J'Boudreau, J'P'Fernndez, K'Gibson,

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J.Boudreau, J.P.Fernández, K.Gibson, G.Giurgiu,
G.Gómez-Ceballos, T.Kuhr, M.Kreps, L.Labarga,
Ch. Liu, P. Maksimovic, J. Morlock, M. Paulini,
A. Schmidt Towards understanding remaining
discrepancies between the BltNtuples for two
periods ( 1st 1.3 fb-1 w.r.t last 1.1fb-1 ) )
discrepancy in JQT jet-type ) discrepancy in
phi-mass resolution
BML Meeting, January 29, 2008
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Recall discrepancy in the JQT jet-type
1st 1.3 fb-1 - last 1.1 fb-1
Jet-type means 0 jet has no tracks requiring
selection criteria 1 jet has a pair of tracks
making a displaced vertex (SVT) 2 jet has a
displaced track 3 jet has tracks requiring
selection criteria but neither 1 nor 2
The distribution obtained with the 1st 1.3 fb-1
is rescaled by the ratio of number of "truly" B0s
? J/?? events in the next 1.1 fb-1
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A NN decides the jet-type-2 for each track in
the event with JQT info. If at least a track
gives a NN-output greater than 0.5 the jet-type
goes from 3 to 2. Looked at all the input
variables of the NN impact parameter
significance of the track in the jet opposite to
the B pt of the track impact parameter of the
track flag for PV ( 1 means there is PV)
?R (track B) ptjet eta of the track w.r.t.
jet HasL00 flag ( 1 means there is at least a
track with L00 hit on the jet) See the jet-type
change goes with L00-hit efficiency change
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JQT jet-type vs. L00 efficiency
JP,LL 20080318
B0s ? J/? ?
SB subs. signal events
0d 0h 0i 0j-p13 p13
JQT-trks with L00 / JQT-trks
jet-type12 / jet-type123
Found the p13 period had half of the L00 detector
off ( there where sub-periods with even no L00
at all)
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The discrepancy on the jet-type of the two
periods is understood in terms of a different L00
efficiency in them. Two reasons for that
1st trend of L00 ladders (mainly on B4, B5) to
loose hit-efficiency 2nd ISL cooling
problem on p13
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2nd topic
Recall discrepancy in the ?-mass resolution
for B0s candidates, ie. sideband subtracted
distribution
1st 1.3 fb-1 - last 1.1 fb-1
The distribution obtained with the 1st 1.3 fb-1
is rescaled by the ratio of number of "truly" B0s
? J/?? events in the next 1.1 fb-1
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Discrepancy in ?-mass resolution Made the
promised study of ?-mass resolution vs opening
angle of Kaons (no sideband subtraction, i.e. all
? in B0s events )
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?-mass resolution vs Eta of ?
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?-mass resolution vs azimutal angle of ?
Both periods are consistent to each other (in
this study)
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Back up
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Start with with B0-mass resolution vs opening
angle of Kaons
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pred-dil lt 0
pred-dil gt 0
pt distribution of candidates to leading
fragmentation tracks