30 research outputs found
On the extra factor of two in the phase of neutrino oscillations
Attempts to modify the standard expression for the phase in neutrino
oscillations by an extra factor of two are based on misuse of quantum
mechanics. Claims to present Bruno Pontecorvo and his coauthors as
``godfathers'' of this ``extra 2'' factor are easily disproved by unbiased
reading their articles.Comment: 5 pages, two sentences at the end of the paper are deleted and two
are adde
A Covariant Path Amplitude Description of Flavour Oscillations: The Gribov-Pontecorvo Phase for Neutrino Vacuum Propagation is Right
An extended study is performed of geometrical and kinematical assumptions
used in calculations of the neutrino oscillation phase. The almost universally
employed `equal velocity' assumption, in which all neutrino mass eigenstates
are produced at the same time, is shown to underestimate, by a factor of two,
the neutrino propagation contribution to the phase. Taking properly into
account, in a covariant path amplitude calculation, the incoherent nature of
neutrino production as predicted by the Standard Model, results in an important
source propagator contribution to the phase. It is argued that the commonly
discussed Gaussian `wave packets' have no basis within quantum mechanics and
are the result of a confused amalgam of quantum and classical wave concepts.Comment: 39 pages, 1 table, 1 figure. Subject matter similar to
hep-ph/0110064, hep-ph/0110066. More pedagogical presentation addressing
referee criticism of earlier paper
Remarks upon the mass oscillation formulas
The standard formula for mass oscillations is often based upon the
approximation and the hypotheses that neutrinos have been
produced with a definite momentum or, alternatively, with definite energy
. This represents an inconsistent scenario and gives an unjustified
reduction by a factor of two in the mass oscillation formulas. Such an
ambiguity has been a matter of speculations and mistakes in discussing flavour
oscillations. We present a series of results and show how the problem of the
factor two in the oscillation length is not a consequence of gedanken
experiments, i.e. oscillations in time. The common velocity scenario yields the
maximum simplicity.Comment: 9 pages, AMS-Te
Unitarity triangle test of the extra factor of two in particle oscillation phases
There are claims in the literature that in neutrino oscillations and
oscillations of neutral kaons and B-mesons the oscillation phase differs from
the standard one by a factor of two. We reconsider the arguments leading to
this extra factor and investigate, in particular, the non-relativistic regime.
We actually find that the very same arguments lead to an ambiguous phase and
that the extra factor of two is a special case. We demonstrate that the
unitarity triangle (UT) fit in the Standard Model with three families is a
suitable means to discriminate between the standard oscillation phase and the
phase with an extra factor of two. If and mass
differences are extracted from the and
data, respectively, with the extra factor of two in the oscillation phases,
then the UT fit becomes significantly worse in comparison with the standard fit
and the extra factor of two is disfavoured by the existing data at the level of
more than 3 .Comment: 16 pages, 2 figure
The CRESST II Dark Matter Search
Direct Dark Matter detection with cryodetectors is briefly discussed, with
particular mention of the possibility of the identification of the recoil
nucleus. Preliminary results from the CREEST II Dark Matter search, with 730
kg-days of data, are presented. Major backgrounds and methods of identifying
and dealing with them are indicated.Comment: Talk at DSU workshop, ITP Beijing, Oct. 2011. 9 figures, 2 table
Oscillations of neutrinos and mesons in quantum field theory
This report deals with the quantum field theory of particle oscillations in
vacuum. We first review the various controversies regarding quantum-mechanical
derivations of the oscillation formula, as well as the different
field-theoretical approaches proposed to settle them. We then clear up the
contradictions between the existing field-theoretical treatments by a thorough
study of the external wave packet model. In particular, we show that the latter
includes stationary models as a subcase. In addition, we explicitly compute
decoherence terms, which destroy interferences, in order to prove that the
coherence length can be increased without bound by more accurate energy
measurements. We show that decoherence originates not only in the width and in
the separation of wave packets, but also in their spreading through space-time.
In this review, we neither assume the relativistic limit nor the stability of
oscillating particles, so that the oscillation formula derived with
field-theoretical methods can be applied not only to neutrinos but also to
neutral K and B mesons. Finally, we discuss oscillations of correlated
particles in the same framework.Comment: v2, 124 pages, 10 figures (7 more); updated review of the literature;
complete derivation of the oscillation probability at short and large
distance; more details on the influence of the spreading of the amplitude on
decoherence; submitted to Physics Report