The first immediate impact of the results obtained in this project involving the computation of interactions among coherent objects will be in the description of elastic scatterings in Monte Carlo models for jet quenching. This is so because the kinematical approximations taken in this first publication are suited to the case of an energetic jet interacting with a soft medium parton. Many models include elastic scatterings and keep track of the recoils, but none could incorporate these effects since they had not been discovered. Given the importance of recoils in jet quenching observables, it is expected that these novel effects will have a sizeable impact in many of those observables, specially jet substructure ones, such as energy correlators.
However, there are a number of questions that still remain unanswered, such as:
-Does the physics change if the recoiling parton is a gluon instead of a quark? If so, why?
-Which is the right way to regulate the collinear divergence when the recoil has very small angle with respect to either leg of the dipole? Which are the right virtual diagrams?
-How does the picture change when one relaxes some kinematical assumptions, such as the one where the recoil energy is much larger than the medium parton rest mass?
-Can we resum an arbitrary number of such scatterings? Do we observe color decoherence because of multiple color rotations, as can be obtained using previous formalisms?
While these questions refer just to the calculation already performed, in order to achieve the longer-term goals of the project (implementation in parton shower and in effective kinetic theory) one will need to extend it in a number of ways:
-Perform dipole-dipole interaction computation
-Relax kinematics to accommodate also soft-soft interaction, in this way allowing for broadening.
-Consider stimulated radiation as a result of the interaction
Once obtained, the implementation of these results will require further non-trivial efforts, concerning mostly modeling assumptions and coding tasks.
In sum, one can say that the consideration of the issues raised and tackled in this project arise naturally if one contemplates the evolution experienced by the field of jet quenching in the last couple of decades, in particular in going from a single parton to a many parton (as produced by an actual jet) scenario. Applying these notions to the description of the interactions among the mini-jets produced in the early times of a heavy-ion collision, or to the non-linear contribution to parton evolution in high-multiplicity jets, offers a great opportunity to gain a better understanding on the striking multi-particle correlations measured across all system sizes.
