共查询到20条相似文献,搜索用时 46 毫秒
1.
The scale-breaking parameter F2ep(x, Q2) of non-singlet component F2ep-F2en and some other quantities in the electro-production process are discussed by usinb the analytic expression for the distribution function of valence quarks in ha.drons up to leading log approximation given by a, previous paper[1]. Comparisons with data are also given.
2.
YU SHOU-MIEN 《中国物理C(英文版)》1982,6(1):36-43
A relativistic equation of motion of a two particle system under the constraints pi2-mi2-U(x2)=0.(i=1,2), where U(x2) is an infinite spherical square well poten-tial, is applied to the SU(4) quark model of mesons. A set of linear mass relations areobtained. Instead of the linear relation between J and M2, the Regge trajectory ob-tained is a relation between pnl2 and M2, where ζnlπ are zeros of the spherical Besselfunctions. The new trajectory seems more satisfactory than the former one. 相似文献
3.
CALCULATION OF THE ELASTIC-SCATTERING CROSS-SECTION OF ENERGETIC ELECTRON BY 40Ca NUCLEUS IN CONSIDERATION OF THE INFLUENCE OF“PION CONDENSATION” 下载免费PDF全文
Zhao Shu-ping 《中国物理C(英文版)》1980,4(5):569-575
Using Migdal's theoretical results of "pion Condensation", the influence of "π condensation" on the distribution of charge of N=Z nucleus is determined. The elastic-scattering differential cross-section of energetic electron by 40Ca nucleus is also calculated. The results of our calculations agree better with the experimental data. 相似文献
4.
The properties of fermion causal Green's function is discussed according to the theory of spectral representation. The definition of effective mass is established from the view point of field theory, and the approximate expression of SF' (p) as |p2|«M2 and the asymptotic formula of SF' (p) as p2→+∞ is given. In terms of these result the problem of quark confinement is discussed. We find that: (ⅰ) Based on the theory of spectral re presentation the concept of relative confinement is allowed, and if renormalization effect is strong, the quarks can demonstrate definitely lighter effective mass when they are far away from the mass shell; (ⅱ) Based on the theory of spectral representation the concept of absolute confinement is unallowable, even the absolute confinement is taken as the limit of relative confinement. That is if the concept of absolute confinement is introduced, we must discard a part of elementary hypothesis of spectral representation theory. 相似文献
5.
The data on muon-pair production in pion interactions on a nuclear target are reanalysed in the light of what we know about nucleon structure functions in a nuclear environment. A consistent picture of the pion structure function is obtained, which is compatible with the evolution of a hard valence quark distribution atQ 2=2.5 GeV2. Vector dominance is used to estimate the hadronic component of the photon structure function atQ 2=2.5 GeV2 and it is found to saturate the data there. 相似文献
6.
We Construct a pion cloud MIT-bag model with chiral symmetry. The pion cloud outside the bag is a classical spherica field. The calculated hadron mass spectra are comparable with the experimental data. The decay width of Δ++(1236) calculated in this model is ΓΔ=115.8 MeV, which is very close to the experimental value. We also calculate the phase shift of P33 resonance. The resultin curve fits the experimental data exceedly well. 相似文献
7.
In this paper the DWBA cross section formula for the(π+,d)reaction is deri-ved in the model of one-nucleon absorption of pion,and the differential cross sectionsfor 12C(π+,d)10Cg.5.2+reactions are estimated in PWBA.This kind of reaction isregarded as a worthnoting one for the studies of π absorption processes and the nu-clear pair structure. 相似文献
8.
Using the renormalized quark mass m(g) obtained by fixing the ρ meson mass, we calculate the masses of the baryon states as a function of 1/g2 in lattice gauge theory with fermions by variational method. The results are in agreement with experimental values in the range of 1/g2 between 0.1 to 0.9. 相似文献
9.
Based on the two nucleon pion absorption mechanism, the reaction (π+d) is studied. The formula of the differential cross section for (π+d) reaction is obtained for S-wave πN interaction. A calculation is also performed for 12C(π+d)10C(0+,2+) at the incident energy of 49.3MeV by using the plane wave approximation. The results indicate that the effect of the D-wave component in the deutron wave function is quite important. The antisymmetric space structure of the neutron pair participated in the process is as the important as symmetric one. 相似文献
10.
We discuss the CP violation problem of SU(7) models of Grand Unified Theoryincluding four genarations[1,2]. It is shown that if we properly choose the complex phaseangles in quark mass matrix elements, we are able to obtain the CP violation phaseangle which agrees well with the experimental value. If the Higgs potential is pro-perly choosen we find that the strong CP violation parameter θ is equal to zero atthe tree level. 相似文献
11.
We study the decay widths of the narrow resonances Dsj*(2317) and Dsj(2460) in the chiral quark model, together with the well-known D* and Ds* mesons. All the parameters in our calculation are taken from Godfrey and Isgur's quark model except the π0-η mixing angle which is fixed by the Ds* decay widths. The calculated electromagnetic decay widths agree with those from other groups and the experimental data available quite well. However, the pionic decay widths of Dsj(2317) and Dsj(2460) are too small to fit the experimental data. We suspect that the simple chiral quark pion axial-vector interaction Hamiltonian is not suitable for hadron strong decays of Dsj(2317) and Dsj(2460). 相似文献
12.
TESTING GLUON DISTRIBUTION FUNCTION OF HADRONS IN LARGE PT PROCESS WITH DIRECT PHOTON EMISSION 下载免费PDF全文
In this paper we disscuse disscuse the physicsical aspect of cross-section differences ΔABcγ=dσ(AB→cγX)-dσ(AB→cγX) and give the simple rules to select the elementary subprocesses which contribute to cross-section differences.
We bind a way to test the gluon distribution functions of hadrons through the measurement of cross-section difference or combination of cross-section differences in the large PT process with direct photon emission. Moreover we obtain simple relations between each combination of cross-sections and the corresponding gluon distribution functions of proton, neutron, pion and daon:
Gp8(x)/(Δpphγ-Δpphγ)=Gn8(x)/(Δpphγ)=Gπ8(x)/(Δπ+phγ+Δπ-phγ=GK8(x)/(ΔK+phγ+ΔK-phγ)which are expected to be test in experiment. 相似文献
We bind a way to test the gluon distribution functions of hadrons through the measurement of cross-section difference or combination of cross-section differences in the large PT process with direct photon emission. Moreover we obtain simple relations between each combination of cross-sections and the corresponding gluon distribution functions of proton, neutron, pion and daon:
Gp8(x)/(Δpphγ-Δpphγ)=Gn8(x)/(Δpphγ)=Gπ8(x)/(Δπ+phγ+Δπ-phγ=GK8(x)/(ΔK+phγ+ΔK-phγ)which are expected to be test in experiment. 相似文献
13.
THE MEASUREMENT OF THE EXCITATION FUNCTIONS OF ISOTOPES OF Fr AND At,PRODUCED IN THE BOMBARDMENT OF 12C ON 209Bi 下载免费PDF全文
Excitation functions for Fr and At isotopes produced in 12C on 209Bi had been measured in the energy range 60—72 MeV. It was quite obvious that 213Fr and 214Fr were formed by the reactions 209Bi (12C,4n) 217Ac and 209Bi (12C,3n) 218Ac following the a decay of the Ac isotopes respectively, and 214mFr was produced probably by compound nucleus evaporation of neutrons and an α particle, i.e. (12C, α 3n). 211At was mainly contributed by a multi-nucleon transfer reaction (e.g. 8Be transfer). The experimental data for neutron evaporation reaction were fitted by the Jackson formula. 相似文献
14.
THE VERTICAL INTEGRATED MOMENTUM SPECTRUM OF THE MUON WITH MOMENTUM LARGER THAN 4 GeV/c AT 3220m ABOVE SEA-LEVEL 下载免费PDF全文
JING GUI-RU HUO AN-XIANG YAN YU-KUI WANG LI-AN LI YAN-GUO SU DENG-JI MENG XIANG-CHENG YAO WEI-ZHONG ZHOU YIN-ZAO PENG SHAO-HUA WANG LI-HUI 《中国物理C(英文版)》1978,2(5):417-422
At an altitude of 3220 meters above sea level in Yunnan Province, we measured, by using a G-M counter-magnetic spectrometer, the vertical integratted momentum spectrum of the cosmic muon with momentum larger than 4 GeV/c. The spectrum obtained from this experiment is expressed by a power function in the form of I(>p)=Q (p+4)-1.86±0.06(cm-2·sr-1·s-1), where p is in GeV/c and Q is a constant. We also measured the charge ratio of muon in the 4—23 GeV/c momentum range. The result is Nμ/Nμ-=1.26±0.11. The error in the momentum measurement with spectrometer has been discussed and calculated. 相似文献
15.
D. McCal J. LeBritton W. Metcalf A.C. Melissinos J. Alspector S. Borenstein G. Kalbfleisch R.C. Strand A. Abashian 《Physics letters. [Part B]》1979,85(4):432-436
It was shown in the preceeding letter that dimuon production by 22 GeV pions proceeds in part through qq? annihilations in agreement with the Drell-Yan model. Using these data we extract the quark distribution function of the pion. Comparison of our structure function with that obtained from data at higher energy reveals differences compatible with the QCD calculations of the Q2-dependence (scale breaking) of the pion structure function. 相似文献
16.
Considering that the original Q2-rescaling model has some shortcomings in explaining the experimental data,we propose animproved Q2-rescaling model in which,in order to compensate for the loss of nuclear momentum,we employ different Q2-rescaling parameters for momentum distributions of valence quark,sea quark and glouns.By using improved Q2-rescaling model,We can well explain the experimental data of the EMC effect in the whole x region,the nuclear Drell-Yan Process and J/ψ photoproduction process. 相似文献
17.
A higher-twist modified parton evolution equation is used to evolve the initial valence quark distributions in pions,which are derived based on light-front quantization via BLFQ collaboration.The results are consistent with the valence quark distributions of the E615 experiment,and the pion structure function of the H1 experiment.The structure function data highlight the necessity for a higher-twist modification in the small x region.Comparisons with some other models are also given. 相似文献
18.
A pairing vibrational model of meson with JP=1- is discussed including their energy spectra, configurations and decay mechanism. While the mixing configurations of valence quarks as well as the sea quark pairs in vacuum are taken into account, it is possible to propose a classification for hadronie decay of mesons and thereby a corresponding explanation of OZI rule. 相似文献
19.
GAO CHUNG-SHOU 《中国物理C(英文版)》1979,3(4):518-522
In this note we propose that the electromagnetic self energy of lepton may beconnected with quantum number n by( (δm)/m)=(1/(2π))n-b ,in which b is a constant.Wefnrther propose that the cut-off value of momentum M is connected with gravitationalconstant κ and fine structure constant α by M=(1/√κ)αe-1-b.So we obtainthe mass formula of charged leptons M=(1/√κ)α exp{-3/4-b-(1/3α)n-b}.By using the masses of e- and μ- and the value of a as in put,we get the calculatedvalues of κ=(6.67231±0.00026)×10-8cm3g-1sec-2and mr=(1782.306±0.078)MeVwhich agree very well with experimental values κ=(6.6720±0.0041)×10-8cm3g-1sec-2 and mτ=(1782-4+3)MeV respectively.The mass of the fourth charged leptonpredicted by the formula should be m=(11725.47±0.51)MeV,which can be checkedby experiments in the near future.We also discuss briefly the proposed formula andthe obtained results. 相似文献
20.
YUAN JIAN YUAN RONG-FANG HUANG BING-YIN WANG XIN-LIN WANG YUAN-DA ZHUANG FEI JIANG SI-YUAN 《中国物理C(英文版)》1982,6(3):355-364
Angular distribution for the elastic and some inelstic scattering of α particle on24Mg isotope between 12°and 178°in steps of 2°(Lab) have been measured at 18.1MeV α bombarding energy. α+24Mg elastic scattering angular distribution at back-ward angles displays more pronounced oscillation and a strong overall rise of crosssection. The calculation by the standard optical model together with compound nuclearscattering (via H-F) cannot predict this anomalous enhancement. The calculation byuse of an L-dependent imaginary potential optical model is in good agreement withthe experimental data. The fits of L-dependent optical model to the experimentalangular distributions of other energies are also discussed. 相似文献