TY  - JOUR
AU  - Dai, Lingyun
AU  - Pennington, M. R.
TI  - Pion polarizabilities from a γ γ → π π analysis
JO  - Physical review / D
VL  - 94
IS  - 11
SN  - 2470-0010
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2017-00457
SP  - 116021
PY  - 2016
AB  - We present results for pion polarizabilities predicted using dispersion relations from our earlier amplitude analysis of world data on two photon production of meson pairs. The helicity-zero polarizabilities are rather stable and insensitive to uncertainties in cross-channel exchanges. The need is first to confirm the recent result on (α1−β1) for the charged pion by COMPASS at CERN to an accuracy of 10% by measuring the γγ→π+π− cross section to an uncertainty of 1%. Then the same polarizability, but for π0, is fixed to be (α1−β1)π0=(0.9±0.2)×10−4  fm3. By analyzing the correlation between uncertainties in the meson polarizability and those in γγ cross sections, we suggest experiments need to measure these cross sections between √s≃350 and 600 MeV. The π0π0 cross section then makes the (α2−β2)π0 the easiest helicity-two polarizability to determine.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000391016800012
DO  - DOI:10.1103/PhysRevD.94.116021
UR  - https://juser.fz-juelich.de/record/826211
ER  -