We introduce a new jet substructure technique called "soft drop
declustering", which recursively removes soft wide-angle radiation from a jet.
The soft drop algorithm depends on two parameters--a soft threshold
$z_\text{cut}$ and an angular exponent $\beta$--with the $\beta = 0$ limit
corresponding roughly to the (modified) mass drop procedure. To gain an
analytic understanding of soft drop and highlight the $\beta$ dependence, we
perform resummed calculations for three observables on soft-dropped jets: the
energy correlation functions, the groomed jet radius, and the energy loss due
to soft drop. The $\beta = 0$ limit of the energy loss is particularly
interesting, since it is not only "Sudakov safe" but also largely insensitive
to the value of the strong coupling constant. While our calculations are
strictly accurate only to modified leading-logarithmic order, we also include a
discussion of higher-order effects such as multiple emissions and (the absence
of) non-global logarithms. We compare our analytic results to parton shower
simulations and find good agreement, and we also estimate the impact of
non-perturbative effects such as hadronization and the underlying event.
Finally, we demonstrate how soft drop can be used for tagging boosted W bosons,
and we speculate on the potential advantages of using soft drop for pileup
mitigation.

本文介绍了一种名为 “soft drop declustering” 的新的喷注亚结构技术，该技术可以用于标记加速的 W 玻色子，并进行了软发射的关键参数 z_cut 和角指数 β 的计算，以及关于高阶效应的讨论，如多重辐射以及非全局对数的缺失。