±(10650)→[B*B¯*]± transitions that are found to dominate the corresponding final states. We measure Born cross sections for the three-body production of σ(e+e-→[BB¯*+c.c.]±π∓)=[17.4±1.6(stat)±1.9(syst)] pb and σ(e+e-→[B*B¯*]±π∓)=[8.75±1.15(stat)±1.04(syst)] pb and set a 90% C.L. upper limit of σ(e+e-→[BB¯]±π∓)<2.9 pb. The results are based on a 121.4 fb-1 data sample collected with the Belle detector at a center-of-mass energy near the ϒ(10860) peak.

Note:

8 pages, 2 figures

electron positron: annihilation
bottom meson: electroproduction
bottom meson: charged particle
bottom meson: neutral particle
Upsilon(10870): hadronic decay
Z/b(10610): intermediate state
Z/b(10650): intermediate state
BELLE
KEK-B
experimental results

References(22)

Figures(3)

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The fits to the Mmiss(π) distributions performed in Ref. [1] give fractions of fZ(10610)± π∓ = 0.423+0.05+0.007 -0.127-0.009 (0.352+0.156+0.001 -0.004-0.134 ) and fZ(10650)± π∓ = 0.602+0.103+0.11 -0.211-0.038 (0.648+0.152+0.067 -0.114-0.155 ) for the hb(1P) (hb(2P)) decays.

Table I