# Gauge dependence and the Standard Model vacuum stability

After reviewing the calculation of the one-loop effective potential in a linear R_\xi gauge, I discuss which are the physical (gauge independent) observables entering the vacuum stability analysis. In particular, the field value at which the effective potential turns negative (the so-called instability scale, often identified with the scale of “new physics”) is essentially gauge dependent. Such a gauge ambiguity is explicitly shown in the case of the Standard Model.

This talk is part of the HEP phenomenology joint Cavendish-DAMTP seminar series.