[Primex2] abstract to DNP meeting

[Gan, Liping]

Hi, all,

Lingling Ma would like to submit a talk to DNP meeting on behalf of the PrimEx. The abstract is attached below.  I would appreciate very much for your comments and suggestion. Thanks a lot!

Best regards,

Liping  


                                                            
Status of the PrimEx-II Analysis on the pi0 Lifetime Measurement
       Lingling Ma
Lanzhou University
(For the PrimEx Collaboration)

As the lightest particle in the hadron spectrum, π0 plays an important role in understanding the fundamental symmetries of QCD. The π0→γγ decay is a key test of the QCD predictions based on chiral anomaly and spontaneous chiral symmetry breaking. Theoretical activities over the last decade have resulted in a high precision (1% level) in the calculations of the decay amplitude of the π0 into two photons. The experimental measurement of this parameter with a comparable precision will be critical to test these important predictions. The PrimEx collaboration at Jefferson Lab has developed and performed experiments to measure the π0 radiative decay width via the Primakoff effect. The published result from the first experimental data (PrimEx-I) has a 2.8% total uncertainty in the π0 radiative decay width.  The second experiment (PrimEx-II) was carried out in fall 2010 with the final goal of 1.4% precision. The status of PrimEx-II data analysis will be presented.