[Primex2] CD-18 and DNP2018 abstracts

[Ilia Larin]

 Dear PrimEx-II members,

 Please send me your comments on two abstracts for CD 2018 and DNP 2018.

 All the best,
 Ilya



 CD-2018

 The PrimEx experimental Projects at Jefferson Lab

 On behalf of the PrimEx collaboration

 The Primakoff method is a powerful tool of radiatvie decay width measurements.
 The high performance tagged photon beam facility at Jefferson Lab in conjunction
 with state of art high resolution electromagnetic calorimeters give
 a unique opprotunity for high precision pseudoscalar meson 2 gamma decay
 width measurements. Two PrimEx experiments at Jefferson Lab Hall-B
 has been succefully performed pi0->gg decay width measurement. Eta->gg
 decay width measurement experiment, PrimEx-D has been scheduled to run
 at Jefferson Lab Hall-D in 2019 on 12GeV tagged photon beam. Another
 measurement: eta'->gg decay width project as well as
 Gamma(g*g->pi0,eta,eta') transition form factor mesurements on electron beam
 are currently prepared to be proposed to the Program Advisory Committee.
 I will give an overview of this program.





 DNP 2018

 pi0->gg decay width: PrimEx I + II combined result

 On behalf of the PrimEx collaboration

 pi0->gg decay width is one of the most precisely calculated
 value in the low energy QCD. While the recent theoretical calcualtions
 have been done with a percent level precision, the experimentally
 measured value before the PrimEx measurement used to have
 much higher uncertainty level: about 7%.
 The first part of the Primakoff experimental program
 at Jefferson Lab: PrimEx-I and -II experiments have been
 succefully performed in Hall-B at Jefferson Lab.
 Two pi0 radiative width measurements
 with total uncertainty of 2.8% and 1.7% have been completed.
 The final combined result of these two PrimEx experiments
 will be presented in the talk.