Quasifree pion scattering at 500 MeV

Physical Review C · 1993-10-01 · 18 citations

Non-charge-exchange inclusive cross sections have been measured at 500 MeV incident pion energy at quasifree scattering kinematics for both positive and negative pion charges. Peaks identified with quasifree knockout are seen at momentum transfers from 314 to 724 MeV/c. The widths and sizes of the peaks seen are consistent with the knockout of single nucleons from the nuclear surface. The data are consistent with no softening of the pion quasifree response at high momentum transfer, in contrast to the result seen in 500-MeV pion charge exchange data.

Neutron induced pion production on C, Al, Cu, and W at 200–600 MeV

Physical Review C · 1992-05-01 · 1 citations

Inclusive double differential neutron induced ${\mathrm{\ensuremath{\pi}}}^{+}$ and ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ production cross sections were measured as a function of neutron energy for four targets: C, Al, Cu, and W. The neutron energy range was 200--600 MeV and the pion angular range was 25\ifmmode^\circ\else\textdegree\fi{}--125\ifmmode^\circ\else\textdegree\fi{} (laboratory). The charge, scattering angle, and energy of the pions were measured. The measurements are compared with intranuclear cascade (INC) calculations and a previous experiment that measured the sum of the ${\mathrm{\ensuremath{\pi}}}^{+}$ and ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ cross sections. Our data agree with the measured data, but the INC calculations give only moderate agreement both with the double differential cross sections as well as with angular distributions and total cross sections as a function of neutron energy. The ratio ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$:${\mathrm{\ensuremath{\pi}}}^{+}$ was found to increase rapidly with decreasing neutron energy and the pion production was found to increase approximately as ${\mathit{A}}^{2/3}$ for the different targets.

Pion absorption in heavy nuclei

Physical Review C · 1992-02-01 · 39 citations

Cross sections have been measured for proton emission following ${\mathrm{\ensuremath{\pi}}}^{+}$ absorption on $^{6}\mathrm{Li}$, $^{12}\mathrm{C}$, $^{27}\mathrm{Al}$, $^{58}\mathrm{Ni}$, $^{118}\mathrm{Sn}$, $^{208}\mathrm{Pb}$, and $^{238}\mathrm{U}$ for pion kinetic energies of 50, 100, 150, and 200 MeV by using a large-solid-angle bismuth germanate detector array. An increasing fraction of transitions to states of large missing energy and with particles other than protons is observed as the energy and mass increase.

Pion absorption in light nuclei

Physical Review C · 1992-07-01 · 21 citations

Cross sections have been measured for proton emission following ${\mathrm{\ensuremath{\pi}}}^{+}$ absorption on $^{6}\mathrm{Li}$, $^{7}\mathrm{Li}$, $^{9}\mathrm{Be}$, $^{10}\mathrm{B}$, $^{11}\mathrm{B}$, $^{12}\mathrm{C}$, and $^{13}\mathrm{C}$, for pion kinetic energies of 50, 100, 140, and 180 MeV using a large-solid-angle bismuth germanate detector array.

Hypernuclear spectroscopy with the (π, K) reaction

AIP conference proceedings · 1991-01-01

Abstract

Charged-particle multiplicities following pion absorption on<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Li</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>6</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>

Physical Review Letters · 1990-01-22 · 14 citations

We have studied particle emission following ${\ensuremath{\pi}}^{+}$ absorption on $^{6}\mathrm{Li}$ at ${T}_{\ensuremath{\pi}}$=150 MeV by using a large-solid-angle detector. We find an absorption cross section leading to two or more energetic protons in the final state to be 98\ifmmode\pm\else\textpm\fi{}15 mb. We find that only about 65 mb can be explained as quasideuteron absorption.

Elastic and inelastic scattering of 0.8 GeV protons from<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Ne</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>20</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Ne</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>22</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>

Physical Review C · 1988-11-01 · 31 citations

Angular distributions for the elastic and inelastic scattering of 0.8 GeV protons from $^{20}\mathrm{Ne}$ and $^{22}\mathrm{Ne}$ are presented. Cross sections for protons exciting states up to about 14 MeV were measured using a high resolution spectrometer. Coupled-channels analyses of scattering cross sections for the ${0}^{+}$, ${2}^{+}$, ${4}^{+}$, and ${6}^{+}$ states in the ground-state rotational band, possible ${2}^{\mathrm{\ensuremath{-}}}$, ${3}^{\mathrm{\ensuremath{-}}}$, and ${5}^{\mathrm{\ensuremath{-}}}$ members of a ${K}^{\ensuremath{\pi}}$${=2}^{\mathrm{\ensuremath{-}}}$ octupole band, and possible ${1}^{\mathrm{\ensuremath{-}}}$, ${3}^{\mathrm{\ensuremath{-}}}$, and ${5}^{\mathrm{\ensuremath{-}}}$ members of a ${K}^{\ensuremath{\pi}}$${=0}^{\mathrm{\ensuremath{-}}}$ octupole band in $^{20}\mathrm{Ne}$ were performed. Also reported are coupled-channels analyses of the experimental angular distributions in $^{22}\mathrm{Ne}$ for the ${0}^{+}$, ${2}^{+}$, and ${4}^{+}$ states in the ground-state band, the ${K}^{\ensuremath{\pi}}$${=2}^{+}$ \ensuremath{\gamma}-vibrational band members, and the ${2}^{\mathrm{\ensuremath{-}}}$ and ${3}^{\mathrm{\ensuremath{-}}}$ members of a ${K}^{\ensuremath{\pi}}$${=2}^{\mathrm{\ensuremath{-}}}$ octupole band. Deformation parameters for states not in the ground-state rotational bands are obtained from a distorted-wave Born approximation analysis of these data. Multipole moments inferred from the deformed optical potentials are compared with moments obtained with electromagnetic measurements, low-energy proton, deuteron, $^{3}\mathrm{He}$, and $^{4}\mathrm{He}$ scattering, and shell-model calculations.

Elastic and inelastic scattering of 0.8 GeV protons from<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Ar</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>40</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>

Physical Review C · 1988-03-01 · 8 citations

Angular distributions for the elastic and inelastic scattering of 0.8 GeV protons from $^{40}\mathrm{Ar}$ are presented. Cross sections for protons exciting states up to about 6 MeV were measured using a high-resolution spectrometer. Distorted-wave Born-approximation analyses of states of spin ${2}^{+}$, ${3}^{\mathrm{\ensuremath{-}}}$, ${4}^{+}$, and ${5}^{\mathrm{\ensuremath{-}}}$ were performed using collective-model transition densities.

Differential cross section and analyzing power measurements for p+p elastic scattering at 497.5 MeV

Physical Review C · 1988-01-01 · 11 citations

Differential cross sections for proton-plus-proton elastic scattering at 497.5\ifmmode\pm\else\textpm\fi{}0.5 MeV are reported for the center-of-momentum angular range 6\ifmmode^\circ\else\textdegree\fi{}\ensuremath{\le}${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.\mathrm{\ensuremath{\le}}97}$\ifmmode^\circ\else\textdegree\fi{}. Statistical and relative point-to-point errors are typically \ensuremath{\le}\ifmmode\pm\else\textpm\fi{}1% and \ensuremath{\le}\ifmmode\pm\else\textpm\fi{}2%, respectively. Elastic analyzing powers over the range 16\ifmmode^\circ\else\textdegree\fi{}\ensuremath{\le}${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.\mathrm{\ensuremath{\le}}97}$\ifmmode^\circ\else\textdegree\fi{} are also reported. Typical statistical and relative point-to-point uncertainties are \ifmmode\pm\else\textpm\fi{}(0.01--0.03) and \ifmmode\pm\else\textpm\fi{}1%, respectively. Absolute normalization of both the d\ensuremath{\sigma}/d\ensuremath{\Omega} and ${A}_{y}$ data is obtained through comparison with absolute data from other experiments. Absolute normalization uncertainties are \ifmmode\pm\else\textpm\fi{}2% (cross section) and \ifmmode\pm\else\textpm\fi{}1% (analyzing power). The data are compared with existing data near 500 MeV and with predictions of solutions from phase shift analysis.

Elastic and inelastic scattering of 0.8 GeV polarized protons from<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Mg</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>24</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Mg</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>26</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>

Physical Review C · 1988-05-01 · 27 citations

Data on 800 MeV polarized proton scattering on $^{24}\mathrm{Mg}$ and $^{26}\mathrm{Mg}$ are presented. Angular distributions and analyzing power data have been extracted from fits to 26 peaks in the spectra for $^{24}\mathrm{Mg}$ and 23 peaks in $^{26}\mathrm{Mg}$. Although there are a variety of shapes for the angular distributions, the analyzing power data for all states are positive and similar in magnitude and seem to be consistent with a two-body operator for the excitation with a spin structure much like that for the free proton-nucleon system. Evidence for a level in $^{26}\mathrm{Mg}$ at 8.03 MeV with J&gt;4 is presented. Comparison between the observed angular distribution, coupled channels, and distorted wave Born approximation calculations, and the angular distributions of excited states in neighboring nuclei, support the assignment of ${J}^{\ensuremath{\pi}}$${=5}^{\mathrm{\ensuremath{-}}}$ or ${6}^{+}$. Coupled channels calculations for the ${0}^{+}$, ${2}^{+}$, ${4}^{+}$,${\phantom{\rule{0ex}{0ex}}\mathrm{and}\phantom{\rule{0ex}{0ex}}6}^{+}$ members of the ground state rotational bands of $^{24}\mathrm{Mg}$ and $^{26}\mathrm{Mg}$ are compared to the data. Deformation parameters from distorted wave Born approximation calculations are determined for most of the angular distributions.