11,740 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
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
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
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
disappearance at the SPL, T2K-I, NOA and the Neutrino Factory
We study the measurement of the atmospheric neutrino oscillation parameters,
and , at the disappearance channel at
three conventional beam facilities, the SPL, T2K-phase I and NOA. These
two parameters have been shown to be of crucial importance in the measurement
of two of the unknowns of the PMNS mixing matrix, and the
leptonic CP-violating phase . In our analyis, the effect of the two
discrete ambiguities, and , is explicitly taken into account. We analyse also the
disappearance channel at the Neutrino Factory, and combine it with the
``golden'' and ``silver'' appearance
channels to study its impact on the measurement of and .
Eventually, we present the sensitivity of the four facilities to different
observables: , , maximal , the sign of the
atmospheric mass difference, , and the -octant,
.Comment: 40 pages using epsfig; bibliography modifie
Determination of plasmid copy number in yeast transformants by means of agarose plugs
The determination of plasmid copy number in Saccharomyces cerevisiaetransformants containing circular or linear plasmids is currently performed with total yeast DNA extracts obtained from cultures grown under selection. The determination is based essentially on quantitative Southern hybridization of an appropirate probe to a sequence present both on plasmid and chromosomal DNA in digested or undigested samples run out on conventional agarose gels. The DNA extraction procedure calls for treatment of cell lysates with organic solvents that could entail systemic losses of eithr plasmid or chromosomal DNA thus producing artifactual results. We propose here a method based on the assumption that quantitative analysis of plasmid and chromosomal DNA extracted from yeast cells embedded in agarose plugs will furnish more reliable results. With this procedure the cells are lysed in situ, thus avoiding possible losses of material, and the chromosomes and plasmid DNAs, trapped within the agarose matrix, can be separated by pulse field electrophoresis
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
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