D. Dekkers

Mean life of the neutral pion

High energy neutral mesons( rature of the d ) were produced in platinum foils of 3-60 micron thickness exposed to the 18-Bev internal proton beam of the CERN proton synchrotron, and the production of positrons relative to all heavier particles was measured in a secondary beam of 5-Bev/c. The momentum spectrum of rature of the d /sup o/, which is effective in producing 5Bev/c positrons, is obtained by weighting the rature of the d /sup o/ spectrum with the probability that a positron from a rature of the d /sup o/ has a momentum of 5-Bev/c. The momentum spectra of rature of the d /sup o/ and rature of the d /sup +/ are assumed to be of equal shape and the latter was measured. This effective rature of the d /sup o/ spectrum is narrow and is charactetized by an average momentum of 7.12-Bev/c and a rms momentum of 7.26-Bev/c. The mean life was determined to be (1.05 ction in DDT-C/ 0.18) x 10/sup -16/ sec. (C.E.S.)

Interference of KoL and KS amplitudes in the π+π- decay mode

Abstract The decay law of a coherent mixture of K o L and K o S has been measured over nine K o S mean lives in the π + π - mode. The relative phase between the interfering amplitudes was found to be ϕη +- ϕif 21 = (1.54 ±0.17) sign ( m L − m S ) rad and the K o L − K o S mass difference fΔm/Γ S ⋎ = 0.480 ± 0.024 .

The antiproton decelerator: AD

A simplified scheme for the provision of antiprotons at 100 MeV/c based on fast extraction is described. The scheme uses the existing p~ production target area and the modified Antiproton Collector Ring in their current location. The physics programme is largely based on capturing and storing antiprotons in Penning traps for the production and spectroscopy of antihydrogen. The machine modifications necessary to deliver batches of 1/spl times/10/sup 7/ p~/min at 100 MeV/c are described. Details of the machine layout and the experimental area in the existing AAC Hall are given.

SEARCH FOR DECAY OF NEUTRAL KAONS INTO CHARGED LEPTON PAIRS.

Abstract A search for decays of K L o and K S o into charged pairs is reported. No event has been found. Upper limits obtained with 90% confidence for the branching ratios are Λ (K L o → μ + μ − )/ Λ (K L o → all) −6 and Λ (K S o → μ + μ − )/ Λ (K S o → all) −5 .

Interference between KL0 and KS0 in the Kμ3 decay mode

Abstract The decay law of a coherent mixture of K L 0 and K S 0 has been studied in the K μ3 mode. The charge asymmetry is analysed as a function of the regeneration phase arg(i ƒ 21 ) and Re(ϵ). In addition arg(i ƒ 21 ) is estimated from recent measurements of K + and K − absorption cross sections in carbon.

The Antiproton Decelerator: AD

Abstract In view of a possible future programme of physics with low-energy antiprotons, a simplified scheme for the provision of antiprotons at 100 MeV/ c has been studied. It uses the present target area and the modified Antiproton Collector (AC) in its present location. In this report the modifications and the operation are discussed.

Status of the antiproton decelerator: AD

A simplified scheme for the provision of antiprotons at 100 MeV/c in fast extraction is described. The scheme uses the existing p production target area and the modified Antiproton Collector Ring in their current location. Some modifications necessary to deliver batches of 1 × 10 7 antiprotons every minute at 100 MeV/c are described, details of the machine layout and the experimental area in the existing AAC Hall are given.

Two-pion decay of the long-lived K0 at 10.7 GeV/c

SummaryThe decay rate of KL0 into π+π- has been measured at a mean KL0 momentum of 10.7 GeV/c with the aim to search for an energy dependence. The branching ratio of this decay mode as compared to charged decay modes found in this experiment is (2.12±0.18)·10−3 in agreement with other results of (1.97±0.16)·10−3 at 1.1 GeV/c and (2.08±0.16)·10−3 at 2.5 GeV/c. This result excludes the possibility to maintainCP invariance by introducing a new long-range vector field. From a fit to the branching ratios at different KL0 momenta we obtain an upper limit on an energy splitting between K0 and

Time-dependent interference effects in two-pion decays of neutral kaons

\bar K^0