A study of the two-electron Fourier amplitudes of atomic and molecular wavefunctions using the (γ,2e) and (e,3e) processes at high energies

1978 ◽  
Vol 11 (20) ◽  
pp. 3587-3601 ◽  
Author(s):  
Yu F Smirnov ◽  
A V Pavlitchenkov ◽  
V G Levin ◽  
V G Neudatchin
Author(s):  
A. Howie ◽  
D.W. McComb

The bulk loss function Im(-l/ε (ω)), a well established tool for the interpretation of valence loss spectra, is being progressively adapted to the wide variety of inhomogeneous samples of interest to the electron microscopist. Proportionality between n, the local valence electron density, and ε-1 (Sellmeyer's equation) has sometimes been assumed but may not be valid even in homogeneous samples. Figs. 1 and 2 show the experimentally measured bulk loss functions for three pure silicates of different specific gravity ρ - quartz (ρ = 2.66), coesite (ρ = 2.93) and a zeolite (ρ = 1.79). Clearly, despite the substantial differences in density, the shift of the prominent loss peak is very small and far less than that predicted by scaling e for quartz with Sellmeyer's equation or even the somewhat smaller shift given by the Clausius-Mossotti (CM) relation which assumes proportionality between n (or ρ in this case) and (ε - 1)/(ε + 2). Both theories overestimate the rise in the peak height for coesite and underestimate the increase at high energies.


2001 ◽  
Vol 16 (1-2) ◽  
pp. 49-85
Author(s):  
A. De Roeck

1970 ◽  
Vol 101 (7) ◽  
pp. 385-428 ◽  
Author(s):  
Igor M. Dremin ◽  
Il'ya I. Roizen ◽  
Dmitrii S. Chernavskii

1976 ◽  
Vol 119 (7) ◽  
pp. 578
Author(s):  
Igor M. Dremin ◽  
G.B. Zhdanov ◽  
V.Ya. Fainberg

Author(s):  
Richard Wigmans

The energy resolution, i.e. the precision with which the energy of a showering particle can be measured, is one of the most important characteristics of a calorimeter. This resolution is determined by fluctuations in the absorption and signal formation processes. In this chapter, the different types of fluctuations that may play a role are examined, and their relative practical importance is addressed. Sources of fluctuations include fluctuations in the number of signal quanta, sampling fluctuations, fluctuations in shower leakage, as well as a variety of instrumental effects. Since the energy dependence of the different types of fluctuations is not the same, different types of fluctuations may dominate the energy resolution at low and and at high energies. An important type of fluctuations is part of the non-compensation phenomena. It concerns fluctuations in the strength of the electromagnetic component of hadronic showers. The effects of these fluctuations, which typically dominate the energy resolution for hadron and jet detection, are examined in detail. In sampling calorimeters, one particular shower particle may sometimes have catastrophic effects on the calorimeter performance. Several examples of such cases are discussed.


2012 ◽  
Vol 349 ◽  
pp. 011001
Author(s):  
Giorgio Giardina ◽  
Fabio Bossi ◽  
Paolo Levi Sandri ◽  
Paolo Pedroni ◽  
Hartmut Schmieden

1950 ◽  
Vol 5 (2) ◽  
pp. 318-318
Author(s):  
F. Fujimoto ◽  
S. Hayakawa ◽  
Y. Yamaguchi

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Clifford Cheung ◽  
Zander Moss

Abstract We argue that symmetry and unification can emerge as byproducts of certain physical constraints on dynamical scattering. To accomplish this we parameterize a general Lorentz invariant, four-dimensional theory of massless and massive scalar fields coupled via arbitrary local interactions. Assuming perturbative unitarity and an Adler zero condition, we prove that any finite spectrum of massless and massive modes will necessarily unify at high energies into multiplets of a linearized symmetry. Certain generators of the symmetry algebra can be derived explicitly in terms of the spectrum and three-particle interactions. Furthermore, our assumptions imply that the coset space is symmetric.


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