Phenomenology with a recoil-free jet axis: TMD fragmentation and the jet shape

Abstract

We study the phenomenology of recoil-free jet axes using analytic calculations and Monte Carlo simulations. Our focus is on the average energy as function of the angle with the jet axis (the jet shape), and the energy and transverse momenta of hadrons in a jet (TMD fragmentation). We find that the dependence on the angle (or transverse momentum) is governed by a power law, in contrast to the double-logarithmic dependence for the standard jet axis. The effects of the jet radius, jet algorithm, angular resolution and grooming are investigated. TMD fragmentation is important for constraining the structure of the proton through semi-inclusive deep-inelastic scattering. These observables are also of interest to the LHC, for example to constrain α s from precision jet measurements, or probe the quark-gluon plasma in heavy-ion collisions.

Transverse momentum dependent distributions in e+e− and semi-inclusive deep-inelastic scattering using jets

“…These studies consider the transverse momentum with respect to the standard jet axis (SJA); instead, as an alternative way to reduce sensitivity to soft radiation, refs. [10,11] performed a similar analysis for the transverse momentum with respect to the Winner-Take-All (WTA) axis. The transverse momentum of the jet itself was also recently considered in photon + jet production [12] and lepton-jet correlation in deep-inelastic scattering [13].…”

Robust Independent Validation of Experiment and Theory: Rivet version 3

“…It has been used for development of new analysis techniques including machine learning applications, jet substructure, boosted-particle tagging and pile-up suppression [32][33][34][35]. Extraction of SM parameters for example using TopFitter [36,37] and other phenomenological studies of the SM [38][39][40][41][42] have used RIVET, and it has also been employed in searching for and constraining BSM physics [43][44][45][46], sometimes making use of the related CONTUR package [47].…”

Jet substructure in high-energy hadron collisions

“…Such a recoil-free axis affects the structure of QCD factorization theorems. Recently phenomenological studies using the winner-take-all jet axis were performed in [24]. Measuring the same observables but with different jet axis definitions can be used as a direct probe of the soft sensitivity of in-medium interactions.…”