SiΛvio: A trigger for Λ-hyperons

Robert Helmut Münzer ,Y Grishkin,Z Seres,N Herrmann,B Sikora,M Kirejczyk,P Crochet,A Reischl,Z Basrak,T Yamazaki,K Suzuki,A Schüttauf,V Simion,V Zinyuk,W Reisdorf,M Dželalija,Y Leifels,Z Fodor,R Čaplar,T Matulewicz,E Widmann,F Rami,A Andronic,M S Ryu ,Krzysztof Piasecki ,O Hartmann ,K S Sim ,K D Hildenbrand ,T I Kang ,J Márton ,P Bühler ,K Siwek‐Wilczyńska ,P Koczoń ,Ivana Carević ,Volha Charviakova ,K Wiśniewski ,R Kötte ,M L Benabderrahmane ,Z Tymiński ,I M Deppner ,J Kecskeméti ,I E Yushmanov ,Xiao Zhang ,L Fabbietti ,A N Lebedev ,A Zhilin,J Zmeskal,M Petrovici,P Dupieux,Martin Berger,M Cargnelli,M Kiš,R Averbeck,N Bastid,X Lopez,P Gasik,V Manko,I Gašparić,P Schmidt,Y.J Kim,J.L Liu,B Hong,P Wagner,V Smolyankin,V Barret,X.Y Zhang,P Kienle

doi:10.1016/j.nima.2014.01.050

Abstract

As online trigger for events containing Λ hyperons in p+p collisions at 3.1GeV a silicon-based device has been designed and built. This system has been integrated close to the target region within the FOPI spectrometer at GSI and was also employed as a tracking device to improve the vertex reconstruction of secondary decays. The design of the detector components, read-out, the trigger capability as well as the tracking performance are presented. An enrichment factor of about 14 was achieved for events containing a Λ-hyperon candidate.

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