Lifetime of the eta' meson at low temperature

Abstract

This work constitutes one part of an investigation of the low-temperature changes of the properties of the eta' meson. In turn these properties are strongly tied to the U(1)_A anomaly of Quantum Chromodynamics. The final aim is to explore the interplay of the chiral anomaly and in-medium effects. We determine the lifetime of an eta' meson being at rest in a strongly interacting medium as a function of the temperature. To have a formally well-defined low-energy limit we use in a first step Chiral Perturbation Theory for a large number of colors. We determine the pertinent scattering amplitudes in leading and next-to-leading order. In a second step we include resonances that appear in the same mass range as the eta' meson. The resonances are introduced such that the low-energy limit remains unchanged and that they saturate the corresponding low-energy constants. This requirement fixes all coupling constants. We find that the width of the eta' meson is significantly increased from about 200 keV in vacuum to about 10 MeV at a temperature of 120 MeV.

49 pages

References in corpus (13)

• Big-Bang Nucleosynthesis
• The pion-pion scattering amplitude. IV: Improved analysis with once subtracted Roy-like equations up to 1100 MeV
• Mesonic low-energy constants
• Anomalous decay and scattering processes of the eta meson
• Introduction to Chiral Perturbation Theory
• Determination of the η'-nucleus optical potential
• Feasibility Study of Observing eta' Mesic Nuclei with (p,d) Reaction
• Determination of the eta'-proton scattering length in free space
• Chiral dynamics predictions for eta' -> eta pi pi
• Determination of the total width of the eta' meson
• Etaprime interactions with nucleons and nuclei
• Low-Energy Constants from Resonance Chiral Theory
• Study of in-medium ${\eta }^{\prime }$ properties in the ($\gamma$, ${\eta }^{\prime }p$) reaction on nuclei