Finite-size scaling exponents in the interacting boson model

Abstract

We investigate the finite-size scaling exponents for the critical point at the shape phase transition from U(5) (spherical) to O(6) (deformed -unstable) dynamical symmetries of the Interacting Boson Model, making use of the Holstein-Primakoff boson expansion and the continuous unitary transfor- mation technique. We compute exactly the leading order correction to the ground state energy, the gap, the expectation value of the d-boson number in the ground state and the E2 transition prob- ability from the ground state to the first excited state, and determine the corresponding finite-size scaling exponents.