Proposal for the Simultaneous Measurement of the Neutron–Neutron and Neutron–Proton Quasi-Free Scattering Cross Section via the Neutron–Deuteron Breakup Reaction at E n = 19 MeV

In order to confirm or refute the present discrepancy between data and calculation for the neutron–neutron quasi-free scattering cross section in the neutron–deuteron breakup reaction, we describe a new experimental approach currently being pursued at TUNL.     

Cross Sections for Neutron–Deuteron Elastic Scattering in the Energy Range 135–250 MeV

We report new measurements of the neutron–deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from 80^? to 130^?. Cross sections for neutron-proton elastic scattering were also measured with the same experimental setup for normalization purposes. Our nd cross section results are compared with predictions based on Faddeev calculations including three-nucleon forces, and with cross sections measured with charged particle and neutron beams at comparable energies.     

Data on the Neutron–Neutron Scattering Length from the nd-Breakup Reaction at En = 8 MeV and En = 11 MeV

Physics of Atomic Nuclei - A kinematically complete experiment devoted to studying the $$nd$$ -breakup reaction at energies of 8 and 11 MeV via detecting all three secondary particles was...     

Differential Cross Section for Elastic Deuteron–Proton Scattering at the Energy of 700 MeV per Nucleon

The results of measurements of the differential cross section for elastic deuteron–proton scattering at the energy of 700 MeV per nucleon that were performed at the internal target station of the nuclotron at the Joint Institute for Nuclear Research (JINR, Dubna) are presented. These data were obtained at angles in the range between 70? and 120? in the c.m. frame. The angular dependence obtained in this way is compared with world-averaged data at similar energies and with the results of theoretical calculations performed within the relativistic theory of multiple scattering.     

Few-Nucleon System Dynamics Studied via Deuteron–Deuteron Breakup Reactions at 160 MeV

An experiment, with the deuteron beams at energy of 160 MeV impinging on the liquid deuterium target, was carried out using the BINA detector at KVI, in Groningen, the Netherlands. Data were collected for the purpose of obtaining high precision differential cross-sections for the deuteron break-up reaction. The elastic scattering channel was also measured alongside for the purpose of cross-section normalization.     

Neutron–Triton Elastic Scattering

The Kohn variational principle and the hyperspherical harmonics technique are applied to study the n ? ³H elastic scattering at low energies. In this contribution the first results obtained using a non-local realistic interaction derived from the chiral perturbation theory are reported. They are found to be in good agreement with those obtained solving the Faddeev–Yakubovsky equations. The calculated total and differential cross sections are compared with the available experimental data. The effect of including a three-nucleon interaction is also discussed.     

Further Analysis of Neutron Double-Differential Cross Section of n ＋ ^16O at 14.1 MeV and 18 MeV

By using a new reaction model for light nuclei, the double-differential cross section of total outgoing neutron with LUNF code for n＋^16O reactions at En=14.1 MeV and 18 MeV have been calculated and analyzed. In this paper the opened reaction channels, which have contribution to emitting the neutrons, are listed in detail. To improve the fitting results the direct inelastic scattering mechanism is involved. The calculating results agree fairly well with the experimental data at E,~ = 14.1 MeV and the deviation from calculated results and experimental data in low energy region at En= 18 MeV has been analyzed. Since the possibility of 5He has been affirmed theoretically [J.S. Zhang, Sci. Chin. G 47 （2004） 137], so 5He emission from n＋ ^16O reaction is taken into account, which plays an important role at the region of the outgoing neutron energy εn〈3 MeV in total outgoing neutron energy-angular spectrum. The calculated results indicate that the pre-equilibrium mechanism dominates the whole reaction processes, and the recoil effect in light nuclear reactions is essentially important.     

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 E ^lab _p  = 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 v ₁₈, 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. Received May 12, 1999; revised March 3, 2000; accepted for publication April 26, 2000     

Calculation of A x for the Proton–Deuteron Breakup Reaction at 135 MeV

Observables in proton–deuteron scattering are sensitive probes of the nucleon-nucleon interaction and three-nucleon force effects (3NF). Several facilities in the world, including Kernfysisch Versneller Instituut (KVI), allow a detailed study a few-nucleon interaction below the pion-production threshold exploiting polarized proton and deuteron beams. In this contribution we explored 3NF effects in the break-up scattering process by performing a measurement of differential cross section and the analyzing power, especially the x component of the analyzing power, using a 135 MeV polarized-proton beam impinging on a liquid-deuteron target. The proton–deuteron breakup reaction leads to a final state with three free particles and a rich phase space that allows us to study observables for continuous set of kinematical configurations of the outgoing nucleons. The results are interpreted with the help of state-of-the-art Faddeev calculations.     

Analysis of 6Li Scattering at 600 MeV

The elastic and inelastic scattering of ⁶Li on ¹²C, ⁵⁸Ni, ⁹⁰Zr, and ²⁰⁸Pb targets at 600 MeV are analyzed via double-folding optical model potentials based on the S1Y effective nucleon–nucleon (NN) interaction and tρρ approximation. Information is provided, by single- and coupled-channel calculations, on the effect of breakup and its feedback on the elastic scattering of ⁶Li ions. Experimental results are successfully reproduced. The in-medium NN cross-section and second-order (double-scattering) correction to the tρρ potential are taken into account. Reaction cross-sections are computed from exact and approximate solutions.     

Testing Nucleon–nucleon Potentials in Three- and Four-nucleon Scattering Observables

We present a theoretical study of three- and four-nucleon continuum within the hyperspherical harmonics method, using a representative variety of realistic nucleon–nucleon potential models, i.e. one of phenomenological type, the Argonne v ₁₈ (AV18), one obtained within chiral effective field theory up to next-to-next-to-next-leading order, the Idaho N3LO (I-N3LO), and a “low-k” model derived from the CD-Bonn potential. In particular, the convergence pattern for the four-nucleon system is found to be problematic for the P-waves phase-shifts in the case of the AV18 potential at higher energies. An extrapolation procedure is presented and discussed. Finally, we present the theoretical results for p?d and p?³ scattering observables at two selected energies, and we compare these with the available experimental data. In particular, some spread in the unpolarized cross section and in some polarization observables has been observed using the three potential models, in particular for A =  4. Furthermore the well known discrepancy in the vector polarization observables remains for the three potential models.     

Neutron–proton analyzing power at 12 MeV and inconsistencies in parametrizations of nucleon–nucleon data

We present the most accurate and complete data set for the analyzing power Ay(θ)$A_y(\theta )$ in neutron–proton scattering. The experimental data were corrected for the effects of multiple scattering, both in the center detector and in the neutron detectors. The final data at En=12.0 MeV$E_n=12.0\text{MeV}$ deviate considerably from the predictions of nucleon–nucleon phase-shift analyses and potential models. The impact of the new data on the value of the charged pion–nucleon coupling constant is discussed in a model study.     

Deuteron Breakup Differential Cross Sections and Analyzing Powers of {\overrightarrow{d} + p} Scattering at E d = 16 and 130 MeV

Deuteron breakup differential cross sections and analyzing powers for ${\overrightarrow{d} + p}$ scattering at E _d  = 16 and 130 MeV are examined using the energy-independent quark-model nucleon–nucleon interaction fss2. The Coulomb effect is incorporated by the sharp cut-off Coulomb force, acting between quarks, without the phase-shift renormalization for the breakup amplitudes. Our results are very similar to those by the meson-exchange potentials, including disagreement for some specific kinematical configurations. The accurate and systematic KVI data at E _d  = 130 MeV are reasonably reproduced by taking the Coulomb cut-off radius ρ ≥ 16 fm.     

Measurement of all Deuteron Analyzing Powers for {\overrightarrow{d} + p} Elastic Scattering at 294 MeV/Nucleon

We have measured all deuteron analyzing powers ${(A_{y}^{d}, A_{yy}, A_{xx}, A_{xz})}$ for deuteron-proton elastic scattering at 294 MeV/nucleon in order to study the properties of three nucleon forces (3 NFs). Measurement was made at in an angular range of ${\theta_{{\rm c.m.}} = 35.6^{\circ} - 163.0^{\circ}}$ . Obtained data were compared with Faddeev calculations with and without the 3 NFs. At ${\theta_{{\rm c.m.}}\lesssim 120^{\circ}}$ all the data have general agreement with the calculations, while the measured data at ${\theta_{{\rm c.m.}} \gtrsim 120^{\circ}}$ are not explained by any theoretical calculations. These results were consistent with those at 250 MeV/nucleon.     

Deuteron stripping on beryllium target in the 100–2300 MeV energy range

Cross sections for stripping and dissociation of deuterons interacting with Be targets in the 100–2300 MeV energy range have been measured. Comparisons with model calculations suggest a dominant contribution of the stripping process. It is also shown that the deuteron break-up cross section exhibits the same energy dependence as the nucleon-nucleon cross section. Received: 8 September 1998 / Revised version: 15 March 1999     

Effects of Distorted Wave on Proton Elastic Scattering from Light Nuclei at 200 MeV

The distorted wave is introduced into the relativistic impulse approximation to generate the Dirac optical potentials for proton elastic scattering. Those potentials, produced by folding the target ground state wavefunction with the free nucleon-nucleon interactions, are used to reevaluate scattering observables, such as differential cross section, analysing power and spin rotation function, for proton elastic scattering from ^12C and ^16O at Elab = 200 MeV, respectively. The inclusion of the distorted wave in the original relativistic impulse approximation has brought out better results of the observables, especially at small scattering angles.     

Parity Violation in Proton–Proton Scattering at High Energies

JETP Letters - A new approach has been proposed to describe parity violation in the scattering of polarized protons by protons at high energies. It has been shown that the P-odd proton- proton...