- th / 9 40 40 24 v 1 2 8 A pr 1 99 4 Two - body Pion Absorption on 3 He at Threshold
نویسندگان
چکیده
It is shown that a satisfactory explanation of the ratio of the rates of the 0 reactions 3 He(π − , nn) and 3 He(π − , np) for stopped pions is obtained once the effect of the short range two-nucleon components of the axial charge operator for the nuclear system is taken into account. By employing realistic models for the nucleon-nucleon interaction in the construction of these components of the axial charge operator, the predicted ratios agree with the empirical value to within 10-20%.
منابع مشابه
- th / 9 80 40 09 v 1 6 A pr 1 99 8 The neutron charge form factor in helium - 3
In order to measure the charge form factor of the neutron, G n E (Q 2), one needs to use a neutron bound in a nuclear target. We calculate the change in the form factor for a neutron bound in 3 He, with respect to the free case, using several versions of the quark meson coupling model. It is found that the form factor may be suppressed by as much as 12% at Q 2 = 0.5 GeV 2 with respect to that o...
متن کامل- th / 9 80 40 53 v 1 2 3 A pr 1 99 8 Non - perturbative chiral approach to K − p → γY reactions
The recently developed nonperturbative chiral approach to describe the S = −1 meson-baryon reactions has been extended to investigate the near threshold K − p → γΛ, γΣ 0 reactions. With the parameters governed by chiral SU(3) symmetry, we show that the predicted branching ratios Γ K − p→γΛ /Γ K − p→all and Γ K − p→γΣ 0 /Γ K − p→all are close to the experimental values. The coupling with the η c...
متن کاملiv : n uc l - th / 0 50 40 81 v 1 2 8 A pr 2 00 5 Formation of mesic nuclei by ( γ , p ) reactions
We present a theoretical study on formation rates of η and ω meson-nucleus systems induced by (γ, p) reactions on nuclear targets at ideal recoilless condition. We find that the smaller distortion effect in the (γ, p) reaction enables us to investigate properties of the mesons created deeply inside nucleus more clearly. We also consider excitation of scalar-isoscalar (σ) mode in nucleus in orde...
متن کاملar X iv : n uc l - th / 9 70 40 51 v 1 2 3 A pr 1 99 7 TPR - 96 - 24 Space - time Characteristics of the Fireball from HBT
We present the Yano-Koonin-Podgoretski˘ ı parametrisation of the correlation function. Compared to the conventionally used Cartesian parametrisation, this one provides more straightforward measurement of the duration of the emission process in the fireball and a clearer signal of the longitudinal expansion, which is expected in ulrarelativistic heavy ion collisions.
متن کاملl - th / 9 90 40 72 v 1 2 8 A pr 1 99 9 Pion cloud and the Q 2 − dependence of γ ∗ N ↔ ∆ transition form factors
Recent experiment indicates that the behavior exhibited by the ratios E1+/M1+ and S1+/M1+ of the γ N ↔ ∆ transition remain small and negative for Q2 ≤ 4.0 GeV 2. It implies that the perturbative QCD is still not applicable at these momentum transfers. We show that these data can be explained in a dynamical model for electromagnetic production of pions, together with a simple scaling assumption ...
متن کامل