Low-Energy Ps-Xe Scattering Analyzed Using a Modified Effective Range Theory

2017 ◽  
Vol 373 ◽  
pp. 23-28
Author(s):  
Kengo Shibuya ◽  
Haruo Saito
Keyword(s):  
Partial Wave ◽  
Wave Scattering ◽  
Low Energy ◽  
Partial Wave Analysis ◽  
Effective Range ◽  
Wave Analysis ◽  
Temperature Dependences ◽  
Range Theory ◽  
Effective Range Theory

We have investigated positronium‒xenon collisions at energies below 100 meV to find a strong temperature dependences of the annihilation rates. A partial wave analysis based on a modified effective range theory (MERT) is tested to explain the temperature dependences and to find significant contributions of the p-wave scattering component. The fact that MERT works well for analyzing positronium‒xenon collisions indicates that positronium is polarized during the collisions as proposed by other theoretical and experimental researchers.

scholarly journals Role of Spin in NN → NNπ

2016 ◽  
Vol 40 ◽  
pp. 1660061
Author(s):  
Vadim Baru
Keyword(s):  
Partial Wave ◽  
Pion Production ◽  
Low Energy ◽  
Partial Wave Analysis ◽  
P Wave ◽  
Wave Analysis ◽  
Theoretical Predictions

The recent measurements of the reactions [Formula: see text] and [Formula: see text] by the ANKE collaboration at COSY are analyzed with the focus on the p-wave pion production amplitudes. These amplitudes are known to provide an important connection between [Formula: see text] and other low-energy few-nucleon reactions. The results of the recent partial wave analysis of the ANKE data are discussed and compared with the theoretical predictions.

Low-energy πN partial wave analysis

1980 ◽  
Vol 336 (3) ◽  
pp. 331-346 ◽  
Author(s):  
R. Koch ◽  
E. Pietarinen
Keyword(s):  
Partial Wave ◽  
Low Energy ◽  
Partial Wave Analysis ◽  
Wave Analysis

Scattering Theory

2019 ◽  
pp. 359-400
Author(s):  
P.J.E. Peebles
Keyword(s):  
Partial Wave ◽  
Interaction Potential ◽  
Scattering Theory ◽  
Wave Scattering ◽  
Wave Packets ◽  
Particle Separation ◽  
Partial Wave Analysis ◽  
Wave Analysis ◽  
Scattering Problems ◽  
Scattering Pattern

This chapter studies applications drawn from scattering theory. A powerful and commonly used way to explore the interaction between particles is to study the way they scatter off each other. In the scattering problems considered here, motions are non-relativistic and particles are conserved: two particles move together, interact, and then move apart again. It is assumed that the range of the interaction is finite, so when the particles are well separated they move freely. In a scattering experiment, one imagines that the particles approach each other as wave packets with fairly definite momenta and positions. The motion is initially free, because the particles are separated by great distances compared to the range of their interaction. As the wave packets move together, the particles interact through a potential V that is some function of the particle separation. The wave packets then move apart in a scattering pattern that is determined by the interaction potential. The chapter simplifies the partial wave analysis by concentrating on s-wave scattering; this allows an easy treatment of interesting effects such as resonances and absorption.

Calculation of Average Collision Cross Sections of Low Energy for Elastic e-Ar Scattering Using MERT4

2014 ◽  
Vol 81 (1) ◽  
Author(s):  
S. Hassanpour ◽  
S. Nguyen-Kuok
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Electron Scattering ◽  
Cross Sections ◽  
Phase Shifts ◽  
Low Energy ◽  
Effective Range ◽  
Collision Cross Sections ◽  
Range Theory ◽  
Effective Range Theory

Cross sections in the very low energy range are also represented by the modified effective-range theory (MERT) for low-energy electron scattering from the rare gas (argon). Simulations using published (theoretical) phase shifts indicate that extended versions of the standard effective-range theory with four adjustable parameters are required to give an adequate description of the phase shifts for argon. A four-parameter MERT fit gives a good representation of a recent electron–argon (e-Ar) total cross section experiment at energies less than 10.0 eV. Cross section Q(l) (E) for collision in dilute gases is given for any order l. Here Q(l) (E) are presented for l = 1. . .6. We present calculations for the elastic cross sections for electron scattering from argon. The improvement in the agreement between our theoretical calculations and the experimental measurements in the case of argon in scattering calculations are showed. Differential scattering experiments have been performed for the systems e-Ar in the energy range E = 0–10 eV and the angular range θ = 0–20° using a crossed-beam arrangement. Differential and integrated cross sections for the elastic scattering of low- and intermediate-energy (0–50 eV) electrons by argon atoms are calculated. For each impact energy, the phase shifts of the lower partial waves are obtained exactly by numerical integration of the radial equation. Transport coefficients of argon plasma are requested exactly, which is why we calculated the average collision cross sections for s = 1. . .11, l = 1. . .6.

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