Reconnection and ion heating in low-$\beta$ hybrid-kinetic plasma turbulence*

Turbulence and kinetic processes in collisionless, magnetized plasmas have been investigated extensively over the past decades via theoretical models, {\em in situ} spacecraft measurements in the heliosphere, and numerical simulations. Alongside the debate about the nature of ion- and electron-scale fluctuations in solar-wind turbulence, one of the fundamental open questions concerns how turbulent energy is partitioned between ions and electrons. In space and astrophysical plasmas, this "turbulent heating" may involve a wide variety of collisionless plasma processes, with their relative importance depending on several plasma parameters. In this talk, we present results from 3D hybrid particle-in-cell (PIC) simulations of continuously driven, critically balanced plasma turbulence at low $\beta$. The interplay between the spectral anisotropy of the fluctuations and different ion-heating mechanisms -- and how to possibly diagnose and/or disentangle them -- will be discussed. Our results have implications for the differential heating of ion and electrons in turbulent low-$\beta$ plasmas such as the solar wind.