Cano Ay , Johannes Gutenberg Universität , [email protected]
description
Transcript of Cano Ay , Johannes Gutenberg Universität , [email protected]
![Page 1: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/1.jpg)
Cano Ay , Johannes Gutenberg Universität , [email protected]
B mixing and flavor oscillations at DØ
Cano Ay University Mainz
for the DØ Collaboration
23 may 2005
Frontiers in Contemporary Physics III
Vanderbilt University Nashville, Tennesse
![Page 2: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/2.jpg)
23 may 2005 FCP III , Cano Ay 2
• Motivation• Mixing and Oscillation• Tevatron and DØ Detector• Flavor tagging• Bd Mixing Limit• Bs Mixing Limit• Prospects and plans• Summary
Outline
![Page 3: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/3.jpg)
23 may 2005 FCP III , Cano Ay 3
Motivation
• The ratio ms/md constrains one side of the unitarity triangle
• also study CP violation in Bs system• studied in Kaon and Bd system
Belle and Babar not sensitiv LHCB not running Tevatron currently only place to study Bs
Mixing
![Page 4: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/4.jpg)
23 may 2005 FCP III , Cano Ay 4
Particle Antiparticle
*tbVtdV
b sd ,tdV*tbV
0B
bsd ,
W W 0B
*tbVtdV
b
tcu ,,
sd ,tdV*tbV
0B
bsd ,
tcu ,,
W
W
0B
tcu ,,
tcu ,,
The transition of a neutralparticle into its antiparticle
iscalled Mixing.
lhds
lhds
dsdshl,
ΓΓ=
mm=Δm
B|q±B|p=B|
,
,
0,
0.
ΔΓ
Mixing
dttm
qqq
q
t
tatBpure
q
s
tmP
2
)cos(1exp )/(
0
),,(0
0
0
:""
:""
s
s
B
B
![Page 5: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/5.jpg)
23 may 2005 FCP III , Cano Ay 5
Standard Model expectation:
Δms= 14 ....28ps-1
Δmd= 0.5ps-1
measurement of Δms/Δmd
Vts/Vtd
constrain unitarity triangle
Unitarity triangle
(0,0) (0,1)
(,)
*ubud
*tbtd
VV
VVarg
*cbcd
*tbtd
VV
VV
*tbtd
*cbcd
VV
VVarg
*cbcd
*ubud
VV
VVarg
*cbcd
*ubud
VV
VV
(0,0) (0,1)
(,)
*ubud
*tbtd
VV
VVarg
*cbcd
*tbtd
VV
VV
*tbtd
*cbcd
VV
VVarg
*cbcd
*ubud
VV
VVarg
*cbcd
*ubud
VV
VV
![Page 6: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/6.jpg)
23 may 2005 FCP III , Cano Ay 6
Measure m asymmetry
high uncertainties f(QCD)
reduce uncertainties by taking ratio
Mixing (2)
![Page 7: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/7.jpg)
23 may 2005 FCP III , Cano Ay 7
• From the CKM fit: ms~ 18 ps-1
• Heavy Flavor Averaging group: combined LEP, SLD, CDF1 results ms > 14.5 ps-1
Mixing (3)
Mixing limit obtained using „Amplitude“ Method Fit data to
Fit for A as a function of ms
o A peaks at 1 for a measuremento Sensitivity given by 1.645A = 1 (95% CL)o Limit given by A<1-1.645A (95% CL)
)cos(12 tmAe st A sm
BSSDN
tsm
eysensitivit
2
22
2
flavor tagging performance resolution selectionWTRT
WTRT
NN
NNDDilution
![Page 8: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/8.jpg)
23 may 2005 FCP III , Cano Ay 8
Tevatron
Big advantage for B physics : Bs meson production
12321017.1
: scm
Achieved
LHCbefore
expected1
1232
84
1035.1:
fb
scmL
![Page 9: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/9.jpg)
23 may 2005 FCP III , Cano Ay 9
Luminosity
460pb-1
200pb-1
![Page 10: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/10.jpg)
23 may 2005 FCP III , Cano Ay 10
D0 Detector
SMT H-disks SMT F-disksSMT barrels
μ+
νμ
π-
K-
K+
BsD-
sBsBd
trigger muon
μ+
νμ
π-
K-
K+
BsD-
sBsBd
trigger muon
Semileptonic decays: • trigger on muon
good muon system• reconstruct tracks and vertex
good tracking system
![Page 11: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/11.jpg)
23 may 2005 FCP III , Cano Ay 11
Silicon Microstrip Tracker (SMT)
• Silicon Microstrip Tracker ~800.000 channels point resolution: 10m Secondary vertex resolution
- 40m (r-)- 80m (r-z) •Trackers
Silicon Tracker: |η|<3Fiber Tracker: |η|<2
•Magnetic field 2T
![Page 12: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/12.jpg)
23 may 2005 FCP III , Cano Ay 12
Muon Sytem
• 2 Tesla toroid magnet between A und BC Layer Muon momentum
propotional drift tubes
pixel scintillators
A minidrift tube with cover partially removed
• Muon system coverage ||<2 and good shielding
![Page 13: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/13.jpg)
23 may 2005 FCP III , Cano Ay 13
B production Fermilab: σ ≈ O(100μb)L1 Trigger acceptance (DØ: Muon) : σ ≈ O(3-5μb)
B production and decay
B0s → D-
s μμ
D-s → (K+K-)-
B0d → D*(2010)-µ+
µ D*(2010)-D0(K+-)-
B+ → D0µ+ µ D0 K-+
Used Decays:
![Page 14: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/14.jpg)
23 may 2005 FCP III , Cano Ay 14
Flavor tagging
1. Soft Lepton Tag (SLT)
2. Opposite Jet charge (Jetq)
3. Same Side Tag (currently only used for Bd)
0 QQOpposite
DDs ,
0,dsB
Opposite
OppositeBsidesamesidesameK ,
Flavor tagging : determine b-flavor at production time!
0)( QQ sidesame 0)( QQ sidesame
oscillated not oscillated
0 QQOpposite
reconstructed sideopposite side
i
iTi
iTiJ ppq )()(Q0 QQJ 0 QQJ
![Page 15: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/15.jpg)
23 may 2005 FCP III , Cano Ay 15
Bd Sample
angle and distance : distance PV D Vertex (xy-plane) D Vertex not before B Vertex Angle between PV B Vertex and PV D Vertex
Charged tracks: pT > 0.65 GeV/c
impact parameter significance:
322 zcadca zcadca
0DB
)2010(0 DBd
Single µ data – 200pb-1
![Page 16: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/16.jpg)
23 may 2005 FCP III , Cano Ay 16
Bd Mixing Limit
)2010(0 DBd
0DB
SSTJetq
SSTJetq SLT
Asy
mm
etr
y
Asy
mm
etr
y
SLT : D0 = (44.85.1)%Jetq+SST: D0 = (14.91.5)%
Jetq+SST: D = 27.9%
md=0.4560.034ps-1(stat) 0.025ps-1(syst)
consistent with md=0.5020.007ps-1 (world average)
![Page 17: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/17.jpg)
23 may 2005 FCP III , Cano Ay 17
Currently only using a single semileptonic decay of the BsBs Ds X (Ds p) ( K K)
Using + SV vertex tag (Opposite side tag, independent of reconstructed side)
The goal was to develop tools and to allow a baseline to build on for the future
Bs Mixing analysis procedure
![Page 18: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/18.jpg)
23 may 2005 FCP III , Cano Ay 18
Eventdisplay : MC BsDs()
Blue Marker recoRed Marker MC true
KK
Ds-VertexBs-Vertex
PV
Eventdisplay : MC BsDs()
Blue Marker recoRed Marker MC true
KK
Ds-VertexBs-Vertex
PV
angle and distance : distance PV D Vertex (xy-plane) D Vertex not before B Vertex Angle between PV B Vertex and PV
D Vertex Angle between PV D Vertex and D
momentum …
Charged tracks: pT > 0.7 GeV/c impact parameter
significance Invariant KK mass
1.006 < M(KK) < 1.30
Bs Sample
13.3K Ds
5K D±
13.3K Ds
5K D±
![Page 19: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/19.jpg)
23 may 2005 FCP III , Cano Ay 19
Inputs to the fitting procedure MC
Sample composition K-factor to take non-reconstructed particles
into account Efficiencies Visible Proper Decay Length (VPDL) resolution
VPDL resolution has been tuned using data Dilution from B0
d and B+u semileptonic
samples
Bs Mixing fitting procedure
![Page 20: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/20.jpg)
23 may 2005 FCP III , Cano Ay 20
Decay Sample composition
Bs→Dsμν 20.6%
Bs→D*sμν 57.2%
Bs→D*0sμν 1.4%
Bs→D*1sμν 2.9%
Bs→DsDsX 11.3%
B0→DsDX 3.2%
B-→DsDX 3.4%cc estimated at ~ 3.5 ± 2.5 %
VPDL (cm)
Efficiency drop at low VPDLdue to impact parameter cuts on tracks from Ds decay
Sample Composition and efficiency
![Page 21: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/21.jpg)
23 may 2005 FCP III , Cano Ay 21
Decay <k>
Bs→Dsμν 0.878
Bs→D*sμν 0.857
Bs→D*0sμν 0.829
Bs→D*1sμν 0.817
Bs→DsDsX 0.738
B0→DsDX 0.681
B-→DsDX 0.687
)(
)(
st
st
BP
DPk
M
B kxcsK K x VPDL
K-factors
![Page 22: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/22.jpg)
23 may 2005 FCP III , Cano Ay 22
VPDL resolution parametrized with three Gaussians
Track by track smearing
dependant on track momentum and polar angle
Tuning results with one scale factor 1.095
VPDL Resolution: MC tuned with data
no smearingafter smearing
VPDLrec – VPDLgen [cm]
![Page 23: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/23.jpg)
23 may 2005 FCP III , Cano Ay 23
0DB
DØ Run II preliminary )2010(0 DBd
DØ Run II preliminary
Dilution
SLT + SV Jetq : D0 = (39.03.2)% D = (47.62.0)%
use mean : Davr=(45.41.7)% for Bs asymmetry
![Page 24: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/24.jpg)
23 may 2005 FCP III , Cano Ay 24
No obvious oscillations in the μDssample
ms > 5.0 ps-1 at 95% CL using “Amplitude” method
Bs Mixing Limit
![Page 25: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/25.jpg)
23 may 2005 FCP III , Cano Ay 25
Scaling of the current sensitivity with luminosity
- if analysis remains unchanged- with expected improvements
Sensitivity vs. LuminositySemileptonic channels
![Page 26: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/26.jpg)
23 may 2005 FCP III , Cano Ay 26
Use both semileptonic and hadronic Bs samples More statistics in semileptonics Better proper decay time resolution in
hadronics (no )
DZero has access to hadronic Bs sample triggering on opposite side muon Muon is used as high purity tag
Detector addition in fall: “Layer 0” Silicon detector
Proposal to increase rate to tape from 50 to 100 Hz in fall sample limited by L3 trigger and offline
CPU – expect large gain in yield thanks to dedicated B-physics bandwidth
Bs Mixing Projections
![Page 27: Cano Ay , Johannes Gutenberg Universität , ayc@uni-mainz.de](https://reader036.fdocuments.in/reader036/viewer/2022062500/5681591b550346895dc641a0/html5/thumbnails/27.jpg)
23 may 2005 FCP III , Cano Ay 27
Summary
measured, which is in agreement with world average
md=0.4560.034ps-1(stat) 0.025ps-1(syst) developed a procedure to measure ms using
semileptonic channel BsDs()
ms > 5.0ps-1 at 95% CL will add more semileptonic channels and hadronic
channels „Layer 0“ Silicon detector and increasing L3 rate
will improve resolution and increase statistics