8,931 research outputs found
disappearance at the SPL, T2K-I and the Neutrino Factory
We study the disappearance channel at T2K-phase I and the SPL and
analyse the achievable reduction of present uncertainties in and
. We analyse the impact of discrete ambiguities in
sign() and sign(). We show how the
disappearance channel at the Neutrino Factory is complementary to the
``golden'' and ``silver'' appearance channels and can be used to reduce the
eightfold-ambiguity problem in ().Comment: 2 pages, 3 epsfig; NUFACT'05, 21-26 June 2005, Frascat
Physics reach of -beams and -factories: the problem of degeneracies
We discuss the physics reach of -Beams and -Factories from a
theoretical perspective, having as a guideline the problem of degeneracies. The
presence of degenerate solutions in the measure of the neutrino oscillation
parameters and is, in fact, the main problem that have
to be addressed in planning future neutrino oscillation experiments. If
degeneracies are not (at least partially) solved, it will be almost impossible
to perform, at any future facility, precise measurements of
and/or . After a pedagogical introduction on why degenerate solutions
arise and how we can get rid of them, we analyze the physics reach of current
-beam and -factory configurations. The physics reach of the
"standard" \BB is severely affected by degeneracies while a better result can
be obtained by higher- setups. At the \NF the combination of Golden and
Silver channels can solve the eightfold degeneracy down to Comment: 5 pages, 6 epsfig; NUFACT'05, 21-26 June 2005, Frascat
Using nu_e -> nu_tau: golden and silver channels at the Neutrino Factory
I briefly review the source of the so-called intrinsic ambiguity and show how
the combination of ``golden'' and ``silver'' channel at the Neutrino Factory
can solve the problem, in the absence of other sources of degeneracies. I then
relaxed the hypothesis and show how the different
dependence of the two channels on can help in solving the
intrinsic and -octant ambiguity at the same time.Comment: 6 pages, 7 figs. using epsfig; proceedings of the NOON 2003 Workshop,
February 10-14, 2003, Kanazawa, Japa
Non-perturbative Renormalization of the Complete Basis of Four-fermion Operators and B-parameters
We present results on the B-parameters , and , at
, with the tree-level Clover action. The renormalization of the
complete basis of dimension-six four-fermion operators has been performed
non-perturbatively. Our results for and are in reasonable
agreement with those obtained with the (unimproved) Wilson action. This is not
the case for . We also discuss some subtleties arising from a
recently proposed modified definition of the B-parameters.Comment: Talk presented at Lattice '97, Edinburgh (UK), July 1997. LaTeX 3
pages, uses espcrc
Quenched Supersymmetry
We study the effects of quenching in Super-Yang-Mills theory. While
supersymmetry is broken, the lagrangian acquires a new flavour
symmetry. The anomaly structure thus differs from the unquenched case. We
derive the corresponding low-energy effective lagrangian. As a consequence, we
predict the mass splitting expected in numerical simulations for particles
belonging to the lowest-lying supermultiplet.Comment: LATTICE98(yukawa), minor change
Degeneracies at a beta-Beam and a Super-Beam Facility
The presence of degeneracies can considerably worsen the measure of the
neutrino oscillation parameters and . We study the
physics reach of a specific ``CERN'' setup, using a standard -Beam and
Super-Beam facility. These facilities have a similar sensitivity in both
parameters. Their combination does not provide any dramatic improvement as
expected due to their almost identical L/E ratio. We analyse if adding the
correspondent disappearance channels can help in reducing the effect of
degeneracies in the measure.Comment: 5 pages, 7 eps figure
Non-Perturbative Renormalisation using Domain Wall Fermions
The viability of the Non-Perturbative Renormalisation (NPR) method of the
Rome/Southampton group is studied, for the first time, in the context of domain
wall fermions. The procedure is used to extract the renormalisation
coefficients of the various quark bilinears, as well as the four-fermion
operators relevant to the effective Hamiltonian. The
renormalisation of the Hamiltonian is also discussed.Comment: LATTICE99(Improvement and Renormalization),3 pages, LaTeX2e; minor
typos correcte
Physical Reach of a Neutrino Factory in the 2+2 and 3+1 Four-Family Scenario
We compare the physical reach of a Neutrino Factory in the 2+2 and 3+1
four-family models, with similar results in the two schemes; in both cases huge
CP-violating effects can be observed with a near detector in the channel. We also study the capability of long baseline experiments
(optimized for the study of the three-family mixing parameter space) in
distinguishing a three (active) neutrino model from a four-family scenario.Comment: 5 latex2e pages, 2 figures; talk given at NuFact '01, Tsukuba, 24-30
May 200
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