首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 312 毫秒
1.
The s-wave pion scattering amplitude is analysed with the aim to clarify the mass spectrum of scalar mesons and to find evidence of lightest glueball. The S-matrix and K¯K coupled channel formalism is used. The existence of scalar mesons S* and is implied by the data. The production K¯K and the elastic K¯KK¯K coupled amplitudes are predicted from the scattering data. The couplings c f S* to and K¯K states are determined.  相似文献   

2.
A heuristic model for deriving the anomalous magnetic moment of the electron is presented. A term /2 – 0.327(/)2 is deduced, in better agreement with experiment than is the QED derivation of /2 – 0.328(/)2. The result is strengthened by the recent non-QED account of the Lamb shift by Yu and Sachs.  相似文献   

3.
    
In this paper we present the results of a search for the charmed strange baryon c + in the final states 0++K and ++. The experiment was performed using the magnetic spectrometer BIS-2 with a hydrogen target located in the neutron beam of the Serpukhov accelerator. A narrow peak in the 0++K state is observed at a mass of 2440 and possibly also of 2310 MeV/c2, corresponding to signals for the c + 0++K and c + 0++K (0 0) decays respectively. The statistics obtained for the ++ state is too low to make any conclusion.We are grateful to K. Hiller, F. Mandl, M. Markytan and J.MacNaughton for useful discussions and valuable remarks.  相似文献   

4.
An investigation is made into P-odd effects due to neutral weak currents in the process of electroproduction of 0 mesons on the deuteron, e+d e+0+d. The general structure of the differential cross section of this reaction (with allowance for the interference between the amplitudes of the electromagnetic and weak mechanisms) is obtained for the experimental conditions when the scattered electron and 0 meson are detected in the final state.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 17–21, September, 1980.  相似文献   

5.
The calculation of the secondary nucleons polarization in thepppp0 andppnp+ reactions at 1000 MeV is effected in the framework of the one-pion exchange model. It is shown that polarization is due to the interference of the resonant amplitude with the non-resonant amplitudes of theN virtual scattering. The angular dependence of the polarization is sensitive to the behaivour of theN scattering amplitudes off the mass shell.Submitted to the symposium Mesons and Light Nuclei, Liblice, Czechoslovakia, June 1981.  相似文献   

6.
We report an experimental and theoretical (PPP method) study of the UV absorption spectra of 2-azaanthracene and four of its methyl-substituted derivatives. We find that the p bands of these compounds consist of two different vibronic * bands. Our experimental and theoretical results suggest a rule for evaluating the effect of methyl groups on * transition energies as a function of the charge on the atoms. We interpret the reasons for the different effects of a polar solvent and hydrogen bonding on the * bands of these compounds.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 7–15, June, 1977.  相似文献   

7.
From an isospin SU(2) × hypercharge U(1)gauge-invariant meson action for K+,+ +, a prediction ofthe Cabbibo angle was obtained earlier. Using anotherresult of the spinor strong interaction theory that the s quark is only a littleheavier than the d quark, the above action can beextended to a weakly broken SU(3) one. The Weinbergangle is found to be 30° in the limit of this SU(3)symmetry. In the approximation and context entailing thislimit, the Weinberg angle can be removed from the listof undetermined fundamental parameters in electroweaktheory. The spinor strong interaction Lagrangian used above and applied to the decay+ e+ is shown tohold for + 0e+ as well, renderingthe conserved vector current hypothesis hithertorequired to account for the latter decaysuperfluous.  相似文献   

8.
Conclusions We have examined the absorption spectra of DS and the dependence of the quantum yield in photodissociation of DC on exciting wavelength, which has shown that the electronic structure of DC allows one to observe *transitions and also n* and * ones, with the a orbital localized on the dissociating C-N bond. The formation of long-lived3(*) excitation leads the DC to dissociation into a neutral nitrogen molecule and an ary1 cation in the triplet state.Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 41, No. 5, pp. 803–809, November, 1984.  相似文献   

9.
The method of complex angular moments is used to analyze the experimental data on the inelastic reactions p ()K, taking into account branch cuts in the j-plane in the eikonal approximation. An optical model for the backward scattering is considered. Agreement with experiment is obtained in the region of small angles for the reactions (0)K0. In the case of P K0(K+) processes, agreement is obtained with the experimental results for large (180) scattering angles.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 26–30, August, 1972.  相似文献   

10.
In the present paper, the feasibility of constructing a model of elementary and particles based on the Poincaré model of the electron [1] is examined with allowance for schemes of particle decay. The muon and pion in stopped states are considered as spherical resonators for virtual neutrino quanta excited inside an elastic lepton shell; the number of these quanta is determined by the scheme of the corresponding particle decay. In the model, the muon differs from the electron by two additional quanta of the neutrino field. The e, , and masses are calculated with the help of a single parameter. The ratio of and e masses is about (6c/e 2)2/3, and the ratio of ° and e masses is (3/2)2/3. The calculated e, , and ° masses are in the 0.547:105.71:134.963 ratios, which is in good agreement with the available experimental data. The calculated electromagnetic radius of the charged pion (±) = 0.5f is close to that calculated from the experimental data. The neutrino mass e is found to be m( e ) 0.02 eV.  相似文献   

11.
The ultraviolet stability for the cosine interaction in two dimensions and finite volume is rederived for values 2 [4, 32/5[ and proven for the remaining 2 [4, 8[ by using renormalization group methods developed in [G, GN1] to portray renormalized effective potentials arising from a multiscale decomposition.Supported by the Studienstiftung des Deutschen VolkesSupported in part by the Schweizerischer Nationalfonds  相似文献   

12.
An expression for the decay rate (0 ) has been derived in the frameworkof the spinor strong interaction theory, a first-principles strong interaction theoryproposed some years ago as an alternative to low-energy QCD. The startingpoint is the SO(3) gauge-invariant action for two quark mesons which has beensuccessful in accounting for confinement, + + , e+, and 0 e+, nonexistenceof the Higgs boson, and other low-energy mesonic phenomena. The quasi-four-quarkmeson equations developed for the decay of a vector meson into twopseudoscalar mesons V PP has been taken over here to apply to P(0) VV(+ ) (plus + and which annihilate each other). This mechanismin principle agrees with that of the assumption of vector meson dominance inthe literature. It, together with the effect of form factors, arises naturally in theformalism and need not be assumed. Equations for the perturbed vector mesonwave functions cannot be simply solved and an assumption has been made toobtain an estimate of their magnitude. Together with a constant associated withthe strong coupling obtained earlier from V() PP(K+K), the estimated decayrate is 19.2 eV, in order-of-magnitude agreement with data (7.74 eV).  相似文献   

13.
The development in time of the transmission through57Fe of a broad Lorenztian radiation is calculated numerically. Examples are given for=0 and/2, for the magnetic hyperfine case, and for=/2 for pure quadrupole splitting.  相似文献   

14.
First results on d are reported. The measurements were made using 8 specially designed neutron counters, which were carefully calibratedin situ. The differential cross sections atT =142, 180, 217, and 254 MeV were obtained at four angles between 0° and 90°, they are compared to + d pp data measured at the same energies and angles with the same setup. At every beam energy, the shape of the angular distributions of d nn and + d pp is the same to ±2%. The absolute cross sections differ by 1 to 10%. The error in this comparison is ±4% implying a small violation of charge symmetry.Dedicated to Prof. I. laus on the occasion of his 60th birthdayDeceased  相似文献   

15.
Nucleon polarizations are examined in the hypernucleus decays5He, 4He + p + ,4H, 3H + p + , and4H, 3He + n + . The effect of the strong interaction in the final state is taken into account. A significant role is predicted for the resonance interaction in the p-4He system in the formation of the proton polarization in the5He decay. It is also shown that in the4H, 3H + p + decay the proton-polarization components should attain significant magnitudes, while in the charge-exchange decay4H, 3He + n + , the neutron polarization is expected to be not too large.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 100–103, October, 1988.  相似文献   

16.
Quantum chromodynamics methods are used to calculate the section of the reaction a0 0 with formation as an intermediate state of the meson a0(980), which is interpreted as a bound state of two quark-antiquark pairs, formed upon dissociation of two virtual photons, with which an electron and positron are exchanged in incident e- and e+-beams. It is shown that the a0 20 decay is significantly more suppressed than the a0 0 decay.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 19–23, July, 1991.  相似文献   

17.
The cross section for the radiative photoproduction of + mesons on hydrogenp + n in dependence on the momentum transfer squared has been measured at the 1·2 GeV electron synchrotron PACHRA. Using extrapolation of the data to pion pole the differential cross section for the pion Compton scattering + + has been obtained, and the electric polarizability of the + meson has been estimated to be =(20±12) x 10-43cm3.Presented at the symposium Mesons and Light Nuclei, Bechyn, Czechoslovakia, May 27–June 1, 1985.The authors thank P. A. Cherenkov for his constant attention to this work and helpful discussions at all stages of the work.  相似文献   

18.
Conclusion We have constructed the pion form factor model satisfying fundamental principles, providing some freedom for the asymptotic behaviour and depending only on the adjustable parameters with a definite physical interpretation. The explicit incorporation of the pion form factor left-hand cut from the second Riemann sheet into a model was carried out for the first time. As a result we have described (contrary to the previous attempts [18, 19]) the pion form factor data from the range of momenta –9·770 GeV2 t 9·579 GeV2 and data on theP-wave isovector phase shift in the elastic region simultaneously with the adjustable parameters acquiring very reasonable values. The asymptotic behaviour was enforced by the data to be consistent with the naive quark model prediction. The calculated values of the pion charge radius as well as theP-wave isovector scattering length coincide with the world averaged values. With regard to these positive features of our pion form factor model it can be employed for the reliable calculation (via unitarity) of theP-wave isovector scattering partial amplitude outside the physical region, which could be useful in a saturation of various sum rules in scattering physics.  相似文献   

19.
The paper considers the processes of formation of pseudoscalar mesons by the interaction of an antineutrino with a leptonv ll K, , K.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 139–143, August, 1974.  相似文献   

20.
We investigate the continuum three-pion problem within a relativistic three-body model that takes into account the S andP waves. The dynamical input of the two-body subsystem is given by separable potentials, which yield a good fit to the scattering data and resonance parameters up to a two-body invariant mass of 900MeV. We introduce a parameter expressing the ambiguity in the reduction of a fully relativistic theory to a three-dimensional one. The masses and widths of the ,a 1(1260), and (1300) mesons, which decay predominantly into three pions, are reasonably well described by our model. Theh 1(1170) meson, however, which also decays into three pions, cannot be explained as a three-pion resonance. Some Argand diagrams are shown in those channels where resonances exist.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号