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Delia Hasch

Delia Hasch. TMDs & friends from lepton scattering -experimental overview-. outline:. introduction: some reminders… status Sivers DF Collins DF azimuthal dependence of unpolarised xsection the ‘soon to come’ menu.

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Delia Hasch

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  1. Delia Hasch TMDs & friends from lepton scattering-experimental overview- outline: • introduction: some reminders… • status Sivers DF • Collins DF • azimuthal dependence of unpolarised xsection • the ‘soon to come’ menu INT workshop on “3D parton structure of the nucleon encoded in GPDs & TMDs”,Seattle, Sept. 14-18 2009

  2. 1/7/07@ 1:09:56 am experimental prerequisites main players in the game: • longitudinally polarised d • long.+transv. polarised p • ~full hadron ID 27 GeV e+/- till 2007 • long.+transv. polarised effective d • long.+transv. polarised effective p • ~full hadron ID 190 GeV m CLAS: long. polarised effective p HallA: long.+transv. polarised effective n ≈6 GeV e- HALL A

  3. deep-inelastic scattering factorisation: Q2 1 GeV2

  4. hadron production @RHIC p0 and jet production xsection vs pT compared to theory

  5. hadron production no SIDIS xsection measurements @HERMES and CLAS  pion multiplicities compared to theory: DSS:fragmentation functions from combined NLO analysis of single-inclusive hadron production in e+e-, pp and SIDIS p+ [deFlorian,Sassot,Stratmann arXiv:0708.0769] p-

  6. hadron production no SIDIS xsection measurements @HERMES and CLAS  pion multiplicities CLAS p0 compared to HERMES and to DSS:

  7. SIDIS cross section sXY beam:target: lSL,ST

  8. SIDIS cross section

  9. leading-tw distribution functions chiral-odd pdf & FF ‘Amsterdam notation’

  10. leading-tw distribution functions on the menu today

  11. leading-tw distribution functions @leading twist, integrated over pT: ‘transversity’

  12. leading-tw distribution functions @leading twist, no pT integration: ‘Boer- Mulders’ ‘Kotzinian- Mulders’ ‘transversity’ ‘pretzelosity’ ‘Sivers’

  13. asymmetries and amplitudes + …

  14. asymmetries and amplitudes Collins moment Sivers moment  taking also into account of the unpolarised cross section

  15. spin-orbit correlations Sivers function: [Matthias Burkardt] a non-zero Sivers fct. requires non-zero orbital angular momentum !

  16. ep  hX Sivers amplitudes [PRL94(2005)] first observation of T-odd Sivers effect in SIDIS u quark dominance suggests sizable u quark orbital motion

  17. ep  hX Sivers amplitudes [arXiv:0906.3918] final data set! first observation of T-odd Sivers effect in SIDIS u quark dominance suggests sizable u quark orbital motion

  18. Sivers amplitudesforp clear rise with z rise at low Ph T plateau at high Ph T p+ dominated by u-quarks  u-quark Sivers DF < 0 [arXiv:0906.3918]

  19. rise at low Ph T plateau at high Ph T Sivers amplitudesforp clear rise with z p+ dominated by u-quarks  u-quark Sivers DF < 0 cancellation for p- : u and d quark Sivers DF of opposite sign [arXiv:0906.3918]

  20. Sivers amplitudesforp [PLB673(2009)] clear rise with z rise at low Ph T plateau at high Ph T p+ dominated by u-quarks  u-quark Sivers DF < 0 cancellation for p- : u and d quark Sivers DF of opposite sign all asymmetries on deuterium target ≈ zero! [arXiv:0906.3918]

  21. Sivers amplitudesforp proton data ? [arXiv:0906.3918]

  22. Sivers distribution for valence quarks transverse SSA of pion cross section difference: Sivers distribution for u-valence is large & <0 or Sivers distr. for d- valence >> u-valence (unlikely)

  23. ep  KX rise at low Ph T plateau at high Ph T Sivers: kaon amplitudes clear rise with z slightly positive

  24. Sivers: the “kaon challenge” p+/ K+ production dominated by scattering off u-quarks

  25. Sivers: the “kaon challenge” p+/ K+ production dominated by scattering off u-quarks • &  non-trival role of sea quarks • convolution integral in numerator depends on kT dependence of FF • differences in dependences on kinematics integrated over

  26. role of sea quarks strange sea pdf [PLB666(2008), 446] • differences biggest in region where strange sea is most different from light sea

  27. see talk by A. Prokudin fragmentation function  e+e- extracting the Sivers function use parametrisations of unpolarised fragmentation functions

  28. h q q h transverse nucleon structure transversity via Collins fragmentationfct.

  29. ep  pX Collins amplitudes p+ distinctive pattern: • p+ positive • p0 ≈zero • p- negative isospin relation for p triplet fulfilled p0 p-

  30. ep  pX Collins amplitudes p+ distinctive pattern: • p+ positive • p0 ≈zero • p- negative p0 approximation: u-quark dominance • Collins FF has favoured (up+) and unfavoured (up-) transitions of similar size and opposite sign p-

  31. ep  pX Collins amplitudes p+ proton data distinctive pattern: • p+ positive • p0 ≈zero • p- negative p0 approximation: u-quark dominance • Collins FF has favoured (up+) and unfavoured (up-) transitions of similar size and opposite sign [note sign change due to different angle definition ] p- all asymmetries on deuterium target ≈ zero!

  32. ep  hX Collins amplitudes p+ K+ amplitudes consistent with p+amplitudes as expected from u-quark dominance p0 K- of opposite sign from p- (K- is all-sea object) p-

  33. see talk by A. Prokudin e+ e- extraction of transversity from Collins asymmetries

  34. Collins amplitudes-- extras: 2D binning -- kinematic dependencies often don’t factorise  bin in as many independent variables as possible: z @`fixed’ x Ph @`fixed’ z T x @`fixed’ z z @`fixed’ Ph T

  35. Collins amplitudes-- extras: 2D binning -- kinematic dependencies often don’t factorise  bin in as many independent variables as possible:

  36. alternative probe for transversity: 2-hadrons

  37. 2-hadron production: interference fragmentation function between pions in s-wave and p-wave • only relative momentum of hadron pair relevant  integration over transverse momentum of hadron pair simplifies factorisation (collinear!) and Q2 evolution • however cross section becomes very complicated (depends on 9! variables)  sensitive to detector acceptance effects

  38. extraction of p+p- amplitudes …facilitate interpretation q integration projects out sp and pp only for full theta acceptance:

  39. extraction of p+p- amplitudes …facilitate interpretation q integration projects out sp and pp only for full theta acceptance: q acceptance is momentum dependent: full acceptance

  40. extraction of p+p- amplitudes  bin data in q in addition: • symmeterization around q=p/2: & fit

  41. p+p- amplitudes [JHEP 0806.017]

  42. h+h- amplitudes [JHEP 0806.017] [note sign change due to different angle definition]

  43. h+h- amplitudes [JHEP 0806.017] [note sign change due to different angle definition]

  44. [Bacchetta, Radici PRD74(2006)] Mpp (GeV) models for 2-hadron asymmetries

  45. [Bacchetta, Radici PRD74(2006)] Mpp (GeV) models for 2-hadron asymmetries [note sign change due to different angle definition]

  46. azimuthal dependence of the unpolarised cross section spin-orbit effect (Boer-Mulders DF): correlation between quark transverse motion and transverse spin

  47. unpolarised cross section access to intrinsic quark transverse momentum

  48. analysis challenge Monte Carlo: generated in 4p measured inside acceptance • acceptance and radiative effects generate cos(nf) moments

  49. analysis challenge Monte Carlo: generated in 4p measured inside acceptance • acceptance and radiative effects generate cos(nf) moments • 5D unfolding of detector and radiative effects:

  50. <cosf>: intrinsic quark transverse momentum • very similar result for deuterium

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