[en] The large crater on the asteroid (2867) Steins attracted much attention when it was first observed by the Rosetta spacecraft in 2008. Initially, it was widely thought to be unusually large compared to the size of the asteroid. It was quickly realized that this was not the case and there are other examples of similar (or larger) craters on small bodies in the same size range; however, it is still widely accepted that it is a crater arising from an impact onto the body which occurred after its formation. The asteroid (2867) Steins also has an equatorial bulge, usually considered to have arisen from redistribution of mass due to spin-up of the body caused by the YORP effect. Conversely, it is shown here that, based on catastrophic disruption experiments in laboratory impact studies, a similarly shaped body to the asteroid Steins can arise from the break-up of a parent in a catastrophic disruption event; this includes the presence of a large crater-like feature and equatorial bulge. This suggests that the large crater-like feature on Steins may not be a crater from a subsequent impact, but may have arisen directly from the fragmentation process of a larger, catastrophically disrupted parent

[en] Kaon electroproduction on hydrogen, deuterium and helium targets has been measured at a beam energy of 3.245 GeV and four-momentum transfer, Q², ranging from 0.34 to 0.5 GeV². Associated hyperon production off a nucleon in the deuteron exhibits a quasifree production mechanism. Excess yield close to the respective thresholds for Λ and Σ production is observed. This can be accounted for by final-state interaction between the electroproduced hyperon and the spectator nucleon. The effects predicted from three different hyperon-nucleon potentials are compared to the data. The measurement on the helium targets is the first ever performed. Very preliminary results are presented

[en] The A(e,eK+)X reaction has been investigated at Jefferson Laboratory. Data were taken for Q² approx. 0.35 GeV² at a beam energy of 3.245 GeV for 1H,3He and 4He targets. Evidence for Lambda-hypernuclear bound states is seen for 3,4He targets. This is the first time that the electroproduction of these hypernuclei has been observed

[en] The A(e,eiK+)YX reaction on H, D, ³He, and ⁴He was investigated in Hall C at CEBAF. Data were obtained for Q² ∼ 0.35 and 0.5 GeV² at 3.245 GeV. The missing mass spectra for both H and D are fitted with Monte-Carlo simulations incorporating peaks corresponding to Lambda production on the proton and Sigma production on both the proton and neutron. For D, the cross section ratio Sigma⁰/Sigma^- ∼ 2, and excess yield close to the thresholds for Lambda and Sigma production can be attributed to final-state interactions; models are compared to the data. The analysis of the data for the He targets is in a more preliminary state with broader quasi-free peaks resulting from the higher Fermi momenta. Evidence for bound Lambda-hypernuclear states is seen and other structure may be present