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1.
Hubert Schneuwly 《Zeitschrift fur Physik C Particles and Fields》1992,56(Z1):S280-S284
The unexpected and, in conventional terms, yet unexplained experimental results, obtained in systematic measurements of muon
transfer from muonic hydrogen to sulphur and oxygen of sulphur dioxide, seem to violate the principle of reproducibility of
muon transfer data. With the hypothesis of ephemeral muonic hydrogen atoms, the number of different hydrogen atoms can be
reduced from four to two. This hypothesis does, however, not help to interpret the transfer data to helium, neon and argon,
where the muonic hydrogen atoms seem to wear colours. 相似文献
2.
In a systematic study of the transfer process to sulphur dioxide, in seven different H2 + SO2 gas mixtures, the time spectra of the muonic sulphur X-rays yield muon transfer rates to the SO2 molecule, deduced from the lifetimes of the p atoms, which agree all well with each other. The muonic oxygen time spectra show an additional structure as if p atoms of another kind were present. Reduced transfer ratesO are reproducible if one uses the model of ephemeral p atoms. The intensity ratios between the different kinds of p atoms are also discussed in the framework of this model and the one of black and white p atoms. 相似文献
3.
A. Werthmüller A. Adamczak R. Jacot‐Guillarmod F. Mulhauser L.A. Schaller L. Schellenberg H. Schneuwly Y.‐A. Thalmann S. Tresch 《Hyperfine Interactions》1998,116(1-4):1-16
The charge exchange reaction of negative muons from the
atom to oxygen has been measured in gaseous mixtures of H2 + O2. The measurements were performed at three different relative oxygen concentrations ranging from 0.2% to 0.8% and total pressures 3.5–15 bar. A mean transfer rate of
, describing the transfer from the ground state of thermalized
atoms to oxygen, was determined. In order to investigate the energy dependence of the transfer rate, Monte Carlo simulations of the
thermalization and the muon transfer were carried out. The comparison of measured and simulated time spectra yielded an epithermal transfer rate
=3.9
1011 s-1 in the energy interval 0.12–0.22 eV. The analysis with the model of Two components shows that all measured time spectra can be reproduced with the same set of parameters. 相似文献
4.
B. Gartner P. Ackerbauer M. Augsburger W.H. Breunlich M. Cargnelli D. Chatellard J.-P. Egger T. von Egidy F.J. Hartmann R. Jacot-Guillarmod E. Jeannet P. Kammel R.C. King A. Kosak B. Lauss J. Marton M. Mühlbauer F. Mulhauser C. Petitjean C. Piller W. Prymas L.A. Schaller L. Schellenberg H. Schneuwly W. Schott Y.A. Thalmann S. Tresch A. Werthmüller J. Zmeskal 《Hyperfine Interactions》1999,119(1-4):103-108
The energy and time distributions of the decay X-rays of excited, metastable, molecular (dμHe)*-resonances were measured. The comparison of the observed energy spectra with calculated ones suggests that decay from
the rotational state J = 1 dominates at the investigated conditions. The muon transfer rates from ground state deuterium to the helium isotopes
3He and 4He at low temperatures were determined from the time distributions of these spectra. Additionally, the temperature dependence
of the muon transfer rate was clearly established in deuterium / 4He mixtures.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
Gartner B. Ackerbauer P. Breunlich W. H. Cargnelli M. Fischer A. Kammel P. King R. Kminek G. Lauss B. Marton J. Prymas W. Steininger E. Zmeskal J. Petitjean C. Chatellard D. Egger J. -P. Jeannet E. Hartmann F. J. Kosak A. Mühlbauer M. von Egidy T. Piller C. Schaller L. A. Schellenberg L. Schneuwly H. Thalmann Y. -A. Tresch S. Werthmüller A. 《Hyperfine Interactions》1996,101(1):249-255
Muon transfer from the ground state of muonic deuterium to a helium atom proceeds mainly via the formation of a muonic molecule in an excited state. A large number of decay X rays ( 6.8 keV) from these (dµHe)* molecules were observed for the4He as well as for the3He case. The time distributions of these X rays allow the determination of the ground state transfer rate. The simultaneous employment of Ge/Si-detectors and CCDs for the same target conditions allows the determination of the branching ratio of radiative to nonradiative decay for the first time. 相似文献
6.
Hubert Schneuwly 《Structural chemistry》1991,2(3-4):(239)447-(242)450
It is shown that the muonicK
/K
intensity ratios in oxygen of oxides of third-row elements are correlated to the bond ionicities. A similar correlation is found in chlorine of corresponding compounds. These correlations confirm the dominant role played by the outer electrons of the bond partners in the coulomb capture mechanism of negative muons. 相似文献
7.
S. Tresch P. Ackerbauer M. Augsburger W.H. Breunlich M. Cargnelli D. Chatellard J.-P. Egger T. von Egidy B. Gartner F.J. Hartmann R. Jacot-Guillarmod E. Jeannet R. King B. Lauss J. Marton M. Mühlbauer F. Mulhauser C. Petitjean C. Piller W. Prymas L.A. Schaller L. Schellenberg H. Schneuwly W. Schott Y.-A. Thalmann A. Werthmüller J. Zmeskal 《Hyperfine Interactions》1999,119(1-4):109-114
The transfer reaction of negative muons from muonic protium to 3 and 4 in binary and triple gas mixtures was studied. In the binary mixtures the transfer rates to the two helium isotopes were
determined from the time distribution of the 7-keV X-rays of the intermediate muonic molecule (pμHe)*. The experimental transfer rate to 4 is in good agreement with theoretical predictions, whereas the rate to 3 is a factor 2 to 3 smaller than the predicted ones. Radiative branching ratios of the (pμHe)8 molecular decay were obtained. Muon transfer from excited states of muonic protium gives the main contribution to the
total intensity of the μHe Lyman series in the binary mixtures. Values of q
1s
He
are determined.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
T. Dubler L. Schellenberg H. Schneuwly R. Engfer J.L. Vuilleumier H.K. Walter A. Zehnder B. Fricke 《Nuclear Physics A》1974,219(1):29-38
Energies of muonic X-rays of the K-series of carbon, nitrogen and oxygen have been measured with an accuracy of about 15 eV. Root mean square radii of the nuclear charge distributions were deduced. The results 2.49±0.05 fm for carbon, 2.55±0.03 fm for nitrogen and 2.71 ±0.02 fm for oxygen are in good agreement at comparable accuracy with recent electron scattering data. 相似文献
9.
An approach to reproduce the experimental Coulomb capture ratios of negative mesons in chemical compounds is proposed. An essential feature of this approach is the assumption that the decisive role in the capture process is played by not too strongly bound electrons. 相似文献
10.
J. L. Vuilleumier W. Dey R. Engfer H. Schneuwly H. K. Walter A. Zehnder 《Zeitschrift für Physik A Hadrons and Nuclei》1976,278(2):109-116
Energies of higherΜ X-rays have been measured in103Rh,natHg and203Tl to test the vacuum polarization correction and the electron screening effect in heavy muonic atoms. For tests of the energy calibration delayed nuclearγ-rays from theΜ-capture reaction were used. The experimental data agree to better than 4% with self-consistent Hartree-Fock calculations of the electron screening. Transitions which are sensitive to the vacuum polarization correction mainly, verify the calculations to better than 1.5%. Comparing all at present existing experiments with latest calculations no significant deviation of more than 0.7% of the vacuum polarization correction can be deduced. 相似文献