2,965 research outputs found
Time and position distributions in large volume spherical scintillation detectors
Large spherical scintillation detectors are playing an increasingly important
role in experimental neutrino physics studies. From the instrumental point of
view the primary signal response of these set-ups is constituted by the time
and amplitude of the anode pulses delivered by each individual phototube
following a particle interaction in the scintillator. In this work, under some
approximate assumptions, we derive a number of analytical formulas able to give
a fairly accurate description of the most important timing features of these
detectors, intended to complement the more complete Monte Carlo studies
normally used for a full modelling approach. The paper is completed with a
mathematical description of the event position distributions which can be
inferred, through some inference algorithm, starting from the primary time
measures of the photomultiplier tubes.Comment: 29 pages, 20 figures, accepted for publication on Nucl. Instr. and
Meth.
On the significance in signal search through the sliding window algorithm
The experimental issue of the search for new particles of unknown mass poses
the challenge of exploring a wide interval to look for the usual signatures
represented by excess of events above the background. A side effect of such a
broad range quest is that the traditional significance calculations valid for
signals of known location are no more applicable when such an information is
missing. In this note the specific signal search approach via observation
windows sliding over the range of interest is considered; in the assumptions of
known background and of fixed width of the exploring windows the statistical
implications of such a search scheme are described, with special emphasis on
the correct significance assessment for a claimed discovery.Comment: 10 pages, 6 figures, misprints corrected, an extended version will be
published on NIM
The single currency and European citizenship
We could expect that the introduction of the single currency had been accompanied by a significant share of studies and researches about the implications and impacts of such a watershed event on European citizenship. On the contrary, we soon discover to be facing a paradox, which could be phrased as follows: while the purpose of building European citizenship is the very rationale for the project of the single currency, the Scholars – but also the policy community – have mostly underestimated if not neglected this relation, both in terms of public policy making and discourse and of interpretation and forecasting. As a consequence of all of that, relevant features of the single currency happened to remain hidden, poorly considered and almost not thematized. In order to fill this gap, the first part of this article will present the main findings emerged from a documentary research conducted by FONDACA between 2010 and 2011, aimed at mapping the existing academic and policy thematizations about the hidden dimensions of the euro. The second part will be devoted to define “the other side of the coin” as an empirical phenomenon
Neutrino oscillations
In the last decades, a very important breakthrough has been brought in the
elementary particle physics by the discovery of the phenomenon of the neutrino
oscillations, which has shown neutrino properties beyond the Standard Model.
But a full understanding of the various aspects of the neutrino oscillations is
far to be achieved. In this paper the theoretical background of the neutrino
oscillation phenomenon is described, referring in particular to the
paradigmatic models. Then the various techniques and detectors which studied
neutrinos from different sources are discussed, starting from the pioneering
ones up to the detectors still in operation and to those in preparation. The
physics results are finally presented adopting the same research path which has
crossed this long saga. The problems not yet fixed in this field are discussed,
together with the perspectives of their solutions in the near future
Periodogram and likelihood periodicity search in the SNO solar neutrino data
In this work a detailed spectral analysis for periodicity search of the time
series of the 8B solar neutrino flux released by the SNO Collaboration is
presented. The data have been publicly released with truncation of the event
times to the unit of day (1 day binning); they are thus suited to undergo the
traditional Lomb-Scargle analysis for periodicity investigation, as well as an
extension of such a method based on a likelihood approach. The results of the
analysis presented here confirm the absence of modulation signatures in the SNO
data. For completeness, a more refined "1 day binned" likelihood is also
illustrated, which approximates the unbinned likelihood methodology, based upon
the availability of the full time information, adopted by the SNO
collaboration. Finally, this work is completed with two different joint
analyses of the SNO and Super-Kamiokande data, respectively, over the common
and the entire data taking periods. While both analyses reinforce the case of
the constancy of the neutrino flux, the latter in addition provides evidence of
the detection at the 99.7% confidence level of the annual modulation spectral
line due to the Earth's orbit eccentricity around the SunComment: 27 pages, 29 figures. Joint periodicity analysis of the SNO and
Super-Kamiokande data added. Accepted for publication on Phys. Rev.
- …