983 research outputs found
Measuring the prompt atmospheric neutrino flux with down-going muons in neutrino telescopes
In the TeV energy region and above, the uncertainty in the level of prompt
atmospheric neutrinos would limit the search for diffuse astrophysical
neutrinos. We suggest that neutrino telescopes may provide an empirical
determination of the flux of prompt atmospheric electron and muon neutrinos by
measuring the flux of prompt down-going muons. Our suggestion is based on the
consideration that prompt neutrino and prompt muon fluxes at sea level are
almost identical.Comment: 4 pages, 3 figure
Scuola, Università e Mercato del lavoro dopo la Riforma Biagi. Le politiche per la transizione dai percorsi educativi e formativi al mercato del lavoro
Quale ruolo per i percorsi di educazione e formazione nella riforma del mercato del lavoro? Se ne è parlato poco, in questi ultimi tempi. Eppure, nell’impianto della legge Biagi, proprio il sistema di istruzione e quello della formazione professionale rappresentano, assieme al nuovo contratto di apprendistato, il principale canale di sviluppo e valorizzazione delle risorse umane. Un canale attraverso cui avvicinare, grazie a investimenti in ricerca, innovazione e capitale umano, le performances del nostro sistema economico-produttivo a quelle degli altri Paesi europei. E non poteva essere diversamente, in una Europa che, da Lisbona in poi, dichiara enfaticamente di voler diventare l’economia basata sulla conoscenza più competitiva e dinamica del mondo. Il ritardo dell’Italia rispetto agli altri Stati europei è, da questo punto di vista, ancora impressionante. È sufficiente ricordare, al riguardo, come i tradizionali percorsi didattici e formativi abbiano sin qui determinato alti tassi di dispersione e, quel che più è grave, un ingresso tardivo nel mercato del lavoro. Le rilevazioni statistiche parlano di 28 anni, quando la media europea è attestata intorno ai 22-23 anni. È da tempo che se ne discute, senza tuttavia approdare a esiti concreti: gli istituti scolastici e le università italiane devono accelerare i processi volti a rafforzare la coerenza tra formazione erogata e fabbisogni del mercato del lavoro. La riforma universitaria che prevede la laurea triennale è entrata in vigore con l’anno accademico 2001/2002, i primi laureati tuttavia in minima parte si sono avvicinati al mondo del lavoro ma hanno proseguito il corso di studi verso la laurea specialistica e quindi se questa tendenza verrà confermata, difficilmente nel nostro Paese ci avvicineremo alla media europea e continueremo ad avere laureati in cerca di prima occupazione ad un’età troppo elevata per rispondere ai bisogni del mercato del lavoro
Relevance of Ion-Channeling for Direct DM Detection
The channeling of the recoiling nucleus in crystalline detectors after a WIMP
collision would produce a larger scintillation or ionization signal in direct
detection experiments than otherwise expected. I present estimates of the
importance of this effect for the total direct detection rate and the daily
modulation of the signal using analytic models produced in the 1960's and 70's
to describe the effects of channeling and blocking in crystals.Comment: Talk given at the TAUP 2009 conference, Rome, Italy, July 1-5 2009. 3
pages, 4 figures. jpconf.cls and jpconf11.clo files need to typeset the tex
fil
Search for photons at the Pierre Auger Observatory
The Pierre Auger Observatory has a unique potential to search for ultra-high
energy photons (above ~1 EeV). First experimental limits on photons were
obtained during construction of the southern part of the Observatory.
Remarkably, already these limits have proven useful to falsify proposals about
the origin of cosmic rays, and to perform fundamental physics by constraining
Lorentz violation. A final discovery of photons at the upper end of the
electromagnetic spectrum is likely to impact various branches of physics and
astronomy.Comment: 5 pages, 5 figures. Presented at CRIS 2008, Malfa, Ital
Cold dark matter in brane cosmology scenario
We analyze the dark matter problem in the context of brane cosmology. We
investigate the impact of the non-conventional brane cosmology on the relic
abundance of non-relativistic stable particles in high and low reheating
scenarios. We show that in case of high reheating temperature, the brane
cosmology may enhance the dark matter relic density by many order of magnitudes
and a stringent lower bound on the five dimensional scale is obtained. We also
consider low reheating temperature scenarios with chemical equilibrium and
non-equilibrium. We emphasize that in non-equilibrium case, the resulting relic
density is very small. While with equilibrium, it is increased by a factor of
O(10^2) with respect to the standard thermal production. Therefore, dark matter
particles with large cross section, which is favored by detection expirements,
can be consistent with the recent relic density observational limits.Comment: 14 pages, 1 figur
A derivative, integral, and proportional features extractor for fault detection in dynamic processes
The Standard Model of Leptons as a Purely Vectorial Theory
We propose a way to reconcile the Standard Model of leptons with a purely
vectorial theory. The observed neutrino is predicted to be massless. The
unobservability of its partner and the structure of the weak currents are
given the same origin.Comment: 10 pages. Latex, 8 postscript figures included. We have corrected 2
(cancelling) sign misprints, and made explicit that we also recover the usual
couplings of the U(1) gauge field B. The conclusions are unchanged. PAR-LPTHE
93/1
Measurement of the gluon PDF at small x with neutrino telescopes
We analyze the possibility that neutrino telescopes may provide an
experimental determination of the slope lambda of the gluon distribution in the
proton at momentum fractions x smaller than the accelerator reach. The method
is based on a linear relation between lambda and the spectral index (slope) of
the down-going atmospheric muon flux above 100 TeV, for which there is no
background. Considering the uncertainties in the charm production cross section
and in the cosmic ray composition, we estimate the error on the measurement of
lambda through this method, excluding the experimental error of the telescopes,
to be ~ +/- 0.2Comment: 16 pages with 16 figures - new version, comments added, same results
and figure
Anomaly mediated SUSY breaking scenarios in the light of cosmology and in the dark (matter)
Anomaly mediation is a popular and well motivated supersymmetry breaking
scenario. Different possible detailed realisations of this set-up are studied
and actively searched for at colliders. Apart from limits coming from flavour,
low energy physics and direct collider searches, these models are usually
constrained by the requirement of reproducing the observations on dark matter
density in the universe. We reanalyse these bounds and in particular we focus
on the dark matter bounds both considering the standard cosmological model and
alternative cosmological scenarios. These scenarios do not change the
observable cosmology but relic dark matter density bounds strongly depend on
them. We consider few benchmark points excluded by standard cosmology dark
matter bounds and suggest that loosening the dark matter constraints is
necessary in order to avoid a too strong (cosmological) model dependence in the
limits that are obtained for these models. We also discuss briefly the
implications for phenomenology and in particular at the Large Hadron Collider.Comment: 37 pages, 20 figures, 1 tabl
On the measurement of the proton-air cross section using longitudinal shower profiles
In this paper, we will discuss the prospects of deducing the proton-air cross
section from fluorescence telescope measurements of extensive air showers. As
it is not possible to observe the point of first interaction
directly, other observables closely linked to must be inferred from
the longitudinal profiles. This introduces a dependence on the models used to
describe the shower development. The most straightforward candidate for a good
correlation to is the depth of shower maximum . We
will discuss the sensitivity of an -based analysis on and quantify the systematic uncertainties arising from the model
dependence, parameters of the reconstruction method itself and a possible
non-proton contamination of the selected shower sample.Comment: 4 pages, Proceedings for ISVHECRI Weihei 200
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