From: Djamel Ouerdane (ouerdane@nbi.dk)
Date: Tue Feb 18 2003 - 11:29:06 EST
Hi all, I'm still investigating the curious TOF effect. I've tried various things without much progress in the understanding except that the slewing correction is not the sinner at all. Actually, the effect is worse without. But something interesting is revealed on the plots you can look at here : http://www.nbi.dk/~ouerdane/cal/weirdtof.html Since H1 and H2 show the same behaviour, I focus on H2 and try to see of identified particles with the RICH can tell us something. In fact they do. I select pions with a momentum > 3 and < 8 GeV/c (below K and p threshold and above pi threshold), I plot dE vs beta (H2) for those particles. I do the same for particles with same momenta but that haven't left any signal in the RICH. dE vs beta is plotted too. Look at the plots and tell me what you think. Djam PS: whether you plot dE top or dE bot or sqrt(dEtop*dEbot) does not have any effect. Track vertex cuts, D1 swim status, hit cut along the slat axis (y), etc, etc do not have any effect either. I'm investigating if this effect comes from averaging the particle tof with TDCtop and TDCbot although I doubt about it. -- Djamel Ouerdane ------------------------------------------o | Niels Bohr Institute | Home: | | Blegdamsvej 17, DK-2100 Ø | Jagtvej 141 2D, | | Fax: +45 35 32 50 16 | DK-2200 Copenhagen N | | Tel: +45 35 32 52 69 | +45 35 86 19 74 | | http://www.nbi.dk/~ouerdane | | ouerdane@nbi.dk | o---------------------------------------------------------o
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