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the baryonic structures found in previous works, allows to get a very good description of the experimental data. The calculation performed in [16, 17] of the Δ ++ peak alone, is unable to fully describe the data. On the one hand, the statistical significance between data and broad PDG Δ resonance is χ 2 $_{D}$=4.7 on the other hand, the statistical significance between data and total spectra including the narrow resonances is χ 2 $_{NR}$=2.1 (see Table 2). 

FIG. 7: (Color online.) Cross-section of the pp → n Δ ++ reaction at T$_{p}$ =0.97 GeV θ = 0 ◦ [16] 

More recent data of the $^{1}$H(p,n)X reaction exist at T$_{p}$ =790 MeV, θ$_{n}$ =0 ◦ , 7.5 ◦ , and 15 ◦ . The corresponding differential cross-sections d $^{2}$σ/dE$_{n}$ d Ω$_{n}$ were measured at LAMPF [18]. These data at the two smallest angles are reanalyzed in Fig. 8. The full curves fitting the small empty triangles, describe the theoretical calculations [19] performed with use of an effective projectile-target-nucleon interaction. These curves are reproduced here just as the data; they describe the broad Δ peak. A few points corresponding to the largest energy loss ( ω ) values are omitted, since they lie over the Jacobian limit, therefore corresponding to decreasing missing masses. The open circles correspond to data integrated by two channels. 

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A nice fit is obtained after introduction of the narrow resonances, leading to an important decrease of the χ 2 (see Table 2). 

