476 research outputs found
Cosmic neutrinos at IceCube: , and initial flavor composition
We discuss the prospect of extracting the values of the mixing parameters
and through the detection of cosmic neutrinos in the
planned and forthcoming neutrino telescopes. We take the ratio of the
muon-track to shower-like events, R, as the realistic quantity that can be
measured in the neutrino telescopes. We take into account several sources of
uncertainties that enter the analysis. We then examine to what extent the
deviation of the initial flavor composition from w_e:w_\mu:w_\tau=1:2:0 can be
tested.Comment: 3 pages, 2 figures, Talk given at the TAUP 2009 conference, Rome,
Italy; J. Phys. Conf. Series to appea
How sensitive is a neutrino factory to the angle ?
We consider the impact of non-standard interactions of neutrinos (NSI) on the
determination of neutrino mixing parameters at a neutrino factory using
\pnu{e}\to\pnu{\mu} ``golden channels'' for the measurement of .
We show how a small residual NSI leads to a drastic loss in sensitivity in
, of up to two orders of magnitude. This can be somewhat overcome
if two baselines are combined.Comment: 4 pages, 3 figure
Status of three-neutrino oscillations after the SNO-salt data
We perform a global analysis of neutrino oscillation data in the framework of
three neutrinos, including the recent improved measurement of the neutral
current events at SNO. In addition to all current solar neutrino data we take
into account the reactor neutrino data from KamLAND and CHOOZ, the atmospheric
neutrino data from Super-Kamiokande and MACRO, as well as the first spectral
data from the K2K long baseline accelerator experiment. The up-to-date best fit
values and allowed ranges of the three-flavour oscillation parameters are
determined from these data. Furthermore, we discuss in detail the status of the
small parameters alpha = Delta_m^2_Sol / Delta_m^2_Atm and sin^2(theta_13),
which fix the possible strength of CP violating effects in neutrino
oscillations.Comment: 16 pages, LaTeX file using RevTEX4, 10 figures and 1 table included.
The conclusions reached in version 1 regarding the restriction on
sin^2(theta_13) are now corrected, the solar bound is weaker than that from
reactors even after the inclusion of the SNO salt data. In addition the full
data set has now been reanalized using the pull method instead of the
standard chi-square approach. A few references have also been adde
LFV and Dipole Moments in Models with A4 Flavour Symmetry
It is presented an analysis on lepton flavour violating transitions, leptonic
magnetic dipole moments and electric dipole moments in a class of models
characterized by the flavour symmetry A4 x Z3 x U(1)_FN, whose choice is
motivated by the approximate Tri-Bimaximal mixing observed in neutrino
oscillations. A low-energy effective Lagrangian is constructed, where these
effects are dominated by dimension six operators, suppressed by the scale M of
new physics. All the flavour breaking effects are universally described by the
vacuum expectation values of a set of spurions. Two separate cases, a
supersymmetric and a general one, are described. An upper limit on the reactor
angle of a few percent is concluded.Comment: 10 pages, 1 figure. Adapted from a talk given at "DISCRETE'08:
Symposium on Prospects in the Physics of Discrete Symmetries", December 11-16
2008, Valencia, Spai
Where we are on : addendum to "Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters"
In this addendum to arXiv:1103.0734 we consider the recent results from
long-baseline searches at the T2K and MINOS experiments and
investigate their implications for the mixing angle and the
leptonic Dirac CP phase . By combining the indication for a
non-zero value of coming from T2K data with global neutrino
oscillation data we obtain a significance for of about
with best fit points for normal
(inverted) neutrino mass ordering. These results depend somewhat on assumptions
concerning the analysis of reactor neutrino data.Comment: 5 pages, 2 figures and 1 tabl
Strongly coupled N=1 SYM theory on the lattice
We propose a strong coupling expansion as a possible tool to obtain
qualitative and quantitative informations about N=1 SYM theory. We point out
the existence of a mapping between strongly coupled lattice N=1 SYM theory and
a generalized SO(4) antiferromagnetic spin system.Comment: Lattice2002(spin), 3 pages, no figure
Neutrino CP violating parameters from nontrivial quark-lepton correlation: a S3xGUT model
We investigate the prediction on the lepton phases in theories with a non
trivial correlation between quark (CKM) and lepton (PMNS) mixing matrices. We
show that the actual evidence, under the only assumption that the correlation
matrix product of and has a zero in the entry , gives
us a prediction for the three CP-violating invariants , , and . A
better determination of the lepton mixing angles will give a strong prediction
of the CP-violating invariants in the lepton sector. These will be tested in
the next generation experiments. To clarify how our prediction works, we show
how a model based on a Grand Unified Theory and the permutation flavor symmetry
predicts .Comment: 7 pages, 3 figures. V2: new figure adde
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