User name R. Michaels
Log entry time 17:02:51 on October 25, 2005
Entry number 157997
keyword=Prelim. Q2Here are preliminary Qsq results for Hydrogen.
Run 2873 from Rob F's final alignment check. All plots have
cuts on tracks at the collimator (this cleans up tails from
junk and background) and requires a hit (ADC cut) in at least
one HAPPEX detector.
Fig 1: Qsq by trigger type. Shows it is independent of trigger
type as long as there's a hit in detector. That is good, but notice
that Qsq on R-arm is 10% higher than L-arm. From angle we expect
R-arm to be 2% higher (and actually R-arm momentum is 0.3% lower).
So, this is strange, but probably due to the rough matrix database
we have and not worth panicking about (yet).
Fig 2: Qsq by detector using "hard" cuts on ADCs to require
that the hit is on one but not both detectors. Note the lack of
data (num of entries) in one L-arm det. My det numbering is
not necessarily the same as HAPPEX DAQ, be careful.
Fig 3: Missing mass (unsquared). It is off by several MeV, which
is normal at this stage of the game and the matrix element database
presumably has a lot to do with it.
Figure 1
Figure 2
Figure 3
