1. University of North Carolina Wilmington
Update on Rare η Decays
Liping Gan
University of North Carolina Wilmington

2. World competition in Rare η Decays
Low energy
-facilities
High energy -facility
CBELSA/TAPS at ELSA
JEF at Jlab

3. Filter Background with η Energy Boost
Jlab: high energy η production
(E = GeV)
Other competitors (CB, KLOE, BES-III,
WASA, C-Barrel) : low energy η production
Signal: 0
η →000
Note:
Statistics is normalized to 1
beam day.
BG will be further reduced by
requiring only one pair of ’s
to have the 0 invariant mass.
S. Prakhov et al. Phy.Rev.,C78, (2008)

4. Our Plan Submit a proposal to PAC40 in May 2013.
Work with theorists to strengthen the physics case.
Establish collaborations with Chinese institutes for FCAL-II upgrade.
We are also in process to contact people in the Panda collaboration to establish possible collaboration for the calorimeter development.
Implement PbWO4 crystal in the standard GlueX monte carlo simulation.