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M. Ericson

Publications and source records attributed to M. Ericson.

At least 19 recordsLinked to original sources

Phase space of electron- and muon-neutrino and antineutrino scattering off nuclei

We discuss the electron and muon neutrino and antineutrino double differential cross sections on carbon in the quasielastic as well as in the multinucleon and one pion production channels. By projecting them in the transferred momentum - transferred energy plane and in the neutrino energy - lepton scattering angle plane, as well as by performing simple considerations on the position of the quasielastic and Delta peaks and on their broadening, we explain the surprising dominance of the muon neutrino and antineutrino cross sections over the electron ones in particular kinematical conditions.

hep-ph

Investigation of the MicroBooNE neutrino cross sections on Argon

Experimental data of charged current inclusive neutrino cross sections on argon as a function of different variables have recently appeared. We have compared them to our theoretical approach. Overall we find an agreement in spite of a tendency of underestimation in some specific regions. A new aspect is the availability of data in terms of the energy transfer to the nucleus, which allows a better separation of the different reaction mechanisms. We explain the deterioration of agreement in specific kinematical conditions by the absence in our model of two-pion production and other inelastic channels, more important for MicroBooNE than for T2K.

hep-ph

Multinucleon excitations in neutrino-nucleus scattering: connecting different microscopic models for the correlations

The problem of nucleon-nucleon correlations and meson exchange currents has been vividly debated in connection with the neutrino-nucleus cross sections. In this work we focus on nucleon-nucleon correlations by discussing a formal correspondence between the approaches based on independent particles and the ab initio approaches involving correlated wave functions. We use a general technique based on unitary transformation mapping the Fermion operators relative to bare nucleons into quasi-particle operators relative to dressed nucleons. We derive formulas for spectral functions, response functions, momentum distribution, separation energy, general enough to be applied with any kind of effective nucleon-nucleon interaction. We establish the relation between the non-energy-weighted sum rule and the Fermi sea depopulation. With our tools we evaluate whether approaches based on effective interactions are compatible with the expected amount of correlations coming from ab initio calculations. For this purpose we use as a test the Fermi sea depopulation and the value of the kinetic energy per nucleon.

nucl-th

RAN Enablers for 5G Radio Resource Management

This paper presents the description of several key RAN enablers for the radio resource management (RRM) framework of the fifth generation (5G) radio access network (RAN), referred to as building blocks of the 5G RRM. In particular, the following key RAN enablers are discussed: i) interference management techniques for dense and dynamic deployments, focusing on cell-edge performance enhancement; ii) dynamic traffic steering mechanisms that aim to attain the optimum mapping of 5G services to any available resources when and where needed by considering the peculiarities of different air interface variants (AIVs); iii) resource management strategies that deal with network slices; and iv) tight interworking between novel 5G AIVs and evolved legacy AIVs such as Long-term Evolution (LTE). Evaluation results for each of these key RAN enablers are also presented.

cs.IT

Electron-neutrino scattering off nuclei from two different theoretical perspectives

We analyze charged-current electron-neutrino cross sections on Carbon. We consider two different theoretical approaches, on one hand the Continuum Random Phase Approximation (CRPA) which allows a description of giant resonances and quasielastic excitations, on the other hand the RPA-based calculations which are able to describe multinucleon emission and coherent and incoherent pion production as well as quasielastic excitations. We compare the two approaches in the genuine quasielastic channel, and find a satisfactory agreement between them at large energies while at low energies the collective giant resonances show up only in the CRPA approach. We also compare electron-neutrino cross sections with the corresponding muon-neutrino ones in order to investigate the impact of the different charged-lepton masses. Finally, restricting to the RPA-based approach we compare the sum of quasielastic, multinucleon emission, coherent and incoherent one-pion production cross sections (folded with the electron-neutrino T2K flux) with the charged-current inclusive electron-neutrino differential cross sections on Carbon measured by T2K. We find a good agreement with the data. The multinucleon component is needed in order to reproduce the T2K electron-neutrino inclusive cross sections.

nucl-th

Assessing the role of nuclear effects in the interpretation of the MiniBooNE low-energy anomaly

We study the impact of the effect of multinucleon interactions in the reconstruction of the neutrino energy on the fit of the MiniBooNE data in terms of neutrino oscillations. We obtain some improvement of the fit of the MiniBooNE low-energy excess in the framework of two-neutrino oscillations and a shift of the allowed region in the $\sin^2 2\vartheta$--$Δ{m}^2$ plane towards smaller values of $\sin^2 2\vartheta$ and larger values of $Δ{m}^2$. However this effect is not enough to solve the problem of the appearance-disappearance tension in the global fit of short-baseline neutrino oscillation data.

hep-ph

Neutrino versus antineutrino cross sections and CP violation

We discuss the nuclear interactions of neutrinos versus those of antineutrinos, a relevant comparison for CP violation experiments in the neutrino sector. We consider the MiniBooNE quasielastic-like double differential neutrinos and antineutrinos cross sections which are flux dependent and hence specific to the MiniBooNE set-up. We combine them introducing their sum and their difference. We show that the last combination can bring a general information, which can be exploited in other experiments, on the nuclear matrix elements of the axial vector interference term. Our theoretical model reproduces well the two cross sections combinations. This confirms the need for a sizeable multinucleon component in particular in the interference term.

nucl-th

Inclusive and pion production neutrino-nucleus cross sections

We analyze the experimental data on the inclusive double differential cross section by neutrinos charged current, measured by T2K, with the same model which was successful for the MiniBooNE quasielastic cross sections. As in our previous analysis the multinucleon component is needed in order to reproduce the data. For the total cross section our evaluation is smaller than the SciBooNE data above 1 GeV. This indicates the opening of a new channel not included in our evaluation, presumably the two pion emission channel. We also check that our description holds for the exclusive single pion production channel by confronting our evaluation with the MiniBooNE double differential cross section for a single charged pion and the Q^2 distribution. Both are compatible with data.

nucl-th

Quasielastic and multinucleon excitations in antineutrino-nucleus interactions

We investigate the MiniBooNE recent data on the antineutrino nucleus interaction, using the same theoretical description with the same parameters as in previous works on neutrino interactions. The double differential quasielastic cross section, which is free from the energy reconstruction problem, is well reproduced by our model once the multinucleon excitations are incorporated. A similar agreement is achieved for the Q^2 distribution.

nucl-th

Energy reconstruction effects in neutrino oscillation experiments and implications for the analysis

Data on neutrino oscillation often involve reconstructed neutrino energies while the analysis implies the real neutrino energy. The corrections corresponding to the transformation from real to reconstructed energy are discussed in the case of Cherenkov detectors where multinucleon events appear as quasielastic ones. These corrections show up as a tendency for the events to escape the region of high flux, with a clear preference for the low energy side. This is an effect of the multinucleon component of the quasielastic cross section. We have applied our corrections to the T2K and MiniBooNE data for electron appearance or $ν_μ$ disappearance data. We show that the inclusion of this correction in the analysis is expected to lead to an increase of the best fit oscillation mass parameters, particularly pronounced for the MiniBooNE neutrino data. This inclusion in the analysis of the MiniBooNE neutrino data should improve the compatibility with the existing constraints.

hep-ph

Neutrino energy reconstruction problems and neutrino oscillations

We discuss the accuracy of the usual procedure for neutrino energy reconstruction which is based on the quasielastic kinematics. Our results are described in terms of a probability distribution for a real neutrino energy value. Several factors are responsible of the deviations from the reconstructed value. The main one is the multinucleon component of the neutrino interaction which in the case of Cherenkov detectors enters as a quasielastic cross section, increasing the mean neutrino energy which can differ appreciably from the reconstructed value. As an application we derive, for excess electron events attributed to the conversion of muon neutrinos, the true neutrino energy distribution based on the experimental one which is given in terms of the reconstructed value. The result is a reshaping effect. For MiniBooNE the low energy peak is suppressed and shifted at higher energies, which may influence the interpretation in terms of oscillation. For T2K at the Super Kamiokande far detector the reshaping translates into a narrowing of the energy distribution.

hep-ph

Neutrino quasielastic interaction and nuclear dynamics

We investigate the double differential neutrino-carbon quasielastic cross sections as measured by the MiniBooNE experiment. Our present treatment incorporates relativistic corrections in the nuclear response functions and includes the multinucleon component. We confirm our previous conclusion that it is possible to account for all the data without any modification of the axial mass. We also introduce the Q^2 distribution for charged and neutral current. The data point at a sizable multinucleon component beside the genuine quasielastic peak. They are also indicative of the collective character of the nuclear response, of interest for hadronic physics.

nucl-th

Scalar field in nuclear matter: the roles of spontaneous chiral symmetry breaking and nucleon structure

Chiral theories with spontaneous symmetry breaking such as the Nambu-Jona-Lasinio (NJL) model lead to the existence of a scalar mode. We present in a detailed manner how the corresponding low momentum effective lagrangian involving the scalar field can be constructed starting from the NJL model. We discuss the relevance of the scalar mode for the problem of the nuclear binding and saturation. We show that it depends on the nucleon mass origin with two extreme cases. If this origin is entirely due to confinement the coupling of this mode to the nucleons vanishes, making it irrelevant for the nuclear binding problem. If instead it is entirely due to spontaneous symmetry breaking it couples to the nucleons but nuclear matter collapses. It is only in the case of a mixed origin with spontaneous breaking that nuclear matter can be stable and reach saturation. We describe models of nucleon structure where this balance is achieved. We also show how chiral constraints and confinement modify the QCD sum rules for the mass evolution in nuclear matter.

nucl-th

Chiral symmetry, scalar field and confinement : from nucleon structure to nuclear matter

We discuss the relevance of the scalar modes appearing in chiral theories with spontaneous symmetry breaking such as the NJL model for nuclear matter studies. We show that it depends on the relative role of chiral symmetry breaking and confinement in the nucleon mass origin. It is only in the case of a mixed origin that nuclear matter can be stable and reach saturation. We describe models of nucleon structure where this balance is achieved. We show how chiral constarints and confinement modify the QCD sum rules for the mass evolution in nuclear matter.

nucl-th

Scalar response of the nucleon chiral symmetry and nuclear matter properties

In this talk we present a description of nuclear binding in a chiral approach based on the existence of a chiral invariant scalar field associated with the generation of the masses through spontaneous chiral symmetry breaking. We discuss the emergence of such a field on the example of the NJL model. We also incorporate the effect of confinement at the level of the nucleon substructure to stabilize nuclear matter. In a particular quark-diquark model we illustrate the simutaneous influences of spontaneous chiral symmetry breaking and confinement on the nucleon mass and on the nuclear matter description.

nucl-th

Neutrino and antineutrino quasielastic interactions with nuclei

We investigate the interaction of neutrinos and antineutrinos with nuclei. We explore in particular the role played by the multinucleon excitations which can contaminate the quasielastic cross section. For neutrinos the multinucleon term produces a sizable increase of the quasielastic cross section. Part of the effect arises from tensor correlations. For antineutrinos this influence is smaller owing to the axial-vector interference which increases the relative importance of the terms which are not affected by these multinucleon excitations.

hep-ph

Proton Decay: Improving the sensitivity through nuclear dynamics?

The kinematics of the decay of a bound proton is governed by the proton spectral function. We evaluate this quantity in 16O using the information from nuclear physics experiments. It also includes a correlated part. The reliability of this evaluation is sufficient to open the possibility of correlated cuts in the missing mass and momentum variables in order to identify the decay events from the bound protons with a possible increase of the signal to noise ratio.

nucl-th

A unified approach for nucleon knock-out, coherent and incoherent pion production in neutrino interactions with nuclei

We present a theory of neutrino interactions with nuclei aimed at the description of the partial cross-sections, namely quasi-elastic and multi-nucleon emission, coherent and incoherent single pion production. For this purpose, we use the theory of nuclear responses treated in the random phase approximation, which allows a unified description of these channels. It is particularly suited for the coherent pion production where collective effects are important whereas they are moderate in the other channels. We also study the evolution of the neutrino cross-sections with the mass number from carbon to calcium. We compare our approach to the available neutrino experimental data on carbon. We put a particular emphasis on the multi-nucleon channel, which at present is not easily distinguishable from the quasi-elastic events. This component turns out to be quite relevant for the interpretation of experiments (K2K, MiniBooNE, SciBooNE). It can account in particular for the unexpected behavior of the quasi-elastic cross-section.

nucl-th