Binding Energy effects in the Decay Properties of Charmonia P C Vinodkumar Department of Physics Sardar Patel University Vallabh Vidyanagar , Gujarat, INDIA

Outline …  Introduction.  Spectroscopic Properties of Heavy Flavour Mesons in Coulomb plus Power Potential.  Decay Properties of Heavy Flavour Mesons.  Conclusion.

Introduction

3872 DD

[Bhavin Patel JPG 36, (2009)]

 Di-gamma BR:

The present study clearly indicates that the coulomb plus linear potential is not adequate enough to explain observed properties of charmonia. A stronger inter quark potential (confinement part of the potential; i.e, \nu~ 1.1) is required for the spectra. The E1 transition results from the present study support this observation as they match with the known experimental values near the potential index, \nu = 1.1. A similar conclusion from M1 transition warranted experimental supports. However, their digamma, dilepton, digluon decay occur at a weaker inter quark potential; i.e, \nu~ 0.7 to 0.8). It is also observed that there is an interplay between the quark mass parameter of the model and the confinement potential. The constituent quark mass no more found to be the same for the spectra and for the decay. The mass of the constituent quark do depend on the interaction process in which they are involved as well as on their partner. Conclusions

Thanks Dr. J N Pandya (MSU,Vadodara), Dr. Ajay Kumar Rai (SVNIT, Surat), Dr. C J Clement (St. Xavier Sci. College, Ahmedabad), Dr. R H Parmar (Modasa Sci. College, Modasa) Dr. Bhavin K Patel Mr. Ajay Majethiya (KITRC, Kalol), Ms. Shereena Joseph (Delhi), Mr. Arpit Parmar and Mr. Kaushal Thakkar. Part of this work is done with a financial support from DST, New Delhi, under a Major Research Project SR/S2-HEP-20/2006.  To our research group :  To the organizers  CSIR, New Delhi  Sardar Patel University, Vallabh Vidyanagar

The area that is phenomenologically understood extends to: Heavy-light mesons, states where the quark-antiquark pair is in relative S wave; Heavy-heavy meson: states below the DD (BB) threshold In the positive parity sector (P wave, L=1) a number of states have been discovered with masses and widths much different than expected from quark potential models. Open charm D sJ (2632) (Selex) D sJ * (2715) (Belle) D sJ (2860) (Babar) D sJ * (2317) - J P =0 + - P cs ~ 2.48 GeV -  < 4.6 MeV D sJ (2460) - J P =1 + - P cs ~ 2.55 GeV -  < 5.5 MeV D 0 * (2308) - J P =0 + - P cn ~ 2.46 GeV -  ~ 276 MeV Charmonium X (3872) - J PC =1 ++ (2 –+ ) - P cc ~ GeV -  < 2.3 MeV Y(4260) : ?? Y(4385) : 4 3 S 1,3 3 D 1 X (3940) Y (3940):2 3 P J=1,2,3 Z (3940) Light - heavy mesons sector Charmonia sector – – New open-charm and charmonium like states

Backup Slide

Challenges in Heavy Flavour Hadron Spectroscopy

Experimental Status