ar X iv : n uc l - ex / 0 10 80 08 v 2 2 2 Ju l 2 00 7 The reaction np → pp π − from threshold up to 570 MeV
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چکیده
The reaction np → ppπ − has been studied in a kinematically complete measurement with a large acceptance time-of-flight spectrometer for incident neutron energies between threshold and 570 MeV. The proton-proton invariant mass distributions show a strong enhancement due to the pp(1 S0) final state interaction. A large anisotropy was found in the pion angular distributions in contrast to the reaction pp → ppπ 0. At small energies, a large forward/backward asymmetry has been observed. From the measured integrated cross section σ(np → ppπ −), the isoscalar cross section σ01 has been extracted. Its energy dependence indicates that mainly partial waves with Sp final states contribute. Note: Due to a coding error, the differential cross sections dσ/dMpp as shown in Fig. 9 are too small by a factor of two, and inn Table 3 the differential cross sections dσ/dΩ * π are too large by a factor of 10/2π. The integrated cross sections and all conclusions remain unchanged. A corresponding erratum has been submitted and accepted by European Physics Journal.
منابع مشابه
ar X iv : n uc l - ex / 0 10 80 08 v 1 7 A ug 2 00 1 The reaction np → pp π − from threshold up to 570 MeV
The reaction np → ppπ − has been studied in a kinematically complete measurement with a large acceptance time-of-flight spectrometer for incident neutron energies between threshold and 570 MeV. The proton-proton invariant mass distributions show a strong enhancement due to the pp(1 S0) final state interaction. A large anisotropy was found in the pion angular distributions in contrast to the rea...
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