Exact modulated hadronic tubes and layers at finite volume in a cloud of $\pi$ and $\omega$ mesons

Abstract

We construct topological soliton solutions describing baryonic tubes and layers with modulation in the $SU(2)$ non-linear sigma model coupled with $\omega$-mesons in $3+1$ dimensions. Using appropriate As\"antze for the pionic matter field and the $\omega$-mesons vector potential, the complete set of seven coupled partial differential equations can be solved analytically. These solutions represent modulated tubes and layers at finite volume with arbitrary baryon number, where the modulation of the solitons in one direction is determined by one of the three degrees of freedom of the pionic field, satisfying the equation of a two-dimensional free massless chiral scalar field. As expected, the inclusion of the $\omega$-mesons to the Non-linear sigma model allows to reduce the repulsion energy between baryons, which leads to a flattening of the tubes and layers in one direction, forming a kind of ``nuclear linguine phase''. Also, we show that this construction can be carried out even when higher order terms in the large $N_c$ expansion are included -- in particular the Skyrme term -- without spoiling the integrability of the field equations.