Tricritical sextic beta function
= Tricritical sextic beta function
{title2=$d\lambda/ds=-C\lambda^2+\cdots$}
In three dimensions, after tuning the quadratic and quartic <relevant operators>, the positive sextic coupling has a <renormalization-group beta function> $d\lambda/ds=-C\lambda^2+\cdots$ with $C>0$ for increasing length scale $s$. The <Wick contractions> connecting two sextic vertices with three propagators give the primitive logarithmic correction. The interaction is <marginally irrelevant>.