Random RNA under tensionF. David1, C. Hagendorf1, 2 and K.-J. Wiese2
1 Service de Physique Théorique, CEA Saclay - 91191 Gif-sur-Yvette, France
2 CNRS-Laboratoire de Physique Théorique de l'Ecole Normale Supérieure - 24, rue Lhomond, 75231 Paris cedex 05, France
received 13 February 2007; accepted in final form 7 May 2007; published June 2007
published online 29 May 2007
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 as a function of pulling force f scales as . The exponent is calculated in an -expansion: At 1-loop order , equivalent to the disorder-free case. 2-loop results yielding are briefly mentioned. Using a locking argument, we speculate that this result extends to the strong-disorder phase.
87.15.Cc - Folding and sequence analysis.
05.70.Jk - Critical point phenomena.
64.70.Pf - Glass transitions.
© Europhysics Letters Association 2007