SuperKEKB and Belle-II

Peter Križan University of Ljubljana and J. Stefan Institute

XVII SuperB Workshop and Kick Off Meeting, La Biodola, Isola d‘Elba, May 30, 2011

University “Jožef Stefan” of Ljubljana PeterInstitute Križan, Ljubljana Contents

Physics case Accellerator upgrade  SuperKEKB Detector upgrade  Belle-II Project status Summary

Peter Križan, Ljubljana Asymmetric B factories

√s=10.58 GeV + - B e e z ~ c Υ(4s) B Υ(4s) B ~ 200m BaBar p(e-)=9 GeV p(e+)=3.1 GeV =0.56

Belle p(e-)=8 GeV p(e+)=3.5 GeV =0.42 Peter Križan, Ljubljana Main motivation for B factories: measure CP violation in the B system

0 B_ tag B0 tag CP violation in B system: from the discovery (2001) to a precision measurement (2006)

sin21/sin2from bccs

_ _ 535 M BB pairs

sin21= 0.642 ±0.031 (stat) ±0.017 (syst)

Peter Križan, Ljubljana B factories: a success story

• Measurements of CKM matrix elements and angles of the unitarity triangle • Observation of direct CP violation in B decays • Measurements of rare decay modes (e.g., B, D) • bs transitions: probe for new sources of CPV and constraints from the bsbranching fraction

+ - • Forward-backward asymmetry (AFB) in bsl l has become a powerfull tool to search for physics beyond SM.

• Observation of D mixing • Searches for rare decays • Observation of new hadrons

Peter Križan, Ljubljana Fantastic performance much beyond designPeter Križan, values! Ljubljana What next?

B factories  is SM with CKM right?

Next generation: Super B factories  in which way is the SM wrong?

 Need much more data (two orders!) because the SM worked so well until now  Super B factory

However: it will be a different world in four years, there will be serious competition from LHCb and BESIII

Still, e+e- machines running at (or near) Y(4s) will have considerable advantages in several classes of measurements, and will be complementary in many more

Peter Križan, Ljubljana  Full Reconstruction Method

• Fully reconstruct one of the B’s to – Tag B flavor/charge – Determine B momentum – Exclude decay products of one B from further analysis

Decays of interest B BXu l , BK  e e+(3.5GeV) (8GeV) BD,  Υ(4S)  full reconstruction B BD etc. (0.1~0.3%)

 Offline beam! Powerful tool for B decays with neutrinos

Peter Križan, Ljubljana -  Event candidate B   

Peter Križan, Ljubljana -  Charged Higgs limits from B      2 b BF(B  )  m2  W/H  r   1 B tan 2    H  2  u  BF(B  )SM  mH   limit on charged Higgs mass vs. tan

-1 0.5 ab-1 50 ab

Peter Križan, Ljubljana B →K(*) arXiv:1002.5012 adopted from W. Altmannshofer et al., Theory JHEP 0904, 022 (2009) B →KB ~ 4·10-6 B →K*  ~ 6.8·10-6  B present exclusion SM: penguin+box limits

Look for departure from the expected value   information on couplings C R   SM and C L compared to (C L)

Again: fully reconstruct one of the B mesons, look for 50 ab-1 signal (+nothing else) in the arXiv:1008.1541 rest of the event.

not possible @ LHCb Peter Križan, Ljubljana Lepton flavour violation and New Physics

   l 3l,l 0 h ()s   ()e ()e  ()s 2  SUSY + Seasaw(ml )23(13)  Neutral Higgs mediated decay.  Large LFV Br()=O(10-7~9)  Important when MSUSY >> EW scale. Br(3)  2 4 mL 1TeV Br()= 106  32  tna 2  m2 6 4 2  7 L 32 tan  100GeV m mSUSY  L  410 2  m 60 m L 