排序方式: 共有24条查询结果,搜索用时 140 毫秒
1.
E. Tomasi-Gustafsson M. Osipenko E. A. Kuraev Yu. M. Bystritskiy 《Physics of Atomic Nuclei》2013,76(8):937-946
World data on the lepton-charge asymmetry in the elastic and inelastic lepton scattering off the proton and nuclei are compiled and discussed. After reviewing the published results, we compare the elastic data to a model calculation of the two-photon-exchange mechanism. We show that the existing data do not provide any evidence for enhancement of the two-photon contribution. At confidence level 95% the data allow to exclude the two-photon exchange as an explanation for the difference between Rosenbluth and polarization transfer measurements of proton electromagnetic form factors. 相似文献
2.
Yu. M. Bystritskiy V. V. Bytev E. A. Kuraev A. N. Ilyichev 《Physics of Particles and Nuclei Letters》2011,8(2):73-77
We consider an alternative explanation of newly found growth of neutral pion transition form factor with high virtuality of
one of photons. It is based on Sudakov suppression of quark-photon vertex. Some applications to scattering and annihilation
channels are considered including the relevant experiments with lepton-proton scattering. 相似文献
3.
The two-photon decay widths of scalar mesons σ(600), f
0(980), and a
0(980) are calculated in the framework of the local Nambu-Jona-Lasinio model. The contributions of the quark loops (Hartree-Fock
approximation) and the meson loops (next 1/N
c
approximation, where N
c
is the number of colors) are taken into account. These contributions, as we show, are the values of the same order of magnitude.
For the f
0 decay the K-loop contribution turns out to play the dominant role. The results are in satisfactory agreement with modern experimental
data. 相似文献
4.
A. B. Arbuzov V. V. Bytev E. A. Kuraev E. Tomasi-Gustafsson Yu. M. Bystritskiy 《Physics of Particles and Nuclei》2011,42(1):55-78
Some Coulomb effects in heavy ion collisions are considered. Among them the process of muon and lepton pair creation, Coulomb and unitary corrections, statistics of multiple pair production. Effects of multiple photon exchange in process of lepton pair production by linearly polarized photon on nuclei are considered. This process is used for measuring the polarization of initial photon. Relativistic muon energy loss due to the light lepton pair production in the Coulomb field are calculated. Also we consider the effects of multiple photon exchange in elastic lepton scattering on unscreened atomic field and discuss the possible experimental testing. 相似文献
5.
Mikhail K. Volkov Eduard A. Kuraev Yury M. Bystritskiy 《Central European Journal of Physics》2010,8(4):580-586
The two-photon decay widths of scalar mesons σ(600), f 0(980) and a 0(980) as well a 0 → ju(ω)γ and f 0 → ju(ω)γ are calculated in the framework of the local Nambu-Jona-Lasinio model. The contributions of the quark loops (Hartree-Fock approximation) and the meson loops (next 1/N c -approximation where N c is the number of colors) are taken into account. The values of these contributions, as we show, are of the same order of magnitude. For the f 0 decay the K-loop contribution plays the dominant role. The results for two-gamma decays are in satisfactory agreement with modern experimental data. The predictions for a 0 → ju(ω)γ and f 0 → ju(ω)γ widths are given. 相似文献
6.
A. B. Arbuzov V. V. Bytev E. A. Kuraev E. Tomasi-Gustafsson Yu. M. Bystritskiy 《Physics of Particles and Nuclei》2010,41(3):394-424
In this review we consider the structure function method, based on the renormalization group approach: when combined with
exact calculation at the lowest order of perturbation theory it allows one to calculate the differential cross sections in
leading and next to leading order approximations, again providing the thousands accuracy. 相似文献
7.
A.?B.?Arbuzov V.?V.?Bytev E.?A.?Kuraev E.?Tomasi-Gustafsson Yu.?M.?Bystritskiy 《Physics of Particles and Nuclei》2010,41(5):593-635
In this review we consider the high energy processes in QED frames in peripherical kinematics. The key feature of this kinematics is that processes have a large cross section which do not decrease with the increasing of the initial center of mass energy. Two purposes to study peripheral processes are: the background processes with large total cross sections and the structure of jets in the fragmentation region.We describe the various QED peripherical processes in terms of Impact Factors and give the explicit expressions for the differential distributions and spin correlation effects, as well as estimates of the total cross section of peripheral processes in photon-photon, photon-lepton and lepton-lepton collisions.A special attention is paid to the small-angle Bhabha scattering process which is relevant for beam monitoring at LEP I, LEP II.Based on analytical properties of the amplitudes some relations (QED sum rules) between the high energy asymptotic of the cross sections of inelastic processes in e + e ? collisions and higher order perturbative contributions to the electron Dirac and Pauli form-factors are derived.For practical using we present some loop momentum integrals. 相似文献
8.
9.
Aleksejevs A. G. Barkanova S. G. Bystritskiy Yu. M. Zykunov V. A. 《Physics of Atomic Nuclei》2020,83(3):463-479
Physics of Atomic Nuclei - A total set of one-loop electroweak radiative corrections, including the contribution of the emission of real hard photons (hard-bremsstrahlung contribution), to... 相似文献
10.
E. A. Kuraev Yu. M. Bystritskiy V. V. Bytev A. Dbeyssi E. Tomasi-Gustafsson 《Journal of Experimental and Theoretical Physics》2012,115(1):93-104
The s-channel annihilation of a proton and an antiproton into a neutral pion and a real or virtual photon followed by lepton pair emission is studied. Such a mechanism is expected to play a role at moderate values of the total energy $ \sqrt s $ , when the pion is emitted in the angular region around 90° in the center-of-mass system. A fair comparison with the existing data is obtained taking scattering and annihilation channels into account. The cross section is calculated and numerical results are given in the kinematical range accessible in the PANDA experiment at FAIR. 相似文献