D.H. Stork

Evidence for a broad scalar Kπ resonance near 1.1 GeV

Abstract A one-pion-exchange pole-extrapolation analysis of K + p→K πΔ ++ at 7.3 GeV/ c provides evidence for the existence of a broad scalar T = 1 2 K π resonance near 1.1GeV. The angular distribution in the Kπ center-of-mass is consistent with this result.

Modulation of nuclear interactions using channeling at multi-hundred GeV energies

Abstract Channeling of protons and positive and negative pions has been observed in a single crystal of germanium at beam momenta of 35, 100 and 250 GeV/c. Both energy loss and scattering have been measured. The channeling effects agree with observations at lower energies suitably scaled to these high energies. The suppression of inelastic nuclear interactions has been directly observed by monitoring multiple-track events.

K+p elastic scattering at 7.3 GeV/c

Abstract A study of K + p elastic scattering at 7.3 GeV/ c has yielded a cross section of 3.86 ± 0.38 mb. For events produced in the forward direction, a diffractive peak is observed which fits the distribution (d σ /d t ) = (d σ /d t ) 0 exp ( αt + βt 2 ) with (d σ /d t ) 0 = (20.6 + 2.6) mb/(GeV/ c 2 , α = (5.46 ±_0.29)(GeV/ c ) -2 an β = (0.38 ± 0.25)(GeV/ c ) -4 . The ratio |Re ƒ(0)/Im ƒ (0)| for the forward scattering amplitude is 0.60 ± 0.14. One elastic scatter was found in the backward direction.

Regge pole exchange analysis of K+p → K∗O π+p at 7.3 GeV/c

Abstract A Regge pole exchange model is applied to the reaction K + p → K ∗ O (890)π + p at 7.3 GeV/c . The reaction is well described by exchanges of pion and Pomeranchuk trajectories with the Pomeranchuk exchange approximated by either a diffraction mechanism or on-mass shell π + p scattering. The model fits the production of the Q enhancement and also gives an adequate description of the virtual π + p scattering.

Spin and parity of the T = 12K ππ system near 1.3 GeV

Abstract The Kππ Dalitz plots for the two reactions K + p→K♂π + p at 7.38 GeV/ c beam momentum in the effective mass interval 1.2 M Kππ ∗++ (1.13 M π + p J P = 1 + to the Kππ system, are supported by the observed correlations of the outgoing K and K ∗ with the incident K + .

FITTING K

Abstract Fits are made to new K − p → K 0 π − p data at 3.3 GeV/ c with a generalized Veneziano model that includes both vector and pseudoscalar exchanges. Tests of the exchange degeneracy properties of the Regge trajectories show that the model prefers exchange degeneracy of the K ∗ (890) and non-exchange degeneracy of the Δ(1238). Several defects in the model are noted.

sup -

We present results from the barrel depleted uranium/TMP calorimeter modules constructed by the UA1 Collaboration. Electromagnetic and hadronic energy resolutions have been measured using electron and pion beams with momenta in the range 7 to 70 GeV/c. Results on the energy linearity and the spatial uniformity of response are reported. The electromagnetic shower position resolution has been measured as a function of energy using a fine grained position detector placed at a depth of − 3.5small chi, Greek0. The noise arising both from the electronics chain and from the uranium radioactivity is compared with 70 GeV/c muon signals. The ratio of the electron to pion response has been measured both as a function of the energy and of the electric field. The high lateral and longitudinal granularity of the calorimeter and the presence of a position detector have been used to determine the electron pion separation as a function of energy.

p

Abstract The decay process KLo → πμν has been studied in a wire chamber experiment using the three-degree KLo beam at SLAC. A sample of 26 500 Kμ3 events have been identified to obtain information on the form factors ƒ ± associated with the V-A hypothesis for this decay. Expressing the energy dependence of the form factors as ƒ ± = ƒ ± (0) (1 + λ ± q 2 m 2 ), where q 2 = (p K −p μ ) 2 , the experiment yields the value λ+ = 0.08 ± 0.01 and reveals a strong coupling between λ_ and ζ_(0) = ƒ_(0) ƒ + (0) .

Yields

Abstract We have extracted the strong interaction form factors from K o e3 and K o μ3 data of our previously reported K o L experiment in a manner which does not assume an explicit q 2 = ( p K − p π ) 2 dependence. We present the unparameterized form factors ƒ + (q 2 ) from the K o L → πeν and K o L → πμν modes and ƒ o (q 2 ) and ξ ( q 2 ) from the K o L → πμν data. A comparison of these unparameterized results is made with the results of the Dalitz plot analyses.

anti K

Abstract A sample of 17 000 K0L → πev decays were measured at the Stanford Linear Accelerator Center using a wire chamber magnetic spectrometer. K0e3 decays were separated from other K0L decay modes by using kinematic tests, muon identification by penetration of a Pb wall and electron identification by a shower counter array. We find the data in fixed q2 bands are in reasonable agreement with the V-A theory and we present the unparametrized form factor ƒ + (q 2 ) . Using the usual linear parametrization ƒ + (q 2 ) ∼ 1 + λ + q 2 /m π 2 , we obtained λ+ = 0.05 ± 0.01.