Summary of E835 meeting 4/25/00

 Present: Stancari(G), Stancari(M), Seo, Graham, Kasper, Negrini, Cibinetto,
          Gollwitzer, Pordes, Garzoglio, Baldini, Hu


 Correction to previous minutes 4/20/00
 add Lasio to present, 
 Giulio's fit was to the chi-1 data.

 The Beams Division plan to start-up beam after the shut-down will be 
 announced Wednesday. In the all experimenters' meeting on Monday, there
 was mention of turning on Friday evening.

 The pit will be in supervised access till Thursday evening. FCal people
 want to look at one or two channels; Gabriele wants to look at a temperature
 readout on the jet which is not giving sensible readings. Both of these
 should be done Wednesday.

 Keith reported that he has fixed one of the DAQ problems - the one in the
 DYC15 crate where first the VSN's were out of order and then the high order 
 bit was missing. It turned out that the TDC used to replace the one which 
 seemed to be causing the first problem was causing the second problem. 
 Apparently the termination SIPs were the wrong ones.

 Wander reported that due to the various helium supply problems the cassettes
 have been allowed to warm to nitrogen while the helium dewar is refilled.
 Cooldown should start Wednesday.

 Giulio described more of his analysis of the chi-1 and psi' scans. He uses
 the actual momentum spectra summed for each energy point as input to the
 likelihood fit. He will make the spectra available. The raw spectra have
 a resolution of 6keV/bin. 
 The plots he has constructed show the predicted likelihood point, the actual 
 data point, the pure resonance curve and the momentum spectrum for each 
 energy point. I trust he will put them in the Y2K forum.
 For the chi-1 he gets essentially the same values as Nadia's analysis. For 
 the psi' he gets a result of 340 +/-40 keV.
 It's interesting to note that the data point taken at the psi' peak has 
 only 60% of the events it would have if we had a delta function beam -
 obvious but more obvious when it's shown on his plot.(Let's hope the 1P1 is
 a bit broader than the psi').
 Giulio mentioned that the psi' data does have some issues - with the 
 luminosity measurements and the orbit lengths.
 The first half of the data apparently has no luminosity measurements and 
 Giulio uses (as Nadia did) the product of beam-current and gas-jet density - 
 calibrated on the runs where there is a luminosity value. The BPM 
 measurements were truncated to a whole mm for the first runs..he adds 1.2 mm 
 (the net value he gets from the non-integer mm part of the orbit measurement 
 of the first run with full readout) to get the correction.

 Matt showed some data on the stability of the FCAL calibration. He uses
 candidate 3 pi-0 events where there are 5 gammas in the CCal and 1 in the
 FCAL. He gets enough events to calibrate all the medium blocks but 2 and
 all the small blocks (once he gets rid of a few rogue events). The 
 calibration seems stable to a few percent and does not show an obvious 
 trend to lower gain.

 Keith showed some fits he has made of the chi-0 data using different values
 of the electron-weight cut (0,1,10) and requiring different levels of fit 
 probability (10^-4, 10^-2, 10^-1). The mass values obtained range from 
 3414.1 to 3415.4 increasing with both electron weight cut and fit probability 
 requirement. The widths do not show any systematic trend varying from 
 9.6 MeV to 11.7 MeV with +/- 25% uncertainty.

 Stephen finished by saying he hopes to have a discussion of proposals for
 the running in May at the Thursday meeting. Marco mentioned Claudia's
 suggestion as attractive. Stephen said that while attractive, he feels that
 it would be operationally burdensome (twice as many decelerations as a
 single point/stack scenario - probably 6 a week and possibly more than the 
 deceleration experts could handle) and a burden on the analysis
 since it would make the chi-0 logistics more complicated and we would need 
 to keep two analyses going simultaneously.
 If we are going to do interspersed data taking, he would suggest 3 stacks of 
 1P1 and 1 stack of chi-0 (for example). (This of course is just Stephen's 
 opinion. Other people are encouraged to join in.)

 Stephen