Production of pentaquarks in pA-collisions

We argue that a hidden-charm pentaquark recently observed in weak decays of Lambda(b) can be produced in proton-nucleus collisions without electroweak intermediaries. We analyze the production cross section for the case when a pentaquark is a molecule of charmonium and a light baryon, as suggested by some models of pentaquark structure, and find that the cross section is sizable. This process can be studied both in collider and in fixed-target experiments. In the former case, the pentaquarks are produced at very forward rapidities, whereas in the latter case, pentaquarks are produced with relatively small rapidities and can be easily detected via invariant mass distribution of a forward J/psi and a comoving proton. Additionally, the suggested process allows us to check the existence of a neutral pentaquark P-c(0) (an isospin partner of P-c(+)) predicted in several models. The rapidity and transverse momentum distributions of pentaquarks could provide comprehensive information about the (c) over barc component of this exotic baryon.