[Frost] pi0 and eta mass from Butanol

[Michael Dugger]

Hi,

I have some mass values for the pi0 and eta.

The data I used is ten runs from the 2.478 MeV CL runs.

The plot at
http://www.jlab.org/~dugger/g9/g9a/tmp/T1.gif
Shows:
Mass X from the reaction gamma p -> p X

Top panel-> Butanol (Black); Carbon (Red); Carbon subtracted Butanol 
(Blue)
Bottom panel -> Carbon subtracted Butanol with fits to the pi0 and eta

The plot at
http://www.jlab.org/~dugger/g9/g9a/tmp/T1600.gif
Shows:
Same as above except that the minimum proton momentum allowed is 600 
MeV/c.

Results:
pi0 mass (no momentum restriction) = 163 MeV
pi0 mass (momentum > 600 MeV/c) = 157 MeV

eta mass (no momentum restriction) = 551 MeV
eta mass (momentum > 600 MeV/c) = 552 MeV

Overall the masses are coming in too high for the pion. The eta mass is 
only off by about 4 or 5 MeV (pdg mass = 547 MeV). Put another way, the 
eta mass is within a percent but the pi0 mass is off by over 20%!

Take care,
Michael