Micro-canonical pentaquark production in and pp collisions

Multiplicity Dependence of Hadron Spectra in Proton-proton Collisions at LHC Energies and Super-statistics

“…According to these models, in highenergy collisions, small thermal "fireballs" or "clusters" are formed and fragment into hadrons. Hadrons stemming from a single cluster inherit the thermal (canonical [37,38,42,43] or microcanonical [4,16,17,34,35,36,41]) distribution of the fireball. However, since the fourmomentum (or four-velocity) and cluster mass [4,16,17,34,35,36,41], or the temperature [1,2,20,21,22,23,29,33] or cluster volume [23,34] or the hadron multiplicity [5,18] fluctuates from cluster to cluster, the average hadron spectrum may become a cut-power law (or Tsallis) distribution.…”

“…These models are based on the conjecture that in high-energy collisions, small thermal droplets of matter (often refered to as "fireballs" or "clusters") are created and these droplets fragment into hadrons. The calculations are carried through either in the canonical [13,14,37,38,42,43] or microcanonical [4,16,17,34,35,36,41] framework, and describe measured data on hadron specra, total hadron multiplicities as well as multiplicity distributions. The latter can be approximated by either the negative binomial or by Euler's gamma-distribution.…”

“…It is worth noting that if we approximate very narrow jets with one-dimensional bunches of massless hadrons, the conservation of four-momentum reduces to the conservation of energy, and the clusters (jets) become massless too (for a discussion, see [18]). Thus, jetfragmentation models [5,6,18] may be considered as an approximation of microcanonical statistical hadronisa-tion models [4,16,17,34,35,36,41] for very high hadron energies and jet-like, very narrow, one-dimensional clusters. The latter models are sensitive to the species of hadrons and multiplicity distributions are obtained from them as a consequence.…”