2,303 research outputs found

### Particle acceleration in sub-cycle optical cells

A single laser pulse with spot size smaller than half its wavelength ($w_0 <
\lambda/2$) can provide a net energy gain to ultra-relativistic particles. In
this paper, we discuss the properties of an optical cell consisting of $N$
sub-cycle pulses that propagate in the direction perpendicular to the electron
motion. We show that the energy gain produced by the cell is proportional to
$N$ and it is sizable even for $\mathcal{O}(1\mathrm{~TW})$ pulses.Comment: 13 pages, 7 figures. Version to appear in PRSTA

### Neutrino oscillation experiments

In this paper, we give a short overview of neutrino oscillation experiments with emphasis on current European programmes of interest for INFN and on mid-term perspectives. In particular, we discuss the results that strengthen the standard three-family interpretation of leptonic mixing and the tension originating from the persistent LSND-Miniboone anomaly together with updated reactor data

### An infrared origin of leptonic mixing and its test at DeepCore

Fermion mixing is generally believed to be a low-energy manifestation of an
underlying theory whose energy scale is much larger than the electroweak scale.
In this paper we investigate the possibility that the parameters describing
lepton mixing actually arise from the low-energy behavior of the neutrino
interacting fields. In particular, we conjecture that the measured value of the
mixing angles for a given process depends on the number of unobservable flavor
states at the energy of the process. We provide a covariant implementation of
such conjecture, draw its consequences in a two neutrino family approximation
and compare these findings with current experimental data. Finally we show that
this infrared origin of mixing will be manifest at the Ice Cube DeepCore array,
which measures atmospheric oscillations at energies much larger than the tau
lepton mass; it will hence be experimentally tested in a short time scale.Comment: 14 pages, 1 figure; version to appear in Int.J.Mod.Phys.

### Three-flavour oscillations with accelerator neutrino beams

The three-flavor neutrino oscillation paradigm is well established in
particle physics thanks to the crucial contribution of accelerator neutrino
beam experiments. In this paper we review the most important contributions of
these experiments to the physics of massive neutrinos after the discovery of
$\theta_{13}$ and future perspectives in such a lively field of research.
Special emphasis is given to the technical challenges of high power beams and
the oscillation results of T2K, OPERA, ICARUS and NO$\nu$A. We discuss in
details the role of accelerator neutrino experiments in the precision era of
neutrino physics in view of DUNE and Hyper-Kamiokande, the programme of
systematic uncertainty reduction and the development of new beam facilities.Comment: 31 pages, 12 fugures. To appear in Univers

### Experimental prospects to observe the g âˆ’ 2 muon anomaly in the electron sector

The long-standing difference between the experimental measurement and the standard model prediction for the muonâ€™s anomalous magnetic moment, aÎ¼ = (gÎ¼ âˆ’ 2)/2, can be due to new particles flowing in loop contributions: such
discrepancy might thus signal the presence of new physics at the TeV scale. The vast majority of models explaining the muon discrepancy in terms of new physics (NP) predict sizable effects in ae = (geâˆ’2)/2, too. We discuss the experimental prospects to reach sub-ppb precision on ae and test the NP origin of the muon anomaly in its electron counterpart

### CP violation and mass hierarchy at medium baselines in the large theta(13) era

The large value of theta(13) recently measured by rector and accelerator
experiments opens unprecedented opportunities for precision oscillation
physics. In this paper, we reconsider the physics reach of medium baseline
superbeams. For theta(13) ~ 9 degree we show that facilities at medium
baselines -- i.e. L ~ O(1000 km) -- remain optimal for the study of CP
violation in the leptonic sector, although their ultimate precision strongly
depends on experimental systematics. This is demonstrated in particular for
facilities of practical interest in Europe: a CERN to Gran Sasso and CERN to
Phyasalmi nu_mu beam based on the present SPS and on new high power 50 GeV
proton driver. Due to the large value of theta(13), spectral information can be
employed at medium baselines to resolve the sign ambiguity and determine the
neutrino mass hierarchy. However, longer baselines, where matter effects
dominate the nu_mu->nu_e transition, can achieve much stronger sensitivity to
sign(Delta m^2) even at moderate exposures.Comment: 14 pages, 14 figures, version to appear in EPJ

### Neutrino oscillation studies with laser-driven beam dump facilities

A new mechanism is suggested for efficient proton acceleration in the GeV
energy range; applications to non-conventional high intensity proton drivers
and, hence, to low-energy (10-200 MeV) neutrino sources are discussed. In
particular we investigate possible uses to explore subdominant $\bar{\nu}_\mu
\to \bar{\nu}_e$ oscillations at the atmospheric scale and their CP conjugate.
We emphasize the opportunity to develop these facilities in conjunction with
projects for inertial confined nuclear fusion and neutron spallation sources.Comment: 30 pages, 9 figures, minor changes, version to appear in
Nucl.Instrum.Meth.

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