[NT/RBRC seminar] The meson f_{PS,V} / m_V ratios and the conformal window

by Dr Daniel Nogradi (Eotvos University)

Friday 28 Jul 2023, 11:00 → 13:00 US/Eastern

Large Seminar Room (https://bnl.zoomgov.com/j/1614715193?pwd=WkwxODVWdzZzb29zQnZRVGp3VTBDQT09)

The mesonic f_PS / m_V and f_V / m_V ratios, with f the decay constant and
the m meson mass, are calculated in mass perturbed conformal gauge
theories to NNLO and N^3LO orders, respectively. Here NNLO and N^3LO refer
to the non-relativistic effective theory expansion which is the applicable
framework. The results are expanded a la Banks-Zaks in order to end up
with scheme-independent predictions. These perturbative results are
unambiguously reliable close to the upper end of the conformal window, N_f
= 16.5 and it is shown that they might be reliable down to = 12. An
attempt is made to match these to previous non-perturbative lattice
results in the range 1 < N_f < 11. An abrupt change in the ratios is
observed at around N_f = 12 - 13, which may signal the lower end of the
conformal window.