Eur. Phys. J. A (2009) 41: 93-100
https://doi.org/10.1140/epja/i2009-10802-x

Regular Article - Theoretical Physics

New constraints on the pion EM form factor using (- Q²)

Centre for High Energy Physics, Indian Institute of Science, 560 012, Bangalore, India

^* e-mail: anant@cts.iisc.ernet.in

Received: 25 March 2009
Revised: 9 April 2009
Accepted: 14 April 2009
Published online: 22 May 2009

Abstract

We study the constraints arising on the expansion parameters c and d of the pion electromagnetic form factor from the inclusion of pure spacelike data and the phase of timelike data along with one spacelike datum, using as input the first derivative of the QCD polarization amplitude (- Q ²) . These constraints when combined with other analyses, provide a valuable check on a determination of c due to Guo et al. and on our previous work where pionic contribution to the (g - 2) of the muon was used as the input. This work further illustrates the power of analyticity techniques in form factor analysis.