We have calculated the temperature dependence of shear η and bulk ζ viscosities of quark matter due to quark-meson fluctuations. The quark thermal width originating from quantum fluctuations of quark-π and quark-σ loops at finite temperature is calculated with the formalism of real-time thermal field theory. Temperature-dependent constituent-quark and meson masses, and quarkmeson couplings are obtained in the Nambu-Jona-Lasinio model. We found a non-trivial influence of the temperature-dependent masses and couplings on the Landau-cut structure of the quark selfenergy. Our results for the ratios η/s and ζ/s, where s is the entropy density (also determined in the Nambu-Jona-Lasinio model in the quasi-particle approximation), are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for η/s has a minimum very close to the conjectured AdS/CFT lower bound, η/s = 1/4π.

We study the prospects for deducing constraints on the interaction of charmed baryons with nucleons from measurements of two-particle momentum correlation functions for Λ c p. The correlation functions are calculated for Λ c N and Σ c N interactions that have been extrapolated from lattice QCD simulations at unphysical masses of m π = 410 − 570 MeV to the physical point using chiral effective field theory as guideline. In addition, we consider phenomenological Y c N models from the literature to explore the sensitivity of the results to the properties of the interaction in detail. We find that a measurement of the Λ c p correlation functions could indeed allow one to discriminate between strongly attractive Λ c N forces, as predicted by some phenomenological models, and a weakly attractive interaction as suggested by the presently available lattice simulations.

We report an atomistic simulation study at low concentration of lithium in scanning all the possible pathways for Li migration in TiO 2 polymorphs. We are particularly interested in showing the effects of the structural properties on the intercalation energies and on the energy barriers for ion diffusion. The most favourable directions for Li + transport are highlighted and we observe an anisotropic diffusion in rutile, brookite and TiO 2-B whereas the diffusion is isotropic in the case of anatase. The lowest energy barrier is calculated in rutile but it is not a key factor to determine the efficiency of Li-battery materials. Intercalation energies of stable and transition states are however important data to take into account as well as the Li pathway in order to evaluate the potentiality of each polymorph for Li migration.