M. Burlein

Pion double charge exchange above the Δ(1232) resonance

Abstract First measurements of exclusive cross sections for the ( π + , π − ) reaction at incident energies of 300–500 MeV are reported. For the analog-state transitions in 14 C and 18 O the 5° cross sections are found to remain nearly constant in this energy interval. This behavior is in disagreement both with predictions based on six-quark cluster models and with simple expectations based on recent single-charge-exchange measurements.

Pion double charge exchange on sup 42,44,48 Ca for 300 le T sub. pi. le 550 MeV

Measurements of cross sections for pion-induced double-charge-exchange reactions to the double-isobaric-analog state for {sup 42,44,48}Ca at incident pion energies of 300--550 MeV at {theta}{sub lab}=5{degree} are reported, together with upper limits for cross sections for transitions to the residual ground states for {sup 44,48}Ca. The data are fitted with a two-amplitude model which gives expressions for cross sections for both transitions. The fit overpredicts the ground-state cross sections, indicating a failure of the model in this energy range.

Pion double charge exchange on Ca 4 2 , 4 4 , 4 8 for 300≤ T π ≤550 MeV

Measurements of cross sections for pion-induced double-charge-exchange reactions to the double-isobaric-analog state for {sup 42,44,48}Ca at incident pion energies of 300--550 MeV at {theta}{sub lab}=5{degree} are reported, together with upper limits for cross sections for transitions to the residual ground states for {sup 44,48}Ca. The data are fitted with a two-amplitude model which gives expressions for cross sections for both transitions. The fit overpredicts the ground-state cross sections, indicating a failure of the model in this energy range.

Pion double charge exchange onCa42,44,48for 300≤Tπ≤550 MeV

Measurements of cross sections for pion-induced double-charge-exchange reactions to the double-isobaric-analog state for {sup 42,44,48}Ca at incident pion energies of 300--550 MeV at {theta}{sub lab}=5{degree} are reported, together with upper limits for cross sections for transitions to the residual ground states for {sup 44,48}Ca. The data are fitted with a two-amplitude model which gives expressions for cross sections for both transitions. The fit overpredicts the ground-state cross sections, indicating a failure of the model in this energy range.