def METHOD_NAME(q2, deltaC, C_name, par, B, P):
    mB = par['m_'+B]
    mP = par['m_'+P]
    scale = config['renormalization scale']['bpll']
    mb = flavio.physics.running.running.get_mb(par, scale)
    N = flavio.physics.bdecays.bpll.prefactor(q2, par, B, P)
    ff = flavio.physics.bdecays.bpll.get_ff(q2, par, B, P)
    wc  = {'7': 0, '7p': 0, 'v': 0, 'a': 0, 's': 0, 'p': 0, 't': 0,'vp': 0, 'ap': 0, 'sp': 0, 'pp': 0, 'tp': 0, }
    wc[C_name] = deltaC
    return flavio.physics.bdecays.angular.helicity_amps_p(q2, mB, mP, mb, 0, 0, 0, ff, wc, N) # ml=0 as this only affects scalar contributions