Re: [BLAST_ANAWARE] Beam asymmetry

From: Tancredi Botto (tancredi@mitlns.mit.edu)
Date: Fri Dec 06 2002 - 15:31:56 EST


I forgot,
black is h+ and left is h-.

-- 
________________________________________________________________________________
Tancredi Botto,  		phone: +1-617-253-9204  mobile: +1-978-490-4124
research scientist		MIT/Bates, 21 Manning Av    Middleton MA, 01949
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

On Fri, 6 Dec 2002, Tancredi Botto wrote:

> > Hi, > I wanted to follow up on the results shown yesterday for the beam > asymmetry. Basically, chris analysis was based on four fills only. > However (not to his fault, but rather to mine) for those runs the > beam-gate inhibited charge was counting charge when coda was dead > (the TS live out going to the scaler inhibit). > > In principle this is not a problem, when you realize that > Q_not/Q_tot = 0.8 is the livetime not the deadtime. However, in our > setup it so happens that in this configuration we count charge also > when filling the ring. > > So I did another analyisis: for each fil we have a different beam > helicity. I slice over an even number of fill and only look for events > that occured in the same range of beam current. As long as the lifetime > was constant (and in practice it is) both h+ and h- have the same charge. > > Then I plot coplanar events. All coplanar events (elastic or not) should > have zero asymmetry. Indeed, summing through many paddles and 3 runs I get > the following (coinc with tof0-5 only) > > Helicity L (11-15) R (11-15) > "+" 1638 1670 > "-" 1582 1667 > > So the "+" and "-" asymmetries are all consistent with zero. Note, > I had no cuts on coplanarity ! > > We'll have to take a better look when beam comes back on > >





This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:29 EST