10,833 research outputs found
Towards Parameterized Regular Type Inference Using Set Constraints
We propose a method for inferring \emph{parameterized regular types} for
logic programs as solutions for systems of constraints over sets of finite
ground Herbrand terms (set constraint systems). Such parameterized regular
types generalize \emph{parametric} regular types by extending the scope of the
parameters in the type definitions so that such parameters can relate the types
of different predicates. We propose a number of enhancements to the procedure
for solving the constraint systems that improve the precision of the type
descriptions inferred. The resulting algorithm, together with a procedure to
establish a set constraint system from a logic program, yields a program
analysis that infers tighter safe approximations of the success types of the
program than previous comparable work, offering a new and useful efficiency vs.
precision trade-off. This is supported by experimental results, which show the
feasibility of our analysis
The flavor of neutrinos in muon decays at a neutrino factory and the LSND puzzle
The accurate prediction of the neutrino beam produced in muon decays and the
absence of opposite helicity contamination for a particular neutrino flavor
make a future neutrino factory the ideal place to look for the lepton flavor
violating (LFV) decays of the kind \mu^+\ra e^+\nuebar\numu and lepton number
violating (LNV) processes like \mu^-\ra e^-\nue\numu. Excellent sensitivities
can be achieved using a detector capable of muon and/or electron identification
with charge discrimination. This would allow to set experimental limits that
improve current ones by more than two orders of magnitude and test the
hypothesis that the LSND excess is due to such anomalous decays, rather than
neutrino flavor oscillations in vacuum.Comment: 19 pages, 4 figure
Detection of polarization from the E^4\Pi-A^4\Pi system of FeH in sunspot spectra
Here we report the first detection of polarization signals induced by the
Zeeman effect in spectral lines of the E^4\Pi-A^4\Pi system of FeH located
around 1.6 m. Motivated by the tentative detection of this band in the
intensity spectrum of late-type dwarfs, we have investigated the full Stokes
sunspot spectrum finding circular and linear polarization signatures that we
associate with the FeH lines of the E^4\Pi-A^4\Pi band system. We investigate
the Zeeman effect in these molecular transitions pointing out that in Hund's
case (a) coupling the effective Land\'e factors are never negative. For this
reason, the fact that our spectropolarimetric observations indicate that the
Land\'e factors of pairs of FeH lines have opposite signs, prompt us to
conclude that the E^4\Pi-A^4\Pi system must be in intermediate angular momentum
coupling between Hund's cases (a) and (b). We emphasize that theoretical and/or
laboratory investigations of this molecular system are urgently needed for
exploiting its promising diagnostic capabilities.Comment: 11 pages, 4 figures, accepted for publication in Astrophysical
Journal Letter
Effective lagrangian for a mass dimension one fermionic field in curved spacetime
In this work we use momentum-space techniques to evaluate the propagator
for a spin mass dimension one spinor field on a curved
Friedmann-Robertson-Walker spacetime. As a consequence, we built the one-loop
correction to the effective lagrangian in the coincidence limit. Going further
we compute the effective lagrangian in the finite temperature regime. We arrive
at interesting cosmological consequences, as time-dependent cosmological
`constant', fully explaining the functional form of previous cosmological
models.Comment: 9 pages, 0 figure
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