H. W. Baer

Energy loss of fast quarks in nuclei

We report an analysis of the nuclear dependence of the yield of Drell-Yan (DY) dimuons from the 800 GeV/c proton bombardment of

Pion induced transitions to double-isobaric-analog states at 35 MeV on 1f72-shell nuclei

^2H

Pion double charge exchange above the Δ(1232) resonance

, C, Ca, Fe, and W targets. A light-cone formulation of the DY process is employed in the rest frame of the nucleus. In this frame, for

Isobaric-analog-state transitions in pion charge-exchange reactions above the Δ(1232) resonance

x_2\ll x_1

Energy dependence of low-energy pion double-charge-exchange on the calcium isotopes

, DY production appears as bremsstrahlung of a virtual photon followed by decay into dileptons. We treat the two sources of nuclear suppression, energy loss and shadowing, in a consistent formulation. Shadowing, involving no free parameters, is calculated within the light-cone dipole formalism. Initial-state energy loss, the only unknown in the problem, is determined from a fit to the nuclear-dependence ratio versus

Measurements of quasi-elastic pion single charge exchange on 3He at Tπ = 245 MeV

x_1

Nuclear dependence of heavy quark production

. With the assumption of constant energy loss per unit path length, we find

Nuclear dependence of dimuon production at 800 GeV.

-dE/dz = 2.32 \pm 0.52\pm 0.5

A dependence of J/ psi and psi ' production at 800 GeV/c.

GeV/fm. This is the first observation of a nonzero energy loss of partons traveling in nuclear environment.

Nuclear dependence of the production of Upsilon resonances at 800-GeV

Abstract Measurements of cross sections at an incident π + beam energy of 35 MeV in the angular range 25°–70° are reported for the double-analog-state transitions on 42,44,48 Ca, 46,50 Ti, and 54 Fe. An overall trend towards flatter angular-distribution shapes with increasing neutron excess is observed. The data are consistent with descriptions based on shell-model correlations.