21-25 May 2018
Budker INP
Asia/Novosibirsk timezone

Study of radiative decays of the $\Upsilon(1S)$ and of three-body decays of the $J/\psi$

25 May 2018, 14:47
17m
Budker INP

Budker INP

Lavrentiev av. 11, Novosibirsk 630090

Speaker

Mr Evgeny kozyrev (binp)

Description

We report on recent studies of quarkonium decays obtained with the data collected by the BaBar experiment at the PEP-II $e^+e^-$ collider. In particular, we use the entire BaBar dataset to study the reaction $e^+ e^- \to \gamma_{ISR} J/\psi$, with $J/\psi \to \pi^+ \pi^- \pi^0$, $J/\psi \to K^+ K^- \pi^0$, or $J/\psi \to K_S K^\pm \pi^\mp$, and the photon $\gamma_{ISR}$ is produced via Initial-State-Radiation. We measure the relative $J/\psi$ branching fractions and perform a Dalitz plot analysis of each $J/\psi$ decay mode using an isobar model and a Veneziano model. We also present a study of the radiative decays of the $\Upsilon(1S)$ to $\pi^+\pi^-\gamma$ and $K^+K^-\gamma$ final states, performed on the data samples collected at the peak of the $\Upsilon(2S)$ and $\Upsilon(3S)$ resonances. The $\Upsilon(1S)$ is reconstructed from the decay chains $\Upsilon(nS) \to \pi^+\pi^-\Upsilon(1S)$, with $n=2,3$. Branching fractions measurements and spin-parity analyses are reported for the $\Upsilon(1S)$ radiative decays to intermediate resonances observed in the $\pi^+\pi^-$ and $K^+K^-$ mass spectra.

Primary author

fabio anulli (INFN Sezione di Roma)

Presentation Materials