Ridge from Strings

Understand

In the colour string picture with fusion and percolation it is shown that long range azimuthal-rapidity correlations (ridge) can arise from the superposition of many events with exchange of clusters of different number of strings and not from a single event.

• Relation of the ridge with the flow harmonics coefficients is derived.
• By direct Monte-Carlo simulations, in the technique previously used to calculate these coefficients, ridge correlations are calculated for AA, pA and pp collisions.
• The azimuthal anisotropy follows from the assumed quenching of the emitted particles in the strong colour fields inside string clusters.