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941.
942.
P. Kammel V. A. Andreev D. V. Balin R. M. Carey T. Case D. B. Chitwood S. M. Clayton K. M. Crowe J. Deutsch P. T. Debevec P. U. Dick A. Dijksman J. Egger D. Fahrni A. A. Fetisov S. J. Freedman V. A. Ganzha B. Gartner J. Govaerts F. E. Gray F. J. Hartmann W. D. Herold D. W. Hertzog V. I. Jatsoura A. G. Krivshich B. Lauss E. M. Maev O. E. Maev V. E. Markushin C. J. G. Onderwater C. Petitjean G. E. Petrov C. C. Polly R. Prieels S. M. Sadetsky G. N. Schapkin R. Schmidt G. G. Semenchuk M. Soroka A. A. Vorobyov N. I. Voropaev 《Hyperfine Interactions》2001,138(1-4):435-443
The aim of the μCap experiment is a 1% measurement of the singlet capture rate Λ
S
for the basic electro-weak reaction μ + p → n + νμ. This observable is sensitive to the weak form-factors of the nucleon, in particular to the induced pseudoscalar coupling
constant g
P
. It will provide a rigorous test of theoretical predictions based on the Standard Model and effective theories of QCD. The
present method is based on high precision lifetime measurements of μ− in hydrogen gas and the comparison with the free μ+ lifetime. The μ− experiment will be performed in ultra-clean, deuterium-depleted H2 gas at 10 bar. Low density compared to liquid H2 is chosen to avoid uncertainties due to ppμ formation. A time projection chamber acts as a pure hydrogen active target. It defines the muon stop position in 3D and
detects rare background reactions. Decay electrons are tracked in cylindrical wire-chambers and a scintillator array covering
75% of 4π.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
943.
IntroductionMostnonlineardynamicsystemsaremulti_degree_of_freedomsystemsinthefieldofengineering[1,2 ],nonlineardynamicsystemsdonothaveexactlytheoreticsolutions.Therefore,itisafocalpointconcernedbyscientiststosearchforapproximatesolutionsforalongtime ,andr… 相似文献
944.
张荣业 《应用数学和力学(英文版)》2001,22(4):436-447
The Hamiltonian mechanics in Newtonian-Riemannian space-time and its application to hydromechanics are discussed.
Biography: Zhang Rong-ye (1938-), Professor 相似文献
945.
讨论了Newton-Riemann时空中的Lagrange力学及其与N-R时空中的Newton力学及Hamilton力学的关系。 相似文献
946.
The kaon meson electromagnetic form factor is calculated in the framework of coupled Schwinger-Dyson and Bethe-Salpeter formulation in simplified impulse approximation (dressed vertex) with modified flat-bottom potential, which is a combination of the flat-bottom potential taking into consideration the infrared and ultraviolet asymptotic behaviours of the effective quark-gluon coupling. All the numerical results give a good fit to experimental values. 相似文献
947.
Jianming Zhang Kohji Tashiro Abraham J. Domb Hideto Tsuji 《Macromolecular Symposia》2006,242(1):274-278
In the present research, we report for the first time the X-ray fiber pattern and polarized IR/Raman spectra taken for the uniaxially oriented disorder α form of PLLA, which can confirm the existence of the disorder PLLA α form (α′-form) and provide some new insight on the structural difference between the order and disorder α forms. 相似文献
948.
We re-study nucleon pole contribution in J/ψ → NN^-π decays by including the imaginary part for the propagator of the off-shell nucleon with energy above π N threshold. It is found that when including the imaginary part in the propagator, the branching ratio of the decay width will descend about 11% compared with the result without including the imaginary part, no matter whether including the off-shell form factors or not. It also leads to a phase of up to 25° for the off-shell nucleon propagator at invariant mass around 1400 MeV. This effect needs to be considered for detailed partial wave analysis of N^* resonances around this mass region. 相似文献
949.
Thomson scattering off a pair (electron--positron) plasma is
theoretically investigated in the collisionless and collisional
limits respectively. Our calculations show that the power spectrum of the
Thomson scattering off a collisionless pair plasma is just
proportional to the velocity distribution function of the
particles in the plasma. Collective modes in the plasma do not
have any effects on the Thomson scattering spectrum because of the
correlation between the negatively- and positively-charged particles.
In the collisional limit, the power spectrum of the Thomson
scattering presents three spikes: two peaks correspond to two
contra-propagating sound waves and one peak corresponds to an entropy
wave. 相似文献
950.
This paper focuses on studying non-Noether conserved quantities of Lie
symmetry and of form invariance for a mechanical system in phase space
under the general infinitesimal transformation of groups. We obtain a new
non-Noether conserved quantity of Lie symmetry of the system, and Hojman and
Mei's results are of special cases of our conclusion. We find a
condition under which the form invariance of the system will lead to a Lie
symmetry, and, further, obtain a new non-Noether conserved quantity of form
invariance of the system. An example is given finally to illustrate these
results. 相似文献