The eta' meson from lattice QCD

Understand

We study the flavour singlet pseudoscalar mesons from first principles using lattice QCD.

• With N_f=2 flavours of light quark, this is the so-called eta_2 meson and we discuss the phenomenological status of this.
• Using maximally twisted-mass lattice QCD, we extract the mass of the eta_2 meson at two values of the lattice spacing for lighter quarks than previously discussed in the literature.
• We are able to estimate the mass value in the limit of light quarks with their physical masses.