Hi chi, blasters
unfortunately for all runs after the shutdown we do have an intermittent
problem with daq such that valid triggers have no tdc info. This may
occurr on both the tof's and the neutron counters, and propagates to
the ntuples. You can check either with raw data or with something like
Draw("ttr","trig==1&&ntl<16&&ntr<16") (see also elog)
obviously these events must have a valid tdc hit. You will find that
most likely ttr is missing, may also be ttl. So all considerations about
rates are pretty much up in air.
About polarization: although this daq problem is not immediately
spin-dependent (..) it will nevertheles be like so for a small sample of
runs or flips. In other words, you start building false asymmetries if
you have a few good runs and bad runs, given the fact that we actually
flip a few times per run.
-- tancredi
________________________________________________________________________________
Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124
research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
On Tue, 6 Jul 2004, Chi Zhang wrote:
>
> Hi, sorry for using the wrong runs. I don't know what I was thinking.
>
> checked, Pzz I sent out yesterday was done with the "fixed" runs. results
> from 8479-8598:
>
> D in left 4479, D in right 5103, total charge 18646 C, 0.51 counts/C
> not a significant increase still. Am I still wrong with the runs and
> charge?
>
> Pzz: 58.0+-4.7%. Better than ever before. But still not consistant with
> Genya's mid 80%. Maybe he has new updates by now.
>
> Chi
>
> PS. these are the run numbers I used, please do let me know if I am using
> bad runs or you find I m having wrong charge integrations.
> 8479-8486 8488-8494 8496 8500-8513 8515-8522 8524-8531 8533-8535 8537-8540
> 8543-8554 8564-8568 8570-8583 8585-8588 8592 8594-8598
>
> On Tue, 6 Jul 2004, vitaliy ziskin wrote:
>
> > Chi,
> > use runs starting with 8479. This is when we think the to problem was
> > fixed. Also, use runs upto 8598.
> >
> > Cheers, Vitaliy
> >
> > Chi Zhang wrote:
> >
> > >Hi, all
> > >
> > >Unfortunately, from the ed events so far, I do not seem to see an increase
> > >in rate AT ALL. rather, I have
> > >deuteron in left 2633 in right 3205 total charge 16267 C
> > >rate: 0.36 events/C which is lower than even the march 40cm runs. missing
> > >counts in electron right still persists.
> > >
> > >I do hope someone could cross check the total charge I got. I used runs
> > >betweem 8390 and 8578.
> > >
> > >Chi
> > >
> > >On Tue, 6 Jul 2004, Aaron Joseph Maschinot wrote:
> > >
> > >
> > >
> > >>there is about 17kC of polarized deuterium data since last thursday (there
> > >>is a little more such data, but root yells about the lrn files not being
> > >>closed correctly).
> > >>
> > >>this data gives me a QE ep rate of 9.5 events/C. this is UP about 60%
> > >>compared to the corresponding rate before the most-recent shutdown.
> > >>
> > >>take a look at the attached plots of the bema-vector asymmetry versus
> > >>missing momentum and Q2, respectively. all show a massive increase
> > >>in vector polarization:
> > >>
> > >>
> > >> dilution | vec pol (assuming h = 0.64+-0.01)
> > >> (left) (right) | (left) (right)
> > >> ------------------------------------------------------------------
> > >>vs p_m : 0.657 +- 0.026 0.576 +-0.020 | 1.027 +- 0.044 0.900 +- 0.034
> > >> |
> > >>vs Q2 : 0.688 +- 0.027 0.611 +-0.021 | 1.075 +- 0.045 0.955 +- 0.036
> > >>
> > >>
> > >>ummm... yeah. maybe this is a little too good. isn't there a realistic
> > >>maximum vector polarization (less than 100%) that one could hope to
> > >>obtain???
> > >>
> > >>the plot versus missing momentum for polarization perpendicular to q
> > >>(i.e. the left sector plot) looks especially good for two reasons.
> > >>
> > >> 1) the asymmetry's "frown" shape for p_m < 0.2GeV shows up very well in
> > >> the data.
> > >>
> > >> 2) though still a little statistics limited, the asymmetry's rise to
> > >> positive values for p_m > 0.3GeV is also very visible.
> > >>
> > >>i would once again remind everyone that much more empty target data is
> > >>needed in order to nail down the background contribution at p_m > 0.3GeV.
> > >>
> > >>aaron
> > >>
> > >>
> >
> >
>
This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:31 EST