Pion charge radius from pion+electron elastic scattering data

Physics Letters B, vol. 822, pp. 136631

Abstract

With the aim of extracting the pion charge radius, we analyse extant precise pion+electron elastic scattering data on Q2∈[0.015,0.144] GeV2 using a method based on interpolation via continued fractions augmented by statistical sampling. The scheme avoids any assumptions on the form of function used for the representation of data and subsequent extrapolation onto Q2≃0. Combining results obtained from the two available data sets, we obtain rπ=0.640(7) fm, a value 2.4σ below today's commonly quoted average. The tension may be relieved by collection and similar analysis of new precise data that densely cover a domain which reaches well below Q2=0.015 GeV2. Considering available kaon+electron elastic scattering data sets, our analysis reveals that they contain insufficient information to extract an objective result for the charged-kaon radius, rK. New data with much improved precision, low-Q2 reach and coverage are necessary before a sound result for rK can be recorded.

Authors 4

1. Zhu-Fang Cui

   Nanjing University

   Affiliation as printed

   Institute for Nonperturbative Physics, Nanjing University, Nanjing, Jiangsu 210093, China

   School of Physics, Nanjing University, Nanjing, Jiangsu 210093, China

2. Daniele Binosi

   European Centre for Theoretical Studies in Nuclear Physics and Related Areas

   Affiliation as printed

   European Centre for Theoretical Studies in Nuclear Physics and Related Areas, Villa Tambosi, Strada delle Tabarelle 286, I-38123 Villazzano (TN), Italy

   European Centre for Theoretical Studies in Nuclear Physics and Related Areas; Villa Tambosi, Strada delle Tabarelle 286, I-38123 Villazzano (TN), Italy

3. Craig D. Roberts corresponding

   Nanjing University

   Affiliation as printed

   Institute for Nonperturbative Physics, Nanjing University, Nanjing, Jiangsu 210093, China

   School of Physics, Nanjing University, Nanjing, Jiangsu 210093, China

4. Sebastian M. Schmidt Aachen III. Physikalisches Institut B

   Helmholtz-Zentrum Dresden-Rossendorf · RWTH Aachen University

   Affiliation as printed

   Helmholtz-Zentrum Dresden-Rossendorf, Dresden D-01314, Germany

   RWTH Aachen University, III. Physikalisches Institut B, Aachen D-52074, Germany