Description: hit time vs slope for runs 20xx and 18xx , Filename: stopping-2d.psThe attached files provide an evidence that we indeed were stopping an observable amount of muons during the "stopping muons" runs. "stopping muons" group of runs used: 2001, 2002, 2003, 2004, 2041, 2043, 2044, 2046, 2049, 2050, 2051, 2052 "straight through" runs for comparison: 1856, 1858, 1859, 1860, 1862, 1864 I submitted a dqs job per run, mofia saved histos every 50,000 events, then the obtained hbook files were merged. Note, that virtually all MOFIA jobs crashed with array bound errors, so that not all events from these runs were processed. stopping-slope.ps shows track slope distribution for the two groups of runs. Events with no track reconstructed were counted in underflows, so that number of entries on this plot corresponds to the total number of processed events. Track slope is sqrt(du/dz**2 + dv/dz**2) For stopping-2d.ps x axis is track slope again, while y is DC TDC hit time (in nanoseconds). If a track was found, all TDC hits in the event were put in the histogram. (I didn't find a way to associate a straight track to it's hits, though that would be more relevant.) Finally, the 90001 histogram for runs 20xx was divided into 4 slices along the x axis, and projection of each slice on the y axis in the range [1500ns, 9000ns] was fit with Background + Norm * Exp( -t/LifeTime) Since data used to fill the histogram are correlated (times of hits for the same track, in many cases) we can't expect a "normal" chi2 or reliable error estimate. Also, smearing of the decay time due to drift time was not taken into account. Still, numbers for the LifeTime look encouraging. Andrei
Description: track slope distribution for runs 20xx and 18xx , Filename: stopping-slope.ps
Description: hit time vs slope for runs 20xx and 18xx , Filename: stopping-2d.ps
Description: muon lifetime fits, runs 20xx , Filename: mu-lifetime.run20xx.ps