CP rate cancellation in baryogenesis
= CP rate cancellation in baryogenesis
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In a symmetric initial population of particles and antiparticles, exact <CP symmetry> equates conjugate decay rates after summing final momenta and helicities. Since <parity> does not reverse baryon number, this equality prevents a total baryon asymmetry even if <charge conjugation> alone is violated. Different same-helicity rates can cancel against the opposite-helicity rates.