Large self-affine fractality in $\pi^{+}p$ and $K^{+}p$ collisions at 250 GeV/c

Taking into account the anisotropy of phase space in multiparticle production, a self-affine analysis of factorial moments was carried out on the NA22 data for $\pi^{+}p$ and $K^{+}p$ collisions at 250 GeV/$c$. Within the transverse plane, the Hurst exponents measuring the anisotropy are consistent with unit value (i.e. no anisotropy). They are, however, only half that value when the longitudinal direction is compared to the transverse ones. Fractality, indeed, turns out to be self-affine rather than self-similar in multiparticle production. In three-dimensional phase space, power-law scaling is observed to be better realized in self-affine than in self-similar analysis.