Pure quark and gluon observables in collinear drop

We construct a class of pure quark and gluon observables by using the collinear drop grooming technique. The construction is based on linear combinations of multiple cumulative distributions of the jet mass in collinear drop, whose specific weights are fully predicted perturbatively. This yields observables which obtain their values purely from quarks (or purely from gluons) in a wide region of phase space. We demonstrate this by showing that these observables are effective in two phase space regions, one dominated by perturbative resummation and one dominated by nonperturbative effects. The nonperturbative effects are included using shape functions which only appear as a common factor in the linear combinations constructed. We test this construction using a numerical analysis with next-to-leading logarithmic resummation and various shape function models, as well as analyzing these observables with PYTHIA and VINCIA. Choices for the collinear drop parameters are optimized for experimental use.

Automated summary

A class of pure quark and gluon observables is constructed using the collinear drop grooming technique, which combines multiple cumulative distributions of jet mass in collinear drop with specific weights predicted perturbatively. These observables obtain values purely from quarks or gluons in a wide phase space region, as demonstrated in both perturbative resummation and nonperturbative dominant regions. The construction includes nonperturbative effects using shape functions as a common factor in the linear combinations. Numerical analysis with resummation and shape function models, as well as analysis with simulation tools PYTHIA and VINCIA, is performed to test the construction, with optimization of collinear drop parameters for experimental use.