RE: [Brahms-l] INEL trigger efficiency in pp

From: Claus O. E. Jorgensen <ekman@nbi.dk>
Date: Thu Feb 12 2004 - 03:07:51 EST
Hi JH,

Thanks for the quick reply. You say that you compare the BB vertex
distributions - but by doing this I guess you bias the data sample towards
more "central" events, or? I mean, the p+p events that give BB vertex are
probably not missed by the INEL trigger to begin with.

Claus


On Wed, 11 Feb 2004, J.H. Lee wrote:

> Hi, Claus,
>
> > these (28%) missing events? How do we evaluate the Ntr in the
> > missed events. If we just calculate the yields by dividing
> > Nev by the trigger efficiency (i.e. multiply the spectrum by
> > 0.72) we somehow assume that the missing events don't have
> > any tracks. Is that fair?
>
> Yes, it's fair.
> This shouldn't be an issue since the spec. triggers include
> inelastic trigger(trigger5).   If you are interested in trigger
> bias from including INEL in spec triggers, see the attached
> message.
>
> JH
>
> -----------------------------------------------------
>  ----- Original Message -----
> From: "J.H. Lee" <jhlee@bnl.gov>
> To: "Flemming Videbaek" <videbaek@bnl.gov>
> Cc: "Chellis Chasman" <chasman@bnl.gov>; <beavis@bnl.gov>; <debbe@bnl.gov>
> Sent: Friday, May 02, 2003 5:41 PM
> Subject: Trigger3 with and without INEL
>
>
> > Hi, Flemming,
> >
> > I've looked at the special run you took today, run 8767,
> > with trigger3 = Hodo+R.C.  I compared the BB vertex distribution for
> > trigger3 in the run with the one from run 8768 taken right after the
> > run with the normal spec trigger condition (trigger3 = Hodo + INEL). I
> > normalized the two distributions with the number of accumulated
> > ZDC(Y+B) counts in the scaler.  I assumed dead time is similar for the
> > two runs.  It looks like there seems to be no obvious bias from INEL
> > in Trigger3 by looking at the distributions.  The INEL in the spec trigger
> > simply cut out tracks outside of the range.   Looks pretty good to me.
> >
> > JH
> >
>
>

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Received on Thu Feb 12 03:08:13 2004

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