Chiral perturbation theory of muonic-hydrogen Lamb shift: polarizability contribution Jose Manuel Alarcón, Vadim Lensky and Vladimir Pascalutsa Eur. Phys. J. C, 74 4 (2014) 2852 Published online: 29 April 2014 DOI: 10.1140/epjc/s10052-014-2852-0