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Cezary Juszczak

Publications and source records attributed to Cezary Juszczak.

18 recordsLinked to original sources

The role of de-excitation in the final-state interactions of protons in neutrino-nucleus interactions

Present and next generation of long-baseline accelerator experiments are bringing the measurement of neutrino oscillations into the precision era with ever-increasing statistics. One of the most challenging aspects of achieving such measurements is developing relevant systematic uncertainties in the modeling of nuclear effects in neutrino-nucleus interactions. To address this problem, state-of-the-art detectors are being developed to extract detailed information about all particles produced in neutrino interactions. To fully profit from these experimental advancements, it is essential to have reliable models of propagation of the outgoing hadrons through nuclear matter able to predict how the energy is distributed between all the final-state observed particles. In this article, we investigate the role of nuclear de-excitation in neutrino-nucleus scattering using two Monte Carlo cascade models: NuWro and INCL coupled with the de-excitation code ABLA. The ablation model ABLA is used here for the first time to model de-excitation in neutrino interactions. As input to ABLA, we develop a consistent simulation of nuclear excitation energy tuned to electron-scattering data. The paper includes the characterization of the leading proton kinematics and of the nuclear cluster production during cascade and de-excitation. The observability of nuclear clusters as vertex activity and their role in a precise neutrino energy reconstruction is quantified.

hep-ph↗

Monte Carlo event generation of neutrino-electron scattering

We describe an extension of the NuWro Monte Carlo neutrino event generator with the neutrino-electron scattering processes. This new dynamical channel includes the charged current and neutral current interactions, together with their interference, for $ν_\ell e$ and $\barν_\ell e$ ($\ell=e,μ,τ$) scatterings, resulting in ten possible final states. We illustrate the performance of the new functionality on few physical examples, including an estimation of the background in the T2K $ν_μ\rightarrowν_e$ oscillation experiment. We show that the background events arising from the neutrino-electron interactions occupy mostly a distinct region of the phase space and can be easily separated.

hep-ph↗

Data based two-body current contribution to neutrino-nucleus cross section

A phenomenological model of two-body current (2p2h) contribution to neutrino cross section is introduced. Predictions of the Valencia model for 2p2h are modified using recent CC0pi measurements from T2K and MINERvA experiments. Our results suggest a significant increase of the 2p2h cross section at neutrino energies bigger than 1 GeV and also a redistribution of 2p2h events as function of energy and momentum transfer. This may have a big impact on neutrino energy reconstruction in neutrino oscillation parameters.

hep-ex↗

NuWro Monte Carlo generator of neutrino interactions - first electron scattering results

NuWro Monte Carlo generator of events is presented. It is a numerical environment containing all necessary ingredients to simulate interactions of neutrinos with nucleons and nuclei in realistic experimental situation in wide neutrino energy range. It can be used both for data analysis as well as studies of nuclear effects in neutrino interactions. The first results and functionalities of eWro - module of NuWro dedicated to electron nucleus scattering - are also presented.

hep-ph↗

The Proton Radius from Bayesian Inference

The methods of Bayesian statistics are used to extract the value of the proton radius from the elastic $ep$ scattering data in a model independent way. To achieve that goal a large number of parametrizations (equivalent to neural network schemes) are considered and ranked by their conditional probability $P(\mathrm{parametrization}\,|\,\mathrm{data})$ instead of using the minimal error criterion. As a result the most probable proton radii values ($r_E^p=0.899\pm 0.003$ fm, $r_M^p=0.879\pm 0.007$ fm) are obtained and systematic error due to freedom in the choice of parametrization is estimated. Correcting the data for the two photon exchange effect turns out to be important to obtain the agreement between the $r_E^p$ and $r_M^p$ values. The results disagree with recent muonic atom measurements.

hep-ph↗

Applications of Neural Networks in Hadron Physics

The Bayesian approach for the feed-forward neural networks is reviewed. Its potential for usage in hadron physics is discussed. As an example of the application the study of the the two-photon exchange effect is presented. We focus on the model comparison, the estimation of the systematic uncertainties due to the choice of the model, and the over-fitting. As an illustration the predictions of the cross sections ratio $d σ(e^+ p\to e^+ p)/d σ(e^- p\to e^- p)$ are given together with the estimate of the uncertainty due to the parametrization choice.

hep-ph↗

Extraction of Axial Mass and Strangeness Values from the MiniBooNE Neutral Current Elastic Cross Section Measurement

Results of the analysis of the MiniBooNE experiment data for the neutral current elastic neutrino scattering off the $CH_{2}$ target with the NuWro Monte Carlo generator are presented. Inclusion in the NuWro the two body current contribution leads to the axial mass value $M_A = 1.10^{+0.13}_{-0.15}$ GeV consistent with the older evaluations based on the neutrino-deuteron scattering data. The strange quark contribution to the nucleon spin is estimated with the value $g_A^s = -0.4^{+0.5}_{-0.3}$.

hep-ph↗

Final State Interactions Effects in Neutrino-Nucleus Interactions

Final State Interactions effects are discussed in the context of Monte Carlo simulations of neutrino-nucleus interactions. A role of Formation Time is explained and several models describing this effect are compared. Various observables which are sensitive to FSI effects are reviewed including pion-nucleus interaction and hadron yields in backward hemisphere. NuWro Monte Carlo neutrino event generator is described and its ability to understand neutral current $π^0$ production data in $\sim 1$ GeV neutrino flux experiments is demonstrated.

nucl-th↗

On extraction of value of axial mass from MiniBooNE neutrino quasi-elastic double differential cross section data

MiniBooNE charge current quasi-elastic double differential cross section data are analyzed and confronted with predictions of two theoretical nucleus models: Fermi gas and spectral function. The fitting procedure includes the overall flux uncertainty multiplicative factor. In order to obtain a reliable value of the axial mass, bins with large contribution from small momentum transfer are eliminated from the analysis. It is shown that the best fit axial mass value becomes smaller as the momentum transfer cut is more restrictive. For $q_{cut}=500$~MeV/c the obtained values of axial mass are $M_A=1350\pm 66$~MeV for the Fermi gas and $M_A=1343\pm 60$~MeV for the spectral function. The value $M_A=1030$~MeV is excluded on the level which goes far beyond $5σ$.

nucl-th↗

Running Nuwro

The NuWro Neutrino Event Generator developed by the Wroclaw Neutrino Group (WNG) is lightweight but full featured. It handles all interaction types important in neutrino-nucleus scattering as well as DIS hadronization and intranuclear cascade. Its input file, by default params.txt, is a plain text file and the output file, by default eventsout.root, is a root file which can be analyzed by means of the included myroot program, or by standard root, after loading supplied dictionary library event1.so.

hep-ex↗

Quark-Hadron Duality in the Rein-Sehgal Model

The quark-hadron duality in CC and NC neutrino interactions is discussed under assumptions that single pion production is described accurately by the Rein-Sehgal model and that it allows reconstruction of the inclusive cross section in the resonance region. The duality is measured by means of integrals of structure functions in the Nachtmann variable for $Q^2<3$ GeV$^2$. The results depend on the precision with which contributions from single pion production channels in the overall cross sections are known. Several approaches to evaluate them are compared. The duality is predicted to be seen for proton target reactions and to be absent for neutron and isoscalar targets. Two-component duality between resonant and valence quark contributions to structure functions is also investigated.

hep-ph↗

Appearance of quark-hadron duality in the Rein-Sehgal model

Quark-hadron duality in neutrino-nucleon reactions is investigated under the assumption that cross sections in the resonance region are given by the Rein-Sehgal model. The quantitative analysis of the duality is done by means of appropriate integrals of the structure functions in the Nachtmann variable. We conclude that with the definition of the resonance region $W\in (M+m_π, 2$ GeV) the duality holds for neutrino-proton reaction $F_2$ structure function for $Q^2\in (0.5, 3)$ GeV$^2$ and it is absent for neutrino-neutron reaction.

hep-ph↗

Simulations from a new neutrino event generator

We construct a new Monte Carlo generator of events for neutrino interactions. The dynamical models for quasi-elastic reactions, $Δ$ excitation and more inelastic events described by the DIS formalism with the PDFs modified according to recent JLab data are used. We describe in detail single pion production channels, which combine the $Δ$ excitation and DIS contribution. Many comparisons of the outcome of simulations with experimental data are presented.

hep-ph↗

Spectrum of outgoing nucleons in quasielastic neutrino-nucleus interactions

We have analyzed the consequences of introducing the local density approximation combined with an effective nuclear momentum-dependent potential into the CC quasi-elastic neutrino-nucleus scattering. We note that the distribution of the recoil nucleons momenta becomes smooth for low momentum values and the sharp threshold is removed. Our results may be relevant for Sci-Fi detector analysis of K2K experiments. The total amount of observed recoil protons is reduced because some of them remain bound inside the nucleus. We compare theoretical predictions for a probability of such events with the results given by NUX+FLUKA MC simulations.

nucl-th↗

Comparison of predictions for nuclear effects in the Marteau model with the NUX+FLUKA scheme

Nuclear effects in neutrino-nucleus reactions simulated by means of the NUX+FLUKA Monte Carlo generator are compared with the theoretical predictions of the Marteau model. Pion absorption in NUX+FLUKA and non-pionic Delta decays in the Marteau model differ by about 30%. The fraction of pions produced due to the re-interactions after primary quasi-elastic vertex is in the NUX+FLUKA scheme much higher then provided by the Marteau model.

nucl-th↗

Classification of osp(2|2) Lie Super-Bialgebras

The co-Lie structures compatible with the osp(2|2) Lie super algebra structure are investigated and found to be all of coboundary type. The corresponding classical r-matrices are classified into several disjoint families. The osp(1|2)+u(1) Lie super-bialgebras are also classified.

math.QA↗

New Quantum Deformation of Osp(1;2)

The complete set of formulas describing the new quantum deformation of the OSP(1;2) supergroup is provided. A general ansatz is solved for the deformation of the Borel subalgebra of its dual quantum deformation of osp(1;2).

math.QA↗

Classification of Low Dimensional Lie Super-Bialgebras

A thorough analysis of Lie super-bialgebra structures on Lie super-algebras osp(1|2) and super-e(2) is presented. Combined technique of computer algebraic computations and a subsequent identification of equivalent structures is applied. In all the cases Poisson-Lie brackets on supergroups are found. Possibility of quantizing them in order to obtain quantum groups is discussed. It turns out to be straightforward for all but one structures for super-E(2) group.

q-alg↗