Performance Studies of Belle II SVD · •Design luminosity of SuperKEKB: 8×1035 cm−2s−1 that...
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. • Design luminosity of SuperKEKB: 8×10 35 cm −2 s −1 that would enable Belle II to collect 50 ab −1 of data, 50 times more than its predecessor (Belle). • To validate the performance of the SVD, a systematic study is needed in the offline reconstruction software. • The excellent performance of the Belle II SVD will provide the measurements of CP asymmetry in the B-meson system with higher precision. • To achieve the physics goals, reconstruction of tracks with a high efficiency and a good resolution is needed. Belle II Detector Performance Studies of Belle II SVD Kavita Lalwani for the Belle II SVD Collaboration Department of Physics, Malaviya National Institute of Technology Jaipur, INDIA Vertex Detector (VXD) Sensor Sensor thickness = 300-320μm Double Sided Si Strip Detector Si-Sensors K L and Muon Detector Scintillator + Si-PM for end-caps EM Calorimeter Cs (Tl), waveform sampling electronics Central Drift Chamber Smaller cell size, long lever arm L5 L3 L4 L6 Si Leads to harsh background environment in the Belle II. Angular acceptance 17⁰ < θ <150⁰ SVD Structure • The two SVD half shells have been assembled in KEK, Japan. • Testing of SVD half shells with cosmic rays is carried out from July to Sep., 2018. • Total 3010 6 cosmic events have been collected. • Performance studies of the SVD using offline reconstruction software are in progress. Summary The Belle II SVD will provide: • Better vertex resolution • Low p T track finding efficiency • Improved reconstruction efficiency Z=e⁻-beam X X Y First cosmic event Complete SVD +X/-X half shells Cluster Energy Distributions Horizontal Sensors Commissioning of the SVD Forward Ladder Structure Backward Layer Structure Layer Institute 3 University of Melbourne 4 TIFR Mumbai 5 HEPHY Vienna 6 IPMU University of Tokyo FW, BW INFN Pisa Four layers Introduction Cross-sectional view of SVD (r-z plane) Rectangular sensor Trapezoidal sensor P⁺ strip Impact Parameter Resolution • Improved resolution at IP with respect • to Belle (20m @ 2 GeV/c.) (PTEP-2018). U Side V Side • The two SVD half shells have been assembled at KEK and run smoothly during the commissioning period from July 2018 to Sep. 2018. • Performance of SVD is evaluated with cosmic runs for each side/sensor. • Cosmic rays are incident at very large angle on vertical sensors as compared to the horizontal sensors. Cosmic rays deposits higher energy in vertical sensors as compared to the horizontal sensors. •The RMS of signal hit time corresponding to a bunch crossing is found to be in the order of 5 ns (expected). SVD Commissioning Preliminary Exp 100, Run 207 0 s K Cluster Time U Side V Side Belle II SVD Commissioning Preliminary Exp 100, Run 207 Belle II SVD Commissioning Preliminary Exp 100, Run 207 V Side The S/N ratio is larger than 25 for N side, slightly lower on P side due to the longer strips and larger capacitance load to the preamplifier. The RMS of cluster times is measured to be 5ns. Cluster Signal to Noise Ratio • The cosmic track is perpendicular to the Horizontal sensors. • Clusters are correctly reconstructed on both sides (U, V). • Cluster energy are in agreement for both sides (U, V). SVD+X (July10, 2018) Full SVD (August 17, 2018) Tracks Position Time Hits dE/dx Charge Deposition Strips Strip Calibration SVD Clusterizer Digits Cluster No of Strips Rectangular Trapezoidal # of p-strips 768 768 p-strip pitch (μm) 75 (L3: 50) 50…75 # of n-strips 512 (L3: 768) 512 n-strip pitch (μm) 240 (L3: 160) 240 Active area (mm 2 ) 7030 (L3:4738) 5890 Cluster Energy vs. Azimuthal Angle R L3 = 39mm R L4 = 80mm Four layers R L5 = 104mm R L6 = 135mm FWD BWD Central K. Adamczyk et al., The silicon vertex detector of the Belle II experiment, Nucl. Instr. and Meth. in Phys. Res. A, 824, 406-410 (2016) Cosmic rays incident at large angle on vertical sensors as compared to horizontal sensors. Relatively high energy deposited in vertical sensors. Longitudinal (z 0 ) Transverse (d 0 ) N⁺ strip Belle II Silicon Vertex Detector (SVD) Results: Commissioning Data Analysis 27 th International Workshop on Vertex Detector (Vertex-2018), Chennai, INDIA, October 21 to 26, 2018 Reconstruction Software: BASF2
Transcript of Performance Studies of Belle II SVD · •Design luminosity of SuperKEKB: 8×1035 cm−2s−1 that...
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• Design luminosity of SuperKEKB: 8×1035 cm−2s−1
that would enable Belle II to collect 50 ab−1 of data,
50 times more than its predecessor (Belle).
• To validate the performance of the SVD, a systematic study
is needed in the offline reconstruction software.
• The excellent performance of the Belle II SVD will provide
the measurements of CP asymmetry in the B-meson system
with higher precision.
• To achieve the physics goals, reconstruction of tracks with a
high efficiency and a good resolution is needed.
Belle II Detector
Performance Studies of Belle II SVD Kavita Lalwani for the Belle II SVD Collaboration
Department of Physics, Malaviya National Institute of Technology Jaipur, INDIA
Vertex Detector (VXD)
Sensor
Sen
sor
thic
kn
ess
= 3
00
-32
0μ
m
Double Sided Si Strip Detector
Si-Sensors
KL and Muon Detector
Scintillator + Si-PM for
end-caps
EM Calorimeter
Cs (Tl), waveform
sampling electronics
Central Drift Chamber
Smaller cell size, long
lever arm
L5
L3
L4
L6
Si
Leads to harsh background environment in the Belle II.
Angular acceptance
17⁰ < θ <150⁰
SVD Structure
• The two SVD half shells have been assembled in KEK, Japan.
• Testing of SVD half shells with cosmic rays is carried out from July to Sep., 2018.
• Total 30106 cosmic events have been collected.
• Performance studies of the SVD using offline reconstruction software are in progress.
Summary
The Belle II SVD will provide:
• Better vertex resolution
• Low pT track finding efficiency
• Improved reconstruction efficiency
Z=e⁻-beam
X
X
Y
First cosmic eventComplete SVD +X/-X half shells
Cluster Energy DistributionsHorizontal Sensors
Commissioning of the SVD
Forward
Ladder Structure
Backward
Layer Structure
Layer Institute
3 University of Melbourne
4 TIFR Mumbai
5 HEPHY Vienna
6 IPMU University of Tokyo
FW, BW INFN Pisa
Four layers
Introduction
Cross-sectional view of SVD (r-z plane)
Rectangular sensor
Trapezoidal sensor
P⁺ strip Impact Parameter Resolution
• Improved resolution at IP with respect
• to Belle (20m @ 2 GeV/c.) (PTEP-2018).
U SideV Side
• The two SVD half shells have been assembled at KEK and run smoothly during the commissioning period
from July 2018 to Sep. 2018.
• Performance of SVD is evaluated with cosmic runs for each side/sensor.
• Cosmic rays are incident at very large angle on vertical sensors as compared to the horizontal sensors.
Cosmic rays deposits higher energy in vertical sensors as compared to the horizontal sensors.
•The RMS of signal hit time corresponding to a bunch crossing is found to be in the order of 5 ns (expected).
SVD Commissioning Preliminary
Exp 100, Run 207
0
sK
Cluster Time
U SideV Side
Belle II SVD Commissioning
Preliminary
Exp 100, Run 207
Belle II SVD Commissioning
Preliminary
Exp 100, Run 207
V Side
The S/N ratio is larger than 25 for N side, slightly lower on P
side due to the longer strips and larger capacitance load to the
preamplifier.
The RMS of cluster times is measured to be 5ns.
Cluster Signal to Noise Ratio
• The cosmic track is perpendicular to the Horizontal sensors.
• Clusters are correctly reconstructed on both sides (U, V).
• Cluster energy are in agreement for both sides (U, V).
SVD+X (July10, 2018)
Full SVD (August 17, 2018)
Tracks
Position Time
Hits
dE/dx
Charge Deposition
StripsStrip Calibration SVD ClusterizerDigits Cluster
No of Strips Rectangular Trapezoidal
# of p-strips 768 768
p-strip pitch
(μm)75 (L3: 50) 50…75
# of n-strips 512 (L3: 768) 512
n-strip pitch
(μm)240 (L3: 160) 240
Active area
(mm2)7030 (L3:4738) 5890
Cluster Energy vs. Azimuthal Angle
RL3 = 39mm
RL4 = 80mm
Four layers
RL5 = 104mm
RL6 = 135mm
FWDBWD
Central
K. Adamczyk et al., The silicon vertex detector of the Belle II experiment,
Nucl. Instr. and Meth. in Phys. Res. A, 824, 406-410 (2016)
Cosmic rays incident at large angle on vertical
sensors as compared to horizontal sensors.
Relatively high energy deposited in vertical
sensors.
Longitudinal (z0)
Transverse (d0)
N⁺ strip
Belle II Silicon Vertex Detector (SVD)
Results: Commissioning Data Analysis
27th International Workshop on Vertex Detector (Vertex-2018), Chennai, INDIA, October 21 to 26, 2018
Reconstruction Software: BASF2
