A
bstract
We measure
CP
asymmetries and branching-fraction ratios for
B
±
→ DK
±
and
Dπ
±
decays with
D →
$$ {K}_{\textrm{S}}^0 $$
K
S
0
K
±
π
∓
, where
D
is a superposition of
D
0
and
$$ ...\overline{D} $$
D
¯
0
. We use the full data set of the Belle experiment, containing 772
×
10
6
$$ B\overline{B} $$
B
B
¯
pairs, and data from the Belle II experiment, containing 387 × 10
6
$$ B\overline{B} $$
B
B
¯
pairs, both collected in electron-positron collisions at the Υ(4
S
) resonance. Our results provide model-independent information on the unitarity triangle angle
ϕ
3
.
Operational experience of the Belle II pixel detector Wang, B.; Abudinen, F.; Ackermann, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2022, Letnik:
1032
Journal Article
Recenzirano
Odprti dostop
The Belle II experiment at the SuperKEKB accelerator has started its physics data taking with the full detector setup in March 2019. It aims to collect 40 times more e+e− collision data compared with ...its predecessor Belle experiment. The Belle II pixel detector (PXD) is based on the Depleted P-channel Field Effect Transistor (DEPFET) technology. The PXD plays an important role in the tracking and vertexing of the Belle II detector. Its two layers are arranged at radii of 14 mm and 22 mm around the interaction point. The sensors are thinned down to 75 μm to minimize multiple scattering, and each module has interconnects and ASICs integrated on the sensor with silicon frames for mechanical support. PXD showed good performance during data taking. It also faces several operational challenges due to the high background level from the SuperKEKB accelerator, such as the damage from beam loss events, the drift in the HV working point due to radiation effect, and the impact of the high background.
Commissioning and performance of the Belle II pixel detector Ye, H.; Abudinen, F.; Ackermann, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2021, Letnik:
987
Journal Article
Recenzirano
The Belle II experiment at the SuperKEKB energy-asymmetric e+e− collider has completed a series of substantial upgrades and started collecting data in 2019. The experiment is expected to accumulate a ...data set of 50 ab−1 to explore new physics beyond the Standard Model at the intensity frontier. The pixel detector (PXD) of Belle II plays a key role in vertex determination. It has been developed using the DEpleted P-channel Field Effect Transistor (DEPFET) technology, which combines low power consumption in the active pixel area and low intrinsic noise with a very small material budget. In this paper, commissioning and performance of the PXD measured with first collision data are presented.
