Is leptogenesis falsifiable at LHC? (0806.0841v3)

Abstract: It is well known that the leptogenesis mechanism offers an attractive possibility to explain the baryon asymmetry of the universe. Its particular robustness however comes with one major difficulty: it will be very hard if not impossible to test experimentally in a foreseeable future, as most of the mechanics typically takes place at high energy or results from suppressed interactions, without unavoidable low-energy implications. An alternate approach is taken by asking: can it be at least falsified? We show that possible discoveries at current and future colliders, most notably that of right-handed gauge interactions, would indeed forbid at least the "canonical" leptogenesis mechanisms, namely those based on right-handed neutrino decay. General lower bounds for successful leptogenesis on the mass of the right-handed gauge boson W_R are given. Other possibilities to falsify leptogenesis, including from the observation of a Z', are also considered.