Subject: RE: Update on UED
From: Greg Landsberg <landsberg@hep.brown.edu>
Date: Tue, 14 Nov 2006 21:58:23 -0500
To: 'pedro mercadante' <mercadan@fnal.gov>
CC: 'Sergio Lietti' <lietti@fnal.gov>, "'Sergio F. Novaes'" <novaes@fnal.gov>, "'Eduardo M. Gregores'" <gregores@fnal.gov>

Hi Pedro,

Indeed the eeuu channel would have twice as high branching fraction as either 4u or 4e, so it's a good channel to investigate. I'd not dismiss the 4e channel completely though.

The question is whether the muon track momentum is calculated using the (0,0) primary vertex constraint or not. I believe that by default the primary vertex is not used in the fit, which determines the muon momentum. If this is the case, you could still improve the resolution by forcing the muon track to the primary vertex.

Unfortunately, I missed Olaf's talk, but I'll look at it on the Web. There are no new results approved in this channel, so I expect them to be similar to those from his previous presentations.

Best,

Greg