Hadron Correlations in Jets and Ridges through Parton Recombination

TL;DR

This paper explores hadron correlations in jets and ridges at RHIC energies, emphasizing the role of parton recombination and final-state interactions in explaining observed phenomena across various transverse momenta.

Contribution

It introduces a comprehensive recombination model for hadronization at intermediate $p_T$, analyzing the effects of semihard partons and medium interactions on correlations and ridge formation.

Findings

Final-state interactions are crucial for the Cronin effect and B/M ratios.

Ridge formation can occur without early thermalization.

Dihadron correlations reveal properties of trigger biases and jet geometry.

Abstract

Hadron correlations in jets, ridges and opposite dijets at all $p_T$ above 2 GeV/c are discussed. Since abundant data are available from RHIC at intermediate $p_T$, a reliable hadronization scheme at that $p_T$ range is necessary in order to relate the semihard partonic processes to the observables. The recombination model is therefore first reviewed for that purpose. Final-state interaction is shown to be important for the Cronin effect, large B/M ratio and forward production. The effect of semihard partons on the medium is then discussed with particular emphasis on the formation of ridge with or without trigger. Azimuthal anisotropy can result from ridges without early thermalization. Dynamical path length distribution is derived for any centrality. Dihadron correlations in jets on the same or opposite side are shown to reveal detail properties of trigger and antitrigger biases with the inference that tangential jets dominate the dijets accessible to observation.