Observation of neutrino induced diffractive Ds*+ production and subsequent decay Ds*+ › Ds+ › ?+ › µ+

We report on the first direct observation of a neutrino induced charged-current interaction with two subsequent decays of short-lived particles close to the interaction vertex. This rare double-kink signature in the CHORUS emulsion target is interpreted as a Ds*+ production followed by the decay chain Ds*+ › Ds+ ?, Ds+ › ?+ v?, ?+ › µ+ vµ v?¯. The event is characterised by small Q2 and small four-momentum transfer squared t to the target nucleon, which indicates a diffractive production mechanism. A complete analysis of the event is presented. © 1998 Elsevier Science B.V. All rights reserved.Japan Society for the Promotion of Science Bundesministerium für Bildung und Forschung: 057MS12P CERN Brussels Instituut voor Milieubeheer Israel Science Foundation: 328/94 Korea Science and Engineering Foundation: BSRI-97-2407 Instituto Nazionale di Fisica Nucleare Foundation for Fundamental Research on MatterOne of us (O.M.) would like to thank P. Marage, L. Sehgal and D. Rein for useful discussions on diffractive production. We gratefully acknowledge the support of all our technical collaborators contributing to the detector construction, operation, emulsion pouring, development and scanning. We thank the neutrino beam staff ensuring the excellent performance of the facility. The accumulation of a large data sample in this experiment has been made possible also thanks to the efforts of the crew operating the CERN PS and SPS. The general technical support from the CERN EP and IT divisions is gratefully acknowledged. The experiment has been made possible by grants from the following funding agencies: the Institut Interuniversitaire des Sciences Nucléaires and the Interuniversitair Instituut voor Kernwetenschappen (Belgium), the Israel Science foundation (grant 328/94) and the Technion Vice President Fund for the Promotion of Research (Israel), CERN (Geneva, Switzerland), the German Bundesministerium für Bildung und Forschung (grant 057MS12P(0)) (Germany), the Institute of Theoretical and Experimental Physics (Moscow, Russia), the Istituto Nazionale di Fisica Nucleare (Italy), the Japan Private School Promotion Foundation and Japan Society for the Promotion of Science (Japan), the Korea Science and Engineering Foundation and the Ministry of Education through Research Fund (BSRI-97-2407)(Republic of Korea), the Foundation for Fundamental Research on Matter FOM and the National Scientific Research Organization NWO (The Netherlands), and the Scientific and Technical Research Council of Turkey (Turkey)