Re: [BLAST_ANAWARE] 3track event

From: zhangchi (zhangchi@general.lns.mit.edu)
Date: Sat Nov 15 2003 - 18:36:48 EST


I did not mean to show any PHYSICS but rather to ENTERTAIN. anyhow it
shows that we are able to treat such events. we have seen events which
should have distribution of WC hits that clearly show two tracks in one
side, but software missed them.

this is the 1st one I come across that do reconstruct more that one
distinctive track in one sector.

To guarantee such events are caught when they happen probably need some
more tweaking in software.

On Sat, 15 Nov 2003, Tancredi Botto wrote:

>
> Well,
> what's worse you have 3 positive charge particles in the final state!!
> And new physics is supposed to conserve charge.. One can expect p(e,e'p
> pi+)pi- but it's my guess that it will take longer to see stuff like
> p(e,e'p pi+ pi+) pi-pi-
> But congratulations! you only had 2 tracks (not 3) in nsed v2, and the
> fast fit sure looks terribly hard (or amusingly funny).
>
> speculation:
> If I look at the vertex (the same!) and I am inclined to believe
> it is not a random coinc, then it could still be a slow recoil that
> does not trigger the tof. There is only 1 top+bottom hit on the left
> sector.
>
> About triples:
> There is only one trigger type 4 (2+1) event in the whole 700's data set
> and it does not have any tracks. I of course do not know how many two
> tracks/sector events we had (I suspect 0 in v2...) with only one valid
> tof hit.
> Note that even if trigger 4 was prescaled x1000, i checked and it was
> enabled. So the tof is really missing else the event would have not been
> there (999 times out of 1000). After correction the total trig4 rate comes
> at 1/10000 of the rate of total coincs. Which is roughly what the scalers
> did tell you. There is/was no need to prescale such a low rate trigger,
> but then it was not important to spic and span the ts2 code...!
>
> -- t
> ________________________________________________________________________________
> Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124
> research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> On Fri, 14 Nov 2003, zhangchi wrote:
>
> >
> > Hi all, just for your entertainment, i just spotted run 707, event 2247
> > which have two positive charges on left sector. unfortunately, this is a
> > hydrogen run.
> >
> > Chi
> >
>
>



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