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1.
Produchon yields were determined for 25 abet fragments produced from the reaction of iron with 80 MeV/u 16O ions. From these data, charge distribution and mass yield distribution have been deduced. The experimental results are compared with those reported from our previous work. It is found that the width parameter σz and the most probable charge Zp of the charge distribution increase slowly with increasing bombarding energy. The mass yield distribution is discussed in terms of the concepts of limiting fragmentation and factorization.  相似文献   

2.
The nuclear emulsion was exposed at CERN by the lead projectile at 160 A GeV. The angles between any pair of fragments with Z = 2-4 have been measured in the emulsion plane for the events which did not contain heavy fragments. The constant characterizing the normal angle (J) distribution of the fragment momentum projection onto the emulsion plane with respect to initial projectile momentum p0 is found to be CJ = (0.37 - 0.02) mrad. Corresponding value C0 = (121 - 6) MeV/c of nucleon momentum distribution in the lead nucleus coincides with that expected from Fermi momentum distribution for this nucleus. The peak in the pair-angle distribution of double-charged fragments, 8Be M 2!, is presented for the region of small angles (<0.1 mrad). The fraction of !-particles coming from the decay of the ground state 8Be is found to be (13 - 2)% of their whole number.  相似文献   

3.
Fractional independent yields of fission products in the thermal neutron-induced fission of233U,235U,239Pu,241Pu and in the spontaneous fission of252Cf have been correlated with the neutron-to-proton ratio of the fission products. The yields of the products from a fissioning system, when plotted as a function of neutron-to-proton (N/Z) ratio of fission preducts, fall on two Gaussian distribution corresponding to light and heavy fission products. The centroids of the distribution or the most probable value of neutron-to-proton ratio is found to be very close to theN/Z of the fissioning nucleus. From the most probable value ofN/Z the various parameters of charge distribution e.g. most probable massA p, most probable chargeZ p, the mass dispersionσ Aand the charge dispersionσ Zhave been obtained and are in good agreement with the experimental values ofA pandZ p.  相似文献   

4.
In this paper we disscuse disscuse the physicsical aspect of cross-section differences ΔAB=(ABcγX)-(ABcγX) 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)/(Δpp-Δpp)=Gn8(x)/(Δpp)=Gπ8(x)/(Δπ+pπ-p=GK8(x)/(ΔK+pK-p)which are expected to be test in experiment.  相似文献   

5.
The yields of 15 and 17 fission, products have been obtained by radiochemical determinations in 12C-induced fission of 209Bi and 238U respectively. From these data, the mass distributions of fission fragments are calculated based on three different hypotheses for the charge distribution. The results seem to indicate that the hypothesis of equal charge displacement gives the best fit to the Gaussian distribution for the masses of the fission fragments. By comparison with the mass distributions for 209Bi (12C, f), 238U(12C, f) and 197Au(12C, f) in our early measurement, we find that for fission parameter Z2/A>37, the width of the mass distributions increases with Z2/A rapidly.  相似文献   

6.
In this paper the experimental value of radiative correction Δr was derived from the new data of sin 2θw and W boson mass Mw given by LEP,CDF and other collaborations.A careful comparison of (Δr)exp with the standard model expectation was carried out.We first calculated the Δr at full one-loop level,and then the main two-loop contributions were included.More stringent upper bounds on Mt were obtained from the analysis of probability distribution:Mt175GeV at 95%C.L. for a given MH=100GeV.The effects on Nt from other experimental and theoretical errors were also computed.  相似文献   

7.
函数的H-导数和分形动力学   总被引:2,自引:1,他引:1       下载免费PDF全文
 给出了函数的Hausdorff测度与H-导数。从而,为开展自给的分形动力学提供了解析的数学工具。同时,给出了分形动力学的演化方程组并做了初步讨论与分析。  相似文献   

8.
The relation between the masses of W± and Z0 in a composite model is disscused phenomenologycally. It is shown that any deviation of experimental data from the predicted value of W-S model will be in favour of the composite model.
By using present experimental data, the calculation results show that is W' (the radial excited state of W) exists, then its mass will be greater than (2—5)mw.  相似文献   

9.
In this paper we study a modified skyrme model with mπ≠0 and compute the static properties of nucleons in this model.The results show that most of theoretical values have been improved,especially 2>1/2=0.56fm is two times as one from the original Skyrme model and it is close to experimental value.  相似文献   

10.
In this paper,we analyse the spatial overlapping behavior of sea quarks of neighboring nucleons in nuclei in the small x region and give a relation between the nuclear shadowing factor R(x,Q2,A) and the spatial overlapping factor ΔVA(x)/VA(x).By using this nuclear shadowing factor R(x,Q2,A),we calculate the ratios of the average nuclear structure functions of nuclei 12C、63Cu and 116Sn,to the deuteron structure function and obtais a better agreement between the calculated result and the experimental data.  相似文献   

11.
From the bosonization of vertex operators for A(1)n-1 face model given by Asai,Jimbo,Miwa and Pugai,using vertex-face correspondence,we obtain bosonized vertex operators for Zn symmetric Belavin R matrix,which realize the Zamolodchikov-Fadeev algebra for that R matrix.  相似文献   

12.
Energy spectra of complex fragments emitted in the reactions of 46.7MeV/u 12C with different targets 197Au,115In and 58Ni have been measured by telescopes,consisting of a gis ionization counter followed by a position Sensitive semiconductor detector.Tha most probable kinematical energies.Ep of complex fragments and temperature parameters of long-live intermediate systems have been deduced by complex fragment ernergy spectra.The experimental values of Ep are lower than the calculated ones by E=Vcoul+2T.The experimental values of complex fragment yields can be reproduced by simple A.Friedman statistical evaporation model satisfactorily.  相似文献   

13.
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)=Qp+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   

14.
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   

15.
 用阻抗匹配法和压电探针技术测量了初始密度为1.714 g/cm3(孔隙率α=ρ000=1.898/1.714=1.107)的水绿矾(FeSO4·7H2O)的冲击压缩线,发现其在0~100 GPa范围内存在两个明显相区:含有部分熔融的低压相和完全熔化的高压相。在两个相区内,冲击波速度D和波后粒子速度u可分别描述为:D=0.59+2.06u(u<3.12 km/s)和D=3.18+1.223u(u≥3.12 km/s)。从冲击压缩数据出发,用欧拉有限应变理论得到了其等熵状态方程。其熔化方程可用pm(GPa) =0.159(Tm(K)/1000)6.3371+0.69来近似描述。  相似文献   

16.
The E2 reduced transition probabilities between the d-a cluster states of 6Li were calculated by the RGM in this paper.The resulting B(E2;E1→E0)=21.06fm4 consistented with the experimental value 25.1±2.0fm4 more than the calculated values of the double-well cluster model including p-state exciting and LCCO.Also,the B(E2;E3→E0)=9.67fm4 coincided with the exprimental value 6.483±3.360fm4 within the error range.  相似文献   

17.
The excitation functions of the 23Na(p,α020Neg·s.and the 23Na(p,α120Nelst reae-tion have been measured from Ep=1 to 2.5 MeV at θL=30°,150° and 30°,respectively.Around the resonance at 2.171 MeV,the excitation functions of the(p,α0)reactionhave been measured at 12 angles,then,some angular distributions have been obtained from these excitation functions.In addition,the angular distribution of the(p,α0)reaction for the resonance at 2.171 MeV has also been measured directly at energy ofthe resonance peak of the excitation function at 150°.For the resonance at 2.117MeV,the angular distribution have been measured at two energies,one at the energyof the resonance peak of the excitation function at 150°,another at the energy of thehalf maximum point of the resonance peak on the higher energy side.Around the re-sonance at 2.075 MeV,the excitation functions have been measured at 16 angles,andthe angular distribution has been obtained from three excitation functions.The an-gular distributions of the three resonances are not symmetric about 90°,and the posi-tions of the resonance peaks of these resonances varies with the angle of measurement.By means of the compound nucleus theory,discussions have been made for these non-solated resonances.  相似文献   

18.
Fission yields of124–132In in the thermal neutron fission of235U were determined for the first time. Charge displacementsΔZ=Z p?Z UCD were calculated for the corresponding mass chains. Both fission yields and charge displacement values were compared with those obtained by systematics by Wahl et al. and Wolfsberg. It was found that the fission yields of the In isotopes obey the gaussian distribution. The displacement function of Wolfsberg seems to give the better representation of the experimental results. Half-lives of124–131In were determined from beta decay curves.  相似文献   

19.
The projectile-like fragments emittd from 46.7MeV/u 12C induced reactions have been measured.The most probable energies of the PLFs due to the projectile fragmentation can be reproduced within the Abrasion picture.Their parallel momentum distribution widths are found to fulfill the Goldhaber relation and the extraced reduced parallel momentum distribution width σ0 is 80±10MeV/c,which is close to the value obtained in the relativistic energy region.Futhermore,the values of σ0 are the same for different reaction systems in our experiment.  相似文献   

20.
Iodine and tellurium isotopes produced in the fission of 232Th with 30.5 MeV alpha particles were separated using a method of sublimation in an air stream and the independent yields of 130I, 131I, 132m,gI, 133I 134I, 134m,gTe, 133mTe and 134Te (cumulative) were determined by means of high resolution Ge(Li) γ-ray spectrometry. A Gaussian fit to the experimental data was used to obtain the width parameter σz and the most probable charge Zp of the nuclear charge distribution in the isobaric chains 130 – 131. The most probable masses for fission fragments with Z = 52 and Z = 53 were also deduced from the measured fission yields.  相似文献   

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