π−pReactions at 456, 505, and 552 MeV/c

Δ(1232)inπN→ππNreaction

“…The data from Refs. [24,25,26] for π + p → π + π + n, [27,28,29,30,31,32,33,34,35,36] for π − p → π + π − n, and [37,38,39,40,41] for π − p → π 0 π 0 n. section indicates the increase by about 25 % with R N ∆ = 0.4 and 65 % with R N ∆ = 0.8 around T π = 300 MeV. These two channels exhibit large influence of the π∆∆ interaction on the total cross section.…”

Phenomenological πN→ππN amplitude and analysis of low energy data on total cross sections and 1--D distributions

“…So large value of systematic error forced us to withdraw the distributions of the paper [71] from our fittings.…”

“…The data on distributions of works [45], [46], [71], [38] were taken from the journal publications. The major part of distributions of the work [18] has never been published.…”

“…We are using the total cross sections data [3], [4], [5], [6], [7], [9], [15], [16], [17], [18], [25], [26], [28], [38], [41], [42], [43], [45], [46], [48], [49], [53], [64], [66], [71], [72], [76]. 94 points were selected on the grounds of the compatibility analysis of the paper [80] from the total list of 105 experimental points.…”

“…The experimental base for fitting the amplitude parameters was built of the total cross sections in all five channels of the considered reaction in the energy region P Lab ≤ 500 MeV/c and the distributions measured in the hydrogen bubble-chamber experiments at these energies [45,46,18,71,38]. The bubble-chamber data were preferred since they satisfy the condition of the coverage of the reaction phase space in the most complete way (the only restrictions are P proton ≥ 120 MeV/c and P π ≥ 30 MeV/c which correspond to 5 mm of the flight distance).…”