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Super Flavour Factory How and Why to construct an high luminosity e + e - Super(B)(Flavour) Factory Giovanni Calderini (LPNHE) Achille Stocchi (LAL) Alessandro Variola (LAL) Séminaire LAL 25 Avril 2007 444 pages 320 signers ~80 institutions
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Giovanni will show which detector we need for fully exploit the physics data coming out from this machine and to perform the physics studies Alessandro will show why “it is possible” to construct an e + e - asymmetric collider with a luminosity of ~10 36 cm -2 sec -1 ~15 ab -1 /per year (100 times what we have now) and a low background in the interaction region : a Super Flavour Factory (SFF) I want to discuss that such SFF is essential for the purpose of studying New Physics in the flavour sector in the LHC era
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Today-2007 Babar (~400fb -1 ) / Belle(700fb -1 ) End-2008 2ab -1 SuperB 75ab -1 B-factories SuperB LHCb 2007 ≥2012 1fb -1 ~ 1M BB 1ab -1 ~ 1G BB ~10 34 cm -2 sec -1 ~10 36 cm -2 sec -1 Evidence for D 0 mixing Observation of direct CP violation in B Observation of CPV in B meson system Observation of B K (*) ll Hint at new physics: CPV in B Ks Evidence for direct CPV in B K + Discovery of X(3872) Observation of b d Evidence for B Some achievements at B factories
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B factories have shown that a variety of measurements can be performed in the clean environment. By doing the work of extrapolating the existing measurements and the ones which will be possible with more statistics we observe that : - Several measurements are statistically limited and so it is worthwhile to collect >50ab -1 - The systematic errors are very rarely irreducible and can almost on all cases be controlled with control samples. On top of it detector improvements can be crucial for some analyses. B D D prim. sec ter. B events continuum events Thanks to better vertex resolution we can distinguish on vertex requirements B vs continuum events ( ~factor 5 background rejection) Not yet included in the extrapolations
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Experimental Reach
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The angle Based on the present “savoir faire” t(ps) 535M Golden B 0 J/ K 0 sin2 gives the best constraint on plane and the error can still be reduced Example other modes : B 0 D 0 h 0 Babar SuperB will be able to make complementary measurements (beyond J K 0 ) that help to ensure that the theoretical uncertainties are under control and to control them on data Important points : - We know how to perform these analyses - Very significant improvement from now 2ab -1 Superb luminosity SuperB
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The angle Isospin analyses performed at the B-factories @ 10 0 Some very important measurements start to be possible only now with about 0.5ab -1 modes consistent with no CP violation eff ~90 o (0/180) o Important measurement because it gives the contributions of Penguins diagram Each of analysis will be allow to get ( ~2 degrees It allow consistency checks and to control theoretical uncertainties on data ~1 o possible SuperB (*) theoretical limited
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The angle Many independent methods GLW, ADS, Dalitz, with many different decay channels ~1 o possible New D 0 decays starting to be explored BaBar Error vs D CP statistics 750pb -1 ( 4-5) o 20fb -1 (< 1) o Bondar Poluektov hep-ph/0510246 SuperB The model error can be reduced by running at threshold Best measurements from Dalitz analysis with D 0 K s
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Many channels can be measured with S~(0.01-0.04) sin2 from “s Penguins”… SuperB (*) theoretical limited dd s b WW B0dB0d t s s K0K0 g s b b s ~ ~ ~
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Exp. likelihood BABAR+BELLE BR(B → τ ν) = (1.31 ± 0.48)10 -4 leptonic decay B l Br(B up to 3-4% (below limited by systematics) Br(B can be measured with the same precision not limited by syst. Milestone : First leptonic decay seen on B meson SuperB (+) systematically limited BR(B → τ ν) = (0.85 ± 0.13)10 -4 SM expectation First test can be done, not yet precise
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Radiative B decays - many measurements on B s - measurements of Br on B - measurement of A CP on exclusive and inclusive modes Significant improvement on b d A CP in inclusive decay at ~0.5% ! (SM~0.5%) -Measurements of Br done -We start to perform A FB measur. CP and FB asymetries in sll exclusive and inclusive decays at few per cent (+) systematically limited(*) theoretically limited SuperB
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Could the SuperB be a Super Flavour Factory ? Which is the interest ?
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Charm physics at threshold D decay form factor and decay constant @ 1% Dalitz structure useful for measurement 0.2 ab -1 Rare decays FCNC down to 10 -8 Consider that running 1 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 should be now better addressed String dynamics and CKM measurements Charm physics using the charm produced at (4S) Charm Physics Better studied using the high statistics collected at (4S) @threshold(4GeV) HFAG preliminary
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In summary.. 1)superb measurements related to tree level/ ~tree level (some depending upon LCQD calculations ) (DK), V ub /V cb 2) superb measurements very sensitive to NP Physics sin(2 ) (Peng.) A FB (X s l + l - ), A FB (K* ), A CP (K* ), A CP (s ), A CP (s+d) ) B K (*), LFV 3) several quantities depending upon LCQD calculations If Lattice QCD Calculations improve as the related experimental quantities, these measurements will be extremely powerfull Br(B ( , ) Br(B l ), Br(B D ) 4) <1% UT Fits for New Physics search (all the measurements mentioned before + others..) 5) charm measurements 6) Specific run at the (5S)
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2 – 3%4 - 5%5.5 - 6.5%11% 3 – 4%---- 13% 0.5% (5% on 1- ) 1.2% (13% on 1- ) 2% (21% on 1- ) 4% (40% on 1- ) B → D/D*lν 0.5 – 0.8 % (3-4% on ξ-1) 1.5 - 2 % (9-12% on ξ-1) 3% (18% on ξ-1) 5% (26% on ξ-1) ξ 1 – 1.5%3 - 4%4 - 5%13% 1 – 1.5%2.5 - 4.0%3.5 - 4.5%14%fBfB 1%3%5%11% 0.1% (2.4% on 1-f + ) 0.4% (10% on 1-f + ) 0.7% (17% on 1-f + ) 0.9% (22% on 1-f + ) 1-10 PFlop Year 60 TFlop Year 6 TFlop Year Current lattice error Hadronic matrix element Estimates of error for 2015
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Phenomenological Impact
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= 0.163 ± 0.028 = 0.344± 0.016 about 10 times better (not all measurements yet included…) = ± 0.0028 = ± 0.0024 SuperB+Lattice improvements In SM Today
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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 2-3..10 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 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
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Two crucial questions : Can NP be flavour blind ? Can we define a “worst case” scenario No : NP couples to SM which violates flavour Yes : the class of model with Minimal Flavour Violation (MFV), namely : no new sources of flavour and CP violation and so : NP contributions governed by SM Yukawa couplings. Today (MFV) > 2.3 0 @95C.L. NP masses >200GeV SuperB (MFV) >~6 0 @95C.L. NP masses >600GeV As soon as you move from the worst case scenario…
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Higgs-mediated NP in MFV at large tan Similar formula in MSSM. M H (TeV) tan 2ab -1 M H ~0.4-0.8 TeV for tan ~30-60 SuperB M H ~1.2-2.5 TeV for tan ~30-60 B Dl Similar to B B l Excl. 2
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In the red regions the are measured with a significance >3 away from zero 1 10 g s b b s ~ ~ ~ New Physics contribution (2-3 families) With the today precision we do not have 3 exclusion 1 10 -1 10 -2 In this case the main constraints are b s ACP(b s ) Today we would have magenta contour covering all the space ACP magenta Br(sg) green Br(sll) cyan All constr. blue MSSM+generic soft SUSY breaking terms Flavour-changing NP effects in the squark propagator NP scale SUSY mass flavour-violating coupling
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Re ( d 13 ) LL vs Im ( d 13 ) LL with present disagreement Constraint from m d Constraint from sin2 cos2 Constraint from sin2 All constraints Re ( d 13 ) LL vs Im ( d 13 ) LL superB if disagreement disapper. SM Due to the actual disagreement between V ub and sin2 we see a slight hint of new physics NP at high significance ! NP scale at 350 GeV
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= 350 GeV
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physics just discussed this morning by M. Roney 10 7 BR ( M 1/2 These evaluations do not agree with those given in SuperKEKB : discussion undergoing LFV from CKM LFV from PMNS SuperB LVF and Littlest Higgs Model
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SFF 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 if NP is not seen at the TeV by LHC, SFF is the way of exploring NP scales of the several TeV (in some scenario several (>10 )TeV..) Summary … and do not forget… SFF is also a Super-Super -charm factory…
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We need to go on in measuring precisely many different quantites A CP (B X ) A FB (B Xll) CPV in CF and DCS D decays Br( ) …… CKM angles r and Dl |V ub |,|V cb | radiative decays : Br(B , K* ) many other measurements… Adjusting the central values so that they are all compatible Could be a nightmare…. I’m sure..will be a dream… Keeping the central values as measured today with errors at the SuperB
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BACKUP MATERIAL
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Br ~ |V ub | 2 in a limited space phase region… Using Babar E l, (X s ElEl Progress on V ub.. Inclusive : improving analyses and improving the control of the theory vs cuts untagged analysis is the most precise Exclusive : we start to have quite precise analysis of Br vs q 2 Important that we measure at high q 2 where Lattice QCD calculates better. B l B X u l Confirming disagreement…
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Precision measurements of |V cb | limiting factor F(1) Inclusive V cb still progress… BaBar/CLEO/CDF/DELPHI Kinetic scheme here we extract : B D*l Essential point is to control /“measure” the effects of strong interaction Same for exclusive.. Study on charm sector help in the understanding of strong dynamics (Babar) Events/0.5
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Rare decays : SuperB can cover all channels mentionned but B s Unless we perform a long run at the U5S CP asymetries in radiative exclusive and inclusive decays at a fraction of 1% B at 4% CP and FB asymetries in sll exclusive and inclusive decays at few per cent B at 5% 13% 2fb1 Only bb back. Linear fit Transv amplit. ?? 18% for 50ab-1 in Jeff
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5 new free parameters C s, s B s mixing C d, d B d mixing C K K mixing Today : fit possible with 10 contraints and 7 free parameters ( C d, d,C s, s, C K ) Constraints Parametrizing NP physics in F=2 processes F=2 Fit in a NP model independent approach CdCd dd C s ss CKCK D X V ub /V cb XX mdmd XX ACP J X X ASLXX XX ACHXXXX s s XX msms X KK XX In future : ACP J ~XX ASL(Bs) XX D s K) X Tree processes 1 3 family 2 3 family 1 2 familiy No new physics C=1 =0
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Model Indep. Analysis in B=2 C = 1.24 ± 0.43 = (-3.0 ± 2.0) o C = ± 0.031 = (± 0.5) o
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* Integrated quantities A SL and A CH at less than 0.5% Even a run at 1ab -1 will give less 1% error. Run at the (5S) Possible with the same luminosity BB from B*B produced in C=+1 after B B decay some sensitivity to S term in time integrated CP asym. BdBdBdBd B d *B d B d *B d * BsBsBsBs B s *B s B s *B s * B d,B + produced with factor 6 less than at (4S) Dominated contribution ~95% For more details see E. Baracchini et al. hep-ph/0703258 * B d (B + ) and B s are produced and can be separated
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Bit more on B s C(Bs) ~ 0.026 Bs) ~ 1.9 o Today at Superb
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m d magenta A SL green cyan All constr. blue New Physics contribution (1-3 families) 1 10 1 10 -1 | 13 | LL Example on how NP parameters can be measured Today SuperB In the red regions the are measured with a significance >3 away from zero With the today precision we do not have 3 exclusion
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SuperB will probe up to >100 TeV for arbitrary flavour structure! Let’s be more quantitative How to read this table, two examples. At the SuperB we can set a limit on the coupling at The natural coupling would be 1 we can test scale up to All this number are a factor ~10 better than the present ones
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