  The low energy radiative capture process n+p -> d+gamma provides a sensitive
probe of the two-nucleon system. The cross section for this process is
dominated by the isovector M1 amplitude for capture from the 1S0 channel via
the isovector magnetic moment of the nucleon. In this work we use effective
field theory to compute the isoscalar M1 and isoscalar E2 amplitudes that are
strongly suppressed for cold neutron capture. The actual value of the isoscalar
E2 amplitude is expected to be within 15% of the value computed in this work.
In contrast, due to the vanishing contribution of the one-body operator at
leading order and next-to-leading order, the isoscalar M1 amplitude is
estimated to have a large uncertainty. We discuss in detail the deuteron
quadrupole form factor and SD mixing.
