INPAC-Seminar 143

Title:  Study of a0(980)-f0(980) mixing and measurement of phase angle between strong and EM amplititues at BESIII

Speaker:  Dr. Yadi Wang , Frascati National Laboratories of the Italian Institute for Nuclear Physics

Location:  Lecture Hall/INPAC

Time: 13:00-14:30, Friday, March 14, 2014

Abstract:

BESIII has been collecting data for more than 5 years from 2008. Largest data sample in the world on $J\psi$, $\psi(2S)$, $\psi(3S)$, R scan, XYZ and so on have been accumulated. BESIII covers a wide range of high energy physics, such as light hadron, charmonium, charm physics, tau and QCD and so on. The nature of the scalar mesons a0(980) and f0(980) has been a hot topic in light hadron physics for many years. Suggestions for their being exotic candidates, such as tetraquark states, hybrids, or KK molecules, can be found in the literature. With the data sample of $J\psi$ collected in 2009, we studied the a0(980)-f0(980) mixing and the mixing intensities have been measured. With the $J\psi$ fine scan data in 2012, one fundamental varible, the phase angle between strong and electromagnetic mechanisms is measured in multi-channels. The measured results are consistent with results from other ways, but there is no solid theoretical explaination for it.