Muon capture

QUANTUM CALCULATION OF COOPERATIVE MUON-NUCLEAR PROCESSES DISCHARGE OF METASTABLE NUCLEI DURING NEGATIVE MUON CAPTURE... 

Target element Spallation Thermal neutron capture Negative muon capture... 

Chemical effects on the muon capture ratio have been studied in several target systems. As this review paper does not aim at providing a complete bibliography on... 

NaNOj-NaNOj, Na2S03-Na2S04, Na2Se03-Na2Se04, muon capture occurs with higher probability for lower oxidation state atoms of the same element Therefore, care must be taken in evaluating the icapture ratios in case of elements with different oxidation numbers. 

Myoneneinfang durch einen Kern, muon capture within a nucleus 528 f. 

It is useful to extrapolate the cosmic ray components of the background in the deep KamLAND detector to shallower depths at which detector construction is more feasible. Most of the cosmic ray induced background comes firom neutrons with energies up to several hundred MeV produced by muon capture and spallation in materials surrounding the detector. Few experiments have been done that give detailed information on the... 

Numerous models have been proposed for describing the formation of exotic atoms via Coulomb capture. The muons in atoms do reach the atomic ground state (as opposed to hadronic atoms), and the lack of strong interaction effects makes them good probes to study Coulomb capture. One of the most important experimental methods is measuring Coulomb capture ratios. In a mixture of two elemental gases (e.g., N2 + O2) or in binary compounds, one can determine the amount of muons captured in the different elements by summing up the amplitudes of the muonic Lyman series, the (n p —> Is) transitions. 

In its atomic ground state, the exotic particle has a Bohr radius that is close to or even smaller than the nuclear radius, so it will interact with the nucleus. Muon capture in nuclei (Measday 2001) is governed by the weak interaction between a lepton and a proton semi-leptonic process) ... 

Muons bound in an atomic orbit in transuranium elements can also cause nuclear fission, but that mechanism is quite involved (Measday 2001). There are two types of fission events, prompt and delayed. The prompt events are induced by energy from the atomic cascade of the muon, whereas the delayed events are from muon capture via the weak interaction. 

As mentioned before, the neutral exotic hydrogen atom (having neither Coulomb nor Pauli repulsion) can penetrate other atoms and lose its exotic particle to a heavier nucleus. As the rate of this reaction is proportional to the number of collisions, it can be detected for hadronic atoms but it is really dramatic for muonic hydrogen as its lifetime is many orders of magnitude longer in the muon-catalyzed fusion measurements, for example, the concentration of heavy impurities has to be below 10 to avoid the distortion of the results by transfer. This feature was used to study muon capture in rare gas isotopes as it is sufficient to have less than 1% krypton in hydrogen to have all muons ended up in muonic krypton states. 

Singer,P. Emission of Particles Following Muon Capture in Intermediate and Heavy Nuclei (Vol. 71)... 

Ivanov, L. N., and Letokhov, V. S. (1976). On the possibility of discharge of metastable nuclei upon a negative muon capture. Journal of Experimental and Theoretical Physics, 43, 9-14. 

The results of calculation of the cross-section for the negative muon capture by atom of He are shown in Figs. 3.1-3.4. The scheme includes 210 points till distance 25aB (aB is the Bohr radius). The main contribution to the capture cross-section is provided by transitions with the moment 1 = 0 — 3. 

Relativistic Theory of Metastable Nucleus Discharge During Negative Muon Capture... 

Finally, availability of more exact data on the. -nucleus and p.-atom interactions is important in astrophysics, studying substance transformation in the Universe, testing the Standard Model etc. [6, 21,49, 50]]. e-p-Y-nuclear spectroscopy of atoms (molecules) opens new prospects in combining nuclear physics and quantum chemistry (atomic physics). These possibilities are strengthened by quickly developed nuclear quantum optics [19-26]. Superintense lasers (raser or even graser) field may provide a definite measurement of the change in the dynamics of the nuclear processes, including the muon capture (and/or y, P-, a-decay) [18-26,48,50],... 

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