Jun 13 – 17, 2011
Künstlerhaus
Europe/Berlin timezone
Proceedings are now available online at <a href="http://www.slac.stanford.edu/econf/C110613/">eConf</a>

Determination of the eta transition form-factor from the eta --> e+ e- gamma decay

Jun 14, 2011, 5:10 PM
20m
Festsaal (Künstlerhaus)

Festsaal

Künstlerhaus

talk Light Mesons Light Mesons

Speaker

Prof. Volker Metag Metag (II. Physikalisches Institut)

Description

Volker Metag University of Giessen, Germany for the A2 collaboration The Dalitz decay η → γe+e− has been investigated in photo-nuclear reactions with the Crystal Ball/TAPS detector system at the electron accelerator MAMI-C. The Dalitz decay events were identified in an exclusive analysis exploiting the full kinematic information. Statistics improved by an order of magnitude compared to the most recent measurement in the e+e− channel allowed to determine the slope bη of the electromagnetic transition form factor F (q2) = (1 − q2/Λ2)−1 to bη = Λ−2 = (1.89 ± 0.35(stat) ± 0.1(syst)) GeV−2. 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 branching ratio BR(η → γe+e−) = (6.21 ± 0.50) · 10−3 has been determined. Funded by DFG(SFB/TR-16)

Primary author

Prof. Volker Metag Metag (II. Physikalisches Institut)

Presentation materials