, Volume 60, Issue 1, pp 25-45,
Open Access This content is freely available online to anyone, anywhere at any time.

Production of excited charm and charm-strange mesons at HERA


The production of excited charm, D 1(2420)0 and D 2 * (2460)0, and charm-strange, D s1(2536)±, mesons in ep collisions was measured with the ZEUS detector at HERA using an integrated luminosity of 126 pb−1. Masses, widths and helicity parameters were determined. The measured yields were converted to the rates of c quarks hadronising as a given excited charm meson and to the ratios of the dominant D 2 * (2460)0 and D s1(2536)± branching fractions. A search for the radially excited charm meson, D *′(2640)±, was also performed. The results are compared with those measured previously and with theoretical expectations.

Dedicated to the memory of our colleague Pavel Ermolov.
Also affiliated with University College London, UK.
Now at BayesForecast, Madrid, Spain.
Also at Institut of Theoretical and Experimental Physics, Moscow, Russia.
Also at INP, Cracow, Poland.
Also at FPACS, AGH-UST, Cracow, Poland.
Partly supported by Moscow State University, Russia.
Royal Society of Edinburgh, Scottish Executive Support Research Fellow.
Also affiliated with DESY, Germany.
Also at University of Tokyo, Japan.
Now at Kobe University, Japan.
Supported by DESY, Germany.
Now at University of Salerno, Italy.
Partly supported by Russian Foundation for Basic Research grant no. 05-02-39028-NSFC-a.
Partially supported by Warsaw University, Poland.
This material was based on work supported by the National Science Foundation, while working at the Foundation.
Now at University of Kansas, Lawrence, USA.
Also at Max Planck Institute, Munich, Germany, Alexander von Humboldt Research Award.
Now at KEK, Tsukuba, Japan.
Now at Nagoya University, Japan.
Member of Department of Radiological Science, Tokyo Metropolitan University, Japan.
Now at SunMelx Co. Ltd., Tokyo, Japan.
PPARC Advanced fellow.
Supported by the research grant no. 1 P03B 04529 (2005–2008).
Also at Hamburg University, Inst. of Exp. Physics, Alexander von Humboldt Research Award and partially supported by DESY, Hamburg, Germany.
Also at Łódź University, Poland.
Member of Łódź University, Poland.
Now at Lund Universtiy, Lund, Sweden.
This work was supported in part by the Marie Curie Actions Transfer of Knowledge project COCOS (contract MTKD-CT-2004-517186).
Now at University of Bonn, Germany.
Now at DESY group FEB, Hamburg, Germany.
Now at University of Liverpool, UK.
Now at CERN, Geneva, Switzerland.
Now at Bologna University, Bologna, Italy.