High-precision measurement of the associated strangeness production in proton-proton interactions

Abstract

A new high precision measurement of the reaction pp Ñ pK`Λ at a beam momentum of 2.95 GeV{c with more than 200 000 analyzed events allows a detailed analysis of differential observables and their inter-dependencies. Correlations of the angular distributions with momenta are examined. The invariant mass distributions are compared for different regions in the Dalitz plots. The cusp structure at the NΣ threshold is described with the Flatté formalism and its variation in the Dalitz plot is analyzed.

Determination of the spin tripletpΛscattering length from the final state interaction in thep⃗p→pK+Hauenstein1, Clement2, Kilian3 et al. 2017Phys. Rev. CSelf Cite

“…2 but it is weaker than in measurements at higher beam momenta [6,13] due to the available phase space at higher beam momentum. The enhancement does not distort the results obtained from the fit of the final state interaction as it was shown in a previous analysis of COSY-TOF data at higher beam momentum [7]. Furthermore, the fit of the final state interaction (see details below) extrapolated to the full m pΛ range describes the spectrum well as shown by the solid line in Fig.…”

“…The details of the detector system including the Straw-Tube-Tracker (STT) can be found in Refs. [6][7][8][9].…”

“…Since the kaon angular distribution is uniform [7], A K N is directly evaluated in terms of associated Legendre polynomials and bins of invariant mass m pΛ , which gives…”

The legacy of the experimental hadron physics programme at COSY

“…A typical setting with the so-called long barrel is shown in Fig. 5 [27]; the calorimeter that gives energy information is generally only used in conjunction with the shorter barrel. It is seen from the figure that the diameter of the stainless steel barrel is also around 3 m, which makes it physically the largest detector installed at COSY.…”

“…Schematic drawing of the COSY-TOF detector, Following the direction of the beam, after the target there are the start counter (Start), the straw tube tracker (STT), the barrel scintillators, the inner ring (Quirl), the outer ring (Ring), and the Calorimeter. All detectors and the liquid target are located inside the vacuum vessel [27].…”