Re: [BLAST_ANAWARE] vertex for "good" d(e,e'p)n events

From: Karen Dow (kdow@mit.edu)
Date: Tue May 04 2004 - 12:44:20 EDT


Vitaliy,

         If these are ep events (trig==1), then the Cerenkov efficiency
shouldn't matter, unless you put a Cerenkov cut in the analysis. Cerenkovs
are not in the hardware trigger except for singles, events that involve a
BAT, and events with (2 TOFs in one sector AND no TOF nor neutron in the
other).

         This is a very useful analysis to make. Because so much of our
rate does NOT come from the target gas, we can't really tell from the raw
trigger rate what the target thickness is.

                                         Karen

At 12:28 PM 5/4/2004 -0400, vitaliy ziskin wrote:
>I include the vertex reconstructed for 60 cm cell (red) and 40 cm cell
>(black) normalized to charge. I seems that we are only gaining 25% not a
>factor of 2. What has changed? Are the cerenkov efficiecies still the
>same? Should we adjust the nozzle to maximize the gas flow into the
>cell? Is the reconstruction efficiency the same?
>
> Cheers,
> Vitaliy
>
>



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