1,647 research outputs found
Missing energy and the measurement of the CP-violating phase in neutrino oscillations
In the next generation of long-baseline neutrino oscillation experiments,
aiming to determine the charge-parity violating phase in the
appearance channel, fine-grained time-projection chambers are expected to play
an important role. In this Letter, we analyze an influence of realistic
detector capabilities on the sensitivity for a setup similar to
that of the Deep Underground Neutrino Experiment. We find that the effect of
the missing energy, carried out by undetected particles, is sizable. Although
the reconstructed neutrino energy can be corrected for the missing energy, the
accuracy of such procedure has to exceed 20\%, to avoid a sizable bias in the
extracted value.Comment: 6 pages, 2 figures. v2 matches the version published in PR
Gauge dependence in topological gauge theories
We parametrize the gauge-fixing freedom in choosing the Lagrangian of a
topological gauge theory. We compute the gauge-fixing dependence of correlators
of equivariant operators when the compactified moduli space has a non-empty
boundary and verify that only a subset of these has a gauge independent
meaning. We analyze in detail a simple example of such anomalous topological
theories, 4D topological Yang-Mills on the four-sphere and instanton number
k=1.Comment: 12 pages, TeX , harvma
A lagrangian formulation of 2-dimensional topological gravity and Cech-de Rham cohomology
We present a very simplified analysis of how one can overcome the Gribov problem in a non-abelian gauge theory. Our formulae, albeit quite simplified, show that possible breakdowns of the Slavnov-Taylor identity could in principle come from singularities in space of gauge orbits. To test these ideas we exhibit the calculation of a very simple correlation function of 2-dimensional topological gravity and we show how in this model the singularities of the moduli space induce a breakdown of the Slavnov-Taylor identity. We comment on the technical relevance of the possibility of including the singularities into a finite number of cells of the moduli space
Weak commutation relations of unbounded operators and applications
Four possible definitions of the commutation relation [S,T]=\Id of two
closable unbounded operators are compared. The {\em weak} sense of this
commutator is given in terms of the inner product of the Hilbert space \H
where the operators act. Some consequences on the existence of eigenvectors of
two number-like operators are derived and the partial O*-algebra generated by
is studied. Some applications are also considered.Comment: In press in Journal of Mathematical Physic
Genus bounds for minimal surfaces arising from min-max constructions
In this paper we prove genus bounds for closed embedded minimal surfaces in a
closed 3-dimensional manifold constructed via min-max arguments. A stronger
estimate was announced by Pitts and Rubistein but to our knowledge its proof
has never been published. Our proof follows ideas of Simon and uses an
extension of a famous result of Meeks, Simon and Yau on the convergence of
minimizing sequences of isotopic surfaces. This result is proved in the second
part of the paper.Comment: Accepted for publication on Journal for Pure and Applied Mathematic
Weak commutation relations of unbounded operators: nonlinear extensions
We continue our analysis of the consequences of the commutation relation
[S,T]=\Id, where and are two closable unbounded operators. The {\em
weak} sense of this commutator is given in terms of the inner product of the
Hilbert space \H where the operators act. {We also consider what we call,
adopting a physical terminology}, a {\em nonlinear} extension of the above
commutation relations
Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments
To be able to achieve their physics goals, future neutrino-oscillation
experiments will need to reconstruct the neutrino energy with very high
accuracy. In this work, we analyze how the energy reconstruction may be
affected by realistic detection capabilities, such as energy resolutions,
efficiencies, and thresholds. This allows us to estimate how well the detector
performance needs to be determined a priori in order to avoid a sizable bias in
the measurement of the relevant oscillation parameters. We compare the
kinematic and calorimetric methods of energy reconstruction in the context of
two muon-neutrino disappearance experiments operating in different energy
regimes. For the calorimetric reconstruction method, we find that the detector
performance has to be estimated with a ~10% accuracy to avoid a significant
bias in the extracted oscillation parameters. On the other hand, in the case of
kinematic energy reconstruction, we observe that the results exhibit less
sensitivity to an overestimation of the detector capabilities.Comment: 16 pages, 14 figures, matches the version published in Phys. Rev.
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