International Journal of Modern Physics A

This document is based on five conversations between Prof. C. N. Yang and others in Beijing in 1986. In the conversations, Yang gave his views on the state and development of physics at that time, and the relationship between physics and philosophy. The conversations also contain Yang’s reminiscences on the creation of Yang–Mills theory and his advice to young people, especially those in China.

The $\mathrm{{\rm Y}}(1S)\to B_c{D}_s^{\ast }$ weak decay is studied with the perturbative QCD approach firstly. It is found that (1) main contributions to branching ratio come from the longitudinal and parallel helicity amplitudes, (2) branching ratio, longitudinal and parallel polarization fractions are sensitive to the wave functions of the $\mathrm{{\rm Y}}(1S)$ meson, (3) branching ratio for the $\mathrm{{\rm Y}}(1S)\to B_c{D}_s^{\ast }$ decay can reach up to $10^{-9}$, which might be promisingly measured by the future experiments.

In this paper, we discuss the chiral anomaly in a Lorentz-breaking extension of QED which, besides the common terms that are present in the Standard Model Extension, includes some dimension-five nonminimal couplings. We find, using the Fujikawa formalism, that these nonminimal couplings induce new terms in the anomaly which depend on the Lorentz-violating parameters. Perturbative calculations are also carried out in order to investigate whether new ambiguous Carroll–Field–Jackiw terms are induced in the effective action.

We consider a pure connection action plus additional algebraic constraints that are suitable for a straightforward supergroup extension. By taking as an internal group $SU(2)$, the action reduces to the Capovilla, Dell and Jacobson approach. By taking as an internal symmetry the supergroup $OSp(2|1)$, and by means of the Bianchi identity and integrability conditions, the equations of motion are those that could be found from antiself-dual supergravity $N=1$ with cosmological constant sector.

We argue that the exceptional field theory is a truncation of the nonlinear realisation of the semi-direct product of $E_{11}$ and its first fundamental as proposed in 2003. Evaluating the simple equations of the $E_{11}$ approach, and using the commutators of the $E_{11}$ algebra, we find the local variations of the fields of exceptional field theory after making a radical truncation. This procedure does not respect any of the higher level $E_{11}$ symmetries and so these are lost. We suggest that the need for the section condition in the exceptional field theory could be a consequence of the truncation.

In this paper, we investigate the entanglement entropy for the generalized charged BTZ black hole through the AdS₃/CFT₂ correspondence. Using the holographic description of the entanglement entropy for the strip-subsystem in boundary CFT₂, we will find the first law-like relation between the variation of holographic entanglement entropy and the variation of energy of the subsystem in terms of the mass and the electric charge up to the second-order. We also obtain appropriate counterterms to renormalize the energy tensor associated with the bulk on-shell actions.

We build unitary representations of the BMS algebra and its higher-spin extensions in three dimensions, using induced representations as a guide. Our prescription naturally emerges from an ultrarelativistic limit of highest-weight representations of Virasoro and ${𝒲}$ algebras, which is to be contrasted with nonrelativistic limits that typically give nonunitary representations. To support this dichotomy, we also point out that the ultrarelativistic and nonrelativistic limits of generic ${𝒲}$ algebras differ in the structure of their nonlinear terms.

The next-to-minimal supersymmetric Standard Model (NMSSM) with an extended Higgs sector offers at least one Higgs boson as the Standard Model (SM)-like Higgs with a mass around 125 GeV. In this work, we revisit the mass spectrum and couplings of non-SM-like Higgs bosons taking into consideration most relevant constraints and identify the relevant parameter space. The discovery potential of these non-SM-like Higgs bosons, apart from their masses, is guided by their couplings with gauge bosons and fermions which are very much parameter space sensitive. We evaluate the rates of productions of these non-SM-like Higgs bosons at the LHC for a variety of decay channels in the allowed region of the parameter space. Although $b\bar{b}$, $\tau \tau$ modes appear to be the most promising decay channels, but for a substantial region of parameter space the two-photon decay mode has a remarkably large rate. In this study we emphasize that this diphoton mode can be exploited to find the non-SM-like Higgs bosons of the NMSSM and can also be a potential avenue to distinguish the NMSSM from the MSSM. In addition, we discuss briefly the various detectable signals of these non-SM Higgs bosons at the LHC.

Following a procedure recently utilized by Accioly et al. to obtain the D-dimensional interparticle potential energy for electromagnetic models in the nonrelativistic limit, and relaxing the condition assumed by the authors concerning the conservation of the external current, the prescription found out by them is generalized so that dual models can also be contemplated. Specific models in which the interaction is mediated by a spin-0 particle described first by a vector field and then by a higher-derivative vector field, are analyzed. Systems mediated by spin-1 particles described, respectively, by symmetric rank-2 tensors, symmetric rank-2 tensors augmented by higher derivatives and antisymmetric rank-2 tensors, are considered as well.