排序方式: 共有70条查询结果,搜索用时 15 毫秒
1.
The process of muon (pion) pair production with small invariant mass in electron-positron high-energy annihilation, accompanied by emission of a hard photon at large angles, is considered. We find that the Drell-Yan picture for the differential cross section is valid in the charge-even experimental setup. Radiative corrections both for the electron block and for the final-state block are taken into account. 相似文献
2.
The convergence of a finite element scheme approximating a nonlinear system of integro-differential equations is proven. This system arises in mathematical modeling of the process of a magnetic field penetrating into a substance. Properties of existence, uniqueness and asymptotic behavior of the solutions are briefly described. The decay of the numerical solution is compared with both the theoretical and finite difference results. 相似文献
3.
N. V. Makhaldiani Z. K. Silagadze 《International Journal of Theoretical Physics》1999,38(7):1933-1939
The critical charge Zc is estimated for elementary particles using a Newton-Wigner position operator-inspired model. Particles with Z Zc (maxicharged particles), if they exist at all, can have unusual properties which make them illusive objects, that are not easy to detect. Dirac's magnetic poles have a (magnetic) charge g Zc. This gives one more argument that it is unexpected for pointlike monopoles to be found in our world, where –1 137. 相似文献
4.
V. M. Aulchenko M. N. Achasov S. E. Baru K. I. Beloborodov A. V. Berdyugin A. G. Bogdanchikov A. V. Bozhenok A. D. Bukin D. A. Bukin A. V. Vasilev V. B. Golubev T. V. Dimova V. P. Druzhinin V. N. Ivanchenko I. A. Koop A. A. Korol S. V. Koshuba A. P. Lysenko A. V. Otboev E. V. Pakhtusova A. A. Salnikov S. I. Serednyakov V. A. Sidorov Z. K. Silagadze V. V. Shary Yu. M. Shatunov 《Journal of Experimental and Theoretical Physics》2003,97(1):24-33
The process e + e ? → η′γ, η′ → η π0π0, η → γγ is investigated by an SND detector in experiment on a VEPP-2M equipment with colliding electron-positron beams. The analysis of experimental data yields a value of B(? → η′γ)=(6.7 ?4.2 +5.0 ±1.5)×10?5 for the decay probability. Taking into account a previous measurement of this quantity by an SND detector in the decay channel η′ → π+π?η, one finally obtains B(?→η ′γ)=(6.7 ?2.4 +2.8 ±0.8)×10?5. 相似文献
5.
Some semileptonic weak decays of vector mesons are considered within the most popular quark models. Unfortunately, the predicted branching ratios are too small to make a study of these decays realistic at meson factories under construction. 相似文献
6.
Achasov M. N. Barnyakov A. Yu. Baykov A. A. Beloborodov K. I. Berdyugin A. V. Bogdanchikov A. G. Botov A. A. Golubev V. B. Dimova T. V. Druzhinin V. P. Zhabin V. N. Kardapoltsev L. V. Kovrizhin D. P. Korol A. A. Kupich A. S. Martin K. A. Melnikova N. A. Muchnoi N. Yu. Obrazovsky A. E. Pakhtusova E. V. Pugachev K. V. Savchenko Ya. S. Serednyakov S. I. Silagadze Z. K. Surin I. K. Usov Yu. V. Kharlamov A. G. Shtol D. A. 《Physics of Atomic Nuclei》2021,84(2):197-200
Physics of Atomic Nuclei - The process $$e^{+}e^{-}\to\eta\pi^{0}\gamma$$ is studied in the range of center-of-mass (c.m.) collision energies between 1.05 and 2.00 GeV on the basis of data... 相似文献
7.
Achasov M. N. Barnyakov A. Yu. Barnyakov M. Yu. Beloborodov K. I. Berdyugin A. V. Bogdanchikov A. G. Botov A. A. Buzykaev A. R. Golubev V. B. Dimova T. V. Druzhinin V. P. Kardapoltsev L. V. Kovrizhin D. P. Korol A. A. Kravchenko E. A. Kupich A. S. Martin K. A. Melnikova N. A. Obrazovsky A. E. Onuchin A. P. Pakhtusova E. V. Pugachev K. V. Serednyakov S. I. Silagadze Z. K. Surin I. K. Usov Yu. V. Kharlamov A. G. Shtol D. A. 《Physics of Atomic Nuclei》2021,84(1):59-62
Physics of Atomic Nuclei - In an experiment with the SND detector at the VEPP-2000 $$e^{+}e^{-}$$ collider, the cross sections for the processes $$e^{+}e^{-}\to K^{+}K^{-}\pi^{0}$$ and... 相似文献
8.
In this paper we establish a new characterisation of star-regular categories, using a property of internal reflexive graphs, which is suggested by a recent result due to O. Ngaha Ngaha and the first author. We show that this property is, in a suitable sense, invariant under regular completion of a category in the sense of A. Carboni and E.M. Vitale. Restricting to pointed categories, where star-regularity becomes normality in the sense of the second author, this reveals an unusual behaviour of the exactness property of normality (i.e. the property that regular epimorphisms are normal epimorphisms) compared to other closely related exactness properties studied in categorical algebra. 相似文献
9.
In this paper we obtain an intrinsic syntactical characterization of protomodularity, via so-called categorical difference terms, similar to the one known in the case of varieties involving binary terms d satisfying d(x, x) = d(y, y). We also show that purely categorical modifications of the condition in the characterization give characterizations of Mal’tsev
and additive categories, thus revealing a new conceptual link between these three classes of categories, and hence, also between
the corresponding classes of varieties. 相似文献
10.
We introduce a notion of a subtractive category. It generalizes the notion of a pointed subtractive variety of universal algebras in the sense of A. Ursini. Subtractive categories are closely related to Mal’tsev and additive categories: (i) a category C with finite limits is a Mal’tsev category if and only if for every object X in C the category Pt(X)=((X,1X)↓(C↓X)) of “points over X” is subtractive; (ii) a pointed category C with finite limits is additive if and only if C is subtractive and half-additive.Mathematics Subject Classifications (2000) 18C99, 18E05, 08B05. 相似文献