CP Violation: SM & Beyond

Transcription

1 CP Violation: SM & Beyond Amarjit Soni HET,BNL INT, Seattle, March 07 1

2 OUTLINE Status of SM CKM paradigm Why is precision of paramount importance? Possible signs of BSM-CP-odd phase? Illustrative candidates for BSM Prospects for needed precision. BSMs & EDMs Summary 2

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4 1 st Hints of confirmation Of CKM-CP violation Atwood&A.S, hep-ph/ Most bands due To theory errors 4

5 Youngjoon Kwon 5

6 Youngjoon Kwon 6

7 Youngjoon Kwon 7

8 Celebration I: SPECTACULAR PERFORMANCE of 2 Machines! (each several times better than design lumi!!) EDM@INT...A.Soni 8

9 Youngjoon Kwon 9

10 Celebration II: A beautiful theory paper which not only suggested the need for the 3 rd family, before the discovery of charm and tau, its framework is vindicated in detail through exhaustive experimentation ~35 years later!! EDM@INT...A.Soni 10

11 And of course we must not forget the C! 11

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13 Should 10% tests be good enough? Vital Lessons from our past LESSON # 1: Remember ε K Its extremely important to reflect on the severe and tragic consequences if Cronin et al had decided in 1963 that O(10%) searches for ε were good enough! Imagine what an utter disaster for our field that would have been. Note also even though CKM-CP-odd phase is O(1) (as we now know) in the SM due to this O(1) phase only in B-physics we saw large effects in K (miniscule), D(very small), t(utterly negligible). Understanding the fundamental SM parameters to accuracy only of O(10%) would leave us extremely vulnerable..improvement of our understanding should be our crucial HOLY GRAIL! EDM@INT...A.Soni 13

14 Lesson #2 Remember m ν Just as there was never any good reason for m ν =0 there is none for BSM-CP-odd phase not to exist m 2 ~1eV 2 ~ > m 2 ~10-4 ev 2 97 Osc. Discovered. Similarly for BSM-CP-odd phase, we may need to look for much smaller deviations than the current O(10%) demanding precision from expt. & theory EDM@INT...A.Soni 14

15 Tantalizing (possible) signs of a BSM-CP phase EDM@INT...A.Soni 15

16 Grossman & Worah PLB 97; London and A.S. PLB 97 16

17 Testing the SM with penguin dominated modes S = C MD O(λ 2 ), expect C MD ~ O(1) Sigificant deviation from this expectation is a sign of BSM-CP-odd phase! Unfortunately C MD is a (QCD) model dependent coefficient EDM@INT...A.Soni 17

18 CLEANEST MODES 18

19 19 Youngjoon Kwon; c also Matthias Neubert

20 Current situation Reference value reduced to 0.68±0.03 Average value from penguin modes increased to 0.52±0.05 New Physics in penguin processes? Deviation reduced to 2.8σ Matthias Neubert 20

21 However, call from Stockholm will demand conclusive evidence for S>0.10 in several separate modes 21

22 Although, at the moment it is not a conclusive effect, it may well become a serious blunder on the part of experimentalists to ignore it! We can try learn some lessons from history. It is extremely important to understand that basically it is a very good test of the SM. EDM@INT...A.Soni 22

23 <-`Leon s shoulder EDM@INT...A.Soni 23

24 Christenson,Hicks,Lederman,Limon,Pope & Zavattini PRD 8,

25 Sensitivity to new CP phases Estimated error in the measurement of time dependent CP violation Discovery region with 50 ab -1 A NP /A SM 2 Masa Yamauchi θ new physics EDM@INT...A.Soni 25

26 Proposed schedule Integrated luminosity (ab -1 ) L peak ~ SuperKEKB ~ Belle is here. 0.58ab -1 Crab cavity installation 2 yr shutdown for upgrade ~10B BB and τ + τ every year Calendar year EDM@INT...A.Soni 26 Masa Yamauchi

27 Mikihiko EDM@INT...A.Soni CKM06; c also Matthias Neubert 27

28 Mikihiko CKM06 ; c also Matthias Neubert EDM@INT...A.Soni 28

29 Mikihiko CKM06 EDM@INT...A.Soni 29

30 B-Factory Signals for a WED (Agashe,Perez,Soni,hepph/ (PRL); ) RS1 with a WARPED EXTRA DIMENSION (WED) provides an elegant solution to the HP In this framework, due to warped higherdimensional spacetime, the mass scales (i.e. flavors) in an effective 4D description depend on location in ED. Thus, e.g. the light fermions are localized near the Plank brane where the effective cut-off is much higher than TeV so that FCNC s from HDO are greatly suppressed.. The top quark,on the other hand is localized on the TeV brane so that it gets a large 4D top Yukawa coupling. EDM@INT...A.Soni 30

31 Key features of WED Amielorating the Flavor Problem. This provides an understanding of hierarchy of fermion masses w/o hierarchies in fundamental 5D params. Thus solving the SM flavor problem. Flavor violations Most flavor-violating effects arise due to the violation of RS- GIM mechanism by the large top mass. This originates from the fact that (t,b) L is localized on the TeV brane. EDM@INT...A.Soni 31

32 Basics of the framework 32

33 NP Contributions due WED There are essentially 3 types of top quark dominated FCNC contributions: i) Contributions to FCNC processes arise from a relatively large dispersion in the doublets 5D masses, specifically large coupling of (t,b) L to gauge modes due to heaviness of the t. EDM@INT...A.Soni 33

34 ii) Contributions to FCNC processs (mostly semi-leptonic) These arise from contribution of i) and mixing between the zero and KK states of the Z due to EWSB. iii) Contribution to radiative B-decays via dipole operators arise from large 5D Yukawa required to obtain m t EDM@INT...A.Soni 34

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36 Notable FCNC characteristic (see table) 36

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38 Contrasting B-Factory Signals from WED with those from the SM 38

39 Two Higgs Doublet Models with Natural Flavor Conservation 39

40 Two Higgs Doublet Model For the top quark (Das and Kao 96) 40

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50 Setting the bar for future Kaon experiments Present (E787/949): BR(K + π νν) = events Mean: E787/949 Current constraint on ρ,η plane? 100 events Mean: SM EDM@INT...A.Soni 50 M.Piccini

51 Rare Kaon Decays and CKM matrix CP K πνν decay is sensitive to V td V td determination independent on B 0 -B 0 mixing Theoretically the cleanest processes in K and B physics Standard Model predictions BR(K + π + νν) ( ) V cb 4 [ση 2 +(ρ c -ρ) 2 ] (8.0 ± 1.1) 10 BR(K L π 0 νν) ( ) V cb 4 η 2 (3.0 ± 0.6) EDM@INT...A.Soni 51 Piccini NA48/3 (Expt CERN

52 B K For past ~decade error has stood at ~17% EDM@INT...A.Soni 52

53 OVER 20 years of B K Bernard & A.S. Lattice 88 EDM@INT...A.Soni 53

54 C.Dawson Lack of chiral symmetry becomes a fine-tuning problem! EDM@INT...A.Soni 54

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57 Expectations from the lattice for B K EDM@INT...A.Soni 57

58 Continuing Quest for for ~quarter century Current Status & Outlook 58

59 K->ππ Blum etal(rbc)hep-lat/

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64 Source of significant quench pathlogy Quench Approx by definition ignores vac. Loops Q 6 ~ (8,1) has quark loops Recall Q 8 ~ (8,8) Even a slight mistreatment messes up the crucial (8,1) since as m q -> 0, Q 6 should ->0 but Q 8 -> constant Proper treatment of Q 6 demands dynamical Lattice simulations EVEN for DWQ!! EDM@INT...A.Soni 64

65 RBC-UKQCD Dynamical 2+1 flavors DWF (24 3 X64X16) after 10 years, March 07 EDM@INT...A.Soni 65

66 Mawhinney at DWF after 10 years 66

67 Mawhinney at DWF after 10 years 67

68 Mawhinney at DWF after 10 years 68

69 BSM implications for edm s EDM@INT...A.Soni 69

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74 Summary & Outlook Asym. B factories + Lattice -> KM phase is the dominant contributor to observed CP Search for BSM-CP-odd phase imposes greater demands of precision on expt. & on theory S test of the CKM-paradigm extremely tantalizing with ~2.5 σ deviations. Given that such effects occur quite naturally in most BSMs the expt. situation needs to be clarified at the highest priority. Most of the BSMs also exhibit nedm ~ ecm & tedm ~ ecm; should pursue both vigorously. EDM@INT...A.Soni 74