排序方式: 共有26条查询结果,搜索用时 109 毫秒
1.
B. Balestri P. Y. Bertin B. Coupat G. Fournier A. Gérard E. W. A. Lingemann J. Miller J. Picard B. Saghai K. K. Seth P. Vernin 《Czechoslovak Journal of Physics》1982,32(3):255-257
Elastic scattering differential cross section data of
±
d at 65 MeV and
±
4He at 51 MeV are presented and compared respectively to fully relativistic 3-body and optical potential calculations including true pion absorption.Presented at the symposium Mesons and Light Nuclei, Liblice, Czechoslovakia, June 1981. 相似文献
2.
B. Saghai J. -C. David B. Juliá-Dıaz T. -S. H. Lee 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):512-514
Differential cross-section and single polarization observables in the process γp→K
+
Λ are investigated within a constituent-quark model and a dynamical coupled-channel formalism. The effects of two new nucleon
resonances and of the K
*(892)- and K1(1270)-exchanges are briefly presented. 相似文献
3.
In this report we investigate η-meson productions on the proton via electromagnetic and hadron probes in a chiral quark model approach. The observables, such as, differential cross section and beam asym-metry for the two productions are calculated and compared with the experiment. The five known resonances S_(11)(1535), S_(11)(1650), P_(13)(1720), D_(13)(1520), and F_(15)(1680) are found to be dominant in the reaction mech-anisms in both channels. Significant contribution from a new S_(11) resonances are deduced. For the so-called "missing resonances", no evidence is found within the investigated reactions. The partial wave amplitudes for π~-p→ηn are also presented. 相似文献
4.
5.
Barreau P. Bernheim E. Bradu P. Fournier G. Gerard A. Magnon A. Marchand C. Meziani Z. E. Miller J. Morgenstern J. Mougey J. Picard J. Reffay D. Saghai B. Turck-Chieze S. Vernin P. Bussiere de Nergy A. Brussel M. K. Dunn P. Capitani G. P. de Sanctis E. Frullani S. Garibaldi F. 《Czechoslovak Journal of Physics》1986,36(2):296-299
Czechoslovak Journal of Physics - 相似文献
6.
A five-level atomic system in M-type configuration has been proposed in this article as a long-wavelength infrared photodetector cell. Coherent population trapping and electromagnetically induced transparency (EIT) is appeared in this kind of atomic structure. In order to overcome the dark current noise problem in the long-wavelength infrared photodetectors, we utilize quantum interference phenomena between the electromagnetic fields and interpret the incoming long-wavelength to short-wavelength detection range, where the dark current noise is not critical. The proposed M-type-arranged atomic system, have high performance in lower intensities of long-wavelength IR which is more interesting from high-sensitive photodetector point of view. 相似文献
7.
The reactions π~-p→ηn and γp→ηp are investigated within a dynamical coupled-channels model of meson production reactions in the nucleon resonance region. The meson-baryon channels included are πN, ηN, π△, σN, and ρN. The direct η-photoproduction process is studied within a formalism based on a chiral constituent quark model approach, complemented with a one-gluon-exchange mechanism, to take into account the breakdown of the SU(6) O(3) symmetry. In the models search, the following known nucleon resonances are embodied: S_(11)(1535), S_(11)(1650), P_(11)(1440), P_(11)(1710), P_(13)(1720), D_(13)(1520), D_(13)(1700), D_(15)(1675), and F_(15)(1680). Data for the π~-p→ηn reaction from threshold up to a total center-of-mass energy of W ≈ 2 GeV are satisfactorily reproduced. For the photoproduction channel, two additional higher mass known resonances, P_(13)(1900) and F_(15)(2000), are also considered. However, reproducing the data for γp→ηp requires, within our approach, two new nucleon resonances, for which we extract mass and width. 相似文献
8.
A. Rostami H. Baghban Asghari Nejad H. Rasooli Saghai M. Noori 《Superlattices and Microstructures》2009
In this paper we have proposed a novel quantum cascade laser active region design to obtain a dual-mid-IR-wavelength laser which is capable of frequency-doubling (13.77–6.88 μm) without utilizing nonlinear processes in two coupled shallow and deep quantum well structures. Optimized design of the active region leads to higher dipole matrix elements and thus higher laser performances. This method can be used to design laser structures with different frequency ratios. 相似文献
9.
Mixing angles are used to describe the SU(6) ? O(3) symmetry breaking in [70, 1?] multiplet in the sector of the lowest mass nucleon resonances, which are investigated extensively in constituent quark models for baryon spectroscopy. The transition amplitudes for the meson photoproduction off nucleon can also be expressed in terms of the mixing angles to take into account the configuration mixing. Those amplitudes are derived as a function of the mixing angles between ${|N^2P_M{J}^-\rangle}$ and ${|N^4P_M{J}^-\rangle}$ states, with J = 1/2 and 3/2, for the processes γp → ηp, K + Λ, K + Σ °, K ° Σ +. The present status of our knowledge on the mixing angles between S 11(1535) and S 11(1650) (θ S ), as well as between D 13(1520) and D 13(1700) (θ D ) is reported. Since these resonances play very important role in the threshold region for both η and kaon production mechanisms, they are expected to provide crucial tests of different quark models for the baryon spectroscopy. 相似文献
10.