https://doi.org/10.1140/epjc/s10052-007-0376-6
Regular Article - Experimental Physics
Double spin asymmetry in exclusive ρ0 muoproduction at COMPASS
1
Fakultät für Physik, Universität Bielefeld, 33501, Bielefeld, Germany
2
Institut für Experimentalphysik, Universität Bochum, 44780, Bochum, Germany
3
Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115, Bonn, Germany
4
Physikalisches Institut, Universität Bonn, 53115, Bonn, Germany
5
Institute of Scientific Instruments, AS CR, 61264, Brno, Czech Republic
6
Burdwan University, 713104, Burdwan, India
7
Matrivani Institute of Experimental Research and Education, Calcutta, 700 030, India
8
Joint Institute for Nuclear Research, 141980, Dubna, Russia
9
Physikalisches Institut, Universität Erlangen–Nürnberg, 91054, Erlangen, Germany
10
Physikalisches Institut, Universität Freiburg, 79104, Freiburg, Germany
11
CERN, Geneva 23, 1211, Switzerland
12
Physikalisches Institut, Universität Heidelberg, 69120, Heidelberg, Germany
13
Helsinki University of Technology ,Low Temperature Laboratory, 02015, HUT, Finland and University of Helsinki, Helsinki Institute of Physics, 00014, Helsinki, Finland
14
Technical University in Liberec, 46117, Liberec, Czech Republic
15
LIP, 1000-149, Lisbon, Portugal
16
Institut für Kernphysik, Universität Mainz, 55099, Mainz, Germany
17
University of Miyazaki, Miyazaki, 889-2192, Japan
18
Lebedev Physical Institute, 119991, Moscow, Russia
19
Department für Physik, Ludwig-Maximilians-Universität München, 80799, Munich, Germany
20
Physik Department, Technische Universität München, 85748, Garching, Germany
21
Nagoya University, 464, Nagoya, Japan
22
Faculty of Mathematics and Physics, Charles University, 18000, Prague, Czech Republic
23
Czech Technical University in Prague, 16636, Prague, Czech Republic
24
Institute for High Energy Physics, State Research Center of the Russian Federation, 142281, Protvino, Russia
25
CEA DAPNIA/SPhN Saclay, 91191, Gif-sur-Yvette, France
26
School of Physics and Astronomy, Tel Aviv University, 69978, Tel Aviv, Israel
27
ICTP–INFN MLab Laboratory, 34014, Trieste, Italy
28
Department of Physics, INFN Trieste and University of Trieste, 34127, Trieste, Italy
29
Physics Department, INFN Turin and University of Turin, 10125, Turin, Italy
30
Sołtan Institute for Nuclear Studies and Warsaw University, 00-681, Warsaw, Poland
31
Institute of Radioelectronics, Warsaw University of Technology, 00-665, Warsaw, Poland
32
Yamagata University, Yamagata, 992-8510, Japan
* e-mail: gerhard.mallot@cern.ch
Received:
14
April
2007
Revised:
10
July
2007
Published online:
16
August
2007
The longitudinal double spin asymmetry A1 ρ for exclusive leptoproduction of ρ0 mesons, μ+N→μ+N+ρ, is studied using the COMPASS 2002 and 2003 data. The measured reaction is incoherent exclusive ρ0 production on polarised deuterons. The Q2 and x dependence of A1 ρ is presented in a wide kinematical range, 3×10-3<Q2< 7 (GeV/c)2 and 5×10-5<x<0.05. The results presented are the first measurements of A1 ρ at small Q2 (Q2< 0.1 (GeV/c)2) and small x (x<3×10-3). The asymmetry is in general compatible with zero in the whole kinematical range.
© Springer-Verlag , 2007