Exotic JPC = 1-+ mesons in a holographic model of QCD

Mesons with quantum numbers JPC = 1-+ cannot be represented as simple quark-antiquark pairs. We explore hybrid configurations in the light meson sector comprising a quark, an antiquark and an excited gluon, studying the properties of such states in a phenomenological model inspired by the gauge/gravity correspondence. The computed mass, compared to the experimental mass of the 1-+ candidates π1(1400), π1(1600) and π1(2015), favours π1(1400) as the lightest hybrid state. An interesting result concerns the stability of hybrid mesons at finite temperature: they disappear from the spectral function (i.e. they melt) at a lower temperature with respect to other states, light vector and scalar mesons and scalar glueballs. (orig.)