Abstract
The Dalitz decay η→γe+e- has been measured using the combined Crystal Ball and TAPS photon detector setup at the electron accelerator MAMI-C. Compared to the most recent transition form-factor measurement in the e+e- channel, statistics have been improved by one order of magnitude. The e+e- invariant mass distribution shows a deviation from the QED prediction for a point-like particle, which can be described by a form-factor. Using the usual monopole transition form-factor parameterization, F(m2)=(1-m2/Λ2)-1, a value of Λ-2=(1.92±0.35(stat)±0.13(syst)) GeV-2 has been determined. This value is in good agreement with a recent measurement of the η Dalitz decay in the μ+μ- channel and with recent form-factor calculations. An improved value of the branching ratio BR(η→γe+e-)=(6.6±0.4(stat)±0.4(syst)).10-3 has been determined.
| Original language | English |
|---|---|
| Pages (from-to) | 562-567 |
| Number of pages | 6 |
| Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
| Volume | 701 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 27 Jul 2011 |
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Keywords
- Meson decays
- Transition form factor
ASJC Scopus subject areas
- Nuclear and High Energy Physics
Cite this
Determination of the η-transition form factor in the γp→pη→pγe+e- reaction. / Berghäuser, H.; Metag, V.; Starostin, A.; Bartolomé, P. Aguar; Akasoy, L. K.; Annand, J. R.M.; Arends, H. J.; Bantawa, K.; Beck, R.; Bekrenev, V.; Braghieri, A.; Branford, D.; Briscoe, W. J.; Brudvik, J.; Cherepnya, S.; Demissie, B. T.; Downie, E. J.; Drexler, P.; Dieterle, M.; Fil'kov, L. V.; Fix, A.; Glazier, D. I.; Heid, E.; Hornidge, D.; Jahn, O.; Jude, T. C.; Kashevarov, V. L.; Knezevic, A.; Kondratiev, R.; Korolija, M.; Kotulla, M.; Koulbardis, A.; Kruglov, S.; Krusche, B.; Lemmer, B.; Lisin, V.; Livingston, K.; MacGregor, I. J.D.; Maghrbi, Y.; Manley, D. M.; Martinez-Fabregate, M.; McGeorge, J. C.; McNicoll, E. F.; Mekterovic, D.; Micanovic, S.; Mushkarenkov, A.; Nefkens, B. M.K.; Nikolaev, A.; Novotny, R.; Ostrick, M.; Owens, R. O.; Pedroni, P.; Pheron, F.; Polonski, A.; Robinson, J.; Prakhov, S. N.; Rosner, G.; Rostomyan, T.; Schumann, S.; Sober, D.; Suarez, I. M.; Supek, I.; Tarbert, C. M.; Thiel, M.; Thomas, A.; Unverzagt, M.; Watts, D. P.; Werthmüller, D.; Zamboni, I.; Zehr, F.
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol. 701, No. 5, 27.07.2011, p. 562-567.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Determination of the η-transition form factor in the γp→pη→pγe+e- reaction
AU - Berghäuser, H.
AU - Metag, V.
AU - Starostin, A.
AU - Bartolomé, P. Aguar
AU - Akasoy, L. K.
AU - Annand, J. R.M.
AU - Arends, H. J.
AU - Bantawa, K.
AU - Beck, R.
AU - Bekrenev, V.
AU - Braghieri, A.
AU - Branford, D.
AU - Briscoe, W. J.
AU - Brudvik, J.
AU - Cherepnya, S.
AU - Demissie, B. T.
AU - Downie, E. J.
AU - Drexler, P.
AU - Dieterle, M.
AU - Fil'kov, L. V.
AU - Fix, A.
AU - Glazier, D. I.
AU - Heid, E.
AU - Hornidge, D.
AU - Jahn, O.
AU - Jude, T. C.
AU - Kashevarov, V. L.
AU - Knezevic, A.
AU - Kondratiev, R.
AU - Korolija, M.
AU - Kotulla, M.
AU - Koulbardis, A.
AU - Kruglov, S.
AU - Krusche, B.
AU - Lemmer, B.
AU - Lisin, V.
AU - Livingston, K.
AU - MacGregor, I. J.D.
AU - Maghrbi, Y.
AU - Manley, D. M.
AU - Martinez-Fabregate, M.
AU - McGeorge, J. C.
AU - McNicoll, E. F.
AU - Mekterovic, D.
AU - Micanovic, S.
AU - Mushkarenkov, A.
AU - Nefkens, B. M.K.
AU - Nikolaev, A.
AU - Novotny, R.
AU - Ostrick, M.
AU - Owens, R. O.
AU - Pedroni, P.
AU - Pheron, F.
AU - Polonski, A.
AU - Robinson, J.
AU - Prakhov, S. N.
AU - Rosner, G.
AU - Rostomyan, T.
AU - Schumann, S.
AU - Sober, D.
AU - Suarez, I. M.
AU - Supek, I.
AU - Tarbert, C. M.
AU - Thiel, M.
AU - Thomas, A.
AU - Unverzagt, M.
AU - Watts, D. P.
AU - Werthmüller, D.
AU - Zamboni, I.
AU - Zehr, F.
PY - 2011/7/27
Y1 - 2011/7/27
N2 - The Dalitz decay η→γe+e- has been measured using the combined Crystal Ball and TAPS photon detector setup at the electron accelerator MAMI-C. Compared to the most recent transition form-factor measurement in the e+e- channel, statistics have been improved by one order of magnitude. The e+e- invariant mass distribution shows a deviation from the QED prediction for a point-like particle, which can be described by a form-factor. Using the usual monopole transition form-factor parameterization, F(m2)=(1-m2/Λ2)-1, a value of Λ-2=(1.92±0.35(stat)±0.13(syst)) GeV-2 has been determined. This value is in good agreement with a recent measurement of the η Dalitz decay in the μ+μ- channel and with recent form-factor calculations. An improved value of the branching ratio BR(η→γe+e-)=(6.6±0.4(stat)±0.4(syst)).10-3 has been determined.
AB - The Dalitz decay η→γe+e- has been measured using the combined Crystal Ball and TAPS photon detector setup at the electron accelerator MAMI-C. Compared to the most recent transition form-factor measurement in the e+e- channel, statistics have been improved by one order of magnitude. The e+e- invariant mass distribution shows a deviation from the QED prediction for a point-like particle, which can be described by a form-factor. Using the usual monopole transition form-factor parameterization, F(m2)=(1-m2/Λ2)-1, a value of Λ-2=(1.92±0.35(stat)±0.13(syst)) GeV-2 has been determined. This value is in good agreement with a recent measurement of the η Dalitz decay in the μ+μ- channel and with recent form-factor calculations. An improved value of the branching ratio BR(η→γe+e-)=(6.6±0.4(stat)±0.4(syst)).10-3 has been determined.
KW - Meson decays
KW - Transition form factor
UR - http://www.scopus.com/inward/record.url?scp=79960173271&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79960173271&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2011.06.069
DO - 10.1016/j.physletb.2011.06.069
M3 - Article
AN - SCOPUS:79960173271
VL - 701
SP - 562
EP - 567
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
SN - 0370-2693
IS - 5
ER -