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1.
Aiming at a complete classification of unitary N = 2 minimal models (where the assumption of space-time supersymmetry has been dropped), it is shown that each modular invariant candidate partition function of such a theory is indeed the partition function of a fully-fledged unitary N = 2 minimal model, subject to the assumptions that orbifolding is a ‘physical’ process and that the space-time supersymmetric A{\mathcal{A}} -D{\mathcal{D}} -E{\mathcal{E}} models are physical. A family of models constructed via orbifoldings of either the diagonal model or of the space-time supersymmetric exceptional models then demonstrates that there exists a unitary N = 2 minimal model for every one of the allowed partition functions in the list obtained from Gannon’s work (Gannon in Nucl Phys B 491:659–688, 1997).  相似文献   

2.
Certain B s 0V 1 V 2 decays (V i is a vector meson) can be related by flavor SU(3) symmetry to corresponding B d 0V 3 V 4 decays. In this paper, we show that the final-state polarization can be predicted in the B s 0 decay, assuming polarization measurements of the B d 0 decay. This can be done within the scenario of penguin annihilation (PA), which has been suggested as an explanation of the unexpectedly large transverse polarization in Bφ K *. PA is used to estimate the breaking of flavor SU(3) symmetry in pairs of decays. Two of these for which PA makes a reasonably precise prediction of the size of SU(3) breaking are (B s 0φ φ,B d 0φ K 0*) and ( ). The polarization measurement in the B d 0 decay can be used to predict the transverse polarization in the B s 0 decay and will allow for testing of PA as well as the other assumptions in the analysis.  相似文献   

3.
The 1/N c -power countings for baryon decays and configuration mixings are determined by means of a nonrelativistic quark picture. Such countings are expected to be robust under changes in the quark masses and, therefore, valid as these become light. It is shown that excited baryons have natural widths of \(\mathcal{O}(N_c^0 )\). These dominant widths are due to the decays that proceed directly to the ground-state baryons, with cascade decays being suppressed to \(\mathcal{O}(1/N_c )\). Configuration mixings, defined as mixings between states belonging to different O(3) × SU(2N f ) multiplets, are shown to be subleading in an expansion in \(1/\sqrt {N_c }\) when they involve the ground-state baryons, while the mixings between excited states can be \(\mathcal{O}(N_c^0 )\).  相似文献   

4.
The dielectron widths of Y(nS)(n = 1, …, 7) and vector decay constants are calculated using the relativistic string Hamiltonian with a universal interaction. For Y(nS) (n = 1, 2, 3) the dielectron widths and their ratios are obtained in full agreement with the latest CLEO data. For Y(10580) and Y(11020) a good agreement with experiment is reached only if the 4S-3D mixing (with a mixing angle θ = 27°± 4°) and 6S-5D mixing (with θ = 40°±5°) are taken into account. The possibility to observe higher “mixed D-wave” resonances, $ \tilde \Upsilon $ \tilde \Upsilon (n 3 D 1) with n = 3, 4, 5 is discussed. In particular, $ \tilde \Upsilon $ \tilde \Upsilon (≈11120), originating from the pure 53 D 1 state, can acquire a rather large dielectron width, ∼130 eV, so that this resonance may become manifest in the e + e experiments. On the contrary, the widths of pure D-wave states are very small, Γ ee (n 3 D 1)≤ 2 eV.  相似文献   

5.
We present selected recent results of multi-hadron correlation measurements in azimuth and pseudorapidity at intermediate and high p T in Au+Au collisions at , from the STAR experiment at RHIC. At intermediate p T , measurements are presented that attempt to determine the origin of the associated near-side (small Δφ) yield at large pseudo-rapidity difference Δη that is found to be present in heavy ion collisions. In addition, results are reported on new multi-hadron correlation measures at high-p T that use di-hadron triggers and multi-hadron cluster triggers with the goal to constrain the underlying jet kinematics better than in the existing measurements of inclusive spectra and di-hadron correlations.  相似文献   

6.
The spectral action on the equivariant real spectral triple over is computed explicitly. Properties of the differential calculus arising from the Dirac operator are studied and the results are compared to the commutative case of the sphere . UMR 6207, – Unité Mixte de Recherche du CNRS et des Universités Aix-Marseille I, Aix-Marseille II et de l’Université du Sud Toulon-Var, Laboratoire affilié à la FRUMAM – FR 2291. Partially supported by Polish Government grants 189/6.PRUE/2007/7; 115/E-343/SPB/6.PR UE/DIE and N 201 1770 33.  相似文献   

7.
By analyzing BX u ν spectra with a model based on soft-gluon resummation and an analytic time-like QCD coupling, we obtain
where the first and the second error refer to experimental and theoretical error, respectively. This model successfully describes the accurate experimental data in beauty fragmentation, which has similar soft-gluon effects. The |V ub | value is obtained from the available measured semileptonic branching fractions in limited regions of the phase space. The distributions in the lepton energy E , the hadron invariant mass m X , the light-cone momentum , together with the double distributions in (m X ,q 2) and (E ,s hmax ), are used to select the phase-space regions. q 2 is the dilepton squared momentum and s hmax is the maximal m X 2 at fixed q 2 and E . The |V ub | value obtained is in complete agreement with the value coming from exclusive B decays and from an over-all fit to the standard model parameters. We show that the slight disagreement (up to +2σ) with respect to previous inclusive measurements is not related to different choices for the b (and c) masses, but to a different modeling of the threshold (Sudakov) region.  相似文献   

8.
We calculate the scalar semileptonic kaon decay in finite volume at the momentum transfer t m =(m K m π )2, using chiral perturbation theory. At first we obtain the hadronic matrix element to be calculated in finite volume. We then evaluate the finite size effects for two volumes with L=1.83 fm and L=2.73 fm and find that the difference between the finite volume corrections of the two volumes are larger than the difference as quoted in Boyle et al. (Phys. Rev. Lett. 100:141601, 2008). It appears then that the pion masses used for the scalar form factor in ChPT are large which result in large finite volume corrections. If appropriate values for pion mass are used, we believe that the finite size effects estimated in this paper can be useful for lattice data to extrapolate at large lattice size.  相似文献   

9.
10.
Restricted active space (RAS) configuration interaction (CI) approach is employed to compute the P,T-odd interaction constant W d for the ground (2Σ1/2) state of YbF molecule. The present estimate of W d = −1.164 × 1025 Hz/e-cm is expected to provide a reliable limit on the electron’s electric dipole moment (EDM), d e.  相似文献   

11.
We investigate quantum Fisher information (QFI) for s u(2) atomic coherent states and s u(1, 1) coherent states. In this work, we find that for s u(2) atomic coherent states, the QFI with respect to \(\vartheta ~(\mathcal {F}_{\vartheta })\) is independent of φ, the QFI with respect to \(\varphi (\mathcal {F}_{\varphi })\) is governed by ??. Analogously, for s u(1,1) coherent states, \(\mathcal {F}_{\tau }\) is independent of φ, and \(\mathcal {F}_{\varphi }\) is determined by τ. Particularly, our results show that \(\mathcal {F}_{\varphi }\) is symmetric with respect to ?? = π/2 for s u(2) atomic coherent states. And for s u(1,1) coherent states, \(\mathcal {F}_{\varphi }\) also possesses symmetry with respect to τ = 0.  相似文献   

12.
In Talagrand (J. Stat. Phys. 126(4–5):837–894, 2007) the large deviations limit for the moments of the partition function Z N in the Sherrington-Kirkpatrick model (Sherrington and Kirkpatrick in Phys. Rev. Lett. 35:1792–1796, 1972) was computed for all real a≥0. For a≥1 this result extends the classical physicist’s replica method that corresponds to integer values of a. We give a new proof for a≥1 in the case of the pure p-spin SK model that provides a strong exponential control of the overlap. This work is partially supported by NSF grant.  相似文献   

13.
We investigate the spin squeezing in a arbitrary superposition of two three-qubit W states. It is shown that the mean spin direction is determined by the superposition coefficients and the relative phase; while the length of mean spin and the spin squeezing parameter are only determined by the superposition coefficients. It is also shown that there is squeezing in the n 2 direction and there is no squeezing in the n 1 direction.  相似文献   

14.
In this article, we assume that there exist scalar D*[`(D)]*{D}^{\ast}{\bar {D}}^{\ast}, Ds*[`(D)]s*{D}_{s}^{\ast}{\bar{D}}_{s}^{\ast}, B*[`(B)]*{B}^{\ast}{\bar {B}}^{\ast} and Bs*[`(B)]s*{B}_{s}^{\ast}{\bar{B}}_{s}^{\ast} molecular states, and study their masses using the QCD sum rules. The numerical results indicate that the masses are about (250–500) MeV above the corresponding D *–[`(D)]*{\bar{D}}^{\ast}, D s *–[`(D)]s*{\bar {D}}_{s}^{\ast}, B *–[`(B)]*{\bar{B}}^{\ast} and B s *–[`(B)]s*{\bar {B}}_{s}^{\ast} thresholds, the Y(4140) is unlikely a scalar Ds*[`(D)]s*{D}_{s}^{\ast}{\bar{D}}_{s}^{\ast} molecular state. The scalar D*[`(D)]*D^{\ast}{\bar{D}}^{\ast}, Ds*[`(D)]s*D_{s}^{\ast}{\bar{D}}_{s}^{\ast}, B*[`(B)]*B^{\ast}{\bar{B}}^{\ast} and Bs*[`(B)]s*B_{s}^{\ast}{\bar{B}}_{s}^{\ast} molecular states maybe not exist, while the scalar D*[`(D)]¢*{D'}^{\ast}{\bar{D}}^{\prime\ast}, Ds¢*[`(D)]s¢*{D}_{s}^{\prime\ast}{\bar{D}}_{s}^{\prime\ast}, B¢*[`(B)]¢*{B}^{\prime\ast}{\bar{B}}^{\prime\ast} and Bs¢*[`(B)]s¢*{B}_{s}^{\prime\ast}{\bar{B}}_{s}^{\prime\ast} molecular states maybe exist.  相似文献   

15.
The spectral functor of an ergodic action of a compact quantum group G on a unital C *-algebra is quasitensor, in the sense that the tensor product of two spectral subspaces is isometrically contained in the spectral subspace of the tensor product representation, and the inclusion maps satisfy natural properties. We show that any quasitensor *-functor from Rep(G) to the category of Hilbert spaces is the spectral functor of an ergodic action of G on a unital C *-algebra. As an application, we associate an ergodic G-action on a unital C *-algebra to an inclusion of Rep(G) into an abstract tensor C *-category . If the inclusion arises from a quantum subgroup K of G, the associated G-system is just the quotient space K\G. If G is a group and has permutation symmetry, the associated G-system is commutative, and therefore isomorphic to the classical quotient space by a subgroup of G. If a tensor C *-category has a Hecke symmetry making an object ρ of dimension d and μ-determinant 1, then there is an ergodic action of S μ U(d) on a unital C *-algebra having the as its spectral subspaces. The special case of is discussed.  相似文献   

16.
A comparative investigation of the magnetic properties of amorphous nanogranular composites (Co41Fe39B20) x (SiO n )100 − x and (Co86Nb12Ta2) x (SiO n )100 − x has been performed in the subpercolation region at temperatures in the range 4.2–300 K. The thermomagnetic dependences in the range 4.2–300 K and the processes of magnetization reversal and remanent magnetization relaxation at liquid-helium temperatures have been studied. It has been established that the average anisotropy constants of amorphous nanograins are equal to 3.6–7.0 kJ/m3 for the (Co41Fe39B20) x (SiO n )100 − x composites and 5–8 kJ/m3 for the (Co86Nb12Ta2) x (SiO n )100 − x composites. The fundamental differences in the concentration dependences of the anisotropy constant K eff and the coercive force H C have been revealed for the two systems under investigation. It has been demonstrated that, as the concentration of the metal phase increases, the quantities K eff and H C increase for the (Co86Nb12Ta2) x (SiO n )100 − x composites and decrease for the (Co41Fe39B20) x (SiO n )100 − x composites.  相似文献   

17.
In this article, we assume that there exists a scalar Ds*[`(D)]s*D_{s}^{\ast}{\bar{D}}_{s}^{\ast} molecular state in the J/ψ φ invariant mass distribution, and we study its mass using the QCD sum rules. The predictions depend heavily on the two criteria (pole dominance and convergence of the operator product expansion) of the QCD sum rules. The value of the mass is about MDs*[`(D)]s*=(4.43±0.16)M_{D_{s}^{\ast}{\bar{D}}_{s}^{\ast}}=(4.43\pm0.16)  GeV, which is inconsistent with the experimental data. The Ds*[`(D)]s*D_{s}^{\ast}{\bar{D}}_{s}^{\ast} is probably a virtual state and is not related to the meson Y(4140). Another possibility, such as a hybrid charmonium, is not excluded.  相似文献   

18.
We construct a 3-3-1 model based on family symmetry S 4 responsible for the neutrino and quark masses. The tribimaximal neutrino mixing and the diagonal quark mixing have been obtained. The new lepton charge \(\mathcal{L}\) related to the ordinary lepton charge L and a SU(3) charge by \(L=\frac{2}{\sqrt{3}}T_{8}+\mathcal{L}\) and the lepton parity P l =(?) L known as a residual symmetry of L have been introduced which provide insights in this kind of model. The expected vacuum alignments resulting in potential minimization can origin from appropriate violation terms of S 4 and \(\mathcal{L}\). The smallness of seesaw contributions can be explained from the existence of such terms too. If P l is not broken by the vacuum values of the scalar fields, there is no mixing between the exotic and the ordinary quarks at tree level.  相似文献   

19.
The final-state interaction of pions in K e4 decay allows to obtain the value of the isospin and angular-momentum-zero ππ scattering length a 00.We take into account the electromagnetic interaction of pions and isospin-symmetry-breaking effects caused by different masses of neutral and charged pions and estimate the impact of these effects on the procedure of scattering-length extraction from K e4 decays.  相似文献   

20.
The Raman spectra of mixed Hg2(Br,I)2 and Hg2(Cl,Br)2 crystals were investigated. The multimode behavior of optical vibrations induced by presence of three types of molecules (Hg2 Hal2, Hg2 Hal2 and Hg2 HalHal″) in the crystals was observed experimentally and is discussed theoretically. Phase transition effects such as soft modes, density of states, IR vibration branches, and anti- and ferroelectric nanoclusters induced by polar Hal′-Hg-Hg-Hal″ molecules and their immediate environment, were observed in the Raman spectra.  相似文献   

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