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991.
群论在H2分子受激喇曼散射中的应用 总被引:1,自引:1,他引:0
本文利用U(4)群代数描述双原子分子振转谱的对称性质,利用群论计算了H_2分子受激喇曼散射跃迁矩阵元,绘出了受喇曼散射的截面与增益系数,较好地与实验结果符合. 相似文献
992.
19F+93Nb耗散反应产物激发函数中截面测量的不重复性 总被引:1,自引:0,他引:1
完成了19F+93Nb重离子耗散碰撞激发函数的两次独立测量.束流的入射能量为100—108MeV,步长250keV.两次测量的宏观条件几乎完全一样,惟一的差别是使用了厚度分别为70和71μg/cm2的两块93Nb同位素靶.实验结果表明:(1)两次测量所得到的耗散反应产物激发函数的涨落具有不可平滑的结构;(2)这种不平滑的涨落截面有不重复的迹象.着重从实验的角度对这一结果进行了讨论. 相似文献
993.
Comparisons are made between calculations based on the double-helix and side-by-side models of DNA and data taken from the
available x-ray diffraction measurements of the B form of DNA. The SBS model invoked here is an improvement on the one which
was published earlier. In our estimation the fibre diffraction patterns do not significantly favour either model. However,
the DH model is incompatible with the on-axis form of the cylindrically-averaged Patterson function, whereas the SBS model
is compatible (this result is relatively insensitive to appreciable modifications to the SBS structure)—the crucial question
is whether the quality of the data is sufficient to make this finding significant. It is shown that the maximum expected effect
on the fibre pattern, of exchanging A-T base pairs for G-C base pairs, is less than the probable experimental error. 相似文献
994.
A comprehensive discussion of the unitarity bounds on inclusive angular distributions, given the elastic amplitudes and the
integrated inelastic cross section, is presented. The role played by the latter constraint in improving the bound is studied
in detail. Calculations are made forπ
±
p →p (inclusive) at 6 GeV/c. 相似文献
995.
996.
997.
Robert M. Guralnick Pham Huu Tiep 《Transactions of the American Mathematical Society》2004,356(12):4969-5023
We classify the small irreducible representations of with even in odd characteristic. This improves even the known results for complex representations. The smallest representation for this group is much larger than in the case when is odd. This makes the problem much more difficult.
998.
Probing the Lightest New Gauge Boson BH in the Littlest Higgs Model via Processes γγ→ ff^- Bg at ILC
WANG Xue-Lei LIU Su-Zhen ZENG Qing-Guo JIN Zhen-Lan 《理论物理通讯》2008,49(2):421-427
The neutral gauge boson BH with the mass of hundreds GeV is the lightest particle predicted by the littlest Higgs (LH) model, and such particle should be the first signal of the LH model at the planed ILC if it exists indeed. In this paper, we study some processes of the BH production associated with the fermion pair at the ILC, i.e., γγ→ ff^- BH. The studies show that the most promising processes to detect BH amongγγ→ ff^- BH are γγ→ l'^+l'^-BH (l' = e,μ), and they can produce the sufficient signals in most parameter space preferred by the electroweak precision data at the ILC. On the other hand, the signal produced via the certain BH decay modes is typical and such signal can be easily identified from the SM background. Therefore, BH, the lightest gauge boson in the LH model, would be detectable at the photon collider realized at the ILC. 相似文献
999.
Based on the theoretical models for light nuclei, the calculations of reaction cross sections and the angular
distributions for d+8Li reaction are performed. Since all of the
particle emissions are from the compound nucleus to the discrete levels, the angular momentum coupling effect in pre-equilibrium mechanism is taken into account. The three-body break-up process and the recoil effect are involved. The theoretical calculated results are compared to existing experimental data. 相似文献
1000.
We provide a microscopic calculation of neutron-proton and proton-proton cross sections in symmetric nuclear matter at
various densities, using the Brueckner-Hartree-Fock approximation scheme with the Argonne V14 potential including the contribution of microscopic three-body force. We investigate separately the effects of three-body force on the effective mass
and on the scattering amplitude. In the present calculation, the
rearrangement contribution of three-body force is considered,
which will reduce the neutron and proton effective mass, and
depress the amplitude of cross section. The effect of three body
force is shown to be repulsive, especially in high densities and
large momenta, which will suppress the cross section markedly. 相似文献