1. Will T2KK see new physics?
Hiroaki Sugiyama
(Theory group, KEK)
Ref: N. Kitazawa, HS, and O. Yasuda, hep-ph/

2. Introduction
Future oscillation experiments search for tiny effects of
high-precision measurements
of oscillation probabilities
Are they sensitive to also new physics?
unitarity violation
near detector
non-standard interaction with source
non-standard interaction with matter
non-standard interaction with detector
We consider only non-standard matter effect
in model-independent way

3. Non-standard matter effect
Hamiltonian in flavor basis
: matter density

4. Low energy
(ex. reactor)
Medium energy
(ex. T2KK)
High energy
(ex. neutrino factory)
vacuum osc.
significant effects?
vacuum osc.
is suppressed
large non-standard effect
pure measurement
of oscillation parameters
(in far future)

5. no phases for simplicity
Constraint on
no phases for simplicity
is bounded stringently by experiments with charged leptons??
NO! (from model-independent viewpoint)
ex.: dim-8 op. with higgs
indep.
constraint by experiments with neutrinos
S. Davidson et al., JHEP 0303, 011 (2003)
A. Friedland et al., Phys. Rev. D72, (2005)
is allowed!!
large effect in T2KK?

6. Setup
three epsilons that can be
(others are zero)
no phases
parameters are fixed
probabilities are obtained numerically
perturbation with respect to is not reliable
for

7. Oscillation probabilities with
(off-axis)
Probs. with have similar size to standard prob. with
T2K can not give clear evidence for non-standard effects
How about T2KK?

8. region for off-axis beam
at a detector in Korea
(a)
(g)
Prob. with can be much larger than standard prob..
(h)
clear evidence
is important in this energy range

9. Difference between and
(g)
(i)
(g)
(i)
gives the difference between probs. for and

10. higher energy region (on-axis beam)
and are also important in this energy range

11. T2KK(1000km) vs. MINOS(735km)
ongoing exp.
Non-standard effect in T2KK is larger than that in MINOS
Korean detector can be placed for off-axis beam
better sensitivity
Even if MINOS does not see (see) the effect,
there is a chance for T2KK to see (improve) that.

12. Conclusion
In T2KK,　 can give large probability
that can not be explained by the standard one with
Even after MINOS (735km),
T2KK can give new information on non-standard interactions.

13. Backup

14. Constraint with atm. and K2K
A. Friedland et al.,
Phys. Rev. D72, (2005)
We can read off
measured value
true values

15. Silver channel in neutrino factory(3000km)
(g)
huge enhancement!
is possible!

16. Two-flavor case
ex. silver channel
in neutrino factory