Nuclear Physics B最新文献

In the present work, we construct the diquark-antidiquark type four-quark currents to investigate the mass spectrum of the ground state hidden-charm-hidden-strange tetraquark states with the quantum numbers $J^{PC}=0^{++}$, $1^{+-}$, $1^{++}$ and $2^{++}$ via the traditional QCD sum rules in a comprehensive way. We update old calculations, perform new calculations and analysis in a rigorous way, and take account of the net light-flavor $SU\left(3\right)$ breaking effects in a consistent way. And we make more reasonable identifications for the $X\left(3960\right)$, $X\left(4140\right)$, $X\left(4274\right)$, $X\left(4500\right)$, $X\left(4685\right)$ and $X\left(4700\right)$ and supersede some old identifications. Furthermore, we consider our previous theoretical predictions, and make reasonable/suitable identifications of the new LHCb states $h_c\left(4000\right)$ and ${\chi }_{c1}\left(4010\right)$.

We present a Dirac mass model based on $A_4$ modular symmetry within Type-I seesaw framework. This extension of Standard Model requires three right-handed neutrinos and three heavy Dirac fermions superfields, all singlet under $SU{\left(2\right)}_L$ symmetry. The scalar sector is extended by the inclusion of a $SU{\left(2\right)}_L$ singlet superfield, χ. Here, the modular symmetry plays a crucial role as the Yukawa couplings acquire modular forms, which are expressed in terms of Dedekind eta function $\eta \left(\tau \right)$. Therefore, the Yukawa couplings follow transformations akin to other matter fields, thereby obviating the necessity of additional flavon fields. The acquisition of vev by complex modulus τ leads to the breaking of $A_4$ modular symmetry. We have obtained predictions on neutrino oscillation parameters, for example, the normal hierarchy for the neutrino mass spectrum. Furthermore, we find that heavy Dirac fermions, in our model, can decay to produce observed baryon asymmetry of the Universe through Dirac leptogenesis.

In this paper, an effective Lagrangian of an itinerant electron system of finite density at a finite magnetic field is obtained. It includes a Chern-Simons term of electromagnetic potentials of lower-scale dimensions compared to those studied before. This term has an origin in the many-body wave function and a unique topological property that is independent of a spin degree of freedom. The coupling strength is proportional to $\frac{\rho }{eB}$, which is singular at $B=0$ for a constant charge density. The effective Lagrangian at a finite B represents the physical effects at $B\ne 0$ properly. A universal shift of the magnetic field known as the Slater-Pauling curve is obtained from the effective Lagrangian.

Modifications of Dirac operators in supergravity flux backgrounds are considered. Modified spin curvature operators and squares of modified Dirac operators corresponding to Schrödinger-Lichnerowicz-like formulas are obtained for different types of flux modifications. Symmetry operators of modified massless and massive Dirac equations are found in terms of modified Killing-Yano and modified conformal Killing-Yano forms. Extra constraints for symmetry operators in terms of different types of fluxes and modified Killing-Yano forms are determined.

In this work, we investigate braneworld models generated by scalar fields in which one field has a split kink profile, in which a kink separates into two kinklike configurations. Our analysis covers models with two and three fields, examining the behavior of the most important quantities associated with the brane, such as the warp factor and the stability of the corresponding gravity sector. The results show that the brane is stable and supports a hybrid character, behaving as a thin and thick configuration.

In this research, we study black hole stability and phase transition in Einstein-Maxwell-dilaton (EMD) gravity. A dilaton field is non-minimally related to the Maxwell field in the EMD gravity and is an intriguing alternative for General Relativity. By using the thermodynamic laws of the black holes, temperature, entropy, heat capacity, pressure, critical points and Gibbs free energy of charged static dilaton black holes in EMD gravity were all thoroughly explored and effects of dilaton constant on these quantities are studied and the results are compared with Schwarzschild, Reissner-Nordström, and Gibbons-Maeda-Garfinkle-Horowitz-Strominger (GMGHS) black holes. In other cases, the system has stable and unstable areas. Since the heat capacity is discontinuous, the system experiences a phase transition, and Van der Waals-like phase transitions occur between the small and large black holes. It has been observed that the heat capacity for the GMGHS and Schwarzschild black holes is always negative, making these systems unstable.

A holographic method for implementing a particular supersymmetry-preserving deformation to 4d SCFTs is presented. At the heart of the procedure is a soliton solution of minimal $d=5$ gauged supergravity. Embedding this solution into ten- and eleven-dimensional string theory backgrounds of the form AdS${}_5\times M$, we systematically construct a range of new solutions. Each holographically realizes a twisted compactification of the SCFT₄ dual to the original background. In the IR, the resulting SQFTs flow to gapped three-dimensional systems. Using a variety of holographic observables, we give evidence for this interpretation and for confinement in the deformed SQFTs. Our method applies to any holographic solutions admitting a consistent truncation to minimal $d=5$ gauged supergravity, and can likely be generalized to solutions with other AdS_d factors.

I calculate $\frac{1}{Q^2}$ power corrections to unpolarized Drell-Yan hadronic tensor for electromagnetic (EM) current at large $N_c$ and demonstrate the EM gauge invariance at this level.

One of the main difficulties in general relativity is the potential conflict between the weak gravity conjecture (WGC) and weak cosmic censorship conjecture (WCCC). Cosmic censorship is a basic assumption that guarantees the coherence of the gravity theory. However, this paper examines the feasibility of harmonizing the WGC and the WCCC by studying the Kerr Newman black hole surrounded by perfect fluid dark matter (PFDM) in asymptotically flat spacetimes. These two conjectures appear to be unrelated, but a recent idea proposed that they have a surprising connection. Specifically, we present a plausible set of for the WCCC in the four-dimensional framework, considering a Kerr-Newman black hole when WGC is active. We show that by applying certain restrictions on the parameters of the metric, the WGC and the WCCC can be consistent. Moreover, we explore the characteristics of the Kerr Newman black hole in the presence of PFDM for $Q>M$ and display some fascinating figures to verify the accuracy of the WGC and the WCCC at the same time. When PFDM is absent ($\lambda =0$), the Kerr Newman black hole has either two event horizons if $Q^2/M^2\le 1$, or none if $Q^2/M^2>1$. The latter case leads to a naked singularity, which violates the WCCC. But when PFDM is present ($\lambda \ne 0$), the Kerr Newman black hole has event horizons depending on Q, a, and M. This means that the singularity is always hidden, and the WGC and the WCCC are satisfied. Furthermore, we prove that there is a critical value of λ, denoted by ${\lambda }_{ext}$, that becomes the extremality Kerr Newman black hole when $\lambda ={\lambda }_{ext}$. In this case, the black hole has an event horizon, and the WGC and the WCCC are still satisfied. We conclude that PFDM can make the WGC and the WCCC compatible for the Kerr Newman black hole and that the WGC and the WCCC concur with each other when PFDM is present.