Pseudo-RNA with parallel aligned single-strands and periodic base sequence as a new universality class

TL;DR

This paper introduces a new universality class for RNA-like polymers with periodic base sequences, derived from a lattice field theory considering excluded volume, sequence, and temperature effects.

Contribution

It proposes a novel universality class arising from a specific directional and sequence pattern in RNA-like polymers, distinct from known classes.

Findings

The new universality class is unstable against natural pairing.

Denaturation/renaturation transition is a continuous crossover.

Transition involves critical points of the new universality class.

Abstract

We investigate a field theory for RNA-like polymers with periodic base sequence GCGCG..., where only single-strands aligned in the same direction form double strands. The field theory is derived from a lattice model that incorporates excluded volume effects, base sequence, and temperature dependent renaturation/denaturation. The artificial directionality leads to a novel universality class, not related to conventional branched polymers and Lee-Yang field theory. This universality class is unstable against natural pairing, where oppositely aligned single-strands form double strands. The denaturation/renaturation transition is a continuous crossover between two $\varphi_{n=0}^{4}$ critical points and the critical point of the new universality class.