The deuteron: structure and form factors

A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic

Testing nucleon strangeness in polarization effects for n+p -> d+eta

Charge symmetry of strong interaction results in a simplified spin structure of amplitude for n + p --> d + eta in "orthogonal" kinematics, where the eta-production angle is equal to 90 degrees in CMS. The presence of singlet and triplet amplitudes in such kinematics induces a rich set of different polarization observables, sensitive to the relative value of these amplitudes. This can be used to test a hypothesis of singlet enhancement of eta-production in NN- and (N) over bar N-collisions, due to a nonperturbative s (s) over bar-component of the nucleon with special polarization properties

The nucleon form factors in space-like and time-like regions

New data about electromagnetic form factors of the proton are discussed in terms of analyticity properties in space-like and in time-like region. From the constraints given by the Phragmen-Lindelof theorem, applied to the Sachs form factors, it turns out that the asymptotic regime can not be reached simultaneously for both form factors (electric and magnetic) up to s similar or equal to 14 GeV2. The angular dependence for the annihilation processes, such as (p) over bar + p e(+) + e(-), is sensitive to the asymptotic properties of form factors

New experimental methods for the determination of the P parity of K mesons

We propose new methods to determine the P parity of the K mesons experimentally, based on the measurement of polarization observables in K-meson production in polarized proton-proton collisions. The first method is based on the measurement of the sign of the spin correlation coefficient with transversally polarized protons. The second one is based on the measurement of the polarization transfer coefficient from the initial proton to the produced hyperon. [S0556-2821(99)01905-0]

Polarization phenomena in the reaction p+alpha -> p+pi(0)+alpha

We present a general analysis of polarization phenomena for three-body processes tin noncoplanar kinematics), in terms of a P- and T-odd acoplanarity parameter. The spin structure of the matrix element and the polarization phenomena contain new contributions, with respect to binary processes, which can be conveniently expressed as functions of this parameter. We apply this formalism to the reaction p+alpha-->p+pi (o) + alpha, in view of characterizing the different mechanisms involved and studying the, excitation of the Roper resonance. We find that the polarization transfer coefficient D-nn, where (n) over right arrow is normal to the proton scattering plane, is especially sensitive to the spin of the exchanged particle

Polarization phenomena for processes (p)over-bar+p -> P+V and mechanisms of OZI violations in phi production

The spin structure of the matrix element for annihilation in flight in the process (p) over bar + p --> P + V with P = pi(0), eta, eta', and V = rho(0),omega,phi, is constructed for collinear kinematics. The expressions for all the one-spin and two-spin polarization observables are found, and the consequences for the triplet enhancement hypothesis of strange particle production in collisions are discussed

Model independent analysis of the decay B -> K+l(+)+l(-)

We demonstrate that the Dalitz-distributions in energies of both unpolarized leptons, produced in the decays B --> K + l(+) + l(-) for l= e, mu, tau, can be a sensitive test for possible new physics beyond the Standard Model. We find measurable characteristics (including the polarization of leptons as well) which are independent of all dirty non-perturbative physics needed in calculating the hadronic form factors. Such characteristics can be used to estimate the presence of possible non-standard mechanisms in a model-independent manner

Determination of the g(V sigma gamma) coupling constant through theprocess gamma plus N -> N plus V with circularly polarized photons

We suggest to measure the t-dependence of the two possible T-even asymmetries for the photoproduction of vector mesons, gamma + rho --> rho + V-0, V-0 = rho or omega, in the collision of circularly polarized photons with a polarized proton target. In the framework of a (pi + sigma)-model, these asymmetries are very sensitive to the relative role of pi- and sigma-exchanges, in the near threshold region

Nonperturbative effects in polarization phenomena for B->K*+gamma and B->K+pi+gamma decays

Polarization characteristics of gamma-quanta, produced in decays B --> K* + gamma and B --> K + pi + gamma are studied in a general parity non-conserving framework. Polarization characteristics of gamma quanta for perturbative (i.e. shea distance) part of the matrix element of these decays are shown to be universal, independent of the process. Nonperturbative effects however violate such universality. (C) 1997 Published by Elsevier Science B.V