Searcharxiv⌕ Search

arXiv · nucl-ex/9810010

Study of the ABC Enhancement in the d d -> alpha X reaction

Abstract

The polarized d d -> alpha X reaction at beam energies close to the eta threshold shows very strong structure in the missing mass corresponding to the ABC enhancement. The deuteron tensor analysing power A_yy, and the slope of the vector analysing power A_y with respect to angle, have been measured for this reaction around the forward direction. Both signals are small, and their variations with the alpha-particle momentum are in broad agreement with a theoretical model in which each pair of nucleons in the projectile and target deuterons undergoes pion production through the NN -> d pi reaction.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R. Wurzinger, O. Bing, M. Boivin, P. Courtat, G. Faldt, R. Gacougnolle, A. Gardestig, F. Hibou, Y. Le Bornec, J. M. Martin, F. Plouin, B. Tatischeff, C. Wilkin, N. Willis, J. Yonnet, A. Zghiche. 1998-10-16. Study of the ABC Enhancement in the d d -> alpha X reaction. https://doi.org/10.1016/s0370-2693(98)01464-6

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Precise and accurate nuclear electric quadrupole moment of $^{223}$Ra from molecular spectroscopy

Nuclear electric quadrupole moments of unstable isotopes are commonly extracted from laser spectroscopy of the atomic hyperfine structure, where the accuracy is limited to the several-percent level by the available electric-field-gradient (EFG) calculations. In this study, we determine the spectroscopic quadrupole moment of $^{223}$Ra (half-life $t_{1/2} = 11.4$ d) from hyperfine-resolved collinear resonance ionization spectroscopy of the radioactive molecule $^{223}$Ra$^{19}$F. The $X\,^2Σ^+$ electronic ground state of RaF provides a large axial EFG at the radium nucleus that can be calculated with relativistic coupled-cluster theory to sub-percent accuracy. Together with a three-fold improvement in spectral resolution over previous fast-beam measurements of radioactive molecules, this yields $Q_s = +1.211(7)_\mathrm{stat}(2)_\mathrm{syst}(5)_\mathrm{theo}\,e\mathrm{b}$ for $^{223}$Ra with a total uncertainty of 0.73%, approximately three times better than atomic and ionic determinations. This result demonstrates that molecular spectroscopy can provide access to the electromagnetic structure of unstable nuclei with a precision competitive with, and in favorable cases better than, atomic spectroscopy, and may thus be envisioned for studies beyond the limitations of current radioactive-atom experiments.

nucl-ex↗

Cumulative protons and pions at the intermediate energies in the FRAGM experiment

One of the important research objectives of the FRAGM experiment operating at the TWAC heavy-ion accelerator-storage complex was the study of particle production in the cumulative region. Differential cross sections were measured for the production of pions - resulting from the fragmentation of carbon nuclei at an energy of 3.2 GeV/nucleon, as well as protons with energy range from 300 to 2000 MeV/nucleon at an angle of 3.5 degrees relative to the incident ion beam. The parameterization of cumulative effect used in experiments investigating nucleus-nucleus interactions is discussed. It is shown, that the energy dependencies of these parameters are analogous to those observed in nucleon-nucleus interactions and indicate the presence of nuclear scaling behavior.

nucl-ex↗

Investigation of Medium Modifications to $^{12}$C Structure Functions in the Resonance Region

We present results from a high precision experimental study of the nuclear modification of the longitudinal ($F_L$) to transverse ($F_1$) structure function ratio for bound nucleons in the resonance region. The inclusive electron scattering cross sections were measured in Jefferson Lab Experimental Hall C on carbon and deuterium nuclei for a large range of kinematics, allowing for separations of the longitudinal and transverse structure functions to be performed at a range of four-momentum transfer values $0.5 \le Q^2 \le$ 3.75 GeV$^2$. In contrast to the significant body of measurements of the nuclear modification of the $F_2$ structure function in the deep inelastic scattering region, there is very little on $F_L$ and $R = F_L / 2xF_1$ in the region of the nucleon resonances. In this paper we present measurements of the nuclear effect on $R$ for $^{12}$C ($R_C$) relative to deuterium ($R_D$). These results indicate regions in which in $R_C>R_D$, requiring that the nuclear modifications be different in all three structure functions, $F_2$, $F_1$ and $F_L$.

nucl-ex↗