Charged-Current and Neutral-Current Neutrino-Nucleus Scattering in a Relativistic Approach
Carlotta Giusti, Andrea Meucci, Franco Davide Pacati
备注:
t pages, 2 figures, Proceedings to the 45th Winter School in Theoretical Physics "Neutrino Interactions: from Theory to Monte Carlo Simulations", Ladek-Zdroj, Poland, February 2--11, 2009
Relativistic models developed for the exclusive and inclusive QuasiElastic (QE) electron scattering have been extended to Charged-Current (CC) and Neutral-Current (NC) neutrino-nucleus scattering. The results of different descriptions of Final-State Interactions (FSI) are compared.
The algebraic solution of RPA equations nucleon re-interactions in the case of quasi elastic charged current neutrino - nucleus scattering is presented. Abelian algebra of matrices allows to extract four independent corrections to cross section separatly.Results of numerical computations are shown.
A relativistic distorted-wave impulse-approximation model to quasielastic neutral-current neutrino-nucleus scattering is developed, using the relativistic mean field theory for the bound state and taking into account the final state interaction in the relativistic scattering state. Results for the neutrino (antineutrino) reaction on 12C target nucleus are presented in an energy range between 500 and 1000 MeV. The sensitivity to the strange quark content of the axial-vector form factor is discussed.
The revised Landau hydrodynamic model is used to discuss the pseudorapidity distributions of the produced charged particles in Au+Au and Cu+Cu collisions at energies of sqrt(s_NN)= 19.6 and 22.4 GeV correspondingly on the BNL Relativistic Heavy Ion Collider. It is found that the revised Landau hydrodynamic model alone can give a good description to the experimental measurements. This is different from that in the same collisions but at the maximum energy of sqrt(s_NN)= 200 GeV. Where, in addition to the revised Landau hydrodynamic model, the effects of leading particles have to be taken into a…
We provide integrated cross sections for quasielastic charged-current neutrino-nucleus scattering. Results evaluated using the phenomenological scaling function extracted from the analysis of experimental $(e,e')$ data are compared with those obtained within the framework of the relativistic impulse approximation. We show that very reasonable agreement is reached when a description of final-state interactions based on the relativistic mean field is included. This is consistent with previous studies of differential cross sections which are in accord with the universality property of the supersc…
The neutral-current neutrino-nucleus scattering is calculated through the neutrino-induced knocked-out nucleon process in the quasielastic region by using a relativistic single particle model for the bound and continuum states. The incident energy range between 500 MeV and 1.0 GeV is used for the neutrino (antineutrino) scattering on ^{12}C target nucleus. The effects of the final state interaction of the knocked-out nucleon are studied not only on the cross section but also on the asymmetry due to the difference between neutrinos and antineutrinos, within a relativistic optical potential. We …
We present a detailed study of charged-current (CC) neutrino-nucleus reactions in a fully relativis- tic framework and comparisons with recent experiments spanning an energy range from hundreds of MeV up to 100 GeV within the SuperScaling Approach, which is based on the analysis of electron- nucleus scattering data and has been recently improved with the inclusion of Relativistic Mean Field theory effects. We also evaluate and discuss the impact of two-particle two-hole meson-exchange currents (2p-2h MEC) on neutrino-nucleus interactions through the analysis of two-particle two-hole axial and …
The analysis of the recent experimental data on charged-current neutrino-nucleus scattering cross sections measured at MiniBooNE requires fully relativistic theoretical descriptions also accounting for the role of final state interactions. In this work we evaluate inclusive quasielastic differential neutrino cross sections within the framework of the relativistic impulse approximation. Results based on the relativistic mean field potential are compared with the ones corresponding to the relativistic Green function approach. An analysis of scaling and superscaling properties provided by both mo…
A relativistic Green's function approach to inclusive quasielastic charged-current neutrino-nucleus scattering is developed. The components of the hadron tensor are written in terms of the single-particle Green's function, which is expanded on the eigenfunctions of the nuclear optical potential, so that final state interactions are accounted for by means of a complex optical potential but without a loss of flux. Results for the (neutrino_mu, mu-) reaction on 16O and 12C target nuclei are presented and discussed. A reasonable agreement of the flux-averaged cross section on 12C with experimental…
After a short review of the recent developments in studies of neutrino-nucleus interactions, the predictions for double-differential and integrated charged current-induced quasielastic cross sections are presented within two different relativistic approaches: one is the so-called SuSA method, based on the superscaling behavior exhibited by electron scattering data; the other is a microscopic model based on relativistic mean field theory, and incorporating final-state interactions. The role played by the meson-exchange currents in the two-particle two-hole sector is explored and the results are…
Within a dynamical transport approach we investigate charged current interactions in neutrino-nucleus reactions for neutrino energies of 0.3 - 1.5 GeV with particular emphasis on resonant pion production channels via the $Δ_{33}(1232)$ resonance. The final-state-interactions of the resonance as well as of the emitted pions are calculated explicitly for $^{12}C$ and $^{56}Fe$ nuclei and show a dominance of pion suppression at moderate momenta $p_π>$ 0.2 GeV/c. A comparison to integrated $π^+$ spectra for $ν_μ+ ^{12}C$ reactions with the available (preliminary) data demonstrates a reasonable agr…
Strange quark contributions to the neutral current reaction in the neutrino scattering are investigated on the nucleon level and extended to the $^{12}$C target nucleus through the neutrino-induced knocked-out nucleon process in the quasi-elastic region within the framework of a relativistic single particle model. The incident energy range between 500 MeV and 1.0 GeV is used for the neutrino(antineutrino) scattering. Effects of the final state interaction for the knocked-out nucleon are included by a relativistic optical potential. We found that the sensitivity of the strange quark contents co…
Investigations have shown that the collective motion not only appears in nucleus-nucleus but also in p-p collisions. The best tool for depicting such collective motion is relativistic hydrodynamics. In this paper, the collective motion is assumed obeying the hydro model which integrates the features of Landau and Hwa-Bjorken theory and is one of a very few analytically solvable models. The fluid is then supposed freezing out into charged particles from a time-like hypersurface with a fixed time of t_FO . The researches of present paper show that this part of charged particles together with lea…
In the Yukawa model for nuclear forces, a simple relation between the charged and neutral pion-nucleon coupling constants is derived. The relation implies that the charged pion-nucleon coupling constant is larger than the neutral one since the np interaction is stronger than the pp interaction. The derived value of the charged pion-nucleon constant shows a very good agreement with one of the recent experimental values. The relative splitting between the charged and neutral pion-nucleon coupling constants is predicted to be practically the same as that between the charged and neutral pion masse…
The superscaling analysis is extended to include quasielastic (QE) scattering via the weak neutral current of neutrinos and antineutrinos from nuclei. The scaling function obtained within the coherent density fluctuation model (used previously in calculations of QE inclusive electron and charge-changing (CC) neutrino scattering) is applied to neutral current neutrino and antineutrino scattering with energies of 1 GeV from $^{12}$C with a proton and neutron knockout (u-channel inclusive processes). The results are compared with those obtained using the scaling function from the relativistic Fer…
The Thermal Quasiparticle Random-Phase Approximation is combined with the Skyrme energy density functional method (Skyrme-TQRPA) to study the response of a hot nucleus to an external perturbation. For the sample nuclei, $^{56}$Fe and $^{82}$Ge, the Skyrme-TQRPA is applied to analyze thermal effects on the strength function of charge-neutral Gamow-Teller transitions which dominate neutrino-nucleus reactions at $E_ν\lesssim 20$~MeV. For the relevant supernova temperatures we calculate the cross sections for inelastic neutrino scattering. We also apply the method to examine the rate of neutrino-a…
In this article, we present the charged and neutral current coherent pion production in the neutrino-nucleus interaction in the resonance region using the formalism based on the partially conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross section to the pion-nucleus elastic cross section. The pion nucleus elastic cross section is calculated using the Glauber model approach. We calculate the integrated cross sections for neutrino-carbon, neutrino-iron and neutrino-oxygen scattering. The results of integrated cross-section calculations are compared with the measured …
We present detailed results of a theoretical investigation on the production of evaporation residue nuclei obtained in a heavy ion reaction when charged particles (proton and $α$-particle) are also emitted with the neutron evaporation along the deexcitation cascade of the formed compound nucleus. The almost mass symmetric $^{82}$Se+$^{138}$Ba reaction has been studied since there are many experimental results on individual evaporation residue (ER) cross sections after few light particle emissions along the cascade of the $^{220}$Th compound nucleus (CN) covering the wide 12--70 MeV excitation …
Nuclear model effects in neutrino-nucleus quasielastic scattering are studied within the distorted wave impulse approximation, using a relativistic shell model to describe the nucleus, and comparing it with the relativistic Fermi gas. Both charged-current and neutral-current processes are considered and, for the neutral-current case, the uncertainties that nuclear effects may introduce in measurements of the axial strange form-factor of the nucleon are investigated.
We study neutral current neutrino-nucleus reaction cross-sections for Mn, Fe, Co and Ni isotopes. An earlier study for a few selected nuclei has shown that in the supernova environment the cross sections are increased for low energy neutrinos due to finite-temperature effects. Our work supports this finding for a much larger set of nuclei. Furthermore we extend previous work to higher neutrino energies considering allowed and forbidden multipole contributions to the cross sections. The allowed contributions are derived from large-scale shell model calculations of the Gamow-Teller strength, whi…
Charged-current neutrino-nucleus scattering is studied in the quasielastic region with the KIDS (Korea-IBS-Daegu-SKKU) nuclear energy density functional. We focus on the uncertainties stemming from the axial mass and the in-medium effective mass of the nucleon. Comparing the result of theory to the state-of-the-art data from MiniBooNE, T2K, and MINER$ν$A, we constrain the axial mass and the effective mass that are compatible with the data. We find that the total cross section is insensitive to the effective mass, so the axial mass could be determined independently of the uncertainty in the eff…
A previous model on inclusive charged-current quasi-elastic nuclear reactions is extended to include neutral- and charged-current nucleon emission reactions. The problem of outgoing nucleon propagation is treated by means of a Monte Carlo simulation.
We use a diagrammatic approach to study color-neutral heavy particle production in nucleus-nucleus collisions in a quasi-classical approximation without small-$x$ evolution. In order to treat the two nuclei symmetrically, we use the Coulomb gauge which gives the appropriate light cone gauge for each nucleus. The resulting cross section is factorized into a product of two Weizsäcker-Williams gluon distributions of the two nuclei when the transverse momentum of the produced scalar particle is around the saturation momentum. We confirm our results in covariant gauge where the transverse momentum …
The superscaling approach is applied to studies of neutral current neutrino reactions in the quasielastic regime. Using input from scaling analyses of electron scattering data, predictions for high-energy neutrino and antineutrino cross sections are given and compared with results obtained using the relativistic Fermi gas model. The influence of strangeness content inside the nucleons in the nucleus is also explored.
We compare the results of the relativistic Green's function model with the experimental data of the charged-current inclusive differential neutrino-nucleus cross sections published by the T2K Collaboration. The model, which is able to describe both MINER$ν$A and MiniBooNE charged-current quasielastic scattering data, underpredicts the inclusive T2K cross sections.
We estimate the theoretical uncertainties of the model developed in Phys. Rev. C70 055503 for inclusive quasielastic charged-current neutrino-nucleus reactions at intermediate energies. Besides we quantify the deviations of the predictions of this many body framework from those obtained within a simple Fermi gas model. An special attention has been paid to the ratio σ(μ)/σ(e) of interest for experiments on atmospheric neutrinos. We show that uncertainties affecting this ratio are likely smaller than 5%
Background: Inelastic neutrino-nucleus scattering through the weak neutral-current plays important role in stellar environment where transport of neutrinos determine the rate of cooling. Since there are no direct experimental data on neutral-current neutrino-nucleus cross sections available, only the modeling of these reactions provides the relevant input for supernova simulations. Purpose: To establish fully self-consistent framework for neutral-current neutrino-nucleus reactions based on relativistic nuclear energy density functional. Methods: Neutrino-nucleus cross sections are calculated u…
The nuclear transparency of the charged hadron produced in the inclusive $(e,e^\prime)$ reaction on the nucleus has been calculated using Glauber model for the nuclear reaction. The color transparency (CT) of the produced hadron and the short-range correlation (SRC) of the nucleons in the nucleus have been incorporated in the Glauber model to investigate their effects on the nuclear transparency of the hadron. The calculated nuclear transparencies for the proton and pion are compared with the data.
The S-matrix approach is applied to charged and neutral pion production in pp collisions, in which the spin/isospin channels filter differently the rescattering mechanism. The chiral perturbation theory rescattering amplitude is employed. The contributions from the single-nucleon, Z-diagrams and Delta-isobar mechanisms are also included. For the reactions investigated, the convergence of the partial wave series is quite satisfactory and J=0 is enough to describe the data close to threshold.
The S-matrix approach is used to calculate charged as well as neutral pion production reactions from NN scattering, with the same set of underlying processes and interactions. The chiral perturbation theory piN scattering amplitude is used. For the nucleon-nucleon distortions a newly developed realistic potential within the Bonn family of potentials, valid well above the pion production threshold, is considered. In the pi+ production case, the NN potential, the piN relative p-waves and the treatment of the exchanged pion energy build up the observed cross-section strength.
We evaluate the quasielastic and multinucleon contributions to the antineutrino nucleus scattering cross section and compare our results with the recent MiniBooNE data. We use a local Fermi gas model that includes RPA correlations and gets the multinucleon part from a systematic many body expansion of the $W$ boson selfenergy in the nuclear medium. The same model had been quite successful for the neutrino cross section and contains no new parameters. We have also analysed the relevance of 2p2h events for the antineutrino energy reconstruction.
On the basis of the Faddeev integral equations method and the Watson- Feshbach concept of the effective (optical) interaction potential, the first fully consistent three-body approach to the description of the penetration of a charged particle through the Coulomb field of a two-particle bound complex (composed of one charged and one neutral particles) has been developed. A general formalism has been elaborated and on its basis, to a first approximation in the Sommerfeld parameter, the influence of the nuclear structure on the probability of the penetration of a charged particle (the muon, the …
We consider a possibility of capture of a heavy charged massive particle $χ^-$ by the nucleus leading to appearance of a bound state. A simple analytic formula allowing to calculate binding energies of the $Nχ^-$ bound state for different nuclei is derived. If the binding energy is sufficiently large the particle $χ^-$ is stable inside the nucleus. The probabilities of the nuclear fissions for such states are calculated. It is shown that the bound states are more stable to a possible fission in comparison to the bare nucleus. This makes an observation of this hypothetical charged massive parti…
Charged multiplicities in nucleus--nucleus collisions are calculated in the Dual Parton Model taking into account shadowing corrections. Its dependence on the number of collisions and participants is analyzed and found in agreement with experiment at SPS and RHIC energies. Using these results, we compute the $J/ψ$ suppression at SPS as a function of the transverse energy and of the energy of the zero degree calorimeter. Predictions for RHIC are presented.
Large liquid xenon detectors aiming for dark matter direct detection will soon become viable tools also for investigating neutrino physics. Information on the effects of nuclear structure in neutrino-nucleus scattering can be important in distinguishing neutrino backgrounds in such detectors. We perform calculations for differential and total cross sections of neutral-current neutrino scattering off the most abundant xenon isotopes. The nuclear structure calculations are made in the nuclear shell model for elastic scattering, and also in the quasiparticle random-phase approximation (QRPA) and …
The analysis of the recent neutral-current neutrino-nucleus scattering cross sections measured by the MiniBooNE Collaboration requires relativistic theoretical descriptions also accounting for the role of final state interactions. In this work we evaluate differential cross sections with the relativistic distorted-wave impulse-approximation and with the relativistic Green's function model to investigate the sensitivity to final state interactions. The role of the strange-quark content of the nucleon form factors is also discussed.
The inclusive neutrino/antineutrino-induced charged and neutral current reaction cross-sections in $^{12}C$, $^{16}O$, $^{40}Ar$, $^{56}Fe$ and $^{208}Pb$ in the energy region of supernova neutrinos/antineutrinos are studied. The calculations are performed in the local density approximation (LDA) taking into account the effects due to Pauli blocking, Fermi motion and the renormalization of weak transition strengths in the nuclear medium. The effect of Coulomb distortion of the lepton produced in the charged current reactions has also been included. The numerical results for the energy dependen…
The general, universal formalism for semi-inclusive charged-current (anti)neutrino-nucleus reactions is given for studies of any hadronic system, namely, either nuclei or the nucleon itself. The detailed developments are presented with the former in mind and are further specialized to cases where the final-state charged lepton and an ejected nucleon are presumed to be detected. General kinematics for such processes are summarized and then explicit expressions are developed for the leptonic and hadronic tensors involved and for the corresponding responses according to the usual charge, longitud…
We review the theoretical status of the models including the multinucleon emission channel in the calculation of quasielastic neutrino cross sections at MiniBooNE kinematics.
We discuss the observed disagreement between the Q^2 distributions of neutrino-nucleus quasielastic events, measured by a number of recent experiments, and the predictions of Monte Carlo simulations based on the relativistic Fermi gas model. The results of our analysis suggest that these discrepancies are likely to be ascribable to both the breakdown of the impulse approximation and the limitations of the Fermi gas description. Several issues related to the extraction of the Q^2 distributions from the experimental data are also discussed, and new kinematical variables, which would allow for an…
We compute the influence of Coulomb effects on the charged kaon distribution at low momentum in high energy nucleus-nucleus collisions. This is accomplished by solving the Vlasov equation for the kaons in the presence of an expanding, highly charged, fireball.
The analysis of the recent charged-current neutrino-nucleus scattering cross sections measured by the ArgoNeuT Collaboration requires relativistic theoretical descriptions also accounting for the role of final-state interactions. In this work, we evaluate differential neutrino-nucleus cross sections with the relativistic Green's function model, where final-state interactions are described in the inclusive scattering consistently with the exclusive scattering using a complex optical potential. The sensitivity to the parameterization adopted for the phenomenological optical potential is discusse…
The results of two relativistic models with different descriptions of the final-state interactions are compared with the MiniBooNE data of charged-current quasielastic cross sections. The relativistic mean field model uses the same potential for the bound and ejected nucleon wave functions. In the relativistic Green's function (RGF) model the final-state interactions are described in the inclusive scattering consistently with the exclusive scattering using the same complex optical potential. The RGF results describe the experimental data for total cross-sections without the need to modify the …
The quasielastic scattering of muon neutrinos on oxygen 16 is studied for neutrino energies between 200 MeV and 1 GeV using a relativistic shell model. Final state interactions are included within the distorted wave impulse approximation, by means of a relativistic optical potential, with and without imaginary part, and of a relativistic mean field potential. For comparison with experimental data the inclusive charged--current quasielastic cross section for $ν_μ$--$^{12}C$ scattering in the kinematical conditions of the LSND experiment at Los Alamos is also presented and briefly discussed.
The analysis of the recent charged-current neutrino-nucleus scattering cross sections measured by the MiniBooNE Collaboration requires relativistic theoretical descriptions also accounting for the role of final-state interactions. In this work, we evaluate differential antineutrino-nucleus cross sections with the relativistic Green's function model, where the final-state interactions are described in the inclusive scattering consistently with the exclusive scattering using a complex optical potential. The sensitivity to the parameterization adopted for the phenomenological optical potential is…
The total cross section for Coulomb photoproduction of neutral pion pairs in the reaction gamma A --> pi0 pi0 A is estimated within the effective chiral lagrangian approach. The amplitude of gamma gamma* --> pi0 pi0 with one off-shell photon is calculated at O(p^6) in the momentum expansion; in addition, nuclear absorption is taken into account. Besides its experimental feasibility, the results of the calculation demonstrate that the reaction gamma A --> pi0 pi0 A is a powerful source of information on the process gamma gamma --> pi0 pi0 close to threshold.
We study the effect of bound nucleon form factors on charged-current neutrino-nucleus scattering. The bound nucleon form factors of the vector and axial-vector currents are calculated in the quark-meson coupling model. We compute the inclusive $^{12}$C($ν_μ,μ^-$)$X$ cross sections using a relativistic Fermi gas model with the calculated bound nucleon form factors. The effect of the bound nucleon form factors for this reaction is a reduction of $\sim$8% for the total cross section, relative to that calculated with the free nucleon form factors.
A formalism based on a relativistic plane wave impulse approximation is developed to investigate the strange-quark content ($g_{A}^{s}$) of the axial-vector form factor of the nucleon via neutrino-nucleus scattering. Nuclear structure effects are incorporated via an accurately calibrated relativistic mean-field model. The ratio of neutral- to charged-current cross sections is used to examine the sensitivity of this observable to $g_{A}^{s}$. For values of the incident neutrino energy in the range proposed by the FINeSSE collaboration and by adopting a value of $g_{A}^{s}=-0.19$, a 30% enhancem…
We perform nuclear shell model calculations of the neutralino-nucleus cross section for several nuclei in the A = 127 region. Each of the four nuclei considered is a primary target in a direct dark matter detection experiment. The calculations are valid for all relevant values of the momentum transfer. Our calculations are performed in the $3s 2d 1g_{7/2} 1h_{11/2}$ model space using extremely large bases, allowing us to include all relevant correlations. We also study the dependence of the nuclear response upon the assumed nuclear Hamiltonian and find it to be small. We find good agreement wi…
The forthcoming LHC measurement of hadron multiplicity in proton-nucleus collisions is a crucial test of the k_t factorization and gluon saturation based models. Here, we provide quantitative predictions for the pseudorapidity distribution of charged particles produced in minimum bias proton-nucleus collisions at the LHC based on the idea of gluon saturation in the color-glass condensate framework. Our formulation gives good descriptions of the LHC and RHIC data for the charged-hadron multiplicities in both proton-proton and nucleus-nucleus collisions, and also the deep inelastic scattering at…
The application of superscaling ideas to predict neutral-current (NC) quasielastic (QE) neutrino cross sections is investigated. Results obtained within the relativistic impulse approximation (RIA) using the same relativistic mean field potential (RMF) for both initial and final nucleons -- a model that reproduces the experimental (e,e') scaling function -- are used to illustrate the ideas involved. While NC reactions are not so well suited for scaling analyses, to a large extent the RIA-RMF predictions do exhibit superscaling. Independence of the scaled response on the nuclear species is very…
We present a model for weak CC induced nuclear reactions at energies of interest for current and future neutrino oscillation experiments. This model is a natural extension of the work of Refs.[1,2], where the QE contribution to the inclusive electron and neutrino scattering on nuclei was analyzed. The model is based on a systematic many body expansion of the gauge boson absorption modes that includes one, two and even three body mechanisms, as well as the excitation of Delta isobars. The whole scheme has no free parameters, besides those previously adjusted to the weak pion production off the …
We solve the problem of a neutral atom interacting with a charged wire, giving rise to an attractive 1/r^2 potential in two dimensions. We show how a suitable average over all possible self-adjoint extensions of the radial Schroedinger Hamiltonian eventually leads to the classical formula for absorption of the atom, a formula shown to be in agreement with a recent experiment.
The Quasi-Elastic (QE) contribution of the nuclear inclusive electron scattering model developed in Nucl. Phys. A627 (1997) 543 is extended to the study of electroweak Charged Current (CC) induced nuclear reactions, at intermediate energies of interest for future neutrino oscillation experiments. The model accounts for, among other nuclear effects, long range nuclear (RPA) correlations, Final State Interaction (FSI) and Coulomb corrections. Predictions for the inclusive muon capture in $^{12}$C and the reaction $^{12}$C $(ν_μ,μ^-)X$ near threshold are also given. RPA correlations are shown to …
The treatment of nuclear effects in neutrino-nucleus interactions is one of the main sources of systematic uncertainty for the analysis and interpretation of data of neutrino oscillation experiments. Neutrinos interact with nuclei via charged or neutral currents and both cases must be studied to obtain a complete information. We give an overview of the theoretical work that has been done to describe nuclear effects in neutral-current neutrin onucleus scattering in the kinematic region ranging between beam energies of a few hundreds MeV to a few GeV, which is typical of most ongoing and future …
Neutrino-nucleus quasielastic scattering is studied in the plane wave impulse approximation for three nuclear models: the relativistic Fermi gas (RFG), the independent-particle shell model (IPSM) and the natural orbitals (NO) model with Lorentzian dependence of the excitation energy. A complete study of the kinematics of the semi-inclusive process and the associated cross sections are presented and discussed for 40 Ar and 12 C. Inclusive cross sections are also obtained by integrating the semi-inclusive expressions over the outgoing hadron. Results are consistent with previous studies restrict…
Inclusive neutrino-nucleus cross sections are calculated using a consistent relativistic mean-field theoretical framework. The weak lepton-hadron interaction is expressed in the standard current-current form, the nuclear ground state is described with the relativistic Hartree-Bogoliubov model, and the relevant transitions to excited nuclear states are calculated in the relativistic quasiparticle random phase approximation. Illustrative test calculations are performed for charged-current neutrino reactions on $^{12}$C, $^{16}$O, $^{56}$Fe, and $^{208}$Pb, and results compared with previous stud…
We present our recent progress in the description of neutrino-nucleus interaction in the GeV region, of interest for ongoing and future oscillation experiments. In particular, we discuss the weak excitation of two-particle-two-hole states induced by meson exchange currents in a fully relativistic framework. We compare the results of our model with recent measurements of neutrino scattering cross sections, showing the crucial role played by two-nucleon knockout in the interpretation of the data.
We show that the distributions of outgoing protons and charged hadrons in high energy proton-nucleus collisions are described rather well by a linear extrapolation from proton-proton collisions. The only adjustable parameter required is the shift in rapidity of a produced charged meson when it encounters a target nucleon. Its fitted value is 0.16. Next, we apply this linear extrapolation to precisely measured Drell-Yan cross sections for 800 GeV protons incident on a variety of nuclear targets which exhibit a deviation from linear scaling in the atomic number A. We show that this deviation can…
The charged and neutral kaon form factors are calculated as a phenomenological application of the QCD Dyson-Schwinger equations. The results are compared with the pion form factor calculated in the same framework and yield \mbox{$F_{K^\pm}(Q^2) > F_{π^\pm}(Q^2)$} on \mbox{$Q^2\in[0,3]$~GeV$^2$}; and a neutral kaon form factor that is similar in form and magnitude to the neutron charge form factor. These results are sensitive to the difference between the kaon and pion Bethe-Salpeter amplitude and the $u$- and $s$-quark propagation characteristics.