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

Nikolaev, A. et al. (2014) Determination of the η mass with the Crystal Ball at MAMI-B. European Physical Journal A, 50(3), p. 58. (doi:10.1140/epja/i2014-14058-1)

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Publisher's URL: http://dx.doi.org/10.1140/epja/i2014-14058-1

Abstract

A new precise determination of the η meson mass is presented. It is based on a measurement of the threshold for the γp → pη 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 η 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 mη = (547.865±0.031stat. ±0.062syst.) 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.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Livingston, Dr Kenneth and Codling, Mr Richard and Glazier, Dr Derek and McGeorge, Dr John and Owens, Professor Robert and Downie, Dr Evangeline and MacGregor, Professor I and Annand, Dr John and Rosner, Professor Guenther
Authors: Nikolaev, A., Aguar-Bartolomé, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Beck, R., Bekrenev, V., Boillat, B., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J. W., Cherepnya, S., Codling, R., Dehn, M., Downie, E. J., Fil’kov, L. V., Glazier, D. I., Gregor, R., Heid, E., Hornidge, D., Jahn, O., Jankowiak, A., Kaiser, K. -H., Kashevarov, V. L., Kondratiev, R., Korolija, M., Kotulla, M., Krambrich, D., Krusche, B., Lang, M., Lisin, V., Livingston, K., Ludwig-Mertin, U., Lugert, S., MacGregor, I. J. D., Manley, D. M., Martinez-Fabregate, M., McGeorge, J. C., Mekterovic, D., Metag, V., Nefkens, B. M. K., Novotny, R., Owens, R. O., Pedroni, P., Polonski, A., Prakhov, S. N., Price, J. W., Reiter, A., Rosner, G., Rost, M., Rostomyan, T., Schumann, S., Sober, D., Starostin, A., Supek, I., Tarbert, C. M., Thomas, A., Unverzagt, M., Walcher, T., Watts, D. P., and Zehr, F.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:European Physical Journal A
Publisher:Springer
ISSN:1434-6001
ISSN (Online):1434-601X

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