# Tag Info

I realise I'm responding to an old question, but perhaps you're still in need of an answer. I'm going to use $B^0_s \to \phi \phi$ as an example. It is a transition of a pseudoscalar meson to two vector mesons. There are 3 possible configurations for angular momentum, $\ell$: aligned, anti-aligned or perpendicular. In the LHCb angular analysis of this ...