We investigate the low-energy behavior of the four-point Green’s function Γ describing virtual Compton scattering off the nucleon. Using Lorentz invariance, gauge invariance, and crossing symmetry, we derive the leading terms of an expansion of the operator in the four-momenta q and q′ of the initial and final photon, respectively. The model-independent result is expressed in terms of the elect...

In this talk, I summarize a global analysis on electron-quark contact interactions using the updated NC DIS data at HERA, Drell-yan production at the Tevatron, total hadronic cross sections at LEP, atomic parity violation measurement, low energy e-nucleon scattering data, and the ν-nucleon scattering data. The global data do not show any evidence for contact interactions. Thus, we obtain limits...

We derive and calculate the multiple scattering expansion of the Kerman-McManus-Thaler optical potential to second order in the free nucleon-nucleon transition amplitude and clarify the physical content of the interaction. Calculations are presented for the elastic scattering of protons from ' 0 at 135, 200, and 300 MeV incident energies, paying particular attention to the nonlocalities inheren...

Within the framework of the relativistic plane wave impulse approximation (RPWIA), complete sets of quasielastic (p, p ′) and (p, n) spin observables are calculated employing a general Lorentz invariant representation of the NN scattering matrix (referred to as the IA2 representation). The use of a complete representation eliminates the arbitrariness of a previously-used five-term parameterizat...

Neutrino scattering physics is discussed for investigating internal structure of the nucleon and nuclei at future neutrino facilities. We explain structure functions in neutrino scattering. In particular, there are new polarized functions g3, g4, and g5, and they should provide us important information for determining internal nucleon spin structure. Next, nuclear structure functions are discus...

I introduce a gauge invariant decomposition of the nucleon spin into quark helicity, quark orbital, and gluon contributions. The total quark (and hence the quark orbital) contribution is shown to be measurable through virtual Compton scattering in a special kinematic region where single quark scattering dominates. This deeply-virtual Compton scattering (DVCS) has much potential to unravel the q...

Inclusive electron scattering from nuclei at large x and Q2 is the result of a reaction mechanism that includes both quasi–elastic scattering from nucleons and deep inelastic scattering from the quark consitituents of the nucleons. Data in this regime can be used to study a wide variety of topics, including the extraction of nuclear momentum distributions, the influence of final state interacti...

A new QCD sum rule analysis on the spin-isospin averaged ρ, ω and φ meson-nucleon scattering lengths is presented. By introducing the constraint relation on the the low energy limit of the vector-current nucleon forward scattering amplitude, we get aρ = −0.47± 0.05 fm, aω = −0.41 ± 0.05 fm and aφ = −0.15 ± 0.02 fm, which suggests that these V − N interactions are attractive. It is also proved t...

We investigate the low-energy behavior of the four-point Green's function ? describing virtual Compton scattering oo the nucleon. Using Lorentz invariance, gauge invariance, and crossing symmetry, we derive the leading terms of an expansion of the operator in the four-momenta q and q 0 of the initial and nal photon, respectively. The model-independent result is expressed in terms of the electro...