def _vmomentsurfaceIntegrand(vz, vR, vT, R, z, df, sigmaR1, gamma, sigmaz1,
    n, m, o):
    """Internal function that is the integrand for the vmomentsurface mass integration"""
    return vR ** n * vT ** m * vz ** o * df(R, vR * sigmaR1, vT * sigmaR1 *
        gamma, z, vz * sigmaz1, use_physical=False)
