Extended Theories of Gravity

http://cds.cern.ch/record/257993/files/9401310.pdf

QCD phenomenology based on a chiral effective Lagrangian

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Gravitation and spacetime.

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C.

The Physics of the B Factories

Polarized deep inelastic scattering (DIS) data are analyzed in leading and next-to-leading order of QCD within the common ``standard'' scenario of polarized parton distributions with a flavor-symmetric light sea (antiquark) distribution $\ensuremath{\delta}\overline{q},$ and a completely ${\mathrm{SU}(3)}_{f}$ broken ``valence'' scenario with totally flavor-asymmetric light sea densities $(\ensuremath{\delta}\ifmmode \bar{u}\else \={u}\fi{}\ensuremath{\ne}\ensuremath{\delta}\overline{d}\ensuremath{\ne}\ensuremath{\delta}\overline{s}).$ The latter flavor-broken light sea distributions are modeled with the help of a Pauli-blocking ansatz at the low radiative or dynamical input scales of ${\ensuremath{\mu}}_{\mathrm{LO}(\mathrm{NLO})}^{2}=0.26 (0.40){\mathrm{GeV}}^{2}$ which complies with predictions of the chiral quark-soliton model and expectations based on the statistical parton model as well as with the corresponding, well established, flavor-broken unpolarized sea $(\overline{d}g\ifmmode \bar{u}\else \={u}\fi{}).$ Present semi-inclusive DIS data cannot yet uniquely discriminate between those two flavor-symmetric and flavor-broken polarized light sea scenarios.

Models for the polarized parton distributions of the nucleon

A unique description avoiding confusion is presented for all flavor oscillation experiments in which particles of a definite flavor are emitted from a localized source. The probability for finding a particle with the wrong flavor must vanish at the position of the source for all times. This condition requires flavor-time and flavor-energy factorizations which determine uniquely the flavor mixture observed at a detector in the oscillation region, i.e., where the overlaps between the wave packets for different mass eigenstates are almost complete. Oscillation periods calculated for ``gedanken'' time-measurement experiments are shown to give the correct measured oscillation wavelength in space when multiplied by the group velocity. Examples of neutrino propagation in a weak field and in a gravitational field are given. In these cases the relative phase is modified differently for measurements in space and time. Energy-momentum (frequency-wave number) and space-time descriptions are complementary, equally valid, and give the same results. The two identical phase shifts obtained describe the same physics; adding them together to get a factor of 2 is double counting.

Flavor oscillations from a spatially localized source: A simple general treatment

Recent neutron interferometry experiments have been interpreted as demonstrating a new topological phenomenon similar in principle to the usual Aharonov-Bohm (AB) effect, but with the neutron`s magnetic moment replacing the electron`s charge. We show that the new phenomenon, called scalar AB (SAB) effect, follows from an ordinary local interaction, contrary to the usual AB effect, and we argue that the SAB effect is not a topological effect by any useful definition. We find that SAB actually measures an apparently novel spin autocorrelation whose operator equations of motion contain the local torque in the magnetic field. We note that the same remarks apply to the Aharonov-Casher effect.

Harry J. Lipkin

Papers

Flavor oscillations from a spatially localized source: A simple general treatment

Topology, locality, and Aharonov-Bohm effect with neutrons.

Expected polarization of Λ particles produced in deep inelastic polarized lepton scattering

Analysis of semileptonic decays and EMC data: No real evidence for strange quarks in the proton

Flavor symmetry, K0– mixing and new physics effects on CP violation in D± and D±s decays