Muons properties

In the following section new results on muonium spectroscopy are presented. Muonium (y e ) is a hydrogen-like atom consisting of two leptons. It provides an ideal system to determine muon properties and measure muon-electron interactions. is one of... 

Second Quantized Description of a System of Noninteracting Spin Particles.—All the spin particles discovered thus far in nature have the property that particles and antiparticles are distinct from one another. In fact there operates in nature conservation laws (besides charge conservation) which prevent such a particle from turning into its antiparticle. These laws operate independently for light particles (leptons) and heavy particles (baryons). For the light fermions, i.e., the leptons neutrinos, muons, and electrons, the conservation law is that of leptons, requiring that the number of leptons minus the number of antileptons is conserved in any process. For the baryons (nucleons, A, E, and S hyperons) the conservation law is the... 

There is now an extensive and rapidly growing theoretical literature on the nature of hydrogen or muonium defects in silicon and to some extent in other semiconductors (Van de Walle, 1991 DeLeo, 1991). Much of this has dealt with isolated hydrogen or muonium where the most frequent comparisons have been with the muon hyperfine parameters, at least qualitatively, and other features of the muonium centers that can be inferred from /rSR experiments. Isolated interstitial hydrogen or muonium is certainly one of the simplest point defects conceivable. Hence explaining the existence and properties of the two drastically different forms of muonium observed in silicon and several other semiconductors has been a particular challenge to current theoretical methods. 

The close correspondence between the properties of Mu in Si as determined by /u,SR and pLCR and those for the AA9 center produced by implanting hydrogen in silicon shows that Mu in silicon and the AA9 center are isostructural and in fact almost identical. They are neutral isolated bond-centered interstitials. Numerous theoretical studies support this conclusion. The observation of such similar centers for muonium and hydrogen supports the generalization that hydrogen analogs of many of the muonium centers exist. Of course, this assumes that the effects of the larger zero-point vibration of the muon relative to the proton do not make a major contribution to structural differences. The p-SR experiments, reinforced by theory, demonstrate that another structure also exists for muonium in silicon, called normal muonium or Mu. This structure is metastable and almost certainly is isolated neutral muonium at a tetrahedral interstitial site. 

The central quantity which determines neutron star properties is the EoS, at T = 0 specified by the energy density e(p). For densities above, say, p = 0.1 fm-3 one assumes a charge neutral uniform matter consisting of protons, neutrons, electrons and muons the conditions imposed are charge neutrality, Pp = Pe + PfM, and beta equilibrium, pn pp + pe with pe = p/t. ... 

The opportunities for concentrating and detecting (probably primordial) quarks and the properties of adducts of atoms, ions and molecules with quarks are discussed. There is a pronounced difference between positive quarks located in the outer valence-regions (or in the conduction electrons of metals) and negative quarks so firmly bound to nuclei that they may not be mobile, and constitute a kind of new elements with (Z - 1/3). Analogies are drawn with neutrinos, muons and other well-established particles. 

Anderson s particle, which is now called the muon after the Greek letter mu, was actually a kind of heavy electron. It had a large mass, but it otherwise exhibited electronlike properties. This was a great puzzle to the physicists of the day, because there seemed to be no reason it should exist. It was not a component of ordinary matter. It could be observed in the high-energy cosmic ray laboratory, but it quickly decayed (that is, disintegrated) into other particles. 

Like the muon, the tauon has electronlike properties. However it is much heavier than its two counterparts. It weighs about 3,500 times as much as the electron and about 170 times as much as the muon. The neutrinos, on the other hand, are very light, so light that, as I write this, their mass has not yet been determined. It wasn t until 1998 that it was even established that neutrinos had any mass. 

MUON. The muon (p ) is an elementary particle of the lepton family. Properties include Spin, mass (MeV). 105.66 lifetime, 2.20 x I0-6 second. The antiparticle is the positive muon (p1). The muon neutrino I n has spin. U 0 mass and is stable. The muon family appears to be simply... 

Keywords Fullerenes Ferromagnetism Jahn-Teller effect Magnetic resonance Muon spin relaxation Structural properties Orbital ordering... 

In this article, we shall focus on the reactions of muonic hydrogen atoms and molecules, and their energy dependent properties revealed by a newly developed time-of-flight spectroscopy technique [2,3,4,5], with particular emphasis on reactions related to muon catalyzed fusion phenomena. 

Another group of fundamental particles are the leptons (light particles), comprising also three families, electron and electron neutrino, muon and muon neutrino, tau particle and tau neutrino. Properties of the leptons are summarized in Table 3.3. The most important particles of this group are the electron and the electron neutrino, which are both stable. 

Muonic atoms (e.g. p" ), on the other hand, are obtained by absorption of negatively charged muons. In these atoms, replaces an electron in the electron shell. Due to the relatively high mass of (T compared with that of e, their interaction with the nucleus is rather strong, and muons serve as probes to study the properties of nuclei. As the ratio of the atomic orbit is inversely proportional to the mass of the... 

To perform unbiased analyses, a collaboration-wide policy of blindness was established, where cut selections are optimized on a fraction of data or on time-scrambled data set. We present upper confidence limits for null results following the treatment described in (Feldman and Cousins, 1998) and incorporate systematic uncertainties into the calculation of confidence intervals according to (Conrad et al., 2003). The contributions to systematic uncertainties is predominantly due to variations of the optical properties of the ice, the absolute sensitivity of the OM, the neutrino cross section and the muon propagation. The combined systematic uncertainty is typically 30%, although the value varies slightly with the analysis method. 

It is not possible to give here a complete review of DMol applications, so only a non-systematic selection of applications is mentioned here. Applications to chemical reactions have been studied by Seminario, Grodzicki and Politzer [10]. Buckminster-fullerenes have been studied by various groups [11] including also nonlinear optical properties [8] and the geometrical structure of Cs4 [13]. Cluster model studies of surfaces with adsorbates are reported in [14-17]. Cluster models for point defects in solids, in particular spin density studies of interstitial muon can be found in [18,19]. Spin density studies of molecular magnetic materials are in ref [20]. Polymers have been studied by Ye et al [21]. 

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