How much do charm sea quarks affect the charmonium spectrum?

Understand

The properties of charmonium states are or will be intensively studied by the B-factories Belle II and BESIII, the LHCb and PANDA experiments and at a future Super-c-tau Factory.

• Precise lattice calculations provide valuable input and several results have been obtained by simulating up, down and strange quarks in the sea.
• We investigate the impact of a charm quark in the sea on the charmonium spectrum, the renormalization group invariant charm-quark mass and the scalar charm-quark content of charmonium.
• The latter is obtained by the direct computation of the mass-derivatives of the charmonium masses.