Isospin breaking splits threshold cusps in ΛN-ΣN scattering into constrained structures whose relative sharpness or type can change, as shown via K-matrix classification and N²LO chiral EFT calculations.
Observation of a cusp-like structure in the pizero-pizero invariant mass distribution from K+- ==> pi+- pizero pizero decay and determination of the pi-pi scattering lengths
1 Pith paper cite this work. Polarity classification is still indexing.
1
Pith paper citing it
abstract
We report the results from a study of ~23 Million K+- ==> pi+- pizero pizero decays recorded by the NA48/2 experiment at the CERN SPS, showing an anomaly in the pizero pizero invariant mass distribution in the region around 2m+, where m+ is the charged pion mass. This anomaly, never observed in previous experiments, can be interpreted as an effect due mainly to the final state charge exchange scattering process pi+ pi- ==> pizero pizero in K+- ==> pi+- pi+ pi- decay. It provides a precise determination of a0 - a2, the difference between the pi-pi scattering lengths in the isospin I=0 and I=2 states.
fields
hep-ph 1years
2026 1verdicts
UNVERDICTED 1representative citing papers
citing papers explorer
-
Isospin-breaking effects on the threshold cusp structures in $\Lambda N$-$\Sigma N$ scattering
Isospin breaking splits threshold cusps in ΛN-ΣN scattering into constrained structures whose relative sharpness or type can change, as shown via K-matrix classification and N²LO chiral EFT calculations.