17582393
Analysis of semileptonic decays of mesons containing heavy quarks.
We analyze semileptonic decays of mesons containing heavy quarks and indicate how to extract the signs and magnitudes of the helicity amplitudes for the exclusive decay modes involving a vector meson, lepton, and neutrino by using the joint distribution of the decay products of the vector meson (into a pair of pseudoscalar mesons) and of the virtual {ital W} (into a charged lepton and its neutrino). We apply this to specific cases of charm- and bottom-meson decays with form factors calculated from quark models.
125631838
ALGEBRAIC PROPERTIES OF ELECTROMAGNETIC AND WEAK CURRENTS AND THEIR REPRESENTATION ON HADRON STATES
119841878
CP violation in K decays
As in the case for much of contemporary research in high energy physics, the area of CP (the product of charge conjugation and parity) violation in K decays is to be seen in the context of a much broader effort of looking for physics beyond the Standard Model. One of the specific types of such physics is represented by the possibility of a fourth family, as exemplified by the title and main focus of this conference. From the broader perspective of looking for new physics of any kind, there are two principal avenues:
14177217
The physics of heavy flavors
Various aspects of the physics of heavy flavors and of CP violation are reviewed. 102 refs., 21 figs.
125396434
TOP DECAYS WHEN m (t) approximates M (W) + m (b)
120213968
Symmetry Predictions from Sum Rules without Saturation
The application of sum rules derived from current commutation relations to give $\mathrm{SU}(6)$-like results is developed without the assumption of saturation. We first derive a consistency condition by comparing sum rules, and then study the sum rules for $\frac{1}{g_{A}^{}{}_{}{}^{2}}$ and the isovector charge radii, replacing the assumption of saturation with a simple dynamical model for the remaining continuuum contribution. This results in several $\mathrm{SU}(6)$-like predictions which contain important correction factors to the results previously derived assuming saturation. We have also re-examined the experimental data for the sum rule for $\frac{{〈r_{N}^{}{}_{}{}^{2}〉}^{V}}{6}$, and find that it converges below 1 GeV like the sum rule for $\frac{1}{g_{A}^{}{}_{}{}^{2}}$ when account is taken of the contribution to the sum rule of the large resonant ${M}_{1+}$ and nonresonant ${\mathrm{E}}_{0+}$ multipoles in pion photoproduction, and of the ${N}^{**}(1520)$.
31144850
Neutron and proton matrix elements for 21+ transitions in T=1 nuclei from pion inelastic scattering.
Cross sections have been measured for ..pi../sup +/ and ..pi../sup -/ inelastic scattering to the 2/sub 1//sup +/ levels of /sup 18/O, /sup 22/Ne, /sup 26/Mg, /sup 30/Si, and /sup 34/S. The data are used to infer neutron and proton quadrupole-matrix elements for these transitions. The matrix elements extracted from the pion data are in good agreement with their corresponding electromagnetic matrix elements. These results indicate that the use of the distorted-wave impulse-approximation is a valid procedure for this class of transition.
45249805
Mass dependence of pion double charge exchange.
Data are presented for pion double charge exchange on targets of /sup 44/Ca, /sup 56/Fe, /sup 58/Ni, /sup 80/Se, /sup 90/Zr, and /sup 118/Sn. These and earlier data are used to examine the mass dependence of double-isobaric-analog transitions and nonanalog ground-state-to-ground-state transitions in the energy region T/sub ..pi../ = 100 to 300 MeV. The implications of the mass dependence to the interpretations of the underlying reaction mechanisms of double charge exchange are discussed.
30808745
Perturbative QCD effects observed in 490 GeV deep-inelastic muon scattering.
Results on forward charged hadrons in 490 GeV deep-inelastic muon scattering are presented. The transverse momenta, azimuthal asymmetry, and energy flow of events with four or more forward charged hadrons are studied. The range of the invariant hadronic mass squared 300[lt][ital W][sup 2][lt]900 GeV[sup 2]/[ital c][sup 4] extends higher than previous deep-inelastic muon scattering experiments. Data are compared to the predictions of the Lund Monte Carlo model with perturbative QCD simulated by matrix elements, parton showers, and color dipole radiation. All of the QCD-based models are consistent with the data while a model without QCD processes is not. Correlations with the multiplicity-independent event variable [Pi][congruent][summation][vert bar][ital p][sub [ital T]][vert bar] are studied. The relationship between the azimuthal asymmetry and transverse momentum of forward hadrons is also presented. The data are most consistent with intrinsic parton transverse momentum squared [ital k][sub [ital T]][sup 2] of 0.25 GeV[sup 2]/[ital c][sup 2].
11416852
Scaled energy (z) distributions of charged hadrons observed in deep-inelastic muon scattering at 490 GeV from xenon and deuterium targets.
Fermilab Experiment-665 measured deep-inelastic scattering of 490 GeV muons off deuterium and xenon targets. Events were selected with a range of energy exchange [nu] from 100 GeV to 500 GeV and with large ranges of [ital Q][sup 2] and [ital x][sub Bj]: 0.1 GeV[sup 2]/[ital c][sup 2][lt][ital Q][sup 2][lt]150 GeV[sup 2]/[ital c][sup 2] and 0.001[lt][ital x][sub Bj][lt]0.5. The fractional energy ([ital z]) distributions of forward-produced hadrons from the two targets have been compared as a function of the kinematics of the scattering; specifically, the kinematic region of shadowing'' has been compared to that of nonshadowing. The dependence of the distributions upon the [ital order] of the hadrons, determined by the fractional energies, has been examined as well; a strong degree of similarity has been observed in the shapes of the distributions of the different order hadrons. These [ital z] distributions, however, show no nuclear dependence, even in the kinematic region of shadowing.
40392372
Sequential contribution to nonanalog pion double charge exchange in the Delta 33 resonance region.
In double charge exchange leading to residual nonanalog 0[sup +] ground states, we examine the relative contribution of sequential charge exchange and delta-nucleon charge exchange. We conclude that the data cannot be quantitatively understood in terms of these two reaction mechanisms.