The existence and properties of the sigma meson have been controversial for almost six
decades, despite playing a central role in the spontaneous chiral symmetry of QCD or in the …

For several decades, the σ/f 0 (500) and κ/K 0∗(700) resonances have been subject to long-
standing debate. Both their existence and properties were controversial until very recently. In …

A bstract We perform a complete calculation of the pion-kaon scattering amplitude in Chiral
Perturbation Theory at finite temperature, paying particular attention to the analytic structure …

A bstract We analyze the contribution of the η′(958) meson in the first two non-trivial
moments of the QCD topological charge distribution, namely, the topological susceptibility …

A bstract Recent lattice data on ππ-scattering phase shifts in the vector-isovector channel,
pseudoscalar meson masses and decay constants for strange-quark masses smaller or …

We analyze the restoration pattern of the members of the scalar and pseudoscalar meson
nonets under chiral O (4) and U (1) A symmetries. For that purpose, we exploit QCD Ward …

We calculate the pion scattering amplitude at nonzero temperature and nonzero μ 5, the
chemical potential associated to chiral imbalance in a locally P-breaking scenario. The …

A bstract We derive the formal Ward identities relating pseudoscalar susceptibilities and
quark condensates in three-flavor QCD, including consistently the η-η′ sector and the UA …

Masses of positive-parity and negative-parity diquarks are investigated at finite temperature
with a quark chemical potential. We employ the three-flavor Nambu-Jona-Lasinio model, in …

We present and analyze a new set of Ward Identities which shed light on the distinction
between different patterns of chiral symmetry restoration in QCD, namely O (4) vs O (4)× U …