A. Ogawa

Nuclear transparency in 90°c.m. quasielastic A(p, 2p) reactions

nuclear transparency deuterons were studied. Second, we review the techniques used in an earlier experiment, E834, and show that the two experiments are consistent for the carbon data. E834 also determines the nuclear transparencies for lithium, aluminum, copper, and lead nuclei as well as for carbon. A determination of the sp + , p + pd transparencies is also reported. We find for both E850 and E834 that the Asp ,2 pd nuclear transparency, unlike that for Ase , e8pd nuclear transparency, is incompatible with a constant value versus energy as predicted by Glauber calculations. The Asp ,2 pd nuclear transparency for carbon and aluminum increases by a factor of two between 5.9 and 9.5 GeV/c incident proton momentum. At its peak the Asp ,2 pd nuclear transparency is ,80% of the constant Ase , e8pd nuclear transparency. Then the nuclear transparency falls back to a value at least as small as that at 5.9 GeV/ c, and is compatible with the Glauber level again. This oscillating behavior is generally interpreted as an interplay between two components of the pN scattering amplitude; one short ranged and perturbative, and the other long ranged and strongly absorbed in the nuclear medium. A study of the A dependent nuclear transparency indicates that the effective cross section varies with incident momentum and is considerably smaller than the free pN cross section. We suggest a number of experiments for further studies of nuclear transparency effects.

The STAR endcap electromagnetic calorimeter

The STAR endcap electromagnetic calorimeter will provide full azimuthal coverage for high-pT photons, electrons and electromagnetically decaying mesons over the pseudorapidity range 1.086⩽η⩽2.00. It includes a scintillating-strip shower-maximum detector to provide π0/γ discrimination and preshower and postshower layers to aid in distinguishing between electrons and charged hadrons. The triggering capabilities and coverage it offers are crucial for much of the spin physics program to be carried out in polarized proton–proton collisions.

Backward emitted high-energy neutrons in hard reactions of p and π+ on carbon

Beams of protons and pions of

Longitudinal momentum fraction XL for two high Pt protons in pp→ppX reaction

5.9 \mathrm{GeV}/c

n-p short-range correlations from (p,2p+n) measurements

were incident on a C target. Neutrons emitted into the backward hemisphere, in the laboratory system, were detected in (triple) coincidence with two emerging particles of tranverse momenta

A new measurement of the energy dependence of nuclear transparency for large momentum transfer 12C(p,2p) scattering

{p}_{t}g0.6 \mathrm{GeV}/c.

Backward emitted high-energy neutrons in hard reactions of pand π+on carbon

We determined that for

Future transversity measurements at RHIC

(46.5\ifmmode\pm\else\textpm\fi{}3.7)%

Measurement of the tensor analyzing power {ital T}ââ for {ital d}{sup â}+¹²Câ{ital p}(0°)+{ital X} in the region of high internal momenta in the deuteron

of the proton-induced events and for