0000000000237461
AUTHOR
L. Gioi
Operational Experience and Performance of the Belle II Pixel Detector
Proceedings of the 29th International Workshop on Vertex Detectors (VERTEX2020), Tsukuba, Japan (Online); Journal of the Physical Society of Japan 34, 010002 (2021). doi:10.7566/JPSCP.34.010002
The Belle II vertex detector integration
Belle II DEPFET, PXD, and SVD Collaborations: et al.
DEPFET pixel detector in the Belle II experiment
Belle II DEPFET and PXD Collaboration: et al.
Belle II pixel detector: Performance of final DEPFET modules
Belle-II DEPFET and PXD Collaboration: et al.
Alignment for the first precision measurements at Belle II
On March 25th 2019, the Belle II detector recorded the first collisions delivered by the SuperKEKB accelerator. This marked the beginning of the physics run with vertex detector. The vertex detector was aligned initially with cosmic ray tracks without magnetic field simultaneously with the drift chamber. The alignment method is based on Millepede II and the General Broken Lines track model and includes also the muon system or primary vertex position alignment. To control weak modes, we employ sensitive validation tools and various track samples can be used as alignment input, from straight cosmic tracks to mass-constrained decays. With increasing luminosity and experience, the alignment is …
Commissioning and performance of the Belle II pixel detector
Belle-II DEPFET and PXD Collaboration: et al.
Searches for violation of lepton flavour and baryon number in tau lepton decays at LHCb
Searches for the lepton flavour violating decay tau(-) -> mu(-)mu(+)mu(-) and the lepton flavour and baryon number violating decays tau(-) -> (p) over bar mu(+)mu(-) and tau(-) -> p mu(-)mu(-) have been carried out using proton-proton collision data, corresponding to an integrated luminosity of 1.0 fb(-1), taken by the LHCb experiment at root s = 7 TeV. No evidence has been found for any signal, and limits have been set at 90% confidence level on the branching fractions: B(tau(-) -> mu(-)mu(+)mu(-) mu(+)mu(-)) p mu(-)mu(-)) (p) over bar mu(+)mu(-) and tau(-) -> p mu(-)mu(-) decay modes represent the first direct experimental limits on these channels.
Measurements of the Absolute Branching Fractions of B± →k±Xc c
A study of the two-body decays B±→XccK±, where Xcc refers to one charmonium state, is reported by the BABAR Collaboration using a data sample of 424 fb-1. The absolute determination of branching fractions for these decays are significantly improved compared to previous BABAR measurements. Evidence is found for the decay B+→X(3872)K+ at the 3σ level. The absolute branching fraction B[B+→X(3872)K+]=[2.1±0.6(stat)±0.3(syst)]×10-4 is measured for the first time. It follows that B[X(3872)→J/ψπ+π-]=(4.1±1.3)%, supporting the hypothesis of a molecular component for this resonance.
Data quality monitors of vertex detectors at the start of the Belle II experiment
The Belle II experiment features a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric e+e− collider at KEK in Tsukuba, Japan. The accelerator completed its first phase of commissioning in 2016, and the Belle II detector saw its first electron-positron collisions in April 2018. Belle II features a newly designed silicon vertex detector based on double-sided strip layers and DEPFET pixel layers. A subset of the vertex detector was operated in 2018 to determine background conditions (Phase 2 operation). The collaboration completed full detector installation in January 2019, and the experiment started full data taking. This paper will report on the fin…