The ultrafine splitting of heavy quarkonium with next-to-next-to-next-to-next-to-leading-order accuracy

Jose M. Escario, Andreas Maier, Clara Peset +1

We compute the hyperfine splitting of P-wave heavy quarkonium states with next-to-next-to-next-to-next-to-leading-order accuracy. The resummation of logarithms with next-to-next-to…