1 Physics Case of L=10 36 e + e - B Factory Achille Stocchi LAL-Orsay Université Paris-Sud and IN2P3-CNRS

2 Two of such projects exist 1. « SuperBelle in Japan » 2. « SuperB in Italy » Today it seems that SuperBelle project converges to the « italian » solution for the machine (« crab waist ») Good new ! Today I defend the physics case for a machine which I call SuperB :  very high luminosity L> cm -2 sec -1 With two possible options :  possibility of running at different energy thresholds (B  -charm..)  possibility of having polarized beams. L= cm -2 sec -1  ∫L= 15ab -1 per year Today ∫L= 1ab -1  ∫L= 100ab -1  SuperB from now on (See Christoph Schwanda talk)

3 Is a SuperB a discovery machine in LHC era ? Why >10 36 luminosity needed ? Is SuperB complementary to LHC ? Would not be LHCb enough to perform flavour studies ? How to built such a Factory ? Its is any interest of running at the  –charm threshold ? Few questions I’ll try to answer in this talk (See Christoph Schwanda talk) Is it important to have al least one beam polarized ?

4 “Relativistic path” “Quantum path” Crucial : Center-of-mass energy Crucial : Luminosity SuperB The quantum stabilization of the Electroweak Scale suggest that NP ~ 1 TeV LHC will search on this range - if NP particles are discovered at LHC we are able flavour structure of the NP to study the flavour structure of the NP NP scale - we can explore NP scale beyond the LHC reach  EW scale ~100GeV  TeV scale

5 B Y(4S) Possible also at LHCb Similar precision at LHCb Example of « SuperB specifics » inclusive in addition to exclusive analyses channels with    ’s  many Ks…

6 (polarized beams)  physics (polarized beams) B s at Y(5S) and threshold Charm at Y(4S) and threshold To be evaluated at LHCb Bs : Definitively better at LHCb

7 SuperB+Lattice improvements Determination of CKM parameters and New Physics Today  = ±  = ±  = ±  = 0.344± Improving CKM is crucial to look for NP

8 X X X- CKM X X X X The GOLDEN channel for the given scenario Not the GOLDEN channel for the given scenario, but can show experimentally measurable deviations from SM. X- CKM Let’s consider (reductively) the GOLDEN MATRIX for B physics X In the following some examples of « SuperB specifics » inclusive analyses channels with    many Ks…

9 Leptonic decay B  l SuperB - 75ab -1 M H ~ TeV for tan  ~30-60 tan  M(H + )(TeV) 2 ab ab ab -1 Exclusion 2  in case of no-signal Today some >2  discrepancy..

10 g s b b s ~ ~ ~ New Physics contribution (2-3 families) New Physcs in b  s transitions In the red regions the  are measured with a significance >3  away from zero 1 TeV Arg(  23 ) LR =(44.5± 2.6) o = (0.026 ± 0.005) Flavour-changing NP effects in the squark propagator  NP scale SUSY mass  flavour-violating coupling B  K*l + l  : A FB Y.-G. Xu et al., PRD74, (2006) 50ab -1

11 Determination of SUSY mass insertion parameter (  13 ) LL with 10 ab -1 and 75 ab -1 Importance of having very large sample >75ab -1 75ab -1 10ab -1 New Physcs in b  d transitions

12 Br(B  K  ) – Z penguins and Right-Handed currents   ~[20-40] ab -1 are needed for observation >>50ab -1 for precise measurement SM today If these quantities are <~10% deviations from the SM can be observed Only theo. errors

BR (    M 1/2 SuperB SO(10) MSSM LFV from PMNS LFV from CKM Lepton Flavour Violation in  decays Masurements and origin of LFV Discrimination between SUSY and LHT The ratio   lll /    is not suppressed in LHT by  e as in MSSM MEG sensitivity   e  ~ Preliminary results <

14 LFV analyses : novel additional handle on backgrounds Polarisation is -an important issue for LFV -opens the possibility of measuring (g-2) -….  anomalous moment (g-2) NP effects ~ Polarized beams Polarized beam is (SuperB specific) The anomalous tau momentum influence both the angular distribution and the  polarization. Measure the Re(F2) and Im(F2) of the (g-2) from factor < Under study

15 Charm physics at threshold D decay form factor and decay 1% Dalitz structure useful for  measurement 0.3 ab -1 Rare decays FCNC down to Consider that running 2 month at threshold we will collect 500 times the stat. of CLEO-C  ~1%, exclusive V ub ~ few % syst. error on  from Dalitz Model <1 o D mixing CP Violation in mixing could now addressed Strong dynamics and CKM measurements Charm physics using the charm produced at  (4S) Charm Physics Better studied using the high statistics collected at  Running at charm threshold (SuperB specific)

16 CP Violation in charm NOW SuperB CPV in D system negligible in SM CPV in D sector is a clear indication of New Physics !

17 SuperB can perform many measurements at <1% level of precision Precision on CKM parameters will be improved by more than a factor 10 NP will be studied (measuring the couplings) if discovered at LHC … and do not forget… SuperB could also a Super-Super  -charm factory, If we run at threshold. if NP is not (or “partially”) seen at TeV, SuperB is the way of exploring NP scales of several TeV (in some scenario several (>10 )TeV..) SuperB Discovery Potential and Complementary to LHC Unprecented precision Unique opportunity of LFV measurements, better if beam polarized. L= cm -2 sec -1  15ab -1 per year We need at least 75 ab -1  L= cm -2 sec -1 is the baseline option That’s is the factory we need !

18 Backup Material

19 The problem of particle physics today is : where is the NP scale  ~ 0.5, 1…10 16 TeV The quantum stabilization of the Electroweak Scale suggest that  ~ 1 TeV LHC will search on this range What happens if the NP scale is at TeV …naturalness is not at loss yet… Flavour Physics explore also this range We want to perform flavour measurements such that : - if NP particles are discovered at LHC we able flavour structure of the NP study the flavour structure of the NP NP scale - we can explore NP scale beyond the LHC reach luminosity to have measurable effects (anyhow) if NP particle with masses at the EW scale luminosity to have measurable effects (anyhow) if NP particle with masses at the TeV scale “Quantum path”

20 3 Chapters : Physics Case Detector Machine 444 pages 320 signers ~80 institutions Super Flavour FactorySuper Flavour Factory > cm -2 sec -1  >15ab -1 per year (today ~10 34 cm -2 sec -1 Babar~400fb -1 Belle~700fb -1 ) Background machine ~ to the present one Possibility of running at lower (  -charm) and higher energy (B s ) Special specific meeting to answer the IRC questions on physics and sharpen the physics case 49 signers ~24 institutions

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24 b  s penguin processes b  d  5  discovery possible (extrapolating from today) Many channels can be measured with  S~( ) dd s b WW B0dB0d t s s  K0K0 g s b b s ~ ~ ~ SuperB (*) theoretical limited Another example of sensitivity to NP : sin2  from “s Penguins”…

25 more..  and  combination exclusion plots in [ M(H + ), tan  tan 

26 LHC is not competitive (Re: both GPDs and LHCb). SuperB sensitivity ~10 – 50  better than NP allowed branching fractions. SuperB Sensitivity (75ab -1 ) BR e  beam polarization  Lower Background LHC(b) SuperB

27 MFV : Snowmass points on  SuperB with 75 ab -1, evaluation assuming the most conservative scenario about syst. errors LFV 1÷2 5  disc LFV from PMNS LFV from CKM Letpon MFV GUT models

28 Tau g-2 Start with the expt. with  <1 Make use of all the informations (total x-section,angular distribution, f-b asymmetry. Measure Re and Im parts

29 Spectroscopy

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32 SPS4 ruled out by present values of  s . SPS1a is the least favorable for flavour, but SuperB and only SuperB can observe 2  deviations in several observables MFV : SNOWMASS points

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