Jet-like correlations


A jet is a spray of hadrons produced by the “hard” scattering of a parton (quark or gluon). A hard scattering is one in which a large amount of energy is transferred between partons.

Hard scatterings occur early in a heavy-ion collision, allowing the scattered partons to act as probes of the medium created in these collisions.

The modifications of jets measured in Au+Au collisions compared to p+p collisions is interpreted to be an effect of the large densities in Au+Au collisions.  Such modifications have been measured in a variety of observables. 

  - Suppression of hadrons measured at high transverse momentum (pT)

  - Suppression of the away-side jet measured in 2-particle correlations, when selecting a high pT trigger particle
Ongoing analyses in this Physics Working Group focus on correlations measured between particles to further understand jet modifications in the medium produced in Au+Au collisions.  Such analyses include:
  - Untriggered 2-particle correlation measurements in 2 dimensions
  - Particle-identified particle correlations
  - 2+1 correlation measurements
  - Direct-photon-triggered correlations
  - Studies of the long range correlation in pseudorapidity observed in central Au+Au collisions
  - Full jet reconstruction
  - High pT single-particle hadron measurements at lower beam energies