PT Journal
AU Casas, JA
   Moreno, JM
   Rius, N
   Ruiz de Austri, R
   Zaldivar, B
TI Fair scans of the seesaw. Consequences for predictions on LFV processes
SO Journal of High Energy Physics
JI J. High Energy Phys.
PY 2011
BP 034
EP 22pp
VL 03
IS 3
DI 10.1007/JHEP03(2011)034
LA English
DE Neutrino Physics; Supersymmetric Standard Model
AB We give a straightforward procedure to scan the seesaw parameter-space, using the common "R-parametrization", in a complete way. This includes a very simple rule to incorporate the perturbativity requirement as a condition for the entries of the R-matrix. As a relevant application, we show that the somewhat propagated belief that BR(mu -> e, gamma) in supersymmetric seesaw models depends strongly on the value of theta(13) is an "optical effect" produced by incomplete scans, and does not hold after a careful analytical and numerical study. When the complete scan is done, BR(mu -> e, gamma) gets very insensitive to theta(13). This holds even if the right-handed neutrino masses are kept constant or under control (as is required for succesful leptogenesis). In most cases the values of BR(mu -> e, gamma) are larger than the experimental upper bound. Including (unflavoured) leptogenesis does not introduce any further dependence on theta(13), although decreases the typical value of BR(mu -> e, gamma).
ER