Precision Physics of the QCD axion and other new light particles

          @misc{ pirsa_PIRSA:16110019,
            doi = {10.48660/16110019},
            url = {https://pirsa.org/16110019},
            author = {Hardy, Edward},
            keywords = {Particle Physics},
            language = {en},
            title = {Precision Physics of the QCD axion and other new light particles},
            publisher = {Perimeter Institute},
            year = {2016},
            month = {nov},
            note = {PIRSA:16110019 see, \url{https://pirsa.org}}
          }
          

Abstract

I will discuss the properties, and constraints on, new light

particles, which appear in many extensions of the Standard Model. An

especially well motivated example is the QCD axion, and I will show how

its mass and couplings can be extracted at high precision. I will also

discuss its properties at finite temperature, and possible distinguishing

features if it makes up dark matter. More generally, strong constraints on

the couplings of new light particles to the Standard Model come from their

production in the hot cores of stars, and the effect on stellar cooling.

The large electron density in stellar cores gives large thermal effects,

and I will show how these can parametrically change the production rates

compared to a 'tree level' calculation.