Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.
-
Upload
alannah-fleming -
Category
Documents
-
view
219 -
download
0
description
Transcript of Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.
![Page 1: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/1.jpg)
Measurement of the
branching ratio of
the K+ decay
UpdateE. De Lucia, R. Versaci
![Page 2: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/2.jpg)
Home works (Hausaufgabe)
1.FILFO correction 2.T3 FILTER correction 3.Efficiency checks 4.Time stability 5.Trigger with not overlapping sectors
![Page 3: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/3.jpg)
Home works (Hausaufgabe)
1.FILFO correction 2.T3 FILTER correction 3.Efficiency checks 4.Time stability 5.Trigger with not overlapping sectors
BR (K+ ) = 0.6357 ± 0.0009 (stat.)
BR (K+ ) = 0.6366 ± 0.0009 (stat.) Trig over
Trig no over
![Page 4: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/4.jpg)
WORK IN PROGRESS
WORK IN PROGRESS
![Page 5: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/5.jpg)
OLD SLIDESOLD SLIDES
![Page 6: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/6.jpg)
T3FILTER correction (trig no over)Using the whole DATA sample:
13
13
6464
FLAGTTAGTAG
FLAGTSIGSIG
TAG
SIG
xNNxNN
NN
BR(K()) BR x CT3
CT3 = 0.9994 0.0003
BRT3FILTER negligible O(10-6)
![Page 7: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/7.jpg)
T3FILTER correction (trig over)Using the whole DATA sample:
13
13
6464
FLAGTTAGTAG
FLAGTSIGSIG
TAG
SIG
xNNxNN
NN
BR(K()) BR x CT3
CT3 = 0.9995 0.0003
BRT3FILTER negligible O(10-6)
![Page 8: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/8.jpg)
FILFO correction
SIGTAG
TAGFILFOC
11
iFILFO
iAFILFO
iAFILFO
i NNN
CFILFO = 1.00006 0.00032 (DATA)CFILFO = 0.99967 0.00015 (MC)
Using the same set of runs for DATA and MC :
In agreement within the errorsIn agreement within the errors
BRFILFO = 3x10-4BR(K()) BR x CFILFO
![Page 9: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/9.jpg)
Efficiency evaluationOn the sample selected using ECAL we look for a signal event
( i.e. K+ reconstructed in the DC FV)using the same event selection used for the signal sample
KTAG
K
NK
NtagKTAG
=
NK
Ntag
![Page 10: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/10.jpg)
Efficiency checks (I)Remember memo #3x10Remember memo #3x1022
The systematic uncertainties on the efficiency are:
1) Low energy cut (LEC)
BR = 5 x 10-4
(from 10 to 40 MeV)
2) High energy cut (HEC)
BR = 2 x 10-4
(from 70 to 90 MeV)
standard cuts: LEC = 20 MeV HEC = 80 MeV pollution of the EMC sample 1.2%
p*(MeV/c)
Calorimeter sampleCalorimeter sample only true KTrue K
![Page 11: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/11.jpg)
Efficiency checks (II): pollution/compensation
p*(MeV/c)
LEC = 40 MeV HEC = 90 MeV
76% generated True K()pollution 3 %
Calorimeter sampleCalorimeter sample only true KTrue K
LEC = 10 MeV HEC = 90 MeV
25% generatedTrue K()pollution 0.7 %
![Page 12: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/12.jpg)
Efficiency checks (III)Changing the cuts for the selection of the EMC sample we observe the following maximal variations:
DATA efficiency 0 0.3074 (2) 0.3169 (3) 0 3%
Pollution in EMC sample 0.7 % 3 %
Correction (CORR) 0.98008 1.0085 CORR 3%
For each EMC sample:1. evaluate the MC corrections CORR 2. apply CORR to the efficiency 0 measured on EMC DATA sample = 0 x CORR
Then the initial 0 3% becomes O(10-4) BR 5 x 10-4
Changing EMC sample :Changing EMC sample :Pollution and compensation have different Pollution and compensation have different behavioursbehaviours !!!!!!!!
![Page 13: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/13.jpg)
Efficiency checks (IV): Double ratio MC/Data
The double ratio stability is related to our sensitivity to changes The double ratio stability is related to our sensitivity to changes of the pollution/compensation effectsof the pollution/compensation effects
DATA(set2)DATA(set1)
MC(set2)MC(set1)
N.B.set1 and set2 appliedon independent DATA samples
set1 : LEC = 20 MeV HEC = 80 MeV
set2 : LEC = 20 MeV HEC = 85 MeV
2 = 90.33/85A0 = 1.007 0.008
![Page 14: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/14.jpg)
Efficiency checks (IV): Double ratio MC/Data
The double ratio stability is related to our sensitivity to changes The double ratio stability is related to our sensitivity to changes of the pollution/compensation effectsof the pollution/compensation effects
DATA(set2)DATA(set1)
MC(set2)MC(set1)
N.B.set1 and set2 appliedon independent DATA samples
set1 : LEC = 20 MeV HEC = 80 MeV
set2 : LEC = 25 MeV HEC = 80 MeV
2 = 85.43/85A0 = 0.9011 0.007
![Page 15: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/15.jpg)
Checking various distributionsfor the kaonfor the kaon
tof (ns)
KINE
Calorimeter sampleTrue K
![Page 16: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/16.jpg)
Checking various distributionsfor the kaonfor the kaon
pK (MeV/c)pK (MeV/c)
KINEREC
Calorimeter sampleTrue K
![Page 17: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/17.jpg)
Checking various distributionsfor the decay vtxfor the decay vtx
Rxyz (cm)Rxy (cm)
KINE
KINE
Kaon interacting withthe inner DC wall
Kaon interacting withthe inner DC wall
Calorimeter sampleTrue K
![Page 18: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/18.jpg)
Checking various distributionsfor the secondaryfor the secondary
pLAB(MeV/c)
KINE
pLAB(MeV/c)
KINEREC
Kaon stopped in the inner DC wall,Decay at rest then Plab = 236 MeV
Kaon stopped in the inner DC wall,Decay at rest then Plab = 236 MeV
Calorimeter sampleTrue K
![Page 19: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/19.jpg)
Checking various distributions
for the secondaryfor the secondary
pLAB(MeV/c)
MC-Data comparison
DATAMC
Kaon stopped in the inner DC wall,Decay at rest then Plab = 236 MeV
![Page 20: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/20.jpg)
Checking various distributionsfor the secondaryfor the secondary
cos
RECKINE
cos
Calorimeter sampleTrue K
![Page 21: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/21.jpg)
Checking various distributionsfor the secondaryfor the secondary
pT(MeV/c)
L(cm)
REC
REC
Calorimeter sampleTrue K
![Page 22: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/22.jpg)
The “missed” time stability plot
![Page 23: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/23.jpg)
BR K+ = 0.6366 0.0009 (stat.) 0.0012 (syst.)
PDG fit = 0.6343
Chiang = 0.6324
Results
![Page 24: Measurement of the branching ratio of the K + decay Update E. De Lucia, R. Versaci.](https://reader036.fdocuments.net/reader036/viewer/2022070605/5a4d1b477f8b9ab0599a3bb1/html5/thumbnails/24.jpg)
Vus = 0.2223 (25)
Results
BR K+ = 0.6366 0.0009 (stat.) 0.0012 (syst.)
fK /f =1.210±0.014(MILC Coll. hep-lat/0407028)
Following the method from Marcianohep-ph/0406324 :
Vud=0.9740±0.0005 (superallowed -decays)