1 / 82

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.

sun
Download Presentation

Parity-Violation and Strange Quarks: Theoretical Perspectives

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  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

More Related