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Parity-Violation and Strange Quarks: Theoretical Perspectives

Parity-Violation and Strange Quarks: Theoretical Perspectives. M.J. Ramsey-Musolf. Hall A Collaboration Meeting: December ‘05. Outline. Historical Context Strange quarks: what have we learned? Other aspects of parity-violation and QCD: radiative corr, N to D , gg.

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Parity-Violation and Strange Quarks: Theoretical Perspectives

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  1. Parity-Violation and Strange Quarks: Theoretical Perspectives M.J. Ramsey-Musolf Hall A Collaboration Meeting: December ‘05

  2. Outline • Historical Context • Strange quarks: what have we learned? • Other aspects of parity-violation and QCD: radiative corr, N to D , gg

  3. 1970’s SLAC DIS Standard Model Atomic PV sin2qW ~ 10% Prehistory 1980’s Mainz 8Be PV eq couplings MIT 12C ~ 10% PV: Past, Present, & Future

  4. Modern Era 1990’s MIT GsE,M ~ few % JLab GA & rad corrections Mainz rn(r) APV sin2qW ~ 1% Anapole moment 2000’s SLAC Moller Standard Model & beyond JLab QWeak sin2qW < 1% APV Anapole moment JLab GAND Mainz HWI (DS=0): dD , Ag VVCS: An PV: Past, Present, & Future

  5. Future 2010’s JLab DIS-Parity Standard Model & beyond Moller (2) sin2qW < 1% 2020’s NLC Moller (3) sin2qW < 0.1% PV: Past, Present, & Future

  6. qq Mesons • What is the internal landscape of the nucleon? • What does QCD predict for the properties of nuclear matter? • Where is the glue that binds quarks into strongly-interacting particles and what are its properties? How does QCD make hadronic matter? PV & strange quarks Hybrids 2.5 exotic nonets 2.0 Tribble Report GPD’s: “Wigner Distributions” (X. Ji) mq-dependence of nuclear properties 1.5 1.0 L = 0 1 2 3 4 Pentaquark, Q+ Gluonic effects Quarks, Gluons, & the Light Elements Lattice QCD

  7. Effects in are much less pronounced than in , OZI violation Strange Quarks in the Nucleon:What have we learned? Jaffe ‘89 Hammer, Meissner, Drechsel ‘95 • Dispersion Relations • Narrow Resonances • High Q2 ansatz

  8. Effects in are much less pronounced than in , Strange Quarks in the Nucleon:What have we learned? HAPPEX SAMPLE MAINZ G0 K. Aniol et al, nucl-ex/0506011

  9. Theory: how do we understand dynamics of small ss effects in vector current channel ? Challenge to understand QCD at deep, detailed level Unknown constants Strange Quarks in the Nucleon: What have we learned? • Strange quarks don’t appear in the conventional Quark Model picture of the nucleon • Perturbation theory is limited QCD / ms ~ 1 No HQET mK / c ~ 1/2 PT ? • Symmetry is impotent Js = JB - 2 JEM, I=0

  10. Strange magnetism O (p2) mq -independent What PT can (cannot) say Ito & R-M; Hemmert, Meissner, Kubis; Hammer, Zhu, Puglia, R-M The SU(3) chiral expansion for mB :

  11. Strange magnetism What PT can (cannot) say Ito & R-M; Hemmert, Meissner, Kubis; Hammer, Zhu, Puglia, R-M The SU(3) chiral expansion for mB : O (p3) non-analytic in mq unique to loops leading SU(3)

  12. Strange magnetism What PT can (cannot) say Ito & R-M; Hemmert, Meissner, Kubis; Hammer, Zhu, Puglia, R-M The SU(3) chiral expansion for mB : O (p4) non-analytic in mq (logs)

  13. M = diag (0,0,1) Strange magnetism What PT can (cannot) say Ito & R-M; Hemmert, Meissner, Kubis; Hammer, Zhu, Puglia, R-M The SU(3) chiral expansion for mB : O (p4) SU(3) Sym breaking Two-deriv operators + 1/mN terms

  14. Strange magnetism O (p2) O (p3) O (p4) What PT can (cannot) say Ito & R-M; Hemmert, Meissner, Kubis; Hammer, Zhu, Puglia, R-M The SU(3) chiral expansion for mB : • converges as (mK / Lc )n • good description of SU(3) SB

  15. Strange magnetism What PT can (cannot) say Ito & R-M; Hemmert, Meissner, Kubis; Hammer, Zhu, Puglia, R-M O (p4) octet only Implications for ms : O (p3,p4) loop only O (p2) singlet O (p4) singlet O (p2,p4) octet • Near cancellation of O (p2,p4) octet & loop terms • Exp’t: b0 + 0.6 b8 terms slightly > 0 • Models: different assumptions for b0 + 0.6 b8 terms

  16. Happex projected G0 projected SAMPLE 2003 Lattice QCD theory Dispersion theory Chiral perturbation theory “reasonable range” for slope Q2 -dependenceof GsM

  17. Strange magnetism O (p4), unknown LEC O (p4), octet O (p3), parameter free O (p4) , cancellation What PT can (cannot) say

  18. Strange magnetism O (p4), unknown LEC O (p3,p4), loops O (p4), octet What PT can (cannot) say

  19. Strange electricity What PT can (cannot) say Ito & R-M; Hemmert, Meissner, Kubis; Hammer, Zhu, Puglia, R-M O (p3): non-analytic in mq (loops) + mq -independent cts The SU(3) chiral expansion for rs :

  20. Strange electricity O (p3), unknown LEC O (p3), loops O (p3), octet What PT can (cannot) say Ito & R-M; Hemmert, Meissner, Kubis; Hammer, Zhu, Puglia, R-M The SU(3) chiral expansion for rs :

  21. Loops “vs” poles • Dispersion Theory  • Models Unknown constants • Lattice QCD No dichotomy: kaon cloud is resonant Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants

  22. Dispersion Theory  • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Kaon cloud Not sufficient to explain GsE,M

  23. Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Kaon cloud models Not reliable guide to sign or magnitude of GsE,M

  24. Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Chiral models Implicit assumptions about b0 , c0 , b0r , …

  25. • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Disconnected Insertions ~ +… Still a challenge

  26. Strong interaction scattering amplitudes e+ e- K+ K-, etc. Contributing States Jaffe Hammer, Drechsel, R-M Dispersion theory

  27. Strong interaction scattering amplitudes e+ e- K+ K-, etc. Jaffe Hammer, Drechsel, R-M Dispersion theory

  28. Strong interaction scattering amplitudes e+ e- K+ K-, etc. Jaffe Hammer, Drechsel, R-M Dispersion theory

  29. Unitarity All orders • Naïve pert th’y O (g2) • Kaon cloud models • Unitarity violating Dispersion theory Hammer & R-M

  30. Unitarity • S-quarks are not inert • Non-perturbative effects dominate (LEC’s) • Kaon cloud is resonant All orders res Dispersion theory Hammer & R-M

  31. Kaon cloud Dispersion theory Hammer & R-M • Kaon cloud not dominant • Not sufficient data to include other states

  32. See also Leinweber et al Lattice Computations Dong, Liu, & Williams (1998) Lewis, Wilcox, Woloshyn (2003) • Quenched QCD • Wilson fermions • 100 gauge configurations • 300-noise estimate/config • Quenched QCD • Wilson fermions • 2000 gauge configurations • 60-noise estimate/config

  33. Charge Sym mB exp’t Disconn s/d Lattice Computations Leinweber et al

  34. Charge Symmetry s/d loop ratio mdloop:Lattice ms:kaon loops • Charge symmetry • Measured octet m.m.’s • Lattice mdloop • Kaon loops Leinweber et al Lattice Computations

  35. • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Disconnected Insertions ~ +… Still a challenge

  36. dRA “Reasonable range”: lattice & disp rel Combining PT, dispersion theory, & lattice QCD SAMPLE

  37. Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Chiral models Implicit assumptions about b0 , c0 , b0r , …

  38. b0,8=0 • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Jido & Weise No Implicit assumptions about b0 , c0 , b0r , …

  39. ms > 0 • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Jido & Weise Implicit assumptions about b0 , c0 , b0r , …

  40. ~ s in g.s. s in excited state (p wave) • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Zou & Riska (QM) Give wrong sign ??? Implicit assumptions about b0 , c0 , b0r , …

  41. ms > 0 ~ s in g.s., (s wave) s in excited state • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Zou & Riska (QM) Give right sign ??? Implicit assumptions about b0 , c0 , b0r , …

  42. ms < 0  • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Zou & Riska (QM) t-channel resonances? Implicit assumptions about b0 , c0 , b0r , …

  43. ms > 0  • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Chiral Quark Soliton Implicit kaon cloud + b3-7… resonances ? Implicit assumptions about b0 , c0 , b0r , …

  44. ms < 0  • Dispersion Theory • Models Unknown constants • Lattice QCD Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? It’s all in the low energy constants Chiral Quark Soliton Implicit kaon cloud + b3-7… resonances ? Implicit assumptions about b0 , c0 , b0r , …

  45. Unknown constants Js = JB - 2 JEM, I=0 Strange Quarks in the Nucleon: What have we learned? New puzzles: higher Q2-dependence

  46. Radiative Corrections & the Hadronic Weak Interaction • GAe • N !D • PV p photo- and electro-production (threshold) • Vector analyzing power (gg)

  47. Models for s Radiative corrections at Q2=0.1 (GeV/c)2 • s-quarks contribute less than 5% (1s) to the proton’s magnetic form factor. • proton’s axial structure is complicated! R. Hasty et al., Science 290, 2117 (2000).

  48. “Anapole” effects : Hadronic Weak Interaction + Nucleon Green’s Fn : Analogous effects in neutron -decay, PC electron scattering… Axial Radiative Corrections

  49. Zhu et al. Zhu, Puglia, Holstein, R-M (cPT) Maekawa & van Kolck (cPT) Riska (Model) “Anapole” Effects Hadronic PV Can’t account for a large reduction in GeA

  50. Suppressed by ~ 1000 Nuclear PV Effects PV NN interaction Carlson, Paris, Schiavilla Liu, Prezeau, Ramsey-Musolf

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