%0 Journal Article %T Phase Transition in the 1d Random Field ising model with long range interaction %A Marzio Cassandro %A Enza Orlandi %A Pierre Picco %J Mathematics %D 2008 %I arXiv %R 10.1007/s00220-009-0778-4 %X We study the one dimensional Ising model with ferromagnetic, long range interaction which decays as |i-j|^{-2+a}, 1/2< a<1, in the presence of an external random filed. we assume that the random field is given by a collection of independent identically distributed random variables, subgaussian with mean zero. We show that for temperature and strength of the randomness (variance) small enough with P=1 with respect to the distribution of the random fields there are at least two distinct extremal Gibbs measures. %U http://arxiv.org/abs/0804.3672v2