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 ~ 200m 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)
sin21/sin2from bccs
_ _ 535 M BB pairs
sin21= 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) • bs transitions: probe for new sources of CPV and constraints from the bsbranching fraction
+ - • Forward-backward asymmetry (AFB) in bsl 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 BXu l , BK e e+(3.5GeV) (8GeV) BD, Υ(4S) full reconstruction B BD etc. (0.1~0.3%)
Offline B meson 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 →KB ~ 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()= 106 32 tna 2 m2 6 4 2 7 L 32 tan 100GeV m mSUSY L 410 2 m 60 m L