Differential Cross Section Data Research Articles

Optical Model Analysis of α + 40Ca at Elab=104 and 141.7 MeV

Optical model analysis of the elastic scattering analysis of α + 40Ca at Elab=104 and 141.7 MeV have been performed using the folding model approach of the nuclear reaction video (NRV) knowledge base code. The M3Y-type effective nucleon-nucleon interaction derived using the lowest order constrained variational (LOCV) approach for mass number A=40 was used to obtain the results. Elastic scattering differential cross section data were obtained for this system at two bombarding energies. The calculated differential cross sections are in good agreement with the experimental results and the anticipated mass dependence of the M3Y-type effective interaction improved the results at forward angles. This shows that, the mass dependence of the M3Y-type effective interaction in our results should be of value in the description of the scattering of other nuclear systems

Photoproduction γp→K*+Λ in a Reggeized model

The high-precision differential cross-section data for the reaction $\gamma p \to K^{*+}\Lambda$ are reanalyzed within a Regge-inspired effective Lagrangian approach. The model adopts Regge phenomenology to constrain the $t$-channel contributions from the $\kappa$, $K$, and $K^*$ exchanges. A minimal number of resonances in the $s$ channel are introduced in constructing the reaction amplitudes in order to describe the data. It is shown that the differential cross-section data for $\gamma p \to K^{*+}\Lambda$ can be satisfactorily described by introducing the only $N(2060){5/2}^-$ resonance in the $s$ channel, which is quite different from our earlier work performed in an effective Lagrangian approach [A. C. Wang {\it et al.}, Phys. Rev. C 96, 035206 (2017)], where the amplitudes are computed by evaluating Feynman diagrams and it is found that introducing at least one additional resonance apart from the $N(2060){5/2}^-$ is indispensable for reproducing the data. The roles of individual contributions from meson and baryon exchanges on the angular distributions are found to be highly model dependent. The extracted mass of $N(2060){5/2}^-$ turns out to be well determined, independent of how the $t$-channel amplitudes are constructed, whereas the width does not.

Nucleon and Δ resonances in γp→K+Σ0(1385) photoproduction

The photoproduction of $\gamma p \to K^+ \Sigma^0(1385)$ is investigated based on an effective Lagrangian approach using the tree-level Born approximation, with the purpose of understanding the reaction mechanisms and resonance contents and their associated parameters in this reaction. In addition to the $t$-channel $K$ and $K^\ast(892)$ exchanges, $s$-channel nucleon ($N$) exchange, $u$-channel $\Lambda$ exchange, and generalized contact term, the exchanges of a minimum number of $N$ and $\Delta$ resonances in the $s$ channel are taken into account in constructing the reaction amplitudes to describe the experimental data. It is found that the most recent differential cross-section data from the CLAS Collaboration can be well reproduced by including one of the $N(1895){1/2}^-$, $\Delta(1900){1/2}^-$, and $\Delta(1930){5/2}^-$ resonances. The reaction mechanisms of $\gamma p \to K^+ \Sigma^0(1385)$ are discussed in detail, and the predictions of the beam and target asymmetries for this reaction are given. The cross sections of $\gamma p \to K^0 \Sigma^+(1385)$ are shown to be able to further constrain the theoretical models and pin down the resonance contents for $\gamma p \to K^+ \Sigma^0(1385)$.

Joint theoretical and experimental study on elastic electron scattering from bismuth

We report on experimental elastic differential and integral cross sections for electron scattering from bismuth. The energy range of those measurements is 10--100 eV, while the scattered electron angular range in the differential cross section data is ${10}^{\ensuremath{\circ}}--{150}^{\ensuremath{\circ}}$. We also supplement our experimental results with theoretical data from our optical potential approach, in this case applying two different sets of scattering potentials to the problem. Good overall qualitative accord is typically observed between our measured and calculated results, particularly when allowance is made for the dimer contribution in the experimental atomic beam.

Double-, energy-, angle- differential and total yield cross section data of 58Ni(n,a)55Fe reaction

The double-, energy-, angle- differential cross section data, and the total yield of 58Ni(n,α)55Fe reaction is investigated in the neutron energy range between 2 and 9 MeV. The measurements were performed with the prompt detection method, detecting the alpha particles of the reaction with a multitelescope consisted of five ΔΕ-ΔΕ-Ε telescopes, placed at angles 14, 51, 79, 109 and 141 degrees relative to the neutron beam direction. The normalisation to the absolute units was made using the known total yield of the reference reactions 27Al(n,α)24Na and 58N(n,p)58Co. The cross section measurements were compared with previous measurements and with theoretical calculations performed with the STAPRE-H [1-4] code.

Analysis of the data on spin density matrix elements for γp→K*+Λ

In our previous work [Phys. Rev. C {\bf 96}, 035206 (2017)], the high-precision differential cross-section data for $\gamma p \to K^{*+}\Lambda$ reported by the CLAS Collaboration has been analyzed within an effective Lagrangian approach. It was found that apart from the $t$-channel $K$, $K^*$, and $\kappa$ exchanges, the $u$-channel $\Lambda$, $\Sigma$, and $\Sigma^*$ exchanges, the $s$-channel $N$ exchange, and the interaction current, one needs to introduce at least two nucleon resonances in the $s$ channel in constructing the reaction amplitudes to describe the cross-section data. One of the needed resonances is $N(2060)5/2^-$, and the other one could be one of the $N(2000)5/2^+$, $N(2040)3/2^+$, $N(2100)1/2^+$, $N(2120)3/2^-$, and $N(2190)7/2^-$ resonances. In this paper, we further include in our analysis the data on spin density matrix elements for $K^*$ meson reported recently by the CLAS Collaboration, with the purpose being to impose further constraints on extracting the resonance contents and to gain a better understanding of the reaction mechanism. It turns out that with the new data on spin density matrix elements taken into account, only the set with the $N(2060)5/2^-$ and $N(2000)5/2^+$ resonances among those five possible solutions extracted from the analysis of the differential cross-section data can satisfactorily describe the data on both the differential cross sections and the spin density matrix elements. Further analysis shows that this reaction is dominated by the $t$-channel $K$ exchange and $s$-channel $N(2060)5/2^-$ and $N(2000)5/2^+$ exchanges.

A Review on Recent Developments in Deuteron Induced Reactions Enhancing NRA Capabilities

Nuclear Reaction Analysis (NRA) is well established as one of the principal IBA methods nowadays. Among the most important NRA characteristics are its high iso- topic selectivity, its enhanced sensitivity for many nuclides, the capability of least destructive depth profiling and the possibility of simultaneous analysis of more than one light element in near–surface layers of materials. Moreover, in the particular case when deuterium is used as probing beam, critical advantages for NRA studies emerge. As NRA quantifies individual light isotopes absolutely, and can depth pro- file with nanometer resolution, it is the most suitable ion beam technique for the determination of the concentration and depth profiling of light elements in complex matrices. However, as already pointed out in the recent literature, the application of NRA to the determination of the concentration and the depth profiling of light elements is frequently impeded by the lack of adequate and/or reliable experimental differential cross section data. It is the ambition of the present work to contribute in the fields of differential cross section measurements, as well as of data evaluation and general theoretical analysis.

Simulations of the measurement results of differential cross sections of n-p and n-d elastic scattering at CSNS Back-n WNS

Differential cross-section data for the n-p and n-d elastic scattering (1H(n, el), 2H(n, el)) are collected and analyzed from EXFOR library. For En > 20 MeV, the experimental results for both reactions are scarce with large uncertainties and discrepancies in general. For En ≤ 20 MeV, the experimental results lack systematicness, most of which were measured around En = 14 MeV even though the differential cross sections of n-p scattering in 1 keV ≤ En ≤ 20 MeV region are recommended as standard. Taking these facts into account, more accurate and systematic measurements are planned. The experiments will be conducted using ΔE-E detectors of the Light-charged Particle Detector Array (LPDA) system at China Spallation Neutron Source (CSNS) Back-n White Neutron Source (WNS), and simulations are carried out. Using polyethylene and deuterated polyethylene as samples, both n-p and n-d scattering reactions are simulated along with the neutron-induced 12C background reactions, and the 2-D spectra and the counting rates of the ΔE-E detectors are obtained. According to the simulations, the applicable neutron energy range and positions of the detectors are recommended, and the beam time for the event and background measurements is suggested.

Electron impact ionization cross sections of hydrogen fluoride molecule.

Partial and total ionization cross sections of hydrogen fluoride molecule are determined from the ionization threshold to high energy (5 KeV) by using a modified Jain-Khare semiempirical approach. Partial single and double differential cross sections with their sums (total) through direct and dissociative ionization have been also evaluated at fixed primary electron energies 100 eV, 200 eV, and 500 eV. There is no other data for partial ionization cross sections and differential ionization cross sections for comparison. In this paper, the total ionization cross sections data have compared with available experimental data and/or with other theoretical data which are available from intermediate to high energy. It is found that the present result gives a better account for the ionization cross sections up to higher energies.

Integer and half-integer channel spins for elastic scattering cross sections

We present analytical expressions for differential cross sections and independent partial amplitudes of elastic scattering of nuclear particles for channels with a spin value of 1/2, 1, 3/2, 2 and 5/2. The independent partial amplitudes are calculated taking into account the spin-orbit splitting for arbitrary orbital angular momentum l. The analytical expressions allow one to carry out full phase shift analysis using experimental data of differential cross sections for processes with channel spins 1/2, 1, 3/2, 2 and 5/2.

Pion induced Drell-Yan: the transverse momentum structure of the pion

We present an analysis of unpolarized Drell-Yan pair production in pion-nucleus scattering with a particular focus into the pion dynamics. The study consists in analyzing the effect of the partonic longitudinal and, especially, transverse distributions of the pion in a Nambu–Jona-Lasinio (NJL) framework, with Pauli-Villars regularization. In order to consistently take into account the QCD evolution effects, we have estimated the hadronic scale corresponding to the NJL model’s degrees of freedom through a minimization procedure at NLO: The NLO evolved pion distributions have been compared to rapidity differential DrellYan cross sections data. That hadronic scale so determined represents the only free parameter in our approach.The NJL transverse momentum PDF, evolved up to next-to-leading logarithmic accuracy, is then tested against the transverse momentum spectrum of dilepton pairs up to a transverse momentum of 2 GeV. We found a fair agreement with available pion-nucleus data. We find sizable evolution effects on the shape of the distributions and on the generated average transverse momentum of the dilepton pair.

Study of the 32S(3He,d)33Cl one-proton transfer reaction with a new generation hodoscope

The 32S(3He,d)33Cl one-proton transfer reaction is a powerful tool to investigate the spectroscopy of low-lying states in the proton-rich 33Cl nucleus. However, the extraction of firm differential cross-section data at various angles, against which benchmarking theoretical models to correctly constrain the spectroscopy of 33Cl, is made challenging by the presence of competitive reaction products contaminating the detected energy spectra. We have recently measured the 32S(3He,d)33Cl reaction at 9.8 MeV incident energy by using a new generation hodoscope of silicon detectors, capable to detect and identify emitted deuterons down to energies of the order of 2 MeV. The high angular segmentation of our hodoscope allowed to unambiguously disentangle the contribution of one-proton transfer reactions in the ground state of 33Cl and in its 0.810 MeV, 2.352 MeV, 2.685 MeV, 2.846 MeV excited states from contaminant deuteron-emitting reactions. These data will be crucial to help to constrain Jπ and spectroscopic factor C2Sp values of low-lying 33Cl states, still ambiguous in the literature. The present status of the analysis is discussed in the paper.

Energy dependence and surface contribution of the folding-model optical potential for nucleon-nucleus scattering at energies up to 1 GeV/nucleon

An energy-dependent microscopic optical model potential (OP) is presented to analyze the elastic scattering of protons with incident energies up to 1000 MeV/nucleon on $^{9}\mathrm{Be}$ nucleus. This microscopic optical model is built from the single-folding optical model. The density- and isospin-dependent M3Y-Paris nucleon-nucleon ($NN$) interaction is used for the real and spin-orbit parts and the $NN$-scattering amplitude of the high-energy approximation for the imaginary one. The microscopic complex spin-orbit OP is taken within Breiva-Rook approximation. The partial-wave expansion analysis with this optical model potential fails to reproduce the differential cross-section data at energies larger than 100 MeV/nucleon, a good improvement is obtained by including the surface contribution to the imaginary OP where most of the basic scattering observables are reproduced well at the considered wide energy range. The volume integrals are found to be have interesting energy dependencies and their parametrizations can be used to build an energy-dependent microscopic OP that is used to reproduce the observables at a wide energy range. This study shows that the partial-wave expansion analysis using the folding optical model can be used to analyze the scattering data at high energies as well as at low energies.

Experimental and theoretical cross sections for elastic electron scattering from zinc

We report on experimental elastic differential and integral cross sections for electron scattering from zinc. The energy range of these measurements is 10--100 eV, while the scattered electron angular range in the differential cross-section data is ${10}^{\ensuremath{\circ}}\text{--}{150}^{\ensuremath{\circ}}$. We also supplement our measured data with applications of our optical potential and relativistic optical potential approaches to this problem. Where possible, the present results are compared against those from earlier B-spline R-matrix [O. Zatsarinny and K. Bartschat, Phys. Rev. A 71, 022716 (2005)] and convergent close coupling [D. V. Fursa, I. Bray, R. Panajotovi\ifmmode \acute{c}\else \'{c}\fi{}, D. \ifmmode \check{S}\else \v{S}\fi{}evi\ifmmode \acute{c}\else \'{c}\fi{}, V. Pej\ifmmode \check{c}\else \v{c}\fi{}ev, D. M. Filipovi\ifmmode \acute{c}\else \'{c}\fi{}, and B. P. Marinkovi\ifmmode \acute{c}\else \'{c}\fi{}, Phys. Rev. A 72, 012706 (2005)] computations. Good overall qualitative accord is typically observed.

Optical model potentials for 16O + 16O elastic scattering

Angular distributions of the elastic scattering differential cross section data for the 16O + 16O nuclear system in the energy range of 75–480 MeV have been analyzed using the double-folding optical potential model. The real part of the interaction potential is derived on the basis of double folding of different models of interaction such as CDM3Y1, CDM3Y6, DDM3Y1, and BDM3Y1. The imaginary part of the potential is taken as the sum of the imaginary volume term expressed in the phenomenological Woods–Saxon squared form and a derivative Woods–Saxon surface term. Renormalization factors Nr for the various concerned interaction models are evaluated. The potential created by the BDM3Y1 model of interaction has the shallowest depth, which reflects the necessity of using higher renormalization factor. The obtained real volume integral and total reaction cross sections are calculated at different energies using the derived potentials. The obtained results are in agreement with the experimental data.

The elastic differential pp cross-section at 13 TeV: an empirical model analysis

We discuss the differential elastic pp cross-section data measured at 13 TeV, through the Coulomb Nuclear Interference region until past the dip. We show that data are consistent with the asymptotic predictions from an empirical model and examine the presence of a zero for the real part of the elastic amplitude near the Coulomb region, well before the dip.

New investigations on the 32S(3He,d)33Cl reaction at 9.6 MeV bombarding energy

The 32S(3He,d)33Cl one-proton transfer reaction is a powerful tool to investigate the spectroscopy of low-lying states in the proton-rich 33Cl nucleus. However, the extraction of firm differential cross-section data at various angles to benchmark and constrain theoretical models is made challenging by the presence of competitive reactions on target contaminants. In this paper we report on arecent measurement using a new generation hodoscope of silicon detectors, capable to detect and identify emitted deuterons down to energies of the order of 2 MeV. The high angular segmentation of our hodoscope combined with a suitable target to control possible contaminants, allowed to unambiguously disentangle the contribution of various states in 33Cl, in particular the 2.352 MeV state lying just few tens of keV above the proton separation energy.

S- and p-wave structure of S = −1 meson–baryon scattering in the resonance region

We perform a simultaneous analysis of s- and p-waves of the S=−1 meson–baryon scattering amplitude using all low-energy experimental data. For the first time, differential cross section data are included for chiral unitary coupled-channel models. From this model s- and p-wave amplitudes are extracted and we observe both well-known I(JP)=0(1/2−) s-wave states as well as a new I(JP)=1(1/2+) state absent in quark models and lattice QCD results. Multiple statistical and phenomenological tests suggest that, while the data clearly require an I=1 p-wave resonance, the new state just accounts for the absence of the decuplet Σ(1385)3/2+ in the model.

Lorentz violation and the electron-ion collider

We investigate the prospects for detecting violations of Lorentz symmetry in unpolarized deep inelastic electron-proton scattering in the context of the future electron-ion collider. Simulated differential cross-section data are used to place expected bounds on a class of quark-sector coefficients for Lorentz violation that induce sidereal time dependence in the scattering cross section. We find that, with $100 \; {\rm fb}^{-1}$ of integrated luminosity, the expected bounds are in the $10^{-5}-10^{-7}$ range and are roughly two orders of magnitude stronger than those that can be extracted from existing HERA data. We also discuss the possibility of extracting bounds on the remaining time-independent coefficients.

Charged current quasi-elastic scattering of off 12C**Supported by Department of Science and Technology, New Delhi, India

In this work, we study charged current quasi-elastic scattering (QES) of off nucleon and nucleus using a formalism based on the Llewellyn Smith (LS) model. Parameterizations by Galster et al. are used for electric and magnetic Sachʼs form factors of the nucleons. We use the Fermi gas model along with the Pauli suppression condition to take into account the nuclear effects in the anti-neutrino–nucleus QES. We calculate and charged current quasi-elastic scattering differential and total cross sections for different values of axial mass MA, and compare the results with data from the GGM, SKAT, BNL, NOMAD, MINERνA and MiniBooNE experiments. The present theoretical approach gives a good description of differential cross section data. The calculations with axial mass and 1.05 GeV are compatible with data from most of the experiments.