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. SPES3 mass 1004 1044 1094 1136 1173 1249 1277 1339 1384 1479 marker ( α ) ( β ) ( γ ) ( δ ) ( ϵ ) ( η ) ( φ ) ( ν ) SPES4 mass 0.8 ◦ 1052 1113 1142 1202 1234 1259 1370 1394 1478 SPES4 mass 2 ◦ 996 1036 1104 1144 1198 1234 1313 1370 1477 SPES3 mass 1505 1517 1533 1542 (1554) 1564 1577 SPES4 mass 2 ◦ 1507 1517 1530 1543 1557 1569 1580 TABLE I: Masses (in MeV) of narrow exotic baryons, observed previously in SPES3 data and extracted from previous p( α, α ’)X spectra measured at SPES4 [11, 13]. A nice fit is obtained after introduction of the narrow resonances, leading to an important decrease of the χ 2 (see Table 2). 7