Status of Belle II

Status of Belle II Introduction Emiss measurements (with comments on the upgrade) Inclusive decays (with comments on the upgrade) Neutral final states (with comments on the upgrade) Summary BoštjanGolob University of Ljubljana/Jožef StefanInstitute Belle/Belle II Collaboration University of Ljubljana “Jožef Stefan” Institute 1/19

Introduction Belle II is an intensity frontier experiment being built at Super-KEKB in Tsukuba, Japan successor of extremely successfull B factories (Belle & BaBar) Intensity frontier 2/19

Introduction Belle II is an intensity frontier experiment being built at Super-KEKB in Tsukuba, Japan successor of extremely successfull B factories (Belle & BaBar) 2001 2012 Intensity frontier 2/19

Introduction Belle II is an intensity frontier experiment being built at Super-KEKB in Tsukuba, Japan successor of extremely successfull B factories (Belle & BaBar) 2001 2012 With current accuracy deviations from SM still possible at O(10%) Intensity frontier 2/19

Introduction Quest for NP..... ...continues Intensity frontier B Factories (BF) → Super B Factory (SBF) • s1/N  O(102) higher luminosity • complementarity to other intensity frontiers • experiments (LHCb, BES III, ....); • accurate theoretical predictions to compare to 3/19

Introduction Quest for NP..... ...continues Intensity frontier B Factories (BF) → Super B Factory (SBF) Illustrative reach of NP searches • s1/N  O(102) higher luminosity • complementarity to other intensity frontiers • experiments (LHCb, BES III, ....); • accurate theoretical predictions to compare to NP reach in terms of mass NP flavor violating couplings( 1 in MFV) 3/19

Introduction Quest for NP..... ...continues Intensity frontier B Factories (BF) → Super B Factory (SBF) Illustrative reach of NP searches • s1/N  O(102) higher luminosity • complementarity to other intensity frontiers • experiments (LHCb, BES III, ....); • accurate theoretical predictions to compare to NP reach in terms of mass Terra Incognita NP flavor violating couplings( 1 in MFV) 3/19

Introduction SuperKEKB Nano beams design (P. Raimondi) b*: beta-function (trajectories envelope) at IP xy: beam-beam parameter small by* large xy (by*/ey)  small ey hourglass effect  small bx* increase I 4/19

Introduction SuperKEKB sx~100mm,sy~2mm Nano beams design (P. Raimondi) e- e+ b*: beta-function (trajectories envelope) at IP xy: beam-beam parameter small by* large xy (by*/ey)  small ey hourglass effect  small bx* increase I 4/19

Introduction SuperKEKB sx~10mm,sy~60nm Nano beams design (P. Raimondi) e- e+ b*: beta-function (trajectories envelope) at IP xy: beam-beam parameter small by* large xy (by*/ey)  small ey hourglass effect  small bx* increase I 4/19

Introduction SuperKEKB sx~10mm,sy~60nm Nano beams design (P. Raimondi) e- e+ ∫L dt [ab-1] b*: beta-function (trajectories envelope) at IP xy: beam-beam parameter small by* large xy (by*/ey)  small ey hourglass effect  small bx* increase I L [s-1cm-2] 4/19

Introduction SuperKEKB sx~10mm,sy~60nm Nano beams design (P. Raimondi) e- e+ ∫L dt [ab-1] b*: beta-function (trajectories envelope) at IP xy: beam-beam parameter small by* large xy (by*/ey)  small ey hourglass effect  small bx* increase I current B factories L [s-1cm-2] design L=8·1035 s-1cm-2 4/19

Introduction SuperKEKB sx~10mm,sy~60nm Nano beams design (P. Raimondi) e- e+ ∫L dt [ab-1] b*: beta-function (trajectories envelope) at IP xy: beam-beam parameter ∫L dt=50 ab-1(2022-2023) small by* large xy (by*/ey)  small ey hourglass effect  small bx* increase I ∫L dt=10 ab-1(2018-2019) current B factories L [s-1cm-2] design L=8·1035 s-1cm-2 4/19

Introduction SuperKEKB sx~10mm,sy~60nm Nano beams design (P. Raimondi) e- e+ ∫L dt [ab-1] b*: beta-function (trajectories envelope) at IP xy: beam-beam parameter ∫L dt=50 ab-1(2022-2023) small by* large xy (by*/ey)  small ey hourglass effect  small bx* increase I ∫L dt=10 ab-1(2018-2019) current B factories L [s-1cm-2] design L=8·1035 s-1cm-2 magnet installation for SuperKEKB; Being built on schedule 4/19

Introduction SuperKEKB Belle II e+ New IR New superconducting /permanent final focusing quads near theIP New beam pipe & bellows Replace short dipoles with longer ones (LER) e- Add / modify RF systems for higher beam current Low emittance positrons to inject Redesign the lattices of HER & LER to squeeze the emittance Positron source Damping ring Low emittance gun Low emittance electrons to inject New positron target / capture section TiN-coated beam pipe with antechambers 5/19

Introduction 6/19

Introduction Damping ring tunnel: built! 6/19

Introduction Installation of 100 new long LER bending magnets done Damping ring tunnel: built! 6/19

Introduction Installation of 100 new long LER bending magnets done Installation of HER wiggler chambers in Oho straight section is done. Damping ring tunnel: built! 6/19

Introduction KL and muon detector: Resistive Plate Counter (barrel outer layers) Scintillator + WLSF + MPPC (end-caps , inner 2 barrel layers) EM Calorimeter: CsI(Tl), waveform sampling (barrel) Pure CsI + waveform sampling (end-caps) Particle Identification Time-of-Propagation counter (barrel) Prox. focusing Aerogel RICH (fwd) electrons (7GeV) Beryllium beam pipe 2cm diameter Vertex Detector 2 layers DEPFET + 4 layers DSSD positrons (4GeV) Central Drift Chamber He(50%):C2H6(50%), small cells, long lever arm, fast electronics 7/19

Introduction Methods and processes where (S)BF can provide important insight into NP complementary to other experiments: 8/19

Introduction Methods and processes where (S)BF can provide important insight into NP complementary to other experiments: Emiss: B(B→tn), B(B → Xctn), B(B → hnn),... 8/19

Introduction Methods and processes where (S)BF can provide important insight into NP complementary to other experiments: Emiss: B(B→tn), B(B → Xctn), B(B → hnn),... Inclusive: B(B → sg), ACP(B → sg), B(B → sll ), ... 8/19

Introduction Methods and processes where (S)BF can provide important insight into NP complementary to other experiments: Emiss: B(B→tn), B(B → Xctn), B(B → hnn),... Inclusive: B(B → sg), ACP(B → sg), B(B → sll ), ... Neutrals: S(B → KSp0g), S(B → h’ KS), S(B → KSKSKS), B(t→ mg), B(Bs→ gg), ... 8/19

Introduction Methods and processes where (S)BF can provide important insight into NP complementary to other experiments: Emiss: B(B→tn), B(B → Xctn), B(B → hnn),... Inclusive: B(B → sg), ACP(B → sg), B(B → sll ), ... Neutrals: S(B → KSp0g), S(B → h’ KS), S(B → KSKSKS), B(t→ mg), B(Bs→ gg), ... Detailed description of physics program at SBF in: ~ 300 pages ~ 100 pages B. O’Leary et al., arXiv: 1008.1541 A.G. Akeroyd et al., arXiv: 1002.5012 8/19

Missing energy Btn, hnn, ... fully (partially) reconstruct Btag; reconstruct h from Bsig→hnnor Bsig→ t(→ hn)n; no additional energy in EM calorim.; signal at EECL~0; 9/19

Missing energy Btn, hnn, ... fully (partially) reconstruct Btag; reconstruct h from Bsig→hnnor Bsig→ t(→ hn)n; no additional energy in EM calorim.; signal at EECL~0; Btag Bsig → tn candidate event 9/19

Missing energy Btn, hnn, ... fully (partially) reconstruct Btag; reconstruct h from Bsig→hnnor Bsig→ t(→ hn)n; no additional energy in EM calorim.; signal at EECL~0; Btag Bsig Bsig → tn candidate event 9/19

Missing energy Btn, hnn, ... fully (partially) reconstruct Btag; reconstruct h from Bsig→hnnor Bsig→ t(→ hn)n; no additional energy in EM calorim.; signal at EECL~0; Missing E (n) Btag Bsig Bsig → tn candidate event 9/19

Missing energy Btn, hnn, ... fully (partially) reconstruct Btag; reconstruct h from Bsig→hnnor Bsig→ t(→ hn)n; no additional energy in EM calorim.; signal at EECL~0; Btag full reconstruction (NeuroBayes) Missing E (n) Btag Bsig Bsig → tn candidate event 9/19

Missing energy Btn, hnn, ... fully (partially) reconstruct Btag; reconstruct h from Bsig→hnnor Bsig→ t(→ hn)n; no additional energy in EM calorim.; signal at EECL~0; Btag full reconstruction (NeuroBayes) Missing E (n) Btag Bsig Bsig → tn candidate event approx. expected precision @ 50 ab-1 9/19

Missing energy Belle preliminary, arXiv:1303.3719, 711 fb-1 Bhnn -- signal -- background 10/19

Missing energy Belle preliminary, arXiv:1303.3719, 711 fb-1 Bhnn -- signal -- background SM W. Altmannshofer et al., arXiv:0902.0160 10/19

Missing energy Belle preliminary, arXiv:1303.3719, 711 fb-1 Bhnn B(B+ K(*)+nn) can be measured to ±30% with 50 ab-1; limits on right-handed currents -- signal -- background approx. expected precision @ 50 ab-1 SM W. Altmannshofer et al., arXiv:0902.0160 10/19

Calorimeter new electronics with 2MHz wave form sampling 2x improved s at 20x bkg. Better suppression of background endcap: pure CsI crystals; (considered for upgrade) 11/19

Calorimeter new electronics with 2MHz wave form sampling 2x improved s at 20x bkg. Better suppression of background Belle II full simulation: B0D0p0, D0 p0p0, p0gg DE= EB* - Ebeam verification and fine tuning detector response default g energy after rough calibr. after calibr. and D0 mass fit Belle B+ r+(p+p0)g endcap: pure CsI crystals; (considered for upgrade) 11/19

KLM KLandmdetector • Endcaps: • scintillators, two orthogonal • directions in one super-layer • avalanche photo-diode in • Geiger mode (GAPD) • 2 inner barrel layers: • upgrade to scintilators 12/19

KLM KLandmdetector • Endcaps: • scintillators, two orthogonal • directions in one super-layer • avalanche photo-diode in • Geiger mode (GAPD) • 2 inner barrel layers: • upgrade to scintilators • main backround from KL‘s, better KL efficiency • better background rejection 12/19

Status of Belle II