5,779 research outputs found
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
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
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
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
The 2+2 and 3+1 Four-Family Neutrino Mixing at the Neutrino Factory
We upgrade the study of the physical reach of a Neutrino Factory in the Four
Family Neutrino Mixing scenario taking into account the latest LSND results
that points out how the 3+1 scheme cannot be completely ruled out within the
present experimental data (although the 2+2 scheme is still the preferred
choice when four neutrinos are considered). A detailed comparison of the
physical reach of the -factory in the two schemes is given, with similar
results for the sensitivity to the mixing angles. Huge CP-violating effects can
be observed in both schemes with a near, O(10) Km, detector of O(10) Kton size
in the channel. A smaller detector of 1 Kton size can
still observe very large effects in this channel.Comment: 38 Latex2e pages, 21 figures using epsfig, minor change
Micro-orbits in a many-branes model and deviations from Newton's law
We consider a 5-dimensional model with geometry , with compactification radius . The Standard Model particles are
localized onto a brane located at y=0, with identical branes localized at
different points in the extra dimension. Objects located on our brane can orbit
around objects located on a brane at a distance , with an orbit and a
period significantly different from the standard Newtonian ones. We study the
kinematical properties of the orbits, finding that it is possible to
distinguish one motion from the other in a large region of the initial
conditions parameter space. This is a warm-up to study if a SM-like mass
distribution on one (or more) distant brane(s) may represent a possible dark
matter candidate. After using the same technique to the study of orbits of
objects lying on the same brane (), we apply this method to detect generic
deviations from the inverse-square Newton's law. We propose a possible
experimental setup to look for departures from Newtonian motion in the
micro-world, finding that an order of magnitude improvement on present bounds
can be attained at the 95% CL under reasonable assumptions.Comment: Two-column format (20 pages), 10 figures; minor corrections and some
added reference
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
Quenched Spectroscopy for the N=1 Super-Yang-Mills Theory
We present results for the Quenched SU(2) N=1 Super-Yang-Mills spectrum at
, on a lattice, in the OZI approximation. This is
a first step towards the understanding of the chiral limit of lattice N=1 SUSY.Comment: 3 pages, Latex, 2 ps figures, contribution to Lattice 97, Edinburgh
22-26 July 1997; to appear on Nucl. Phys. B. (Proc. Suppl.
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