Possibility: Atomic protonium

Transcription

1 Possibility: Atomic protonium Sommerfeld-Schwinger factor C dual to Bohr spectrum below threshold Coulomb-bound proton-antiproton amplitudes decay via annihilation to mesons KeV binding energies P-waves: Photon decays Hyde-Wright, sjb True muonium, true tauonium bound states 82

2 e +!*! H A2 e H Coulomb correction is part of current matrix element Coulomb final-state phases: different for different partial waves! Coulomb phases can give Py SSA even at threshold 83

3 FSI from Coulomb Interactions e + H +!*! A2 e H Coulomb phase different in G E and G M Produces polarization asymmetry A 84

4 e + H +!* g! A2 e QCD analog: H Hoang, Kuhn, Tuebner, sjb α C F α s Small BLM scale Actually part of Hadron Form Factor! QCD Coulomb phases 85

5 Spin Asymmetries and the Baryon Form Factors Dubnickova, Dubnicka, Rekalo; Rock Carlson, Hiller, Hwang, sjb Phase difference between timelike form factors produces Single-Spin Asymmetry Py normal to production plane Polarization of initial leptons not necessary for Py: k p Sp, Analyze final state baryon spin from second scattering or decay Strong Discriminant of Models Three polarizations: Px, Py, Pz 86

6 Spin Asymmetries and the Baryon Form Factors Dubnickova, Dubnicka, Rekalo; Rock Carlson, Hiller, Hwang, sjb P y = sin 2θ ImG E G M D τ = (τ 1) sin 2θ ImF 2 F 1 D τ (1) P x = P e 2 sin θ ReG E G M D τ P z = P e 2 cos θ G M 2 P DP. k p Sp, P y = cos θ P x P e Im G M G E Re G M G E = cos θ P e tan(δ E δ M ) 87

7 P y = sin 2θ ImG E G M D τ 0.4 = (τ 1) sin 2θ ImF 2 F 1 D τ (1). Polarization P y (for! = 45 ) /Q fit (log 2 Q 2 )/Q 2 fit impr. (log 2 Q 2 )/Q 2 fit IJL fit k p Sp, Baldini: relative G E, G M phase needed to separate F1,F2! q 2 (GeV 2 ) 88 Dubnickova, Dubnicka, Rekalo; Roc Carlson, Hiller, Hwang, sjb

8 0.6 P x = P e 2 sin θ ReG E G M D τ P x (for! = 45 ) /Q fit (log 2 Q 2 )/Q 2 fit impr. (log 2 Q 2 )/Q 2 fit IJL fit q 2 (GeV 2 ) 89

9 1 P z = P e 2 cos θ G M 2 D 0.8 P z (for! = 45 ) /Q fit (log 2 Q 2 )/Q 2 fit impr. (log 2 Q 2 )/Q 2 fit IJL fit q 2 (GeV 2 )

10 Single-spin asymmetry P y for QED e + e τ + τ Sensitive to the imaginary part of the timelike Schwinger correction to the lepton anomalous moment and Pauli form factor. Different Coulomb phases for F1, F2 91

11 Strange Electromagnetic and Axial Nucleon Form Factors A combined analysis of HAPPEx, G 0, and BNL E734 data First determination of the strange axial form factor. Stephen Pate G0 & E734 [to be published] HAPPEx & E734 [Pate, PRL 92 (2004) ]

12 Parity Violation experiments S. Kox S. Pate Weak form factors measurements! EM and Weak contributions but M Z << M! in our energy domain! Must get rid of the dominant M! 2 term " Parity violation (PV) in polarized elastic electrons scattering on unpolarized proton target e! $ + Z 0 Parity e PV Asymmetry ( ) A PV! " # " + # $ %e M &.M Z " + + " # M & 2 N (" + ) (" # ) N (" + ) % " # (= P(" + ))! Systematic errors (normalization) cancel in the ratio! A PV : 1 ppm to 50 ppm (part per million : 10-6 ) for Q 2 = (GeV/c) 2! A PV = A 0 (s =0) + A S " Need to reach a precision of a few % (stat. + syst.) on A PV! 93

13 S. Kox A V e N j µ W,e J µ W,N e! 0 (Q 2 ) N X e N j µ EM,e J µ EM,N e " # (Q 2 ) N V V Interference gives parity violation (! G,N) (q,n) E,M = " Q q G E,M G (Z,N) q E,M = c V G (q,n)! E,M q=u,d,s q=u,d,s Flavor u, c, t d, s, b Q q 2/3-1/3 C q V 1-8/3 sin 2 " W /3 sin 2 " W A PV =! G F Q2 4 2"# $ G E %,p e flavor decomposition : ( ) G ( Z,p) E + & G (%,p) Z,p M G M (%,p) $ G E ( )! 1! 4sin2 ' W ( ) 2 + & ( (%,p) G ) 2 M ( ) $'G M %,p ( ) G A e 94

14 Strange Quark Contribution : Q 2 dependence D. S Armstrong et al., PRL 95, (2005) S. Kox EM form factors - parameterization NVS A NVS subtraction -SM, axial FF Some conclusions! Good agreement with HAPPEX data measured at similar kinematics " A null strange quark contribution (G s E = Gs M = 0) is rejected at 90 % CL

15 Strange Form factors extraction Speculation! Fit of the world data set (H, He) with sum of 2 strange Form Factors! Use parameterization for their Q 2 dependence (G p M and Gn E types) s G s G M ( Q ) 2 = M ( 0) (proton) 1+ Q 2 s 2! M ( ) 2 S. Kox s G E ( Q ) 2 = a 1 Q 2 1+ b 1 Q 2 + b 2 Q 4 + b 3 Q 6 (neutron) (! 2 /Ndf ~ 0.86) From the fit! Large positive value for G s M (0)! E and M contributions have opposite sign! Sharp Q 2 dependence 10% contribution to nucleon form factors " Need additional data (separation) to come to any firm conclusion

16 Origin of nonzero strange quark contribution to vector current of nucleons VMD (φ) or different s(x) and s(x) distribution? Roelof Bijker, Riska, Thomas Intrinsic strangeness Λ(uds) + K(su) Fluctuation Evidence from charm production in charged current DIS reactions Burkardt,Warr Ma, sjb, Thomas Intrinsic heavy quarks: Dimension 6 G 3 µν m 2 Q operator Polyakov et al. Intrinsic charm at high x 97

17 Origin of nonzero strange quark contribution to vector current of nucleons Analog in atomic physics: intrinsic muons strongly asymmetric in tauonium [τ + e ]: µ attracted to τ + µ + attracted to e Λ(uds) + K(su) Fluctuation Burkardt,Warr Ma, sjb, Thomas 98

18 Evidence for nonzero strange quark contribution to vector current of nucleons φ contribution to vector current Roelof Bijker, Iachello φ couples in t channel to proton via ggg OZI suppressed but not zero analogous to electron-loop light-by-light contribution to muon g 2 99

19 Novel Timelike Experiments Timelike photon-to-meson transition form factor e + No background from radiative return # #* A3 e F γm (Q 2 ) = Basic measure of QCD 0 100!!,"," c dxφ M (x, Q)T H γ M(x, Q 2 ).

20 Annihilation Channels: ISR and Direct Annihilation Measure timelike form factors All Exclusive channels Solodov p + Delta 101

21 Exclusive Two-Photon Process e +!* H + e H e +!* H A1 e!* Interference produces charge asymmetry Critical test of two-photon explanation of Rosenbluth failure H Afanasev, Carlson, Chen, Vanderhaeghen, sjb 102

22 Interference of ISR and FSR Produces electron-positron charge asymmetry e +! e +!!* + e e!* e +!* +! A5 e 103

23 Timelike Annihilation DVCS Afanasev, Carlson, Salme, sjb (in progress) New window into hadron physics e +!*! H A4 e H M(γ H + H γ) M(γ H γh) Interference with ISR produces charge asymmetry 104

24 Assume Dominance of J=0 Fixed Pole (seagull) R pp 2γ (q2 1, q2 2, s) = T (γ 1 γ 2 HH) T (γ 1 γ 2 µ µ + ) e + = (e 2 u + e2 d ) 1 x q F H (s).!*! H A4 e H M(γ H + H γ) M(γ H γh) 105

25 e + e #* g q H + q H g!,j/" A6 Gluonium Factory G J S. J. Brodsky, A. S. Goldhaber and J. Lee, Phys. Rev. Lett. 91, (2003) [arxiv:hep-ph/ ]. Coyne, DeGrand, sjb 106

26 Belle Associated Charm Anomaly R J/ψ σ(e+ e J/ψ cc) σ(e + e J/ψ X) = 0.8 Huge Probability for associated charm pair Theory estimates (Bodwin) R J/ψ 0.1 Measure R φ σ(e+ e φ ss) σ(e + e φ X) 107

27 Photon-Photon Collisions e + e +!* X!* A7 e e Doubly-Virtual Photon Processes 108

28 Threshold pion production: e + e pp π 0, pn π Beautiful soft-pion theorems for Rotated proton distribution amplitudes Extend PQCD predictions, measure axial vector form factors Braun, Polyakov et al. U. Mueller 109

29 e + e HX H Hwang, Schmidt, sjb e +!* q g e q H e +!* q g A9 e q Relative phases for different L produce Sivers SSA Pseudo T-odd Correlation S H p e p H 110

30 The Future Frascati: Upgrade of Daphne 1.2 GeV/beam, high Luminosity /sec/cm 2 GSI Fair : Panda, PAC -- Test Color transparency T, A NN BES VEPP-2000 Jlab 12 GeV J-Parc: neutrino charged and neutral current form factors 111

31 Transversity in Drell-Yan Processes Polarized Antiproton Beam Polarized Proton Target (both transversely polarized) Key experiment at GSI Q l + Q Q2 = l - M 2 p Q T p L M invariant Mass of lepton pair F. Rathsman

32 Spin Correlations in Elastic p p Scattering R NN Ratio reaches 4:1! p T Collisions Between Spinning Protons (A. D. Krisch) Scientific American, 255, (August, 1987). p lab Rome Colloquium p T Colli Insights for QCD from AdS/CFT 113

33 Eva Experiment BNL Bunce, Carroll, Heppelman... Rome Colloquium Insights for QCD from AdS/CFT 114 Rapid Angular Variation!

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38 4 Prediction of AdS/CFT Holographic Model log G M (q 2 ) q 2 (GeV 2 ) New Perspectives on the Nucleon in QCD 119

39 Thanks to the organizers! Enzo De Sanctis, Rinaldo Baldini, Donatella Pierluigi, Alessandra Fantoni "Unique Form of Continuity in Space" by Umberto Boccioni Workshop on Nucleon Form Factors Frascati, October,