SLIDE 28 Review on Hadron Spectroscopy and Resonances Chuan Liu Introduction The conventional spectrum Single channel scattering Summary and
. . . . . .
Dashen scheme of renormalization
1 + 1 + 1 flavor QCD+QED (non-compact)
The electromagnetic correction to meson mass, M2
γ = M2(g2, e2 ⋆, m⋆ u, m⋆ d, m⋆ s )−M2(g2, 0, mQCD u
, mQCD
d
, mQCD
s
) . (12) However, what are the values of mQCD
u/d/s? No experimental
inputs are available here. The so-called Dashen scheme is defined to be that neutral meson masses exactly matches the real-world mass values (after tuning mQCD
q
M2
q¯ q(g2, e2 ⋆, m⋆ u, m⋆ d, m⋆ s ) = M2 q¯ q(g2, 0, mQCD u
, mQCD
d
, mQCD
s
) . (13) which means that the electromagnetic self-energy for the neutral meson mass vanishes exactly (R. Dashen). Scheme change is accomplished by one-loop lattice perturbation theory.