arXiv subjects

F. Terranova

Publications and source records attributed to F. Terranova.

At least 91 records · Page 5Linked to original sources

arXiv2009

European facilities for accelerator neutrino physics: perspectives for the decade to come

Very soon a new generation of reactor and accelerator neutrino oscillation experiments - Double Chooz, Daya Bay, Reno and T2K - will seek for oscillation signals generated by the mixing parameter theta_13. The knowledge of this angle is a fundamental milestone to optimize further experiments aimed at detecting CP violation in the neutrino sector. Leptonic CP violation is a key phenomenon that has profound implications in particle physics and cosmology but it is clearly out of reach for the aforementioned experiments. Since late 90's, a world-wide activity is in progress to design facilities that can access CP violation in neutrino oscillation and perform high precision measurements of the lepton counterpart of the Cabibbo-Kobayashi-Maskawa matrix. In this paper the status of these studies will be summarized, focusing on the options that are best suited to exploit existing European facilities (firstly CERN and the INFN Gran Sasso Laboratories) or technologies where Europe has a world leadership. Similar considerations will be developed in more exotic scenarios - beyond the standard framework of flavor oscillation among three active neutrinos - that might appear plausible in the occurrence of anomalous results from post-MiniBooNE experiments or the CNGS.

hep-ex↗

arXiv2008

Bandwidth enhancement for parametric amplifiers operated in chirped multi-beam mode

In this paper we discuss the bandwidth enhancement that can be achieved in multi-Joule optical parametric chirped pulse amplification (OPCPA) systems exploiting the tunability of parametric amplification. In particular, we consider a pair of single pass amplifiers based on potassium dideuterium phosphate (DKDP), pumped by the second harmonic of Nd:glass and tuned to amplify adjacent regions of the signal spectrum. We demonstrate that a bandwidth enhancement up to 50% is possible in two configurations; in the first case, one of the two amplifiers is operated near its non-collinear broadband limit; to allow for effective recombination and recompression of the outgoing signals this configuration requires filtering and phase manipulation of the spectral tail of the amplified pulses. In the second case, effective recombination can be achieved simply by spectral filtering: in this configuration, the optimization of the parameters of the amplifiers (pulse, crystal orientation and crystal length) does not follow the recipes of non-collinear OPCPA.

physics.optics↗

arXiv2007

Detectors and flux instrumentation for future neutrino facilities

This report summarises the conclusions from the detector group of the International Scoping Study of a future Neutrino Factory and Super-Beam neutrino facility. The baseline detector options for each possible neutrino beam are defined as follows: 1. A very massive (Megaton) water Cherenkov detector is the baseline option for a sub-GeV Beta Beam and Super Beam facility. 2. There are a number of possibilities for either a Beta Beam or Super Beam (SB) medium energy facility between 1-5 GeV. These include a totally active scintillating detector (TASD), a liquid argon TPC or a water Cherenkov detector. 3. A 100 kton magnetized iron neutrino detector (MIND) is the baseline to detect the wrong sign muon final states (golden channel) at a high energy (20-50 GeV) neutrino factory from muon decay. A 10 kton hybrid neutrino magnetic emulsion cloud chamber detector for wrong sign tau detection (silver channel) is a possible complement to MIND, if one needs to resolve degeneracies that appear in the $δ$-$θ_{13}$ parameter space.

physics.ins-det↗

arXiv2007

Neutrino hierarchy from CP-blind observables with high density magnetized detectors

High density magnetized detectors are well suited to exploit the outstanding purity and intensities of novel neutrino sources like Neutrino Factories and Beta Beams. They can also provide independent measurements of leptonic mixing parameters through the observation of atmospheric muon-neutrinos. In this paper, we discuss the combination of these observables from a multi-kton iron detector and a high energy Beta Beam; in particular, we demonstrate that even with moderate detector granularities the neutrino mass hierarchy can be determined for $θ_{13}$ values greater than 4$^\circ$.

hep-ph↗

arXiv2007

Sterile neutrinos at the CNGS

We study the potential of the CNGS beam in constraining the parameter space of a model with one sterile neutrino separated from three active ones by an $\mathcal{O}(\eVq)$ mass-squared difference, $\Dmq_\Sbl$. We perform our analysis using the OPERA detector as a reference (our analysis can be upgraded including a detailed simulation of the ICARUS detector). We point out that the channel with the largest potential to constrain the sterile neutrino parameter space at the CNGS beam is $ν_μ\to ν_τ$. The reason for that is twofold: first, the active-sterile mixing angle that governs this oscillation is the less constrained by present experiments; second, this is the signal for which both OPERA and ICARUS have been designed, and thus benefits from an extremely low background. In our analysis we also took into account $ν_μ\to ν_e$ oscillations. We find that the CNGS potential to look for sterile neutrinos is limited with nominal intensity of the beam, but it is significantly enhanced with a factor 2 to 10 increase in the neutrino flux. Data from both channels allow us, in this case, to constrain further the four-neutrino model parameter space. Our results hold for any value of $\Dmq_\Sbl \gtrsim 0.1 \eVq$, \textit{i.e.} when oscillations driven by this mass-squared difference are averaged. We have also checked that the bound on $θ_{13}$ that can be put at the CNGS is not affected by the possible existence of sterile neutrinos.

hep-ph↗

arXiv2006

A Beta Beam complex based on the machine upgrades for the LHC

The Beta Beam CERN design is based on the present LHC injection complex and its physics reach is mainly limited by the maximum rigidity of the SPS. In fact, some of the scenarios for the machine upgrades of the LHC, particularly the construction of a fast cycling 1 TeV injector (``Super-SPS''), are very synergic with the construction of a higher $γ$ Beta Beam. At the energies that can be reached by this machine, we demonstrate that dense calorimeters can already be used for the detection of $ν$ at the far location. Even at moderate masses (40 kton) as the ones imposed by the use of existing underground halls at Gran Sasso, the CP reach is very large for any value of $θ_{13}$ that would provide evidence of $ν_e$ appearance at T2K or NO$ν$A ($θ_{13}\geq 3^\circ$). Exploitation of matter effects at the CERN to Gran Sasso distance provides sensitivity to the neutrino mass hierarchy in significant areas of the $θ_{13}-δ$ plane.

hep-ph↗

arXiv2005

Enabling pulse compression and proton acceleration in a modular ICF driver for nuclear and particle physics applications

The existence of efficient ion acceleration regimes in collective laser-plasma interactions opens up the possibility to develop high-energy physics facilities in conjunction with projects for inertial confinement nuclear fusion (ICF) and neutron spallation sources. In this paper, we show that the pulse compression requests to make operative these acceleration mechanisms do not fall in contradiction with current technologies for high repetition rate ICF drivers. In particular, we discuss explicitly a solution that exploits optical parametric chirped pulse amplification and the intrinsic modularity of the lasers aimed at ICF.

physics.acc-ph↗

arXiv2005

Perspectives for a neutrino program based on the upgrades of the CERN accelerator complex

In this paper, we discuss the possibilities offered to neutrino physics by the upgrades of the CERN accelerator complex. Emphasis is on the physics reach of a medium $γ$ (350-580) $β$-beam that fully exploits the improvements in the CERN accelerator complex for the luminosity/energy upgrade of the LHC. We show that, this design not only profits of the ongoing efforts for the upgrades of the LHC, but also leverage out the existing infrastructures of the LNGS underground laboratory. Furthermore, given the involved high neutrino energies, above 1 GeV, a non-magnetized iron detector could efficiently exploit the neutrino beam. We show that the performance of this complex for what concerns the discovery of the CP violation in the leptonic sector, in case $θ_{13}$ is discovered by Phase I experiments, is comparable with the current baseline design based on a gigantic water Cherenkov at Frejus. Furthermore, this complex has also some sensitivity to the neutrino mass hierarchy.

hep-ph↗

arXiv2005

Measurement of three-family neutrino mixing and search for CP violation

The measurements of the parameters of the neutrino mixing matrix in the present and future neutrino oscillation experiments at accelerators are presented. The perspectives for high intensity new neutrino facilities as SuperBeams, BetaBeams and Neutrino Factories devoted to precise measurements subleading numu to nue oscillation parameters at the atmospheric scale are discussed. Emphasis is on the determination of the currently unknown 1-3 sector of the leptonic mixing matrix (i.e. the mixing between the first and third generation and the CP violating Dirac phase) and on possible experimental programs to be developed in Europe.

hep-ph↗

arXiv2004

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 $\barν_μ\to \barν_e$ 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.

hep-ph↗

arXiv2004

High energy beta beams without massive detectors

In this paper, the possibility to exploit a high energy beta beam without massive detectors is discussed. The radioactive ions are boosted up to very high $γ$ with the neutrino beam pointing towards an instrumented surface located at a moderate baseline (e.g. from CERN to the Gran Sasso Laboratories). $ν_e \to ν_μ$ oscillations and their CP conjugate are tagged as an excess of horizontal muons produced in the rock and tracked by the low-mass instrumented surface installed in one of the LNGS experimental halls. We show that the performance of this complex for what concerns the determination of the $θ_{13}$ angle of the leptonic mixing matrix is comparable with the current low-$γ$ design based on a gigantic water Cherenkov at Frejus.

hep-ph↗

arXiv2004

The OPERA magnetic spectrometer

The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the lead-nuclear emulsion targets. The magnet is made up of two vertical walls of rectangular cross section connected by return yokes. The particle trajectories are measured by high precision drift tubes located before and after the arms of the magnet. Moreover, the magnet steel is instrumented with Resistive Plate Chambers that ease pattern recognition and allow a calorimetric measurement of the hadronic showers. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained from the magnet and RPC prototypes and the installation of the final apparatus at the Gran Sasso laboratories. We discuss the mechanical and magnetic properties of the steel and the techniques employed to calibrate the field in the bulk of the magnet. Moreover, results of the tests and issues concerning the mass production of the Resistive Plate Chambers are reported. Finally, the expected physics performance of the detector is described; estimates rely on numerical simulations and the outcome of the tests described above.

physics.ins-det↗

arXiv2003

Peak finding through Scan Statistics

We discuss the conditions under which Scan Statistics can be fruitfully implemented to signal a departure from the underlying probability model that describes the experimental data. It is shown that local perturbations (``bumps'' or ``excesses'' of events) are better dealt within this framework and, in general, tests based on these statistics provide a powerful and unbiased alternative to the traditional techniques related with the chi2 and Kolmogorov distributions. Approximate formulas for the computation of Scan Statistics in the range of interest for high energy and nuclear physics applications are also presented.

physics.data-an↗

arXiv2003

The synergy of the golden and silver channels at the Neutrino Factory

We deepen the study of the so-called ``silver channel'' $ν_e \to ν_τ$ \cite{Donini:2002rm} and of its relevance to solve some of the ambiguities that can arise in the simultaneous measurement of $(θ_{13},δ)$ at the Neutrino Factory by presenting in full detail the characteristics of the considered OPERA-like detector and the experimental treatment of the different backgrounds and signals. Furthermore, we perform a detailed study of the systematic errors associated both with the OPERA-like and the magnetized-iron detectors and their effects on the sensitivity. Finally, we also apply a refined statistical analysis of the simulated events based on the frequentist approach.

hep-ph↗

arXiv2003

Next generation long baseline experiments on the path to leptonic CP violation

In this paper we quantify the trade-off between setups optimized to be ancillary to Phase II Superbeams or Neutrino Factories and experiments tuned for maximal sensitivity to the subdominant terms of the neutrino transition probability at the atmospheric scale (``maximum discovery potential''). In particular, the theta(13) sensitivity is computed for both Phase I superbeams (JHF-SK and NuMI Off-Axis) and next generation long baseline experiments (ICARUS, OPERA and MINOS). It is shown that Phase I experiments cannot reach a sensitivity able to ground (or discourage in a definitive manner) the building of Phase II projects and that, in case of null result and without a dedicated $\barν$ run, this capability is almost saturated by high energy beams like CNGS, especially for high values of the ratio $Δm^2_{21}/|Δm^2_{31}|$.

hep-ph↗

arXiv2003

Modeling skin effect in large magnetized iron detectors

The experimental problem of the calibration of magnetic field in large iron detectors is discussed. Emphasis is laid on techniques based on ballistic measurements as the ones employed by MINOS or OPERA.In particular, we provide analytical formulas to model the behavior of the apparatus in the transient regime, keeping into account eddy current effects and the finite penetration velocity of the driving fields. These formulas ease substantially the design of the calibration apparatus.Results are compared with experimental data coming from a prototype of the OPERA spectrometer.

hep-ex↗

arXiv2002

Sensitivity to theta(13) of the CERN to Gran Sasso neutrino beam

The sensitivity of the present CNGS beam to the sub-dominant $ν_μ\leftrightarrow ν_e$ oscillations in the region indicated by the atmospheric neutrino experiments is investigated. In particular, we present a revised analysis of the OPERA detector and discuss the sensitivity to $θ_{13}$ of ICARUS and OPERA combined. We show that the CNGS beam optimised for $ν_τ$ appearance, will improve significantly (about a factor 5) the current limit of CHOOZ and explore most of the region $\sin^22θ_{13}\simeq\mathcal{O}(10^{-2})$.

hep-ph↗

arXiv1999

Measurement of neutrino oscillations by means of a high density detector on the atmospheric neutrino beam

A high-density calorimeter, consisting of magnetized iron planes interleaved by RPCs, as tracking and timing devices, is a good candidate for a next generation experiment on atmospheric neutrinos. With 34 kt of mass and in four years of data taking, this experiment will be sensitive to $ν_μ\to ν_x$ oscillation with $Δm^2 > 6 \times 10^{-5}$ and mixing near to maximal and fully cover the region of oscillation parameters suggested by Super-Kamiokande results. Moreover, the experimental method will enable to measure the oscillation parameters from the modulation of the L/E spectrum ($ν_μ$ disappearance). For $Δm^2 > 3 \times 10^{-3}$ eV$^2$, this experiment can also establish whether the oscillation occurs into a tau or a sterile neutrino, by looking for an excess of muon-less events at high energies produced by upward-going tau neutrinos ($ν_τ$ appearance).

hep-ex↗