Jan Czyzewski | Searcharxiv

arXiv1996

Correlations in transverse momentum in pion-proton and kaon-proton collisions at 250 GeV/c

We have measured the second-order normalized differential factorial moments as a function of the difference of transverse momentum ($Δp_T$) in $\p^+ p$ and $K^+ p$ collisions at 250 GeV/$c$. The second-order differential factorial moments for like-charged pairs reveal a strong increase with decreasing $Δp_T$. In a small central rapidity window this increase is described by a simple power law. Such a behavior, if interpreted as originating from Bose-Einstein correlations, may indicate a structure of the transverse spatial distribution of the source similar to that recently predicted by Białas and Peschanski for color-dipole emission in onium-onium scattering. The power of the rise obtained in the fit agrees with the predicted value.

hep-ex↗

arXiv1996

Single spin asymmetry of vector meson production in the string model

Azimuthal asymmetry of vector-meson production in single-transversely polarized proton-proton collisions ($p\up p$) is calculated in a model based on the string fragmentation. The string is spanned by a valence quark of the projectile scattered on the target. The asymmetry is generated only during fragmentation of the scattered quark into hadrons. The obtained asymmetry of the $ρ$ mesons is opposite in sign to that of pions. On the other hand, if the asymmetry were generated during the quark scattering then the asymmetries of the vector and of the pseudoscalar mesons would be close to each other.

hep-ph↗