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1.
A k·p effective Hamiltonian is important for theoretical analysis in condensed matter physics. Based on the kdotp-symmetry package, we develop an upgraded package named as kdotp-generator. This generator takes in arbitrary magnetic symmetries with their representations and returns symmetry-allowed k·p Hamiltonians. Using this package, we calculate k·p Hamiltonians for irreducible co-representations in 1651 magnetic space groups up to the third order, and their linear coupling to external fields including the electromagnetic field and the strain tensor. We hope that the package will facilitate related research in the future.  相似文献   

2.
<正>(Updated September 2013.COMPAS group.IHEP,Protvino)Using new results from FNAL-COLLIDER-D0 experiment in pp elastic collisions at s~(1/2)=1.96 TeV[1],CERN-LHC-TOTEM experiment in p p elastic collisions at s~(1/2)=7,8 TeV[2-3]and PAO experiment in proton-air collisions at 57 TeV[4]the amplitudes of the elastic p p and p p collisions are investigated in a most broad region in s~(1/2)and t via three observables da/dt(s,t).σ~(tot)(s),and p(s).The summary of the database for dσ/dt(s,t)is presented in Figure 50.10.where projection of the dσ/dt(s~(1/2),t)to the(da/dt,—t)plane orthogonal to the s~(1/2)axis is displayed.  相似文献   

3.
4.
The cross-sections for the reactions of the strange production p + p ↦ p + Λ + K+ and p + p ↦ p + Σ0 + K+ near thresholds of the final states pΛK+ and pΣ0K+ are calculated in the effective Lagrangian approach. Our approach is based on the dominant contribution of the one-pion exchange and strong interaction of the colliding protons in the initial state. The theoretical values of the cross-sections agree reasonably well with the experimental data. The polarization properties of the Λ- and Σ0-hyperons are discussed.  相似文献   

5.
Nuclear emulsions were used to study the energy spectrum and forward-backward asymmetry of neutrons from the Co59(p,n) reaction forE p 6·5 MeV. It was found that the decay of the compound nucleus makes a maximum contribution of 50% to the reaction yield. Energies of some excited states of the Ni59 nucleus were also determined.
Co59(p,n) E p 6,5 MeV
- Co59(p,n) E p 6,5 MeV. , 50%. , Ni59.


The authors would like to thank all those who helped in this work, particularly all members of the cyclotron group of the Nuclear Research Institute of the Czechoslovak Academy of Sciences, who so willingly helped with the irradiation, and H. Koutová from the Faculty of Technical and Nuclear Physics, who carefully measured the emulsions. Our thanks are also due to R. Krejová from the Faculty of Technical and Nuclear Physics for developing the emulsions and J. Kopecký from the Nuclear Research Institute for providing the cobalt target.  相似文献   

6.
Polarization properties of strange baryons produced in pp reactions, p + p↦p + Λ0 + K+ and p + p↦p + Σ0 + K+, near thresholds of the final states pΛ0K+ and pΣ0K+ are analysed relative to polarizations of colliding protons. The cross-sections for pp reactions are calculated within the effective Lagrangian approach accounting for strong pp rescattering in the initial state of colliding protons with a dominant contribution of the one-pion exchange and strong final-state interaction of daughter hadrons (Eur. Phys. J. A 9, 425 (2000)). Received: 22 October 2001 / Accepted: 14 November 2001  相似文献   

7.
8.
We analyze the ellipticity of the standard k · p wurtzite model for the symmetrized and the Burt–Foreman operator ordering. We find that for certain situations the symmetrized Hamiltonian is unstable, leads to unplausible results and can cause spurious solutions. We show that the operator ordering in wurtzite must be completely asymmetric to be stable. The asymmetric operator ordering is elliptic and consequently no spurious solutions are obtained. Therefore we recommend the use of a complete asymmetric operator ordering for nitride device simulation.  相似文献   

9.
Gamma-ray energy correlations have been measured for several reactions leading to light-mass Hf isotopes with 160 ?A?166. The correlation spectra show ridge-valley structures up to high rotational frequencies from which a drop in J c (2) is deduced at high frequencies. This drop suggests that a large portion of the angular momentum is generated by aligning particles. It may also be explained by the theoretically predicted triaxial states with large deformation.  相似文献   

10.
Based on three methods of particle identification (PID) of BES,we study the identification of p and p in momentum range from 0.3 to 1.2 GeV using real particle samples of e,μ,π,K,p and p which were collected in 2-5GeV R scan,J/(ψ) and ψ′ data taking periods. The paper presents the optimized method of PID:p(p) is identified by dE/dx only if momentum below 0.6GeV,and by TOF or the combination of dE/dx and TOF for higher momentum.The PID efficiency of p, p and contamination from the other charged particles are also given.  相似文献   

11.
精确计算在π0重整化链图传播下p(p)→p(p)'微分截面   总被引:1,自引:0,他引:1  
本文采用中性介子π0与核子N-反核子(N)强相互作用的Lorentz不变耦合模型,对质子p-反质子(p)在中性介子π0重整化链图传播下的散射微分截面,作了严格解析计算后获得了"精确"理论结果;进而,又对该计算结果与π0树图传播下的微分截面作了对比分析,获得了相关辐射修正的重要结果.这对于深入研究质子p-摊贩质子(p)在高、中、低能区中的弹性碰撞及其描述强相互作用的Lorentz不变耦合模型理论,都将提供某些值得借鉴与参考的理论研究价值.  相似文献   

12.
The interactions¯pp¯n p are compared with predictions of several models for diffraction dissociation and the validity of these models is tested.  相似文献   

13.
用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高离化态类钴Pd19+离子3p63d9-3p53d10,3p63d9-3p83d84p跃迁和振子强度,并与实验符合得较好。  相似文献   

14.
用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高离化态类钴Ag20 离子3p63d9-3p53d10,3p63d9-3p63d84p跃迁和振子强度,并与实验符合得较好.  相似文献   

15.
We study Drell-Yan process in proton–proton collisions through the exchange of vector mesons using the holographic hard wall model to describe the dynamics and interactions of vector mesons and baryons. We estimate the angular parameters λ,?μ, ν of the produced dileptons in a region of ${q_{T}^2 << Q^{2}}$ , where the effective coupling of perturbative QCD is large due to logarithm corrections.  相似文献   

16.
I. Horn  A. V. Anisovich  G. Anton  R. Bantes  O. Bartholomy  R. Beck  Y. Beloglazov  R. Bogendörfer  R. Castelijns  V. Credé  A. Ehmanns  J. Ernst  I. Fabry  H. Flemming  A. Fösel  M. Fuchs  Ch. Funke  R. Gothe  A. Gridnev  E. Gutz  S. Höffgen  J. Hößl  J. Junkersfeld  H. Kalinowsky  F. Klein  E. Klempt  H. Koch  M. Konrad  B. Kopf  B. Krusche  J. Langheinrich  H. Löhner  I. Lopatin  J. Lotz  H. Matthäy  D. Menze  J. Messchendorp  V. Metag  V. A. Nikonov  D. Novinski  M. Ostrick  H. van Pee  A. V. Sarantsev  C. Schmidt  H. Schmieden  B. Schoch  G. Suft  V. Sumachev  T. Szczepanek  U. Thoma  D. Walther  Ch. Weinheimer 《The European Physical Journal A - Hadrons and Nuclei》2008,38(2):173-186
The reaction γppπ0η has been studied with the CBELSA detector at the tagged photon beam of the Bonn electron stretcher facility. The reaction shows contributions from Δ+(1232)η , N(1535)+π0 and pa 0(980) as intermediate states. A partial-wave analysis suggests that the reaction proceeds via formation of six Δ -resonances, Δ(1600)P 33 , Δ(1920)P 33 , Δ(1700)D 33 , Δ(1940)D 33 , Δ(1905)F 35 , Δ(2360)D 33 , and two nucleon resonances N(1880)P 11 and N(2200)P 13 , for which pole positions and decay branching ratios are given.  相似文献   

17.
彭宏安  泰克诚  何祯民 《中国物理 C》1994,18(12):1078-1085
讨论从ISR到SSC能区p+p(p)→p+J/ψ(Υ)+X过程.假定Pomeron(p)的结构以胶子为主且在小x处有的行为后,在QCD最低阶计算了两个主要子过程的硬衍射截面和作为背景项的Drell-Yan模式的相应截面.与背景项在高能时随Ins增加不同,硬衍射项基本上随(InS)2增加,因而在TeV能区以上时后者将大大超过前者.这种性质对其它硬衍射过程具有普适性.因此如果关于P的上述假定正确,在准确地测定P的结构后,选择适当的硬衍射过程,可能在超高能时提供探测物理粒子的新实验方法.  相似文献   

18.
Significant enhancements of J/ψ production at very low transverse momenta were recently observed by the ALICE and STAR collaborations in peripheral hadronic A+A collisions. The anomalous excess points to coherent photon-nucleus interactions in violent hadronic heavy-ion collisions, which were conventionally studied only in ultra-peripheral collisions. Assuming that the coherent photoproduction is the underlying mechanism responsible for the excess observed in peripheral A+A collisions, its contribution in p+p collisions with nuclear overlap, i.e. nonsingle-diffractive collisions, is of particular interest. In this paper, we perform a calculation of exclusive J/ψ photoproduction in non-single-diffractive p+p collisions at the RHIC and LHC energies based on the pQCD motivated parametrization using the world-wide experimental data, which could be further employed to improve the precision of the phenomenological calculations for photoproduction in A+A collisions. The differential rapidity and transverse momentum distributions of J/ψ from photoproduction are presented. In comparison with the J/ψ production from hadronic interactions, we find that the contribution of photoproduction is negligible.  相似文献   

19.
We describe the production of (AA) in p(p) collisions using a constituent quark model which has been successfully applied to the N(N)system.  相似文献   

20.
用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高离化态类钴3p63d9-3p53d10,3p63d9-3p63d84p跃迁和振子强度,并与实验符合得较好.  相似文献   

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