Flavour Physics Belle II experiment at SuperKEKB Tsukuba, Japan Upgrade of KEKB, 40x luminosity: 8 x 1035 cm-2s-1 First beam: February 2016 First Physics: End of 2018 Belle II Collaboration: 100 Institutions, ~600 physicists Major upgrade of Belle (pixel detector, tracking, TOP) MPP’s contribution: DEPFET pixel detector Director: Allen Caldwell, Group leader: Hans-Günther Moser + 2 senior, 3 postdoc, ~3 PhD, ~ master Nano Beams: 10µm x 60nm Increase beam current (x2) Reduce asymmetry (boost) KEB: bg = 0.42 (8 GeV, 3.5 GeV) SuperKEKB: bg = 0.28 (7 GeV, 4 GeV)

Physics at B-factories Main Motivation: CP-violation Measurements of CKM matrix elements and angles of the unitarity triangle Measurements of rare decays (e.g., Btn, Dtn) Others (t,..) Motivation for upgrade: Test Standard Model (SM) as precisely as possible => Overconstrain unitarity triangle => Look for deviations from SM => Increase sensitivity for rare decays => Indirect discovery of New Physics via loops (need high precision) Nobel Prize 2008: Kobayashi & Maskawa Confirmation of CKM theory by BaBar & Belle <= Babar/Belle 2015 (~1.5 ab-1) With 50 ab-1 (same central values) With 50 ab-1 =>

Time dependent measurements of CP violation U(4S) decaying into B0B0 pairs Oscillation induced CP violation as function of decay time difference Boosted CMS to measure decay time by decay length reconstruction Bphys Btag Dt probability parametrization

Vertexing @ Belle II σ [µm] Higher background ( 10-20) Higher event rate ( 10) Improvements to the tracking detectors: new drift chamber improved SVD (DSSD with fast readout) 2 layers of DEPFET pixel sensors Critical issues at L= 8 x 1035/cm2/sec: Significant improvement in z-vertex resolution PXD+SVD 15mm 30mm Belle Belle II pbsin(q) [GeV/c] 0.4 2.0 0.8 1.2 1.6 100 20 50 σ [µm] PXD

DEPFET Sensors Development of MPP and MPI Semiconductor lab (now independent) Active pixel sensor 20 µs frame readout Gating 75 µm sensor thickness Including frame & ASICs: 0.21 % X0 30 wafers produced Prototypes completed High yield >50% for 99% good pixels

Support & Assembly MPP Tasks: Mechanical support Kapton attachment Gluing of two modules to a ladder Assembly of ladder on support

CO2 Cooling PXD and SVD will be cooled by a 2-phase CO2 . Copy of the cooling plant used for ATLAS IBL: 3 kW cooling power at -35oC Chiller Pump unit Accumulator Control Cabinet Components were manufactured and tested in the MPP workshop Plant completed & commissioned, shipment to KEK in August 2016

Services & Installation Service routing and interface boxes for the PXD: Power and data cables for the 40 PXD modules CO2 transfer lines for cooling of PXD and SVD VXD installation procedure: Decouples VXD installation from QCS magnets. Remote connection of the beam pipe (by DESY)

Beam Test of Sensors April 2016: combined PXD and VXD beam test at DESY Inner and outer layer modules mounted on a cooling block. Completed by 4 SVD layers and a beam telescope. Cd source 14 µm (pitch:50 µm) 8 µm (pitch 60 µm) Position resolution of an inner module for tracks at normal incidence measured at a beam test. Hit map showing beam spot

Belle Analysis B0 → r+r- Precision improvement with respect to the previously published result is factor 2 (Most precise measurement of B0 → r+r-), PRD 93, 032010 (2016) Increase of data, simultaneous extraction of observables and analysis optimization for high signal yield. Input for measurements of angle f2 of the Unitarity Triangle Isospin analysis: f2= (93.7 ± 10.6)° S(U3) flavor analysis: f2= (93.7 ± 10.6)° Isospin SU3

Belle Analysis: B0→ w Ks This decay proceeds via loop diagram First evidence for CP violation in B0 → ωK0S, PRD 90, 012002 (2014) It is possibly affected by new particles in various extension of the Standard Model Sensitive to sin(2f1) Simultaneous analysis of B0 → ωK0S and B+ → ωK+ B(B0 →ωK0) = (4.5 ± 0.4 (stat) ± 0.3 (syst)) x 10-6 B(B+ →ωK+) = (6.8 ± 0.4 (stat) ± 0.4 (syst)) x 10-6 A(B0 →ωK0S) = -0.36 ± 0.19(stat) ± 0.05(syst) S(B0 →ωK0S) = +0.91 ± 0.32(stat) ± 0.05(syst) A(B+ →ωK+) = -0.03 ± 0.04(stat) ± 0.01(syst) Further published results: PRD 88, 092003 (2013) B0 → p+p- : Branching ration and time dependent CP asymmetry PRD 89, 072008 (2014) B0→ r0r0: Branching ration and fraction of longitudinal polarization PRD 93, 031101(R) (2016) First measurement of B(B0 → y(2S) p0)

All tracks used apart from the ones from Ks Physics Preparation L. Li Gioi Kinematic fit: J/y → m m Vertexing Kinematic vertex fits Kfit : for decay side RAVE for tag side fit (inclusive) (from CMS) Belle II Shift = 2.0 mm Resolution = 22 mm Belle Shift = 0.2 mm Resolution = 63 mm Tag side vertex fit Belle II Shift = 1.0 mm Resolution = 63 mm All tracks used apart from the ones from Ks Belle Shift = 29 mm Resolution = 89 mm

Belle II Physics Preparation Flavor tagging B-flavor tagging determines if a B meson is a B0 or anti-B0 It is based on trained multivariate methods Efficiency: 35 % Sensibly better than Belle: 29 % Efficiency = 35 % Belle = 29 % B0tag B0tag

Schedule IR 6 Oct 2015 February 2016: first beam in SuperKEKB February – June 2016 commissioning and BEAST I beam currents of ~ 1A reached December 2016 Belle II roll in June 2017 – April. 2018: SuperKEKB commissioning (with Quads & Beast II, no VXD) October 2017: PXD at KEK, integration with SVD (VXD) May –Sept. 2018 installation of VXD October 2018 physics run with full Belle II IR 6 Oct 2015 IR and Belle II in park position, Oct 2015 Signals from two injected bunches by CLAWS (talk by F. Simon)

Summary Main activities at MPP for Belle/Belle II: Belle analysis Belle II physics preparation Vertexing, tracking, flavour tagging Contribution to computing Slow control software (EPICs) (Component) Database Design and construction of PXD system components: Kapton tapes (Design) CO2 cooling plant Module & ladder assembly and tooling Module testing and characterization Ladder support structure and assembly General work for services layout Integration procedure (AIM) Schedule Series assembly of modules & ladders: 2016/2017 Shipment of PXD to KEK: October 2017 First physics data: October 2018