Hee Genova team
Recall the standard procedure adopted in the Hee analysis:
New
scheme tested in order to account for events with hard ISR:
The
new scheme has been applied to the event 111886/551 (Hee candidate with
mass ~110 GeV in the usual scheme and |miss. Pz| > 20 GeV).
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So
the new fit scheme brings this event to "canonical" ZZ masses in fair agreement
with G. Borissov evaluation [M(ee) = 90.9 GeV; M(qq) = 94.0 - the differences
may be attributed to a different evaluation of the electron energy and
different error tuning].
BUTa
hard ISR is not likely in high mass Higgs production. Test the procedure
on a sample of MC Hee events (E=206 GeV, M=110 GeV).
The
jet mass
plots
show a broadening of the mass peak. The effect is more clear (see plots)
selecting ISR like events (theta and |Pz miss| selection).
So
this method
does not improve the mass resolution
for high mass higgs although occasionally
it provides more sensible results on backround events.
Test
the method on the main background source (MC eeqq at 206 GeV).
The
plots, produced selecting ISR-like events after the last cut of the Hee
analysis (i.e. esssentially on shell ZZ), show comparisons for
TENTATIVE CONCLUSION: