Flavour Physics Speaker: Andreas Hoecker Convener: Ewa Rondio Sc.Secretary: Ulrik Egede Orsay, 31’th January 2006

Is 50 ab –1 enough to do substantially better than the hadron colliders ? If NP is doscovered at the LHC: NP parameters cannot be measured model-independently in hadronic modes ? requires precise measurement of leptonic and rare semi-leptonic modes ? what can be done at LHC ? what is the required Super-B luminosity ? If no NP is discovered at LHC: continue indirect search with all modes How many of the rare modes will be systematics limited at 50 ab –1 ? What is the timescale of the “proof of principle” of the linear Super-B factory ? Can the linear Super-B factory also be  /charm and  factory ? q u e s t i o n s I guess that CERN's SPSC-P-326 K +  + proposal should get our strong support ? What about plans for an ambitious K L  0 experiment at CERN ? In which area is a fb –1  /charm factory better than a fb –1 Super-B factory ? LFV importance boosted by neutrino discoveries. Can we build a   e conversion experiment in Europe (CERN) ? what is the required luminosity for a competitive  measurement at Super-B ? B Physics K /c/c LFV

Contributions to the discussion ILC/LHC synergies with flavour physics Need for more studies of sensitivity and limits for b-factories and ILC/LHC  The current "Flavour at LHC" workshop attempts to address this point. need of sensitivity plots for specific theories  even if such plots are very model dependent, indeed need to do more work in this area LHC will give us new degrees of freedom in the flavour sector –We need a paradigm change in the flavour physics area to reflect this.

Super B factories plans for SuperKEKB linear SuperB factory What is the time scale of the linear super B ? … and what is the relative price in comparison to SuperKEKB ? Total integrated luminosity: We saw the projections from KEK-B. What are they for a linear super B. Capabilities: The linear superB has the possibilities of polarised beams and further flexibility of energy. Super KEK-B has a much stronger energy constraint.

Yamauchi’s Schedule for Super B KEKB SuperKEKB >1000fb -1 Calendar year Crab cavity KEKB machine SuperKEKB const. J-PARC 1 construction ILC construction Construct. fund “Minor” upgrade “Major” upgrade (cost: 400M$) Belle Operation fund T2K A Super B proposal was submitted from KEK to MEXT in August Window of oportunity for construction after 2008, cost 400M$ KEK open for discusion and colaboration welcomed Super B Letter of Intent (KEK Report ) in April 2004

Super B Physics Reach 50ab -1 CKM w/ FCNC CPV (b  s) B B   ll   l  ’ 3l3l   l Ks   B  10  9 10  8 10  7 10  6 10  5 Upper limit on Br w/ improvementsimple projection

linear superB  lower energ y options possible: i n the tau/charm region the loss of luminosity will be quite small, if all the way down to the f the luminosity may be a factor ~ 100 lower.  possibility of polarization (what is the physics case ?)  the study group is working, will provide a report during summer 2006 a possible timescale, cost estimates significant simulation work. Is linear superB a competitor to a super KEK-B ??? Answer not clear rather not a competitor, but also comment that only one can be build We should let the physics drive this. Other comment of B factories plans: wait and see how well B physics can be done in the hadron environment  what is left after LHCb/ATLAS/CMS

Other points in the discussion: * LHCb at high luminosity LHCb will initially run at a luminosity of 2 x which is well below the LHC design luminosity [different focusing in the LHCb int. point]. There are studies now for running at luminosities up towards However it seems clear that SLHC will mean the end of LHCb. ** Latice calculation for flavour physics Further lattice calculations will not be able to help us for e ’ /e For most other observables the precision should [by the time a super-B comes online] reach a precision of 2-4%. We should also keep in mind that any new theory will introduce flavour physics.

Opportunity to study Rare Kaon Decays K +    –Present result in agreement with SM within errors –Next round of exp. need to collect O(100) events to be useful –Proposal for in-flight decays: CERN P-326 –Letter of Intent at J-PARC to continue the study with decays rest K 0 L    –Upper limit is 4 order of magnitude from the SM prediction –LOI to continue at J-PARC –KOPIO TERMINATED –Could be started at SPS and continued at SPS+ K 0 L    ee(  ) –Long distance contributions under good control –Measurement of K S modes has allowed SM prediction –K S rates to be better measured –Background limited (study time dep. Interference?) –100-fold increase in kaon flux to be envisaged Strong support

FRASCATI short Range Future Change of machine layout Adding: Superconducting cavities Superconducting wigglers Ramping Dipoles Energy (cm) (GeV) Integrated Luminosity per year (ftbarn -1 ) 10 Total integrated luminosity (5 years, ftbarn -1 ) >503 Peak luminosity > (cm -1 sec -2 ) PHYSICS case K physics Nuclear physics Nucleon form factors Kaonic nuclei Light source Total cross section  physics importance of a network of European labs. In future – part of ILC developement

 -  e - : New project LOI to J-PARC: PRISM/PRIME B(  e conversion) < proposed in Japan, but can also be done in other places - Needs intensive proton beam PRISM/ PRIME Importance of Lepton Flavour Violation study

12 Open Symposium, Orsay, Jan 30 – Feb 1, 2006A. Höcker – The Challenge of Flavour Physics New physics Quark sector Lepton sector Energy frontier experiments, g  –2,    e , EDM, … Super-B factory, LHCb, K experiments… LHC, ILC mass and mixing CPV and LFV mass spectrum interactions flavour mixing CPV phases  LFV  CPV “A Unified and Unbiased Attack on New Physics” slide from: T. Browder, FNAL Seminar, 2006