Low energy interaction studies of negative kaons in light nuclear targets by AMADEUS

The AMADEUS collaboration is performing experimental investigations in the sector of the low energy strangeness hadron physics by taking advantage of the DAΦNE collider, which provides a unique source of monochromatic low-momentum kaons and exploiting the KLOE detector as an active target. The K− single and multi-nuclear absorption on H, 4He, 9Be and 12C, both at-rest and in-flight, are studied with the aim to determine the nature of the controversial Λ(1405), the non-resonant hyperon pion formation amplitude below the K̅N threshold, the yield and cross sections of K− multi-nucleon absorptions intimately connected to the antikaon multi-nucleon clusters properties and the K− scattering cross sections on light nuclear targets. These studies have a strong impact on the non-perturbative strangeness QCD with implications ranging from nuclear physics to the equation of state of neutron stars.

Measurements of J/ψ Production and Polarization in p+p and p+Au Collisions at s NN = 200 GeV with the STAR Experiment

We present the measurements of [Formula: see text] production at mid-rapidity via the di-muon decay channel in p+p and p+Au collisions at [Formula: see text] = 200 GeV by the STAR experiment at RHIC. In p+p collisions, the measured inclusive [Formula: see text] cross section can be qualitatively described by model calculations. The [Formula: see text] polarization parameters, [Formula: see text], [Formula: see text] as well as the frame-invariant quantity [Formula: see text], are presented as a function of transverse momentum in both the helicity and Collins-Soper frames. No significant polarization is observed. In addition, the nuclear modification factor for inclusive J/[Formula: see text] in p+Au collisions is similar to that measured in d+Au collisions and favors an additional nuclear absorption effect on top of the nuclear PDF effect.