Stephen L. Olsen Seoul National University

1. Stephen L. Olsen Seoul National University From: http://luchins.com/what-were-they-thinking/insanely-bad-science/

2. 2008 Nobel Physics Prize Kobayashi & Maskawaexplained CP violation within the framework of the Standard Model, but required that the Model be extended to three doublets of quarks. These predicted, hypothetical new quarks have recently appeared in physics experiments. As late as 2001, the two particle detectors BaBarat Stanford, USA and Belle at Tsukuba, Japan, both detected CP violations independently of each other. The results were exactly as Kobayashi and Maskawa had predicted almost three decades earlier. Kobayashi Maskawa

3. Thread of this talk CP violation What is it? three doublets of quarks Why three? B mesons (BaBar & Belle experiments) Why B mesons? Stockholm

4. CP Violations Differences between matter & antimatter antimatter e- e+ P+ P- Different? hydrogen antihydrogen

5. Dilemma Laws of physics are very symmetric between matter & antimatter Nature is very asymmetric between matter & antimatter no antimatter here

6. Big-Bang Cosmology Then: a“no-hair” Universe matter = antimatter Now: people Only mass, electric charge & angular momentum no antipeople

7. Where are the antipeople? Need to study violations of “CP” symmetry

8. P = Parity(x,y,z)  (-x,-y,-z) Field (& rules) of football are parity symmetric Rules of baseball are not parity symmetric

9. Parity violation in physics-a nano history-

10. Parity Conservation in QM 1924: Atomic Wave functions are either even or odd. Laporte rule: dipole transitions connect evenodd (& not eveneven or oddodd) Otto Laporte 1902-1971 1927: Nature is Parity symmetric Laporte rule = Parity conservation Eugene Wigner 1902-1995

11. q-t puzzle 1949 1947 cloud chamber q+ photographic emulsion p+ t+ p+p+p- mt = 970 me (495 MeV) R.Brown et al., Nature 163, 47,82 (1949) q+ p+p0 mq ≈ mp/2 G.D. Rochester & C.C.Butler, Nature 160, 855 (1947) p has odd parity: P(p) = -p P(q+) =+ q+ q has even parity same mass, same lifetime, opposite P P(t+) = -t+ t has odd parity

12. Lee and Yang Phys Rev 104, 254 (1956) T.D.Lee C.N.Yang The q+ and t+ are the same particle, and its decays violate Parity. (now known as the K+ meson)

13. Parity violation discovered Co60 Ni60 e-n more electrons are emitted opposite to the nuclear spin direction than along it _ J J WU, Chien Shiung 1912-97 C. S. Wu et al., Phys. Rev. 105 (1957), 1415. The mirror image, where electrons are emitted parallel to the spin, doesn’t occur in Nature.

14. 1957 Nobel Prize WU, Chien Shiung Yang, Chen-Ning Lee, Tsung-Dao

15. P-violations in m- & m+ decay _ m- e-nndecays: e- emission opposite to spin direction preferred e+ m+ m- C is violated ParticleAntiparticle operator _ m+ e+nndecays: e+ emission parallelto spin direction preferred e- R L Garwin, L M Lederman and M Weinrich Phys. Rev. 105, 1415 (1957)

16. C x Pin m decay Mirrored antimatter case doesoccur in Nature Violated Violated CP CPsymmetry is OK m+ m- e+ e- “charge conjugate” mirror

17. CP in the neutral K meson system “Flavor” eigenstates CP(Hamiltonian?) eigenstates d s s d Short life-timeKShort Violate CP Long life-timeKLong

18. Christenson-Cronin-Fitch-Turlay Experiment (1964) Search for long-lived neutral kaon  p+p- p+ Long-lived neutral Kaons p-

19. Long-lived neutral Kp+p-(~2 parts in 103) Small CP violation (2x10-3) is seen J. H. Christenson et al., PRL 13 (1964), 138.

20. 1980 Nobel Prize No prizes for Christenson or Turlay

21. Incorporating CPV into QM

22. It‘s difficult to generate matter-antimatter differences in QM antiparticle process amplitude = A’ Particle process amplitude = A A’ A Time-reversal (t-t) CPT theorem: |A|2 = |A’|2 A & can differ at most by a complex phase A ‘

23. In QM, processes are  |Amp|2 A +fCP |A’|2 |A |2 = -fCP Still no matter-antimatter difference (even though there is a CPV phase) A’

24. Phase measurement needs interference (a second way to get to the same final state) A + X A +fCP |A + X|2 = | +X|2 A’ X -fCP A’ + X Still no matter-antimatter difference (even though there is a CPV phase & an interfering process) A’

25. X must have a “common” phase same phase for particle & antiparticle A A + X X |A + X|2 = | +X|2 A’ +fCP d Finally an matter-antimatter difference -fCP A’ + X A’

26. Matter-antimatter differences in QM • Amplitude needs a complex phase • Opposite signfor matter & antimatter • Need an interfering amplitude • Competing process  same final state • Interfering amplitude needs a “common” phase • Same sign for matter & antimatter

27. Incorporating a CPV phase into the Standard Model for Particle Physics

28. Quark mixing In the late 1973, there were 3 known quarks (u,d,s): K & M were convinced of the existence of a 4th quark: the hypothesized “charmed” quark (c): c q=+2/3 q=-1/3

29. In the Weak Int. the s & d quarks mix Mass (& flavor) eigenstates Weak-interaction eigenstates quark-flavor-mixing Matrix

30. The weak interaction quark doublets The CPV KLongp+p- decays correspond to this transition d d p - u KLong d p+ u s b Incorporate CP violation by making bcomplex?

31. : Not so simple a 2x2 matrix has 8 parameters unitarity: 4 conditions 4 quark fields: 3 free phases # of irreducible parameters: 1 Cabibbo angle Cabibbo 1st proposed quark flavor-mixing in 1963 N.Cabibbo Phys.Rev.Lett.10:531-533,1963

32. A complex phase cannot be includedin a 4-quark mixing matrix

33. Kobayashi-Maskawapaper (1973) Prog. of Theor. Phys. Vol. 49 Feb. 2, 1973 1 CP-violating phase 3 “Euler” angles 4 irreducible parameters

34. a 3x3 matrix has 18 parameters unitarity: 9 conditions 6 quark fields: 5 free phases # of irreducible parameters: 4

35. Why were K&M so sure of the c quark? In 1972, they both were in Nagoya, where Kiyoshi Niu was on the Expt’l Particle Physics Faculty 2mm K.Niu 2009: mD=1.87 GeV, mLc=2.29 GeV

36. History November 1974: Charmed (4th) quark “discovered” @ Brookhaven & SLAC J/y = c c 1976 Nobel prize M(e+e-) Ecm(e+e-) ppJ/y + X; J/ye+e- e+e- hadrons Phys.Rev.Lett.33:1404-1406,1974. Phys.Rev.Lett.33:1406-1408,1974 Kiyoshi Niu Sam Ting Burt Richter

37. More History February 1995: Top (5th) quark discovered @ Fermilab November 1977: Bottom (5th) quark discovered @ Fermilab  = b b ℓ+n _ _ pp t t X _ bc CDF: Phys.Rev.Lett.74:2626-2631,1995 Phys.Rev.Lett.39:252-255,1977. D0: Phys.Rev.Lett.74:2632-2637,1995

38. Now there are 6 quarksas required by Kobayashi-Maskawa CPV mechanism Mass (& flavor) eigenstates Weak-interaction eigenstates Related by a 3x3 mixing matrix

39. Cabibbo-Kobayashi-Maskawa6-quark mixing matrix CKM hierarchy u c t V≈1 Nearly (but not exactly) diagonal V≈0.2 V≈0.04 d s b V≈0.004

40. The KM phases are in the corners u f3 Vub b W+ f1 d Vtd t W+

41. The experimental challenge * Vub u Vtd d b t W+ W+ Measure a complex phase for bu or in td or, even better, both

42. Use B mesonsi.e. mesons containing the b- (5th) quark B0 = d B0 = b b d B0/B0 similar to K0/K0

43. Why B mesons? _ • B0 B0 mixing is strong 2 ps B0 B0 B0 N(B) – N(B) -------------------------------- N(B) + N(B) _ _ eiDmt _ _ B0 B0 _ If you start with a B0, it changes to a B0 (& vice versa) with a ¼-period (1/Dm≈2ps) that is comparable to the B0 lifetime (≈1.5ps) • b quarks are sensitive to CPV phases • - they probe the corners of the CKM matrix

44. Sanda, Bigi , Carter technique for f1 _ Interfere BfCPwith BBfCP J/y Vcb B0 KS  + V*2 td mixing provides the “common” phase J/y sin2f1 V* Vtb Vcb td B0 B0 eiDmt B0 KS V* Vtb td td Phys.Rev.D23:1567,1981 Nucl.Phys.B193:85,1981

45. What do we measure? _ “Flavor-tag” decay (B0 or B0 ?) _ B0 & B0 in an “entangled” quantum state J/ e e fCP Asymmetric energies KS z B - B B + B sin21 more B tags t t z/cbg (tags) more B tags t=0 This is for fCP=+1; for fCP=-1, the asymmetry is opposite

46. The Belle experiment at KEK

47. KEK laboratory in Japan Tsukuba Mountain KEKB Collider KEK laboratory

48. elle A magnetic spectrometer based on a huge superconducting solenoid

49. _ Find B0(B0?)J/y KS decays p+p- B0(B0?) J/ Ksevent m+m- Tracking chamber only

50. Check the other tracks to see if the accompanying meson is a B0 or a B0 ? ? ? ? ? ?