1. Constraints from LFV prosecces in the Higgs Triplet Model
Hiroaki SUGIYAMA
(Ritsumeikan Univ., Shiga)
based on ‘T. Fukuyama, H.S., K. Tsumura, arXiv: ’
to appear in JHEP
Sorry: We have not updated our results
with Belle update on decay
(arXiv: )

2. Higgs Triplet Model Complex Higgs triplet Higgs potential
A simple extension of the SM to give neutrino masses
by adding a complex Higgs triplet of
No (no see-saw)
Complex Higgs triplet
: doubly charged Higgs
Higgs potential
no NG-boson (Majoron) for breaking
: spontaneous breaking of
: explicit breaking of

3. “Yukawa” interaction with a complex Higgs triplet
Majorana mass matrix
Small breaking parameter
light ( ) new particles. (cf. GUT scale in see-saw)
not too small ( ) couplings. (cf. Dirac Yukawa )
sizable new (flavor-rich) effects with relations to neutrino physics
constrained well by current knowledge on

4. Current Knowledge on Neutrino Mass Matrix
: real, positive
: Majorana phases
Oscillation experiments
“normal”
“inverted”
( or )
: free
Cosmological observations
(WMAP only)
(WMAP+BAO+SN)

5. Lepton Flavor Violating Processes
(the ones we used)
severe constraint

6. : correlate with each other in the HTM
severe constraint

7. : correlate with each other in the HTM
severe constraint

8. This Work We translate constraints as a lower-bound on
considering the correlation through
Which process does give the strongest bound?
We obtained analytical solution
Naively, will give it.
for arbitrary Majorana phases
However, for
E.J. Chun, K.Y. Lee, S.C. Park, PLB566, 142
M. Kakizaki, Y. Ogura, F. Shima, PLB566, 210
and for
A.G. Akeroyd, HS, M. Aoki, PRD79,
How much can we relax the lower-bound?
for all
the bound vanishes
impossible in the HTM because

9. Constraint from
contour of lower-bound on

10. Which process does give the strongest bound?
examples for
lower bound on

11. The process of the strongest bound :
white region:
can not be zero
lower bound on

12. examples for
lower bound on

13. The process of the strongest bound :
white region:
can not be zero
lower bound on

14. possible only for
Which process does give the strongest bound?
examples
lower bound on

15. The process of the strongest bound :
lower bound on

16. The Most Relaxed Bound If and/or ,
bound on from is almost independent of parameters.

17. Conclusion The process of the strongest bound on : and Other (or )
The most relaxed bound :