Determination of the mass with the Crystal Ball at MAMI-B

Crystal Ball MAMI TAPS A2, A. Nikolaev*, P. Aguar-Bartolome, J. Ahrens, J. R. M. Annand, H. J. Arends, R. Beck, V. Bekrenev, B. Boillat, A. Braghieri, D. Branford, W. J. Briscoe, J. W. Brudvik, S. Cherepnya, R. Codling, M. Dehn, E. J. Downie, L. V. Fil'kov, D. I. Glazier, R. GregorE. Heid, D. Hornidge, O. Jahn, A. Jankowiak, K. -H. Kaiser, V. L. Kashevarov, R. Kondratiev, M. Korolija, M. Kotulla, D. Krambrich, B. Krusche, M. Lang, V. Lisin, K. Livingston, U. Ludwig-Mertin, S. Lugert, I. J. D. MacGregor, D. M. Manley, M. Martinez-Fabregate, J. C. McGeorge, D. Mekterovic, V. Metag, B. M. K. Nefkens, R. Novotny, R. O. Owens, P. Pedroni, A. Polonski, S. N. Prakhov, J. W. Price, A. Reiter, D. P. Watts

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

A new precise determination of the meson mass is presented. It is based on a measurement of the threshold for the reaction using the tagger focal-plane microscope detector at the MAMI-B facility in Mainz. The tagger microscope has a higher energy resolution than the standard tagging spectrometer and, hence, allowed an improvement in the accuracy compared to the previous mass measurement at MAMI-B. Special emphasis was put on a very careful energy calibration of the electron beam and the tagging device, which reduced considerably the systematic uncertainty compared to the previous MAMI experiment. The result MeV agrees very well with the precise values of the NA48, KLOE, CLEO and COSY-ANKE Collaborations and deviates by from the smaller value obtained by the GEM Collaboration at COSY.

Original languageEnglish
Article number58
Number of pages10
JournalThe European Physical Journal A (EPJ A)
Issue number3
Publication statusPublished - 24 Mar 2014

Keywords / Materials (for Non-textual outputs)



Dive into the research topics of 'Determination of the mass with the Crystal Ball at MAMI-B'. Together they form a unique fingerprint.

Cite this