First results from subthreshold K +-production measurements with ANKE

• Published in: Nuclear physics. A Vol. 675; no. 1; pp. 230 - 233
• Main Authors: Barsov, S, Bechstedt, U, Borchert, G, Borgs, W, Büscher, M, Debowski, M, Drochner, M, Erven, W, Eßer, R, Fedorets, P, Gotta, D, Hartmann, M, Junghans, H, Kacharava, A, Kamys, B, Klehr, F, Koch, H.R, Komarov, V.I, Koptev, V, Kulessa, P, Kulikov, A, Kurbatov, V, Macharashvili, G, Maier, R, Mikirtichyants, S, Merzliakov, S, Müller, H, Mussgiller, A, Nioradze, M, Ohm, H, Petrus, A, Prasuhn, D, Pysz, K, Rathmann, F, Rimarzig, B, Rudy, Z, Schleichert, R, Schneider, Chr, Schneider, H, Schult, O.W.B, Seyfarth, H, Sistemich, K, Stein, H.J, Ströher, H, Wüstner, P
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31.07.2000
• ISSN: 0375-9474
• DOI: 10.1016/S0375-9474(00)00256-6

The new spectrometer ANKE has been put into operation at the accelerator COSY of the Forschungszentrum Jülich. An initial scientific goal is to study K +-production in pA collisions at subthreshold energies below the free NN-threshold of T = 1.58 GeV. First measurements of double differential cross sections in p 12C collisions at emission angles around 0° have been performed at T = 1.0, 1.2 and 2.0 GeV. The challenge is to identify the kaons in a huge background of pions and protons, since the signal to background ratio decreases to about 10 −6 at T = 1.0 GeV. For background suppression detectors and a trigger system based on energy-loss and time-of-flight measurements have been developed. In the analysis the decay of kaons ( τ = 12.4 ns) stopped in the detection system into μ + and π + is exploited as well as the track information from the wire chambers.