Induced Deuteron Breakup Research Articles

Experimental Studies of the Three Nucleon System Dynamics in the Proton Induced Deuteron Breakup at 108 MeV

Experimental Studies of the Three Nucleon System Dynamics in the Proton Induced Deuteron Breakup at 108 MeV

Differential Cross Section for Proton Induced Deuteron Breakup at 108 MeV

The differential cross sections for the proton-deuteron breakup reaction have been measured for more than 200 angular configurations of outgoing protons in the range of polar angles from 13 to 27 degrees with a proton beam at 108 MeV. The paper presents the experimental results of the selected configurations, which are compared to state-of-the-art theoretical calculations. In some regions of the phase space, a strong influence of the Coulomb interaction is observed.

Modern Chiral Forces Applied to the Neutron-Deuteron Breakup Reaction

We report on applications of the recent chiral potentials from the Bochum-Bonn group to the description of the neutron induced deuteron breakup observables. Specifically, we discuss the convergence of predictions with respect to the chiral order and the dependence of our results on the value of the regularization parameter. To that end we use the chiral forces with semi-local coordinate or momentum space regularization up to the N^4LO^+ order of chiral expansion. We find a satisfactory picture revealing high quality of the chiral forces used.

Application of a momentum-space semi-locally regularized chiral potential to selected disintegration processes

We apply the chiral potential with the momentum space semi-local regularization to the $^2$H and $^3$He photodisintegration processes and to the (anti)neutrino induced deuteron breakup reactions. Specifically, the differential cross section, the photon analyzing power and the final proton polarization have been calculated for the deuteron photodisintegration at the photon energies 30 MeV and 100 MeV. For the $^3$He photodisintegration predictions for the semi-inclusive and exclusive differential cross sections are presented for the photon energies up to 120 MeV. The total cross section is calculated for the (anti)neutrino disintegrations of the deuteron for the (anti)neutrino energies below 200 MeV. The predictions based on the Argonne V18 potential or on the older chiral force with regularization applied in coordinate space are used for comparison. Using the fifth order chiral nucleon-nucleon potential supplemented with dominant contributions from the sixth order allows us to obtain converged predictions for the regarded reactions and observables. Our results based on the newest semi-local chiral potentials show even smaller cutoff dependence for the considered electroweak observables than the previously reported ones with a coordinate-space regulator. However, some of the studied polarization observables in the deuteron photodisintegration process reveal more sensitivity to the regulator value than the unpolarized cross section. The chiral potential regularized semi-locally in momentum space yields also fast convergence of results with the chiral order. These features make the used potential a high quality tool to study electroweak processes.

Three-nucleon force effects in inclusive spectra of the neutron-deuteron breakup reaction

We investigate the sensitivity of the non-exclusive nucleon induced deuteron breakup reaction to the three-nucleon interaction and distributions of three-nucleon force effects in inclusive spectra. To this end we solve the three-nucleon Faddeev equation at a number of incoming nucleon laboratory energies using the CD Bonn nucleon-nucleon interaction alone or combined with the 2{\pi}-exchange Tucson-Melbourne three-nucleon force. Based on these solutions energy spectra of an outgoing nucleon, at a specified detection angle as well as spectra integrated over that angle, are calculated. By integrating the spectra at a given angle over the energy of the outgoing nucleon the angular distributions of three-nucleon force effects in the breakup process are additionally obtained. Contrary to elastic nucleon-deuteron scattering, where at higher energies significant three-nucleon force effects were encountered for scattering angles around the minimum of the cross section, for the breakup process only moderate effects are found and they are restricted to forward angles. Results of the present investigation show that the large three-nucleon force effects found for some specific complete breakup configurations are reduced substantially in the incomplete spectra when averaging over contributing complete geometries is performed.

Application of the JISP16 potential to the nucleon induced deuteron breakup process at E=13 MeV and E=65 MeV

The JISP16 nucleon-nucleon potential has been applied to investigations of the nucleon induced deuteron breakup reaction at the incoming nucleon laboratory energies E = 13 MeV and E = 65 MeV. We have found that for the studied process the JISP16 force gives a description of the exclusive cross section, which is generally similar to the ones obtained with the standard realistic nucleon-nucleon AV18 interaction. However, there are some regions of the phase space where the differential cross sections predicted by the JISP16 and AV18 models, differ by more than 100 %. These special kinematical configurations may possibly be useful to refit the JISP16 force parameters.

The JISP16 potential applied to the nucleon induced deuteron breakup process

The JISP16 nucleon-nucleon potential is applied to investigate the nucleon induced deuteron breakup reaction at energies E=13 and 65 MeV. Our study reveals that this force delivers, in general, a qualitatively similar description of the exclusive cross section for the studied reaction to the one based on the standard realistic nucleon-nucleon AV18 interaction. However, in some regions of the phase space the differential cross sections based on the JISP16 and on the AV18 forces differ by more than 100% and 50% at E=13 MeV and E=65 MeV, respectively. Such specific parts of the phase space can be used to fine-tune the JISP16 potential parameters.

Systematic Study of Three-Nucleon System Dynamics in Deuteron–Proton Breakup Reaction

We report on preliminary results of the first measurement of elastic scattering of protons from deuterons and proton induced deuteron breakup at proton beam energy of 108 MeV conducted at new Cyclotron Center Bronowice IFJ PAN in Krakow. The experiment is aimed at precise determination of the differential cross section for extensive set of kinematical configurations in a wide range of angular acceptance. In the first data taking run the average statistical per-point accuracy of about 5% has been reached.

Proton Induced Deuteron Break-up with Emission of a Fast Forward Proton Pair

A kinematically complete study of the pd → (pp)sn reaction with forward emission of an S-wave proton pair (pp)s has been performed at six beam energies 0.6, 0.7, 0.8, 0.95, 1.35 and 1.9 GeV. The experiment was carried out at the ANKE spectrometer installed at the internal beam of the proton synchrotron COSY (Jülich). The 3-momenta of both final state protons have been measured and events with a relative proton energy less than 3 MeV were selected as 1S0 diprotons. The differential cross sections of such pair production averaged over the c.m. polar angle of the total momentum of the pair in the range 0°–8.1° have been obtained. A comparison of the result with a theoretical model based on the mechanism of pd-backward elastic scattering is described as well.

Three-nucleon force effects in nucleon induced deuteron breakup. I. Predictions of current models

An extensive study of three-nucleon force effects in the entire phase space of the nucleon-deuteron breakup process, for energies from above the deuteron breakup threshold up to 200 MeV, has been performed. $3N$ Faddeev equations have been solved rigorously using the modern high precision nucleon-nucleon potentials AV18, CD Bonn, Nijm I, II, and Nijm 93, and also adding $3N$ forces. We compare predictions for cross sections and various polarization observables when $\mathrm{NN}$ forces are used alone or when the $2\ensuremath{\pi}$-exchange Tucson-Melbourne (TM) three nucleon force (3NF) was combined with each of them. In addition AV18 was combined with the Urbana IX 3NF and CD Bonn with the ${\mathrm{TM}}^{\ensuremath{'}}$ 3NF, which is a modified version of the TM 3NF, more consistent with chiral symmetry. Large but generally model dependent 3NF effects have been found in certain breakup configurations, especially at the higher energies, both for cross sections and spin observables. These results demonstrate the usefulness of the kinematically complete breakup reaction in testing the proper structure of $3N$ forces.

Three-nucleon force effects in nucleon induced deuteron breakup. II. Comparison to data

Selected Nd breakup data over a wide energy range are compared to solutions of Faddeev equations based on modern high precision NN interactions alone and adding current three-nucleon force models. Unfortunately currently available data probe phase space regions for the final three nucleon momenta which are rather insensitive to 3NF effects as predicted by current models. Overall there is good to fair agreement between present day theory and experiment but also some cases exist with striking discrepancies. Regions in the phase space are suggested where large 3NF effects can be expected.

Proton induced deuteron breakup reaction at 65 MeV: Unspecific configurations

Cross sections and vector-analyzing powers for four unspecific configurations of the 2H(p,pp)n breakup reaction at Elabp = 65MeV were measured in a kinematically complete experiment. Measured observables are compared with rigorous Faddeev calculations using four realistic charge-dependent interaction models, the CD Bonn, Argonne v18, Nijmegen I, and Nijmegen II potentials with or without inclusion of the Tucson-Melbourne three-nucleon force. Coulomb effects are completely omitted. A satisfactory agreement between theory and experiment has been found. There exist, however, some discrepancies between measured and calculated analyzing-power distributions in certain kinematical regions. The effects of the Tucson-Melbourne three-body force are either negligible or slightly increasing the disagreement.

On the measurement of the tensor analysing power in proton induced deuteron break-up experiments

The tensor analysing powerAzz is calculated in the reaction with polarized deuteron break-up d+p→p+p + n. Peculiarities and possibilities of the experiments with different kinematical set-up are discussed from the point of view what information can be extracted about the high-momentum component of the deuteron wave function.

Coulomb effects in the alpha-induced deuteron breakup.

New calculations including an approximate treatment of Coulomb effects in the \ensuremath{\alpha}-induced deuteron breakup reaction are compared with existing experimental results at ${E}_{\mathrm{d}=6}$ and 7 MeV and with new measurements at ${E}_{\ensuremath{\alpha}}$=11.3 MeV. The \ensuremath{\alpha}-p Coulomb potential allows the coupling to the $^{1}\mathrm{S}_{0}$ np channel which can give rise to a sharp peak in the ${E}_{\mathrm{np}=0}$ region. We display the relevance of the two-body final state interactions and, in particular, of the isospin forbidden np singlet interaction, both theoretically and experimentally.

The neutron induced deuteron break-up process with the inclusion of a three-nucleon force

A three-nucleon interaction (TNI) is included in the calculation of the n-d break-up process based on separable two-nucleon forces. Several kinematical configurations are displayed, where the TNI causes noticeable shifts in the cross section. This enriches the number of observables considerably, which can be used to test the presence of a TNI.

Special Features of the Alpha Induced Deuteron Breakup

The alpha induced deuteron breakup reactions have been of interest since the nucleon induced deuteron breakup problem was addressed with tractable and predictive models based on the Faddeev formalism and with appropriate nucleon-nucleon forces. In this paper we discuss a few special features of the alpha induced deuteron breakup reactions. Specifically, we point out the importance of the n-p tensor force in the predictions of the three-body model that fit the tensor analyzing powers better and the concomitant deterioration of the fit to the vector analyzing power caused by the inclusion of the tensor force. We suggest that there exists evidence for the 1S0 n-p interaction, which is isospin forbidden, in both the cross section and spin observables data. Finally, we discuss certain characteristics of the p-α quasi-free-scattering and n-p final-state-interaction processes.

Form factor dependence of proton induced deuteron breakup at low energy

Proton induced deuteron breakup has been studied experimentally and theoretically. The precision of the data makes it possible to distinguish between calculations made with different separable two-body forces. The possibility to observe off-shell effects and three-body forces is discussed.