The Chiral Magnetic Effect and an experimental bound on the late time magnetic field strength

We first compare different approaches to estimates of the magnitude of the chiral magnetic effect in relativistic heavy ion collisions and show that their main difference lies in the assumptions on the length of persistence of the magnetic field generated by the colliding nuclei. We then analyze recent measurements of the global polarization of $\Lambda$ and $\bar \Lambda$ hyperons in terms of the bounds they set on the magnitude of the late time magnetic field.