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 15 毫秒
1.
A brief survey of the phenomenology (with emphasis on its present status) of CP, T and CPT invariance in neutral kaon decays is given. Existing limits on the invariances of the mass matrix of the K0−K̄0 system are stated. Also included are our new results and also those of DASS and KABIR for limits on these invariances for the decay amplitudes, obtained by using existing data, and the available information on the total mass matrix. The CPT invariant part of amplitudes for decay to the I = 0 and I = 2, ππ channels is T (and CP) invariant, in the Eberhard phase convention, to about 0.4% and about 4% respectively; the corresponding T invariant part of these amplitudes is CPT (and CP) invariant to about 1% and about 5% respectively. A limit similar to this last one (5%) was already obtained in the literature by making a further approximation. The CP, T and CPT invariant part of the averaged ΔS = − ΔQ amplitude in K13 decay is found to be less than about 5% of the corresponding ΔS = ΔQ amplitude; the T invariant part of the difference of the averaged ΔS = ΔQ and the averaged ΔS = − ΔQ amplitudes is CPT (and CP) invariant to about 1%. A limit similar to this one (1%) was also obtained in the literature by making a further assumption about the mass matrix. These amplitude limits are expected to have about one significant figure accuracy. Due to large experimental errors, the amplitude limits on the other non-invariance parameters for the above channels are not very good. Difficulties in deriving corresponding parameters for the 3π channel are noted. In certain respects, CPT invariance has been verified experimentally to a poorer accuracy than CP invariance and T invariance.  相似文献   

2.
3.
We comment on CP, T and CPT violation in the light of interesting new data from the CPLEAR and KTeV Collaborations on neutral kaon decay asymmetries. Other recent data from the CPLEAR experiment, constraining possible violations of CPT and the ΔSQ rule, exclude the possibility that the semileptonic-decay asymmetry AT measured by CPLEAR could be solely due to CPT violation, confirming that their data constitute direct evidence for T violation. The CP-violating asymmetry in KLee+ππ+ recently measured by the KTeV Collaboration does not by itself provide direct evidence for T violation, but we use it to place new bounds on CPT violation.  相似文献   

4.
5.
6.
Under the general assumptions of quantum field theory in terms of local algebras of field operators fulfilling the split property, we prove that any two local coveriant implementations of the gauge group (or, in the case of a connected and simply connected Lie gauge group, any two choices of local current algebras) relative to a pair of double cones 1, 2, are related by a unitary equivalence induced by a unitary in the algebra of observables localized in 2 which commutes with all fields localized in 1, where 1 is any double cone contained in the interior of 1, and 2 any double cone containing 2 in its interior.  相似文献   

7.
8.
It is shown that the point spectrum of internal symmetries is always symmetric. It is a group provided the intersection of all local subalgebras is trivial.  相似文献   

9.
10.
A method for integration of classical and quantum Hamiltonian systems, based on the use of approximate symmetries, is proposed in this paper. The proposed method is similar to the averaging method in classical mechanics; however, it does not use canonical transformations to the variables action-angle. This allows one in some cases to apply this method to quantum equations. A nontrivial example is analyzed in the paper.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 114–117, August, 1993.  相似文献   

11.
The possible violation of the CP, T and/or CPT symmetries in the system is studied from a phenomenological point of view. With this aim, we first introduce parameters which represent the violation of these symmetries in the mixing parameters and decay amplitudes in a convenient and well-defined way and, treating these parameters as small, derive formulas which relate them to the experimentally measured quantities. We then perform numerical analyses, with the aid of the Bell–Steinberger relation, to derive constraints on these symmetry-violating parameters, firstly paying particular attention to the results reported by the KTeV Collaboration and the NA48 Collaboration, and then with the results reported by the CPLEAR Collaboration as well taken into account. A case study, in which either CPT symmetry orT symmetry is assumed, is also carried out. It is demonstrated that the CP andT symmetries are violated definitively at the level of in decays and presumably at the level of in the mixing, and that the Bell–Steinberger relation helps us to establish that CP andT violations are definitively present in mixing and to testCPT symmetry to a level of . Received: 14 February 2000 / Revised version: 24 April 2000 / Published online: 8 September 2000  相似文献   

12.
We elucidate the way by which the quantum group symmetries of the WZW models arise within the canonical formalism of the classical field theory.  相似文献   

13.
14.
We report the results of a search for T, CP, CPT, and violation in B0-B0 mixing using an inclusive dilepton sample collected by the BABAR experiment at the PEP-II factory. Using a sample of 232 x 10(6) BB pairs, we measure the T and CP violation parameter |q/p| - 1 = (-0.8 +/- 2.7(stat) +/- 1.9(syst) x 10(-3), and the CPT and CP parameters Imz = (13.9 +/- 7.3(stat) +/- 3.2(syst)) x 10(-3) and Delta Gamma x Rez = (7.1 +/- 3.9(stat) +/- 2.0(stat)) x 10(-3) ps(-1). The statistical correlation between the measurements of Imz and Delta Gamma x Rez is 76%.  相似文献   

15.
16.
The problem of the doubling of states is investigated in the framework of the theory of discrete quantum gravity under the assumption that the theory has a continuum (macroscopic) limit. It is demonstrated that irregular (in some sense) modes of fields (i.e., modes that change abruptly on scales of a lattice step and have a finite energy when the lattice step tends to zero) are separated from the normal modes. Some cosmological consequences of this finding are discussed.  相似文献   

17.
An idea that the experimentally-observed meson resonances are excited states of fundamental mesons is presented, and is tested for several models of quantum field theory. It is shown that in the considered models, the excited states of mesons do exist and form infinite trajectories in the plane mass square-spin: these trajectories are either linear for all J or approximate ly linear for small J7, depending on the form of the interaction Lagrangian.Supported in part by the National Science Foundation under the grant INT 73-20002 A01, formerly GF-41958.  相似文献   

18.
By considering a system of spinning particles in an external magnetic field we demonstrate that the system develops non-local spin interactions due to discrete time quantum effects. Such interactions can lead to a domain like structure in the early universe possibly serving as generic seeds to large scale structure.  相似文献   

19.
20.
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