[BLAST_SHIFTS] polarization values

From: Aaron Joseph Maschinot (ajmasch@MIT.EDU)
Date: Tue Feb 22 2005 - 17:48:56 EST


i ran some checks on the data we've been collecting (up to run 13636,
taken on 12/21/05). most runs are "good"; the following runs are "bad":

  bad d(e,ep) rate (due to ABS problems)
  --------------------------------------
  13564 13600-13601 13603-13604

  too few "flr" events ("a crappy run cut short")
  -----------------------------------------------
  13621

so, up to run 13636, the list of "good" runs is as follows:

  13565-13566 13568-13575 13577-13592 13594-13599 13605-13610 13612-13619
  13622-13628 13630-13636

for these runs, i ran the "full" beam-vector determination software (i.e.
the subroutines that i use for my personal analysis but that are not
currently available to anyone else, mostly b/c they've got a sort of
complicated usage procedure). i get the following beam-vector dilution
values:

         Left Sector Right Sector
       ----------------------------------------
  h*Pz | 0.4620 +- 0.0288 | 0.4422 +- 0.0232 |

assuming a beam helicity value of h = 0.65, these beam-vector dilution
values give a vector polarization value around Pz = 0.70.

one point to note, though, is that my macros are assuming that the
background is the same as when we were running last year. provided that
the beam tune is close to what we were using last year, this assumption
should be valid.

for these same runs, chi's ed_xs.C macro gives Pzz = 0.49 +- 0.05.

aaron



This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:32 EST