Nuclear Physics B最新文献

In Gepner's pioneering work, the requirement that leads to a model having the desired $N=1$ Spacetime supersymmetry and $E\left(8\right)\times E\left(6\right)$ Gauge symmetry was the requirement that the spacetime symmetry is compatible with modular invariance. In this work we show that the requirement for the simultaneous fulfillment of mutual locality of the left-moving vertices of physical states with the space-time symmetry generators and of right-moving vertices with generators of $E\left(8\right)\times E\left(6\right)$-gauge symmetry, which arises after some special reduction together with the requirement of mutual locality of complete (left-right) vertices of physical states among themselves leads to the same Gepner models.

By considering the basis-covariant constituents of N-Higgs-doublet potentials, we derive necessary and sufficient conditions for canonical $\mathrm{SO}{\left(4\right)}_C$ Custodial Symmetry (CS) of potentials with $N>2$ doublets, based on representation-theoretical and geometrical relations. In essence, our characterization relates the presence of canonical CS to basis-covariant vectors corresponding to particular bases of the defining representation of the orthogonal Lie algebras. For $N=3,4$ and 5, the conditions demand little computational effort to be evaluated, and we provide practical algorithms that may be efficiently implemented in a computer program, for deciding whether or not a potential is custodial-symmetric.

In this letter, we revisit the quantisation problem for a fundamental model of classical mechanics—the Zhukovsky-Volterra top. We have discovered a four-parametric pencil of compatible Poisson brackets, comprising two quadratic and two linear Poisson brackets. Using the quantisation ideal method, we have identified two distinct quantisations of the Zhukovsky-Volterra top. The first type corresponds to the universal enveloping algebras of $so\left(3\right)$, leading to Lie-Poisson brackets in the classical limit. The second type can be regarded as a quantisation of the four-parametric inhomogeneous quadratic Poisson pencil. We discuss the relationships between the quantisations obtained in our paper, Sklyanin's quantisation of the Euler top, and Levin-Olshanetsky-Zotov's quantisation of the Zhukovsky-Volterra top.

Muography is an innovative imaging technique using naturally produced elementary particles – atmospheric muons – used to determine the distribution of density inside massive objects. The modification of the particles flux – by scattering or absorption – reflects the contrasts in density within the medium and therefore offers the possibility for an image of the crossed volumes. In most muography setups the imaging process is based on the tracking of the particles which accounts for the absorption or the scattering of the muons trajectories. Neither the energy nor the identity of the particles (the so-called PID) is exploited since this information traditionally relies on the use of calorimeters and/or high intensity magnetic fields. Both these techniques hinder detector portability which in the case of muography is important and this renders them impractical for its purpose. In this paper we characterize the performance of a simple and small water Cherenkov detector capable of providing some insights on the energy of muons and the PID for the crossing particles that could potentially improve the background rejection for a muography survey when operating in conjunction with a muon telescope. We tested a prototype of such water Cherenkov detector in combination with two small muon hodoscopes. Both systems are using the same opto-electronics chain – optical fibers and pixellized photosensors – and the same data acquisition (DAQ) readout system which ensures an easy integration and implementation within presently running systems. This article presents the test setup, the detector response to cosmic muons and its performance evaluation against a basic simulation of its geometry and detection principle.

We consider black holes with quintessence matter and cloud of strings to study shadow, optical appearance and stability by using the extended generalized uncertainty principle. We first evaluate the relations for modified Hawking temperature, heat capacity, equation of state and remnant mass for the considered model and then plot these relations in order to analyze the quantum correction effects on the stability of the black holes. In the visual plot of specific heat, we observe critical regions where the black hole transitions from being thermodynamically stable to unstable and vice versa. Moreover, we also observe that the regions of stability and instability are not uniform across, suggesting that extended generalized uncertainty principle plays a vital role in thermodynamic properties. We also investigate the silhouette and optical properties of the Lovelock black hole, particularly analyzing illumination with two theoretical models of static accretion. We observe that different values of Lovelock coupling constants significantly influence the size of image and intensities of the black hole.

In this manuscript, we investigate the properties of Casimir wormholes within the framework of extended teleparallel gravity, incorporating the Generalized Uncertainty Principle. Both the Casimir effect and the Generalized Uncertainty Principle (GUP) originate from the concept of a fundamental minimum length. Our analysis explores the geometric and physical traits of these wormholes, examining two distinct GUP constructions namely the Kempf, Mangano, and Mann (KMM) model and the Detournay, Gabriel, and Spindel (DGS) model and their corresponding equations of state. We find that the resulting wormhole solutions exhibit anisotropic effects and violate the null energy condition, implying the presence of exotic fluid. By employing volume integral techniques, we compute the quantity of exotic fluid, providing new insights into the nature of these wormholes. Our study sheds light on the implications of GUP-corrected Casimir wormholes for our understanding of gravity and the structure of spacetime.

In this paper, we investigate the thermodynamic topology of four and five-dimensional Hořava-Lifshitz (HL) black holes within Hořava gravity. To analyze their thermodynamic topology, we treat these HL black holes as topological defects in their thermodynamic spaces and compute the winding numbers at these defects. Our study is conducted in two different ensembles: the fixed ϵ ensemble and the fixed ζ ensemble, where ϵ is a parameter of the HL black holes, and ζ is its conjugate parameter. In the fixed ϵ ensemble, we consider three different horizon types: spherical ($k=+1$), flat ($k=0$), and hyperbolic ($k=-1$), while in the fixed ζ ensemble, we examine two horizon types: spherical ($k=+1$) and hyperbolic ($k=-1$). For all the aforementioned cases, we study the local and global topology of these black holes and classify them into topological classes based on their topological charges. We calculate the topological number for each case. This process uncovers some novel phase diagrams that reveal a number of multiple defect curve phenomenon. Additionally, we explore how the topological charge of these black holes depends on the values of the thermodynamic parameters. Our findings indicate that the thermodynamic topology of Hořava-Lifshitz black holes in $D=4,5$ is significantly influenced by the type of horizon, the choice of ensemble, the values of pressure, and the parameters ϵ or ζ.

In this study, the Universe's rip cosmology theories have been provided for the $f(Q,C)$ gravity theory, where Q and C stand for the non-metricity scalar and boundary term. We assume $f(Q,C)=\alpha Q^n+\beta C$ and analyze the nature of the physical parameters for the Little Rip (LR), Big Rip (BR) and Pseudo Rip (PR) models. In the LR and PR models, the EoS parameter exhibits phantom characteristics but remains closely aligned with the ΛCDM line. The non-metricity term Q has direct effect on the rip models. After investigating the energy conditions, we recognise that our model violates the strong energy constraint. Avoiding singularity situations has been noted in all of these accelerated models. The characteristics of the jerk and snap parameters have been investigated. Our model provides an effective description of the Universe's evolutionary history and fits well with contemporary cosmic data.

The paper studies the quantum action for the four-dimensional real ${\varphi }^4$-theory in the case of a general formulation using the background field method. The three-loop renormalization is performed with the usage of a cutoff regularization in the coordinate representation. The absence of non-local singular contributions and the correctness of the renormalization $R$-operation on the example of separate three-loop diagrams are also discussed. The explicit forms of the first three coefficients for the renormalization constants and for the β-function are presented. Consistency with previously known results is shown.

Motivated by the latest CDF W-mass measurement as well as the muon $g-2$ anomaly and the discrepancies observed in $b\to s{\ell }^{+}{\ell }^{-}$ transitions, we propose an extension of the Standard Model (SM) with the $SU{\left(2\right)}_L$-singlet vector-like fermion partners that are featured by additional $U{\left(1\right)}^{\prime }$ gauge symmetry. The fermion partners have the same SM quantum numbers as of the right-handed SM fermions, and can therefore mix with the latter after the electroweak and the $U{\left(1\right)}^{\prime }$ symmetry breaking. As a result, desirable loop-level corrections to the ${(g-2)}_{\mu }$, the W-boson mass $m_W$ and the Wilson coefficient $C_9$ in $b\to s{\mu }^{+}{\mu }^{-}$ transitions can be obtained. The final allowed parameter space is also consistent with the constraints from the $Z\to {\mu }^{+}{\mu }^{-}$ decay, the neutrino trident production and the LHC direct searches for the vector-like quarks and leptons.