Random RNA under tension
François David1, Christian Hagendorf1,2, Kay Jörg Wiese2
1SPhT-Service de Physique Théorique, CEA/Saclay - 91191 Gif-sur-Yvette Cedex, France
2CNRS-Laboratoire de Physique Théorique de
l'Ecole Normale Supérieure,
24 rue Lhomond, 75005 Paris, France
Abstract
The Lässig-Wiese (LW) field theory for the
freezing transition of random RNA secondary structures is generalized
to the situation of an external force. We find a second-order phase
transition at a critical applied
force f = fc. For f
< fc forces are irrelevant. For f
> fc, the extension L as a function of
pulling force f scales as L(f) ~
(f-fc)1/γ-1. The exponent
γ is calculated in an epsilon-expansion: At 1-loop order γ =
1/2, equivalent to the disorder-free case. At 2-loop order γ =
0.6. Using a locking argument, we speculate that this result extends
to the strong-disorder phase.
q-bio.BM/0701049[pdf]
EPL 78 (2007) 68003 [pdf]
Copyright (C) by Kay Wiese. Last edited March 17, 2008.