Test of isospin symmetry via low-energy 1H(pi{-},pi{0})n charge exchange.
We report measurements of the pi;{-}p-->pi;{0}n differential cross sections at six momenta (104-143 MeV/c) and four angles (0 degrees -40 degrees ) by detection of gamma-ray pairs from pi;{0}-->gammagamma decays using a photon-pair spectrometer at TRIUMF. This kinematic region exhibits a vanishing zero-degree cross section from destructive interference between s and p waves, thus yielding special sensitivity to pion-nucleon dynamics. Our data and previous data do not agree, with important implications for earlier claims of large isospin-violating effects.
Jia
Y
Y
University of Kentucky, Lexington, Kentucky 40506, USA.
Gorringe
T P
TP
Hasinoff
M D
MD
Kovash
M A
MA
Ojha
M
M
Pavan
M M
MM
Tripathi
S
S
Zołnierczuk
P A
PA