TY  - JOUR
AU  - Baru, V.
AU  - Epelbaum, E.
AU  - Filin, A. A.
AU  - Hanhart, Christoph
AU  - Mizuk, R. V.
AU  - Nefediev, A. V.
AU  - Ropertz, S.
TI  - Insights into Z b ( 10610 ) and Z b ( 10650 ) from dipion transitions from ϒ ( 10860 )
JO  - Physical review / D
VL  - 103
IS  - 3
SN  - 2470-0010
CY  - Melville, NY
PB  - Inst.812068
M1  - FZJ-2021-01216
SP  - 034016
PY  - 2021
AB  - The dipion transitions Υ(10860)→π+π−Υ(nS) (n=1, 2, 3) are studied in the framework of a unitary and analytic coupled-channel formalism previously developed for analyzing experimental data on the bottomoniumlike states Zb(10610) and Zb(10650) [Phys. Rev. D 98, 074023 (2018)] and predicting the properties of their spin partners [Phys. Rev. D 99, 094013 (2019)]. In this work we use a relatively simple but realistic version of this approach, where the scattering and production amplitudes are constructed employing only short-ranged interactions between the open- and hidden-flavor channels consistent with the constraints from heavy quark spin symmetry, for an extended analysis of the experimental line shapes. In particular, the transitions from the Υ(10860) to the final states ππhb(mP) (m=1, 2) and πB(*)¯B∗ already studied before, are now augmented by the Υ(10860)→π+π−Υ(nS) final states (n=1, 2, 3). This is achieved by employing dispersion theory to account for the final state interaction of the ππ subsystem including its coupling to the K¯K channel. Fits to the two-dimensional Dalitz plots for the π+π−Υ final states were performed. Two real subtraction constants are adjusted to achieve the best description of the Dalitz plot for each Υ(nS) (n=1, 2, 3) while all the parameters related to the properties of the Zbs are kept fixed from the previous study. A good overall description of the data for all Υ(10860)→π+π−Υ(nS) channels achieved in this work provides additional strong support for the molecular interpretation of the Zb states.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000620346700003
DO  - DOI:10.1103/PhysRevD.103.034016
UR  - https://juser.fz-juelich.de/record/890808
ER  -