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Jan T. Sobczyk

Publications and source records attributed to Jan T. Sobczyk.

At least 37 records · Page 2Linked to original sources
arXiv2015

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↗
arXiv2014

Electroweak Form Factors of the $Δ$(1232) Resonance

Nucleon $\to Δ(1232)$ transition electroweak form factors are discussed in a single pion production model with nonresonant background terms originating from a chiral perturbation theory. Fits to electron-proton scattering $F_2$ as well as neutrino scattering bubble chamber experimental data are performed. Both $ν$-proton and $ν$-neutron channel data are discussed in a unified statistical model. A new parametrization of the $N\toΔ(1232)$ vector form factors is proposed. Fit to neutrino scattering data gives axial mass $M_{AΔ}=0.85{+0.09}{-0.08}\;$(GeV) and $C_5^A(0) = 1.10{+0.15}{-0.14}$ in accordance with Goldberger-Treiman relation as long as deuteron nuclear effects are considered.

hep-ph↗
arXiv2013

Multinucleon ejection model for Meson Exchange Current neutrino interactions

A model is proposed to describe pairs or triples of nucleons ejected from nucleus as a result of Meson Exchange Current neutrino interaction. The model can be easily implemented in Monte Carlo neutrino event generators. It can provide a help in identifying true charge current quasielastic events and allow for better determination of the systematic error of neutrino energy reconstruction in neutrino oscillation experiments

hep-ph↗
arXiv2013

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↗
arXiv2012

Recent Developments in Neutrino/Antineutrino - Nucleus Interactions

Recent experimental results and developments in the theoretical treatment of neutrino-nucleus interactions in the energy range of 1-10 GeV are discussed. Difficulties in extracting neutrino-nucleon cross sections from neutrino-nucleus scattering data are explained and significance of understanding nuclear effects for neutrino oscillation experiments is stressed. Detailed discussions of the status of two-body current contribution in the kinematic region dominated by quasi-elastic scattering and specific features of partonic nuclear effects in weak DIS scattering are presented.

hep-ex↗
arXiv2012

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↗
arXiv2011

Quasi-elastic Neutrino Scattering - an Overview

A non-technical overview of charge current quasi-elastic neutrino interaction is presented. Many body computations of multinucleon ejection which is proposed to explain recent large axial mass measurements are discussed. A few comments on recent experimental results reported at NuInt11 workshop are included.

hep-ph↗
arXiv2010

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↗
arXiv2010

Recent developments in modeling neutrino interactions in 1 GeV energy region

Recent experimental and theoretical research in the area of neutrino interactions in the ~ 1 GeV region are reviewed including topics like: the problem of value of quasielastic axial mass, neutral current Pi0 production, coherent pion production. Many comments are devoted to status and current development of Monte Carlo events generators.

hep-ex↗
arXiv2009

$C_5^A$ form factor from ANL experiment

$C_5^A(Q^2)$ axial form factor is extracted from the ANL neutrino-deuteron scattering data with deuteron structure effects taken into consideration. The best fit of the $C_5^A(Q^2)$ axial form factor is obtained assuming dipole parametrization with $C_5^A(0)=1.13\pm0.15$ and $M_A=0.94\pm 0.08$ GeV.

hep-ph↗
arXiv2008

Construction of spectral functions for medium nuclei

This article is aimed at improving the description of lepton-nucleus interactions in the sub-GeV energy range. Approximate spectral functions for oxygen, calcium, and argon are constructed and used to obtain the electron cross sections in a given scattering angle. Comparison with a sample of available experimental data shows satisfactory agreement. Discrepancy between the presented model and the systematic computations available for oxygen [O. Benhar et al., Phys. Rev. D 72, 053005 (2005)] is also found to be very small. Analysis of appropriate kinematical regions leads to the conclusion that the obtained argon spectral function should describe well neutrino scattering in the 800-MeV energy region. Several approximations used in the model are critically reviewed. All the details needed to implement the presented approach in Monte Carlo simulations are given.

nucl-th↗
arXiv2007

Lepton mass effects in weak CC single pion production

Different approaches to take into account nonzero lepton mass in the Rein-Sehgal model are compared. Modification of the axial current due to pion pole term are included and it is shown that they lead to large reduction of antineutrino cross section and a change of the shape of $dσ/dQ^2$.

hep-ph↗
arXiv2007

Spectral functions for medium-sized nuclei

The spectral functions for calcium and argon are constructed. It is verified that their predictions for the quasielastic electron-nucleus cross sections in the energy range ~1 GeV agree with the data. The argon spectral function is then used to obtain the quasielastic neutrino-nucleus cross section.

nucl-th↗
arXiv2006

Argon spectral function and neutrino interactions

The argon spectral function is constructed and applied to neutrino-argon cross section computations in the plane wave impulse approximation with the Pauli blocking final state interaction effect taken into account. The approximations of the construction method are critically analyzed using the example of oxygen for which more detailed computations are available. An effective description of nucleus based on the information contained in a spectral function is proposed. It is demonstrated that its predictions are close to those obtained from the complete spectral function. The effective description can be easily applied in Monte Carlo event generators.

nucl-th↗
arXiv2006

Hadron production in Wroclaw neutrino event generator

Results from the Wroclaw Monte Carlo neutrino generator of events are reported. Predictions for charged hadron multiplicities, neutral pion and strange particle production are presented and compared with available data.

hep-ph↗
arXiv2006

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↗