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1.
Based on the charge conjugation invariance and the vazuum property of the Pomeron, we point out that the commonly used vector vertex of the Pomeron coupling to quarkis incorrect since it contradicts with the Pomeron property. We also claim that the soft Pomeron could be a tensor glueball ξ(2230) with quantum numbers I^GJ^PC = 0^+2^++ and total decay width Гtot ≌ 100 MeV, which lies on the soft Pomeron trajectory αp = 1.08+ 0.20t. Therefore, the coupling vertex of the soft Pomeron to quark should be tensorial which is invariant under the charge conjugation and can explaIn why the inadequate vector coupling, γ^μ, of the soft Pomeron to quark is successful in dealing with Pomeron physics.  相似文献   

2.
The Pomeron-nucleon coupling vertex is theoretically derived from the fundamental theory of strong interaction QCD. The empirical vertex βγ^μF1 (t) used commonly in diffractive processes with a coupling strength β = 6.0 GeV^-1 is initially obtained from QCD theoretically. Our study not only reproduces the Pomeron-nucleon coupling from QCD but also clearly shows the gluonlc origin and glueball nature of Pomeron, which is a longstanding puzzle. From this investigation, we claim that Pomeron can be regarded as a Reggeized tensor glueball ζ(2230) with quantum numbers of I^GJ^PC = 0+2++. Since the tensor glueball ζ(2230) lies on the Pomeron trajectory αp(t = Mζ^2) = 2, the longstanding puzzle that no physical particle lies on the Pomeron trajectory, αp(t) = 1.08 + 0.20 GeV^-2 .t, seems to be solved.  相似文献   

3.
Using the Regge pole phase rule for contrilbutions to both amplitudes the DAM is applied to πp elastic scattering in the plab≥10 GeV/c and |t|≤0.8(GeV/c)2 region. It is found that the DAM has a mixed success in describing πp scattering. The p contribution to both amplitudes is in accord with the DAM while the f-non-flip contribution does not have a peripheral zero.The Pomeron imaginary part is in accord with the DAM with a non-negligible Pomeron phase so that the DAM approximation Rep=O is unsatisfactory. There is also a Pomeron-flip contribution contrary to the expectation of the model. The O-flip contribution is taken into account and a small f-flip contribution i s also required.  相似文献   

4.
High spin states of the yrast band in 50Ti, 52Cr, 54 and 46Ti are investigated in a microscopic approach allowing a coupling of rotations, vibrations and quasiparticle excitations. The lowering of the 6+ state in N = 28 nuclei is shown to originate mainly from proton K = 0 two-quasiparticle excitations. Using as a basis the entire pf-shell 8+ and 10+ states can be predicted for 50Ti and 54Fe.  相似文献   

5.
N. Kaiser 《Nuclear Physics A》1990,510(4):759-773
We make use of the topological chiral soliton model of the nucleon to predict the form factors related to the parity-violating meson-nucleon vertices. We find that these are of monopole type at low q2 with cut-offs similar to the equivalent strong meson-nucleon form factors. We furthermore investigate the parity-violating πΔN vertex. We find that while the isoscalar coupling vanishes identically, the isovector parity-violating πΔN vertex has a coupling stant of about 2 × 10−8 being of comparable magnitude as the equivalent weak pion-nucleon vertex strength. We also discuss the parity-violating ωΔN and ρΔN vertices in the model and furthermore comment on the pv meson ΔΔ vertices. In the appendix we will correct the formula for hω0 of ref. 5), where some terms have been omitted.  相似文献   

6.
邢伟  刘慧  施德恒  孙金锋  朱遵略 《物理学报》2016,65(3):33102-033102
采用考虑Davidson修正的内收缩多参考组态相互作用(icMRCI+Q)方法结合相关一致基组aug-ccpV5Z和aug-cc-pV6Z计算了CF~+离子第一离解极限C~+(~2p_u)+F(~2P_u)对应的12个∧-S态(X~l∑~+,a~3∏,1~3∑~+,1~3Δ,1~1∑~-,1~1∑~-,1~3∑~-,2~1∑~+,1~1∏,2~3∏,2~1∏和2~3∑~+)所产生的23个Ω态的势能曲线.计算中考虑了旋轨耦合效应、核价相关和标量相对论修正以及将参考能和相关能分别外推至完全基组极限.基于得到的势能曲线,获得了束缚和准束缚的9个∧-S态和16个Ω态的光谱常数,并且X~1∑~+,a~3∏~(势阱一)∧-S态的光谱常数与已有的实验结果非常符合.此外,计算了CF自由基X~2∏态到CF~+离子束缚和准束缚的9个∧-S态的垂直电离势和绝热电离势,并且CF~+(X~1∑~+)←CF(X~2∏)和CF~+(a~3∏(势阱一))←CF(X~2∏)的垂直电离势和绝热电离势与相应的实验结果也非常符合.由a~3∏,1~1∏态和其他激发∧-S态势能曲线的交叉现象,借助于计算的旋轨耦合矩阵元,分析了a~3∏~(势阱一),1~1∏~(势阱一)和2~1∑~+态的预解离机理.计算的23个Ω态离解极限处的相对能量与实验结果十分吻合.最后计算了(2)0+~(势阱一)(v'=0-5),(1)1~(势阱一)(v'=0-5)和(2)1~(势阱一)(v'=0)到X0~+态跃迁的Franck-Condon因子和辐射寿命.  相似文献   

7.
Fn the present paper, the linear Eliashberg equation is converted into a new integral equation and from it, the following TC formula is derived analytically in the weak coupling limit:Tc=28/πωlog·(πlog/πc*** exp{-1+λ/λ-μ*}, where In γ=C=0.5772 is the Eater constant.  相似文献   

8.
邢伟  孙金锋  施德恒  朱遵略 《物理学报》2018,67(6):63301-063301
采用考虑Davidson修正的内收缩多参考组态相互作用(icMRCI+Q)方法,结合相关一致基组aug-ccpV5Z和aug-cc-pV6Z,计算了BF+离子前两个离解极限B~+(~1S_g)+(~2P_u)和B+(~3P_u)+F(~2P_u)对应的14个Λ-S态(X~2Σ~+,1~2Π,2~2Π,2~2Σ~+,1~4Σ~+,1~4△,1~4Σ~-,1~2△,1~2Σ~-,3~2Σ~+,1~4Π,2~4Π,2~4Σ~+和3~2Π)和30个Ω态的势能曲线.在势能曲线的计算中,考虑了旋轨耦合效应、核价相关和标量相对论修正以及将参考能和相关能分别外推至完全基组极限.基于得到的势能曲线,获得了束缚和准束缚的12个A-S态和28个Ω态的光谱常数,并且X~2Σ~+态的光谱常数与已有的实验结果符合.此外,计算了BF分子X~1Σ~+态到BF+离子X~2Σ~+,1~2Π和2~2Σ~+态的垂直电离势和绝热电离势,并且BF~+(X~2Σ~+)←BF(X~1Σ~+)的垂直电离势和绝热电离势与相应的实验结果非常符合.由X~2Σ~+,2~2Π,1~4Σ~+,3~2Σ~+和3~2Π态和其他的激发A-S态势能曲线的交叉现象,借助于计算的旋轨耦合矩阵元,首次分析了X~2Σ~+和3~2Π态的预解离机理以及2~2Π(v′≥9),1~4Σ~+(v′≥4)和3~2Σ~+(v′≥4)的振动能级受到其他电子态的微扰.计算了30个Ω态离解极限处的相对能量,并且与实验结果十分符合.最后计算了2~2Π(v′=0—9)—X~2Σ~+,2~2Σ~+(v′=0—2)—X~2Σ~+,(3)1/2—(1)1/2~(势阱一)和(2)3/2(v′=0—9)—(1)1/2~(势阱一)跃迁的Franck-Condon因子、爱因斯坦自发辐射系数和辐射寿命.  相似文献   

9.
罗旺  李瑞  盖志强  艾瑞波  张宏民  张晓美  闫冰 《中国物理 B》2016,25(7):73101-073101
Lead oxide(Pb O), which plays the key roles in a range of research fields, has received a great deal of attention. Owing to the large density of electronic states and heavy atom Pb including in Pb O, the excited states of the molecule have not been well studied. In this work, high level multireference configuration interaction calculations on the low-lying states of Pb O have been carried out by utilizing the relativistic effective core potential. The effects of the core-valence correlation correction, the Davidson modification, and the spin–orbital coupling on the electronic structure of the Pb O molecule are estimated. The potential energy curves of 18 Λ-S states correlated to the lowest dissociation limit(Pb(~3P_g) + O(~3P_g)) are reported. The calculated spectroscopic parameters of the electronic states below 30000 cm~(-1), for instance, X~1Σ~+, 1~3Σ~+,and 1~3Σ~-, and their spin–orbit coupling interaction, are compared with the experimental results, and good agreements are derived. The dipole moments of the 18 Λ-S states are computed with the configuration interaction method, and the calculated dipole moments of X~1Σ~+and 1~3Σ~+are consistent with the previous experimental results. The transition dipole moments from 1~1Π, 2~1Π, and 2~Σ to X~1Σ~+and other singlet excited states are estimated. The radiative lifetime of several low-lying vibrational levels of 1~1Π, 2~1Π, and 2~1Σ~+ states are evaluated.  相似文献   

10.
11.
We calculate the masses of the 0++, 0-- and l+- glueballs from QCD in 3+1 dimensions using an eigenvalue equation method for Hamiltonian lattice QCD developed and described by S.H. GUO et al. The mass ratios become approximately constants in the coupling region 6/g2∈[6.0,6.4], from which we estimate M(0--)/M(0++) = 2.44 ± 0.05 ± 0.20 and M(l+-)/M(0++) = 1.91 ± 0.05 ± 0.12.  相似文献   

12.
《中国物理 B》2021,30(7):73702-073702
A two-ion pair in a linear Paul trap is extensively used in the research of the simplest quantum-logic system; however,there are few quantitative and comprehensive studies on the motional mode coupling of two-ion systems yet. This study proposes a method to investigate the motional mode coupling of sympathetically cooled two-ion crystals by quantifying three-dimensional(3 D) secular spectra of trapped ions using molecular dynamics simulations. The 3 D resonance peaks of the ~(40)Ca~+ – ~(27)Al~+ pair obtained by using this method were in good agreement with the 3 D in-and out-of-phase modes predicted by the mode coupling theory for two ions in equilibrium and the frequency matching errors were lower than 2%.The obtained and predicted amplitudes of these modes were also qualitatively similar. It was observed that the strength of the sympathetic interaction of the ~(40)Ca~+ – ~(27)Al~+ pair was primarily determined by its axial in-phase coupling. In addition,the frequencies and amplitudes of the ion pair's resonance modes(in all dimensions) were sensitive to the relative masses of the ion pair, and a decrease in the mass mismatch enhanced the sympathetic cooling rates. The sympathetic interactions of the ~(40)Ca~+ – ~(27)Al~+ pair were slightly weaker than those of the ~(24)Mg~+– ~(27)Al~+ pair, but significantly stronger than those of ~9Be~+ – ~(27)Al~+ . However, the Doppler cooling limit temperature of ~(40)Ca~+ is comparable to that of ~9Be~+ but lower than approximately half of that of ~(24)Mg~+. Furthermore, laser cooling systems for ~(40)Ca~+ are more reliable than those for ~(24)Mg~+and ~9Be~+ . Therefore, ~(40)Ca~+ is probably the best laser-cooled ion for sympathetic cooling and quantum-logic operations of ~(27)Al~+ and has particularly more notable comprehensive advantages in the development of high reliability, compact, and transportable ~(27)Al~+ optical clocks. This methodology may be extended to multi-ion systems, and it will greatly aid efforts to control the dynamic behaviors of sympathetic cooling as well as the development of low-heating-rate quantum logic clocks.  相似文献   

13.
The (Na+) Sternheimer antishielding factor γ (Na+) was determined by 23Na NMR spectroscopy on sodium oxide chloride, Na3OCl. The quadrupolar coupling constant of the sodium ion in Na3OCl was determined to QCC=11.34 MHz, which presents the largest coupling constant of a sodium nucleus observed so far. Applying a simple point charge model, the largest principal value of the electric field gradient at the sodium site was calculated to Vzz=−6.76762·1020 V/m2. From these values we calculated the (Na+) Sternheimer antishielding factor to γ (Na+)=−5.36. In sodium oxide, Na2O, we observed an isotropic chemical shift of δCS=55.1 ppm, referenced to 1 M aqueous NaCl (δ=0 ppm).  相似文献   

14.
15.
Based on analysis of scattering matrix S, and its properties such as analyticity, unitarity, Lorentz invariance, and crossing symmetry relation, the Regge theory was proposed to describe hadron-hadron scattering at high energies before the advent of QCD, and correspondingly a Reggeon concept was born as a mediator of strongly interaction. This theory serves as a successful approach and has explained a great number of experimental data successfully, which proves that the Regge theory can be regarded as a basic theory of hadron interaction at high energies and its validity in many applications. However, as new experimental data come out, we have some difficulties in explaining the data. The new experimental total cross section violates the predictions of Regge theory, which shows that Regge formalism is limited in its applications to high energy data. To understand new experimental measurements, a new exchange theory was consequently born and its mediator is called Pomeron, which has vacuum quantum numbers. The new theory named as Pomeron exchange theory which reproduces the new experimental data of diffractive processes successfully. There are two exchange mediators: Reggeon and Pomeron. Reggeon exchange theory can only produce data at the relatively lower energy region, while Pomeron exchange theory fits the data only at higher-energy region, separately. In order to explain the data in the whole energy region, we propose a Reggeon-Pomeron model to describe high-energy hadron- hadron scattering and other diffractive processes. Although the Reggeon-Pomeron model is successful in describing high-energy hadron-hadron interaction in the whole energy region, it is a phenomenological model. After the advent of QCD, people try to reveal the mystery of the phenomenological theory from QCD since hadron-hadron processes is a strong interaction, which is believed to be described by QCD. According to this point of view, we study the QCD nature of Reggeon and Pomeron. We claim that the Reggeon exchange is an exchange of mult  相似文献   

16.
The average polarization of 12B produced by the capture of polarized muons in 12C has been measured using recoil implantation techniques. From the result we deduce the average polarization of the 12B ground state 12B(0) corresponding to the 12C → 12B(0) Gamow-Teller reaction: Jμ(0) = 0.43 ± 0.10. The sizeable deviation of this polarization from the value of 2/3, characteristic of a “bare” 0+ → 1+ process, is a fair evidence for induced axial-vector interaction(s) in muon capture. The ratio of the induced pseudoscalar and the axial-vector coupling constants is deduced to be: gμP/gμA = 12 ± 5.  相似文献   

17.
Discussion Compton scattering on the new states we establish the following: The spin JP = 2+ state, an orbital excitation of ψ, must exist, and its coupling to the ψ(3084) is related to the coupling ψX(2800). A spin higher than 2 (probably 3) with negative charge conjugation must exist, and its couplings can be related to the ψ2+γ and ψ′2+γ couplings. This state might have a substantial radiative width to the 2+. These results depend on a saturation assumption of the sum rules, which has always worked well. Its failure will also be of interest.  相似文献   

18.
The infrared behavior of the running coupling constant in QCD has been studied using the Schwinger-Dyson equation of the gluon propagator based on the Slavnov-Taylor identities in axial gauge. It is shown that the infrared running coupling constant behavior g-2(Q2)=g22/Q2) in the infrared limit Q22→0.  相似文献   

19.
We have used the ab initio cluster model approach to study the dependence of the CO stretching frequency on CO surface coverage. We have also investigated the relative importance of the various factors that can affect the position of the CO stretching band as coverage increases. Two effects can change the CO stretching frequency: the adsorbate–adsorbate dipole coupling, which is a purely physical effect, and the changes in the 2π* CO molecular orbitals, due to the different chemical environment at higher coverages. From our vibrational analysis, we conclude that CO–CO dipole coupling is the main cause of the upward shift of the CO stretching band when the CO coverage is increased. The population of the 2π* CO molecular orbitals does not change at any coverage within the region considered. We have also estimated the 12CO–13CO dipole coupling, which previous studies have assumed to be weak. Our results demonstrate that the 12CO–13CO dipole coupling is indeed weak compared with the 12CO–12CO dipole coupling. At a CO surface coverage of 0.5 monolayers (ML), we have calculated a band shift of 40 cm−1 to higher frequency. However, we should point out that when one 12CO molecule is surrounded by a 13CO environment, the 12CO stretching band shifts 10 cm−1 upwards. We have also computed the heat of adsorption of CO on Pt{100}-(1×1) as a function of CO coverage. The initial heat of adsorption is calculated to be about 192 kJ mol−1 and then drops to 180 kJ mol−1 at 0.5 ML. These results agree quite well with recent calorimetric measurements. Besides that, we have estimated that the CO–CO interaction energy at 0.5 ML is repulsive and has a value of 5 kJ mol−1.  相似文献   

20.
邢伟  刘慧  施德恒  孙金锋  朱遵略  吕淑霞 《物理学报》2015,64(15):153101-153101
采用考虑Davidson修正的内收缩多参考组态相互作用(icMRCI+Q)方法结合相关一致基组aug-cc-pV5Z和aug-cc-pV6Z首次计算了一氟化碳(CF)11个Λ-S 态(X2Π , a4Σ-, A2Σ+, B2Δ, 14Π, 12Σ-, 24Π, 1{4}Δ , 14Σ+, 22Σ-和24Σ-) 所产生的25个Ω 态的势能曲线. 计算中考虑了旋轨耦合效应、核价相关和标量相对论修正以及将参考能和相关能分别外推至完全基组极限. 基于得到的势能曲线, 获得了束缚和准束缚的Λ-S态和Ω 态的光谱常数, 与已有的实验结果非常符合. 分析了束缚和准束缚的Λ-S态在各自平衡核间距Re处的主要电子组态. 由于14Π 和24Π态的避免交叉, 发现准束缚态24Π. 由Λ-S态势能曲线的交叉现象, 借助于计算的旋轨耦合矩阵元, 分析了a4Σ-和B2Δ 态的预解离机理. 计算了25个Ω 态的离解关系, 给出了它们的离解极限. 最后研究了A2Σ+-X2Π 跃迁特性, 本文计算得到的A2Σ+-X2Π跃迁的Frank-Condon 因子和辐射寿命与已有实验值也符合得非常好.  相似文献   

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