Estimation of the Sea Level Muon Spectra at Different Zenith Angles below 10 TeV Energy

The moderate energy primary cosmic ray nucleon spectrum has been calculated from the direct measurements of Webber et al., Seo et al., and Menn et al. along with the other results surveyed by Swordy. Using these directly measured primary mass composition results all particle primary nucleon energy spectrum has been constructed using superposition model to estimate the energy spectra of muons from the decay of the cosmic ray non-prompt and prompt mesons in the atmosphere. The Z-factors have been estimated from the CERN LEBC-EHS on the Lorentz invariant cross section results on pp ^±X and pp K^±X inclusive reactions and FNAL data on ^±p ^±X reactions, and duly corrected for A--A collisions. Using these Z-factors the meson energy spectra in the atmosphere have been calculated. The sea level muon energy spectra at zenith angles 0°, 45°, 72°, and 75° have been derived from the decay of non-prompt mesons by adopting standard diffusion equation of hadronic cascades. The contribution of charmed mesons to muon spectrum has also been accounted by adapting the conventional procedure. The derived differential sea level muon energy spectra for energies 10 TeV have been found to follow the power law fits of the form N (E) const. E ^-. Our estimated muon energy spectra at zenith angles 75° have been found comparable with the global spectrograph muon flux results of MARS, DEIS, and MSU groups.     

Muon Spectra at Different Altitudes Derived from Bose-Type Model

The spectra of cosmic pions and kaons produced at the top of the atmosphere have been derived from the primary cosmic ray spectrum of GRIGOROV et al. by using the Bose-type model. With the help of pion and kaon atmospheric diffusion equations the muon spectra at different atmospheric depths viz., 690, 535 and 1033 g cm^?2 have been estimated. The results are in accord with the magnetic spectrograph data of KOCHARIAN et al. and ALLKOFER et al.     

Effective Muon Losses in the Muon Catalyzed Fusion Cycle in a Double D/T Mixture at High Temperature and Density

The effective muon losses w measured in the last experiment of the JINR group with D/T mixture are analyzed. They are considered as a function of the tritium concentration C _t taken for different temperatures. The obtained results indicate different muon transfer rates from deuterium and tritium to impurities with Z>1 (λ _dZ and λ _tZ ) and show that the ratio λ _tZ /λ _dZ increases with temperature. This revised version was published online in August 2006 with corrections to the Cover Date.     

Time-Dependent Local Density Approximation Calculations for Absorption Spectra of Small Carbon Clusters

Absorption spectra for Cn clusters (n = 2-8) are calculated using an adiabatic time-dependent density functional formalism within the local density approximation (TDLDA). We compare the calculated spectra with those computed using a simple local density approximation approach. It is readily observed that the TDLDA spectra display a significant blue shift with respect to the Kohn-Sham eigenvalue spectra. The calculated spectra exhibit a variety of features that can be used for comparison against future experimental investigations. We also obtain a significant threshold absorption, which can distinguish different ground states of the carbon clusters.     

宇宙线大气簇射μ子定点密度及原初能谱“膝”的研究

用梁王山宇宙线观测站的数据研究宇宙线大气簇射μ子定点密度谱,谱呈现明显的拐折.通过MonteCarlo模拟,得到拐点对应的能量约为1.7×10¹⁵eV,拐点前后原初能谱指数差约为0.43,证实了KASCADE实验μ子定点密度谱呈现拐折的首次观测结果,又一次推证了原初宇宙线能谱膝的存在.     

Muon physics with the proposed pulsed lepton source at LAMPF

The proposed pulsed lepton source (PLS) at LAMPF is described, with special attention to the muon area. Important applications to tests of QED and muon capture physics, as well as to materials science, are discussed.     

Doppler Spectra of Centimeter and Millimeter Microwaves Backscattered from a Rough Water Surface at low Grazing Angles

We present the results of processing of X- and Ka-band radar signals backscattered from a rough water surface at low grazing angles. Processing is made by the method of decomposing a Doppler spectrum into three basic line profiles. Each of these profiles corresponds to a certain scattering mechanism. Comparative evaluations of the contribution of the Bragg mechanism described by the Gaussian line profile and two non-Bragg mechanisms described by the Lorentz and Voigt profiles are obtained.     

Squark Pair Production at Muon Colliders in the MSSM with CP Violation

We study the pair production of scalar quark in a muon collider within the MSSM with CP violation. We show that including the CP phases can strongly affect the cross section of the process: \(\mu^{+}\mu^{-}\rightarrow \tilde{q}_{i}\bar{\tilde{q}}_{j}\). This could have an important impact on the search for squarks and the determination of the MSSM parameters at future colliders.     

Estimation of Sea Level Muon Energy Spectrum at High Latitude from the Latest Primary Nucleon Spectra Near the Top of the Atmosphere

The vertical muon energy spectra at sea level have been estimated from directly measured primary cosmic-ray nucleon spectrum. The hadronic energy moments have been calculated from the CERN LEBC EHS data on the Lorentz invariant cross-section results on pp ^±X and pp K^±X inclusive reactions and are duly corrected for A–A collisions. Finally, the sea level muon energy spectra have been calculated from the decay of conventional mesons, using standard formulation. The estimated muon spectra are found to be in good agreement with the directly measured muon spectra obtained from the different experiments.     

槲皮素与不同浓度氢氧化钠反应的紫外-可见时间分辨吸收光谱

采用带有快门的增强型光谱探测器ICCD,对槲皮素与不同浓度NaOH的反应过程进行了实时监测,测得了浓度为5×10-5 mol·L-1的槲皮素分别与浓度为2, 0.2, 0.1, 0.04和0.02 mol·L-1的NaOH反应的紫外-可见时间分辨吸收光谱。对每种浓度,一次连续拍摄200幅,每幅光谱曝光时间为0.1 ms, 每两幅间时间间隔为前5幅20 ms,中间50幅1 s, 最后100幅2 s。实验结果表明槲皮素极易与NaOH发生反应,反应过程中有中间产物生成,对应不同浓度的反应物,反应中吸收光谱的变化是相同的,只是变化发生的时刻不同,且整个反应时间从1～100 s不等。所拍光谱图清楚地显示出槲皮素的特征峰254和374 nm的消失,槲皮素-NaOH反应过程中中间产物的吸收峰427 nm的产生和消失,及反应最终产物的吸收峰314 nm产生的过程。所获得的瞬态光谱在国内外还未见有报道,这些光谱信息为研究槲皮素和NaOH反应的微观过程提供了实验依据。     

Near-Vertical Local Density Spectra of the EAS Charged Particles in the Energy Range of 10 14 –10 17 eV

The results of the long-term measurements of extensive air showers with the calibration telescope system of the Cherenkov water detector are presented for an energy range of 1014–1017 eV. We have used two independent methods for reconstruction of the charged particle local density spectrum: by the multiplicity of the hit counters and by their amplitude responses. By means of Geant4 calculations, we have shown how the structure of the building and the water tank affect the results of the spectrum reconstruction. We obtained two different exponents of charged particles’ local density spectra for CTS top and bottom plane. The results are compared with CORSIKA calculations and data from other setups.     

圆柱形散射子二维光子晶体的态密度与局域态密度

二维光子晶体只有赝带隙,因此能否利用二维光子晶体有效控制原子自发辐射是令人感兴趣也是有实际意义的问题。其中最重要的因素是态密度和局域态密度的性质。采用平面波展开结合晶体群论的方法计算了二维正方格子光子晶体的态密度和局域态密度。其中散射子为空气圆柱,放置在均匀的电介质背景上。结果显示两个特点:第一,总态密度和局域态密度在原来二维光子晶体赝带隙处虽然已经不为零,但是取值明显低于赝带隙范围之外的值,即存在一个准光子带隙。第二,局域态密度在空气散射子界面处发生突变,空气散射子区域的局域态密度相对较大,这可由电位移矢量的连续性来理解。由于这两个特点在其他二维光子晶体中也被发现过,它们可能是普遍存在的。     

Forward Proton Scattering in Association with Muon Pair Production via the Photon Fusion Mechanism at the LHC

JETP Letters - Dilepton production in proton–proton collision through γγ-fusion with one proton scattered elastically while the second produces a hadron jet is considered....     

Density functional formalism at finite temperatures with some applications

A density functional theory of inhomogeneous electron systems at finite temperatures is developed. Some applications are discussed. In particular, an atom in a hot, dense plasma is studied as a prototype problem of considerable current interest.     

Heavy-Ion Physics with the Compact Muon Solenoid (CMS) Detector at the Large Hadron Collider (LHC)

Physics of Atomic Nuclei - The present article gives a brief account of some interesting results obtained most recently in studying heavy-ion physics—in particular, quark–gluon...     

经不同pH值不同时间酸处理的DNA溶液拉曼光谱分析

小牛胸腺DNA被配制成pH 3.0,pH 2.0,pH 1.0的酸性溶液,在其进行水合的过程中分别测试了样品经过1,2,12和24 h后的拉曼谱图。实验结果表明,DNA分子内部发生了明显的质子化作用,其拉曼特征频率和强度均发生了不同程度的变化,而且随着不同的pH值和不同时间的酸处理它们的变化程度也不同。在pH 3.0的DNA溶液中仅在1 h处理后的拉曼谱图出现了微弱的A构型DNA的特征峰,溶液中主要以存在B构型为主,并有C构型特征峰的出现且随着水合时间的延长,该峰强增加。在pH 2.0的DNA溶液中仅见B构型和C构型特征峰,随着时间的增加,B型特征峰峰强逐渐减弱且伴随着C型特征峰峰强的增加。在pH 1.0的DNA溶液中B,C构型特征峰基本消失,出现了强度很大的891 cm-1峰以及1 265和1 418 cm-1峰,它们是Z构型的特征峰,891和1 265 cm-1峰随时间的延长峰强增加而1 418 cm-1随时间延长峰强减弱。从pH 3.0开始,随着酸性的增强和时间的延长,DNA溶液质子化程度逐渐加深,直到pH 1.0时其双螺旋结构遭到严重的修饰和发生变化。     

Vibrational Spectra of Cd(NH3)2Br2 with 2H Isotopic Substitution and Local Symmetry Force Field

The infrared and Raman spectra of the cadmiumdiammindibromide with ²H - isotopic substitution, have been measured. In order to examine the transferabilities of the skeletal and -NH₃, ligand force constants, a normal coordinate analysis was carried out based on a Local Symmetry Force Field (LSFF). The results support the experimental assignments.     

Density measurement through elastic electron scattering with a gaseous target at the Jefferson Lab

We report the density measurement through e-³He elastic scattering with a 1.23 GeV electron beam in Jefferson Lab experiment E06-010. The extracted ³He density is (9.26±0.06) amagats and the N₂/³He ratio is (1.49±0.08)%. In addition, these results are consistent with the deduced target densities based on pressure broadening measurement.