Nucleon Resonance Structure at Large Q 2 Ralf W. Gothe 25 th Annual - PowerPoint PPT Presentation

Nucleon Resonance Structure at Large Q 2 Ralf W. Gothe 25 th Annual Hampton University Graduate Studies Program Jefferson Lab Newport News, June 1-18, 2010  Essentials: Phase Space Cells, Coherence, Form Factors, …  QCD Knowns: Deep Inelastic Scattering and Heavy Quark Systems  QCD Unknowns: Nonperturbative QCD, Mass, Confinement, … Ralf W. Gothe PHYS 745G 1

Matter E=mc 2 E=CV/2=1kJ m=E/c 2 =1.1 . 10 -11 g C=80  F and V=5kV d=1mm A=9000m 2 Ralf W. Gothe HUGS 2010 2

Resolution Momentum Space Volume Ralf W. Gothe HUGS 2010 3

Double Slit Experiment Probes Photons Photons Electrons Neutrons Carbon (60) Balls . . . Incoherent Coherent    x > x slit  x < x x p slit p  p x ~ h  p ~ x z Ralf W. Gothe HUGS 2010 4

Quasi-Elastic Electron Scattering K 2  N P 2  * K  K 1  N P 1  • Localization ↔ Statistical Motion • Phase Space & Phase Space Cells • Fermi Momentum • Fermi Broadening Ralf W. Gothe HUGS 2010 5

Quasi-Elastic Electron Scattering Ralf W. Gothe HUGS 2010 6

Coherent Electron Scattering Ralf W. Gothe HUGS 2010 7

Form Factors and Charge Density Distribution Ralf W. Gothe HUGS 2010 8

Form Factors and Charge Density Distribution Ralf W. Gothe HUGS 2010 9

Form Factors and Charge Density Distribution Ralf W. Gothe HUGS 2010 10

Form Factors and Charge Radii Ralf W. Gothe HUGS 2010 11

Nucleon Form Factors Dirac magnetic dipole moment of a structureless spin 1/2 particle Ralf W. Gothe HUGS 2010 12

Nucleon Form Factors 12 Ralf W. Gothe HUGS 2010 13

Form Factor Scaling 6n n n n bonds and n+1 constituents Ralf W. Gothe HUGS 2010 14

Deep Inelastic Scattering Elastic DIS Ralf W. Gothe HUGS 2010 15

Point-Like Constituents ~ Q -8 Prog. in Phys. 4 (1982) PRL 23 (1969) 935 Ralf W. Gothe HUGS 2010 16

Point-Like Constituents with Spin 1/2 PRL 22 (1969) 156 F 1 structure function vanishes for spin-zero particles Callan-Gross relation follows for spin ½ Dirac Particles Ralf W. Gothe HUGS 2010 17

Quasi-Elastic Scattering Quark-Hadron Duality PRL 16 (1970) 1140, PR D4 (1971) 2901 E.D. Bloom and F.J. Gilman W = 1.9 GeV E’ = 17.6 GeV  = 2.37 GeV Q 2 = 1.72 GeV = Q 2 /2  m q = 0.36 GeV m q p F = 0.67 GeV  r F * √ 9  /2 =  c r F = 0.79 fm  p F PR D22 (1975) 1884 S. Stein et al. Ralf W. Gothe HUGS 2010 18

Quark Charges and Momentum Distributions Isospin Symmetry x . v x . q= x . s/2 Ralf W. Gothe HUGS 2010 19

Di-Quarks in Deep Inelastic Scattering Nucl. Phys. B371 (1992) 3 = 2/3 = 1/4 Only the u valence quark carries large x in the proton and the only the d valence quark in the neutron. Ralf W. Gothe HUGS 2010 20

Di-Quarks in Deep Inelastic Scattering Arrington et al. (2009) Preliminary Bonus (2010) Holt and Roberts, arXiv:1002.4666v3 (2010) = 1/4 Only the u valence quark carries large x in the proton and the only the d valence quark in the neutron. Ralf W. Gothe HUGS 2010 21

Heavy Quark Systems Ralf W. Gothe HUGS 2010 22

Heavy Quark Systems Virial Theorem:  s = 3/4  c/r min mc 2 = 0.25 for r cc = 0.4fm and  s = 3/4  c/r min mc 2 = 0.18 for r bb = 0.2fm Ralf W. Gothe HUGS 2010 23

Dirac Delta Function, Fields, Potentials, and Sources  0 only for n  2 and r > 0 Ralf W. Gothe HUGS 2010 24

Heavy Quark Systems Bali et al . he-la/0512018 Ralf W. Gothe HUGS 2010 25

Heavy Quark Systems Bali et al . he-la/0512018 Ralf W. Gothe HUGS 2010 26