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ANALISYS Of FINAL MANUAL SCANNING
DATA
U DORE june 3 204
THE ANALYS HAS BEEN MADE USING
ASCII FILES CONTAINING MANUAL
SCANNING RESULTS
1) GOLDEN selection 0MU data ev 661
2) SATO
selection 0MU
ev 781
3)GOLDEN selection CHARMS ev 2816
In THE following I will give some information
and some personal considerations waiting for
comments and CORRECTIONS
The netscan tracks associated with the kink
have been matched with the dt tracks
Results in column 4
Notes
At least one muon
If several association are possible choose the bes
So for 62/81 tracks is possible to have
Momentum determination
Charm kink will have positive momentum
Tau decays negative
COMPARING SATO and GOLDEN SELECTION
We can measure efficiencies of the two selections
WE HAVE
SATO
GOLDEN events
Yes
no
49
No
yes
22
Yes
yes
59
From these numbers we obtain
eps(Sato)=
72%
eps(Golden)= 54%
THESE efficiencies are only the selection criteria ones
To have total efficiency multiply by location and netscan
Ones
LUCA gives for netscan and selection 24% (??????)
TOWARDS LIMITS
For events for which the momentum has been
measured
We can look for candidates
AN EXAMPLE
Require
1) Good track quality GLBHTR FLAG >4
2) p(chi2)>1%
3) Negative momentum P+3*s(P)<0
4) PT <0.25 GEV
5) no muons associated to the event
We obtain
SATO selection 1 event
GOLDEN “
0 events
NEED efficiencies
Background estimate for golden selection
compare charms with 0 mu
Mom distr of kink
COMPARISON OF charms kinks with 0mu kinks
IF we apply same cuts for kinks candidate
(except the nomuon requirement)
we have
11 EVENTS
Charms have been obtained for 90kevents
So for 20k 0c we expect 11*20/90 =2 events
We assume that the number of wk is the
same in cc and 0c events
COMPARISON OF CHARM and 0MU
samples
BOTH golden selection
we obtain fort the ratio 0mu/CHARMS
FOR THE DIFFERENT TOPOLOGIES
C1
0.17+-0.02
V2
C3
0.17+-0.01
0.14+-0.02
V4
total
0.18+-0.03
0.16+-0.01
The RATIO IS TOPOLOGY
independent AS EXPECTED
Some COMMENTS
1 THE RATIO FOR KINKS
INDICATES THAT WK CONTRIBUTION
IS NEGLIGIBLE
2 THE RATIO INDICATES THAT
THE CONTRIBUTION OF cc
IN 0MU IS 0.17*90k =15 K
ALL THE 0MU ARE 25K
SO REAL NC IS 25-15=5K NC/CC=0.1
where IS MY MISTAKE ?????????
TOWARDS LIMITS
We can think of using events wit no measurement
of momentum
GOLDEN SELCTION
Make a cut at 50 mrad
Golden 0mu
36 candidates
Golden charms 223
“
THE EXPECTED NUMBER OF EVENTS
will be 0.17*223 =38
so the effect will be 36-38=-2
Upper limit 90% CL 6 events
THE ratio of sensitivity with the measured
Momentum sample will
6/2.3*(0.32/0.68)=~ 1
0.32 effic for momentum reconstruction
EXPERIMENTAL DETERMINATION
OF WK BACKGROUND
the charm sample has 478 kink events (461 good).
of these
382 have a matching between the manual scan angular coe
and the ang coeff of one track as mesaured in the electroni
203 have a good momentum measurement in the DT
(rank bigger than 4)
155 have a probability of the momentum fit larger than 1%.
there are 22 events with a negative momentum
This number reduces to 11
if we require that -P+3.*s(P) still negative
and Pt < 250 mev
and
and to 18 if we require teta(kink)>50 mrad
COMPARISON wih Gianfranca paper
12
if we assume that the number of negative and positive
wk is the same then we would expect
18/0.32*2~~=110 wk
in a situation in which all kinks are considered
the charm sample is obtained in a sample of 100k CC events
in the nubar sample of 2000 eventes (G Derosa)
we would have 110*2/100=2.2events
in the DE Rosa paper an expected background of 0.5+-0.3 is quoted
Determination of interaction lenght
We have in average 5 shower tracks so the total lenght f track
scanned will be 5*100000*lmed*0.001*eps(kink)*eps(mom)=180m
L =180/11=16.4m
Assume lmed=4 mm (guess),Eps(kink)=0.3,eps(mom)=0.3
previous limit paper L=24.0+-8