E-711 (Levinthal) A Study of the Angular and Energy Dependence of Constituent Scattering through Measurements of the Reaction P + N +hị + h2 + X The experiment will use a primary proton beam and nuclear targets to measure the reaction p + N to h1 + h2+ X where h1 and h2 are both high transverse momentum hadrons roughly back-to-back in the PN center of mass system. By determining the angular distribution and mass dependence of the cross-section of the di-hadron system, the experiment will extract the angular and energy dependence of the underlying hard constituent scattering. The experiment will trigger on events containing two high transverse momentum hadrons using a hadron calorimeter and uses a magnetic spectrometer to measure the charge and obtain the momenta of the two hadrons with good resolution. The apparatus is designed to take interaction rates up to 5 x 107 by using the spectrometer magnet to sweep most of the low transverse particles away from the active region of the apparatus. momentum E-731 (Winstein) A Precision Measurement of the CP Violation The goal of this experiment is a measurement of the ratio of the CP nonconservation parameters, '/, in the KOKO system to a precision of ± 0.001. The best previous result for this ratio was consistent with zero and had an error of about 0.006; this was obtained by Fermilab E-617. of So far the only manifestations of CP nonconservation are a result a lack of time symmetry in the AS = +2 processes K°←K°. This experiment addresses the issue as to whether the CP nonconservation is confined to a AS = 2 interaction (the superweak model) or has a AS = 1 component, as naturally arises in, for example, the Kobayashi-Maskawa model. Although there is considerable uncertainty in the predictions for the size of '/ε, a measurement with a sensitivity in the range of ±0.001 would severly constrain the models and, if non-zero, would give an important new "handle" on the phenomenon of CP nonconservation. The experiment makes use of a double beam whereby both KL and Ks decays are studied simultaneously: a thick B&C regenerator is placed in one of the beams to provide a Ks component and the regenerator is alternated from beam to beam to reduce the effects of any detector asymmetries. In this manner, about 105 KL 2π events will be collected along with about 3 x 105 Kg 2 π O "normalizing" events; then about 3 x 105 KL + events will be collected with about 106 Ksπ ̄ ones. For this effort, a new neutral beam has been constructed which takes full advantage of the 800 GeV primary protons and the superior duty cycle of the Tevatron to provide a factor of five higher usable KL flux in the 100 GeV/c region than ever before at Fermilab. Attention has also been paid to significantly reducing other sources of background which traditionally plague high sensitivity neutral kaon experiments: soft neutrons and photons. The neutral final state is detected with an 800 element 1.9m diameter lead glass array while the π are detected with a 2000 sense wire high rate drift chamber spectrometer. Triggering in the neutral mode is effected by requiring a single photon conversion in a thin lead sheet at the downstream end of the decay region. The most serious background, KL +3π, is greatly reduced by means of several anticoincidence planes designed to detect extra gammas outside the solid angle of the lead glass. Inelastic regeneration will be significantly reduced by means of hodoscope planes within the regenerator to detect the production of secondaries. The experiment will begin testing in data during this run and the next Tevatron March of 1985 and will take run in 1986. |