The triumf low energy pion spectrometer and channel

doi:10.1016/0167-5087(84)90221-7

Nuclear Instruments and Methods in Physics Research

Volume 219, Issue 3, 1 February 1984, Pages 501-507

https://doi.org/10.1016/0167-5087(84)90221-7 Get rights and content

Abstract

A low energy pion spectrometer has been developed for use with the TRIUMF M13 pion channel. The combined channel and spectrometer resolution is presently 1.1. MeV at T = 50 MeV. This is limited by the amount of gas and detector material in the spectrometer in addition to the inherent resolution of the channel. Improvements to both the spectrometer and channel are discussed.

References (29)

K. Nakai
Phys. Rev. Lett.
(1980)
R.R. Johnson
Nucl. Phys.
(1978)
S.A. Dytman
Phys. Rev.
(1979)
C. Kost et al.
REVMOC, a Monte Carlo beam transport program
TRIUMF Internal Report TRI-DN-83-28
(1983)
E.A. Wadlinger
Nucl. Instr. and Meth.
(1976)
R.A. Arndt et al.
SAID: scattering analysis interactive dial-in program, Centre for Analysis of Particle Scattering
Virginia Polytechnic Institute and State University Internal Report CAPS-80-3
(June 1982)
P.Y. Bertin
Nucl. Phys.
(1976)
W. Gyles
Bull. Can. Assoc. Phys.
(1983)
J.P. Albanese
Nucl. Instr. and Meth.
(1979)

H.A. Thiessen et al.

Los Alamos National Laboratory Report LA-4534-MS

(1970)

D. Ashery

Phys. Rev.

(1981)

I. Navon

True absorption and scattering of 50 MeV pions

TRIUMF preprint TRI-PP-83-14

(1983)

R.R. Johnson

Phys. Rev. Lett.

(1979)

Cited by (27)

Threshold behaviour of the π+π- invariant mass in nuclei
1993, Nuclear Physics, Section A
We present π⁺π⁻ invariant-mass distributions between 300 and 380 MeV for the ²H, ⁴He, ¹⁶O, $^{208} Pb (π^{+}, π^{+} π^{−})$ reaction at an incident π⁺ energy of 280 MeV. A prominent feature is the shift of their maximum downward to the 2m_π threshold as A increases. This behaviour finds a qualitative explanation in the framework of a model that investigates the modification of the strength function for an interacting (ππ)_{I = L = 0} system embedded in the nuclear medium. Also, the π⁺π⁻ invariant-mass cross sections are compared with the predictions of an A(π⁺, π⁺π⁻) model that uses a microscopical approach for the elementary process of pion production, πN → ππ N. Four-fold differential cross sections as a function of the energy of outgoing π⁺ and p, and missing-mass distributions for the A(π⁺, pπ⁻) reaction are also presented for some of the examined nuclei. The experimental results are discussed within the framework of the two available models.
π+π- coincidence measurement in the 4He(π+, π+π-) reaction at T<inf>π+</inf> = 280 MeV
1992, Nuclear Physics, Section A
The pion-induced pion-production reaction (π⁺, π⁺π⁻) on ⁴He has been studied at an incident pion kinetic energy of 280 MeV. The outgoing pions were detected in coincidence and the measured four-fold differential cross sections are compared with a quasifree πN → ππN microscopic model. Finally, the results are directly compared with recent data from the ¹⁶O(π⁺, π⁺π⁻) and²H(π⁺, π⁺π⁻)pp reaction at the same incident energy.
Pion-induced pion production on deuterium: a quasifree process
1992, Nuclear Physics, Section A
A detailed experimental analysis of the π⁺d → π⁺π⁻pp in-plane coincidence data first presented by Rui et al. is compared to an expanded version of the Oset and Vicente-Vacas model for pion-induced pion production on a free nucleon. This extended model averages over Fermi motion to describe the assumed quasifree nature of the process occurring on the deuteron and includes nine additional diagrams to account for the $N^{∗} → N (ππ)_{p-wave}$ reaction channels. Experimental effects such as pion energy loss in the target and in the detectors, pion decay and muon detection are investigated and incorporated into the comparison of experimental data and theory. Inclusion of Fermi motion was found to be essential to provide good agreement between data and model confirming the quasifree nature of the reaction. When compared to the total-cross-section measurements of Manley et al., the free-reaction model yields a model-dependent estimate of the overall strength of the diagram containing the $N^{∗} → N (ππ)_{s-wave}$ vertex.
Pionic charge exchange in nuclei
1992, Progress in Particle and Nuclear Physics
The status of pionic single and double charge exchange reactions on nuclei is reviewed. The present data base extending from very low pion energies up to 550 MeV reveals many surprising facets of these processes. Measurements and their interpretations are discussed with the main emphasis being put on the double charge exchange reaction, its reaction mechanism, the role of nucleon-nucleon correlations and its relation to double beta decay.
π+ π- Coincidence measurement in the π+ d → π+ π-pp reaction at T<inf>π</inf>+ = 280 MeV
1990, Nuclear Physics, Section A
The pion induced pion production (π, 2π) reaction on deuterium has been studied at an incident pion energy of 280 MeV. The outgoing pions were detected in coincidence and the measured four-fold cross sections were compared with a πN → ππ N microscopic model, and, upon integration, with the available experimental total cross sections from the same reaction on H and ²H. Finally, the results were directly compared with recent data from the ¹⁶O(π⁺, π⁺ π⁻) reaction at the same incident energy.
Pion production by pions in the 16O(π+,π+π-) reaction at T<inf>π+</inf> = 280 MeV
1989, Nuclear Physics, Section A
The results of an experiment of pion-induced pion production on ¹⁶O at a laboratory energy of 280 MeV are reported. The four-fold-differential cross section, $d^{4} σ dΩ_{π}$ +dΩ_π+dE_π+dE_π, was measured, and the missing mass, M_x, for the reaction ¹⁶Ofs(π⁺,π⁺π⁻) at laboratory angles of 50°, 80° and 115° for the π⁻, and from 22° to 128° for the π⁺ was deduced. The angular and energy distributions of the many-fold differential cross sections are compared with an A(π⁺,π⁺π⁻) model for the reaction. The observed cross sections are reproduced in magnitude and shape when the theoretical calculations consider a proper pion dispersion relation, $\ ̃$ gw(q), inside the nuclear medium. The total cross section, deduced by integrating the four-fold differential cross sections, is compared with the available theoretical predictions for the ¹⁶O(π⁺, π⁺π⁻) reaction.

View all citing articles on Scopus

^☆: Research supported in part by Natural Sciences and Engineering Research Council of Canada.

^∗: Mailing address: TRIUMF, 4004 Westbook Mall, Vancouver BC, Canada V6T 2A3.

View full text

Article preview

Nuclear Instruments and Methods in Physics Research

Abstract

References (29)

Phys. Rev. Lett.

Nucl. Phys.

Phys. Rev.

REVMOC, a Monte Carlo beam transport program

TRIUMF Internal Report TRI-DN-83-28

Nucl. Instr. and Meth.

SAID: scattering analysis interactive dial-in program, Centre for Analysis of Particle Scattering

Virginia Polytechnic Institute and State University Internal Report CAPS-80-3

Nucl. Phys.

Bull. Can. Assoc. Phys.

Nucl. Instr. and Meth.

Los Alamos National Laboratory Report LA-4534-MS

Phys. Rev.

True absorption and scattering of 50 MeV pions

TRIUMF preprint TRI-PP-83-14

Phys. Rev. Lett.

Cited by (27)

Threshold behaviour of the π<sup>+</sup>π<sup>-</sup> invariant mass in nuclei

π<sup>+</sup>π<sup>-</sup> coincidence measurement in the <sup>4</sup>He(π<sup>+</sup>, π<sup>+</sup>π<sup>-</sup>) reaction at T<inf>π<sup>+</sup></inf> = 280 MeV

Pion-induced pion production on deuterium: a quasifree process

Pionic charge exchange in nuclei

π<sup>+</sup> π<sup>-</sup> Coincidence measurement in the π<sup>+</sup> d → π<sup>+</sup> π<sup>-</sup>pp reaction at T<inf>π</inf><sup>+</sup> = 280 MeV

Pion production by pions in the <sup>16</sup>O(π<sup>+</sup>,π<sup>+</sup>π<sup>-</sup>) reaction at T<inf>π<sup>+</sup></inf> = 280 MeV

The triumf low energy pion spectrometer and channel☆

Abstract

Phys. Rev. Lett.

Nucl. Phys.

Phys. Rev.

TRIUMF Internal Report TRI-DN-83-28

Nucl. Instr. and Meth.

Virginia Polytechnic Institute and State University Internal Report CAPS-80-3

Nucl. Phys.

Bull. Can. Assoc. Phys.

Nucl. Instr. and Meth.

Los Alamos National Laboratory Report LA-4534-MS

Phys. Rev.

True absorption and scattering of 50 MeV pions

TRIUMF preprint TRI-PP-83-14

Phys. Rev. Lett.