E-704 (Yokosawa) Experiments with the Polarized Beam Facility

Experiment 704, the Integrated Proposal on First Round Experiments with the Polarized Beam Facility, constitutes a proposal to simultaneously perform substantial parts of previously proposed Experiments 674, 676, 677 and 678. Experimenters involved in these measurements are from Argonne National Laboratory, Fermilab, Kyoto University (Japan), LAPP (Annecy, France), Los Alamos National Laboratory, Northwestern University, Rice University, CEN Saclay (France), IHEP-Serpukhov (USSR), University of Texas, and Trieste (Italy).

Prior to carrying out E-704, a polarized beam line (MP Beam, E-581) must be constructed. The initial plan is for a 200-GeV/c conventional magnet beam line, which will obtain polarized protons from decaying lambdas. The completion of the MP beam line is scheduled for March 1986. 400 hours of beam time is required to commission the polarized beam jointly by Fermilab and the experimenters.

The first 1200 hours of beam time for E-704 will be allocated as follows:

The experimenters intend to explore the spin dependence of the interactions in a global way using a straightforward experiment which will measure the difference in total cross section between pp and pp between the states with helicities of target and beam parallel and antiparallel. Experience shows that accuracy of 100 microbarns can easily be achieved.

3)

600 hours for simultaneous measurements using a hydrogen target for AN in Large-P", Large-x ", and Lambda production.

Studies of the inclusive production of neutral pions around xp "O and large P, of neutral and charged pions at large x, and of A°(K) at large x will be carried out simultaneously. The measurement will investigate the spin effect as a function of xp and P. Interpretation of the polarization of A° produced inclusively from an unpolarized initial state has given rise to extensive discussion about the origin of this polarization. It is expected that information on spin transfer from initial to final state in this reaction will enlighten the debate.

Two gamma spectrometers (each consisting of 500 lead-glass cells) will be used to detect y's from °-decay. The magnetic spectrometer with proportional- and drift-chamber systems is to detect and Ap■ decay products.

The technique for measuring single spin asymmetries in hadron production is considerably improved over the previous experiment since the polarized beam allows the use of a liquid hydrogen target.

E-705/721 (Cox/Rosen)

E-705 has

constructed

and

A Study of Charmonium and Direct Photon production by 300 GeV/c Antiproton, Proton and ■*

Beams

that is

and p

commissioned a large aperature spectrometer intended to study direct photon and charmonium production using 300 GeV/c beams in the High Intensity Laboratory in the Proton West Area. The unique features of this spectrometer include a high resolution electromagnetic shower detector constructed from scintillation glass. The good electromagnetic energy resolution for photons should allow the separation of the closely spaced charmonium states which are detected through their

decay modes.

X + Y

น μ

Comparison of the production of direct photons and charmoniun states using different beam types should allow the separation of gg and qq components of the production process. The high resolution, high statistics measurements of the x states will allow the determination of the decay angular distributions of the charmoniun states yielding more information on the production processes.

The T721 test will use the E-705 spectrometer to study K's produced by antiprotons in the central production region near x-0. A relatively low statistics measurement will be made of n from the K°

+

L

+

decay to ascertain whether these

are different in their CP violating decay

from KL produced in by quarks in proton induced reactions.

E-706 (Slattery) A Comprehensive Study of Direct Photon Production in Hadron Induced Collisions

We propose to study the gluon structure functions of hadrons, and to investigate gluon fragmentation, through analyzing the production of direct photons and their accompanying hadrons in collisions of pions, kaons, and protons with a variety of nuclear targets. At the constituent level, the qy and gqgy.

reactions to be investigated are qg

+

We are also

+

the

YY and

interested in carrying out an essentially unbiased comparison between two fundamental quark-antiquark annihilation reactions, qq qqete by studying, in a single experiment, the relative yields of YY and ete triggered events.

An important secondary goal of the experiment is to study associated hadronic jet production through triggering on the simultaneous production of pairs of high transverse momentum particles. Of particular interest is our ability to directly compare, in the same experiment, the production of jets with leading charged fragments (primarily pions) and leading neutral fragments (both O's and n's).

The experiment is to be carried out using 400 and 800 GeV/c protons and 530 GeV/c pions (both signs) using beam intensities > 107 per second. Stage II approval for 1000 hours of beam time was granted in October 1983.