Journal of High Energy Physics最新文献

We consider a class of models in even spacetime dimensions 2n which share many similarities with Chern-Simons theories in odd spacetime dimensions 2n + 1. The independent dynamical variables of these models are a GL(2n)-connection and a metric in internal space. The action is a polynomial of degree n in the curvature of the connection, with indices saturated by means of the metric and the Levi-Civita tensor. We show that the theory has no local degree of freedom in 2 spacetime dimensions (n = 1), where it can be reformulated as a constrained BF model, but that its dynamics is more intrincate in higher dimensions (n > 1), where local degrees of freedom are present. We treat in detail the cases of 2 and 4 spacetime dimensions.

Following a proposal for an experiment with sensitivity to an electric dipole moment (EDM) of the muon d_μ of order 6 × 10⁻²³ e cm, three to four orders of magnitude below the current bound, but still seven orders of magnitude above the current bound on the EDM of the electron d_e, we explore the discovery potential of such an experiment. Within the dimension-six CP violating operators of the Standard Model effective field theory (SMEFT), we identify two dipole operators where d_μ has the strongest sensitivity, and four classes of four-fermion operators where it has the best sensitivity for regions of parameter space that are far from minimal flavor violation. We further consider three UV completions: vector-like leptons (VLLs), heavy vector boson with off-diagonal leptonic couplings, and two Higgs doublet model. For each, we identify the region in parameter space that will be uniquely explored by the proposed d_μ experiment. In case of VLLs, we also find measurements of Γ(h → μμ) offer competitive sensitivity, highlighting the complementary role of collider observables. Generically, the potential reach is to ( mathcal{O} )(10 TeV) scale of new physics.

The 11D pure spinor worldline has been proved to successfully describe the physical states of 11D supergravity in a manifestly super-Poincaré covariant fashion. Within this framework, the computation of scattering amplitudes requires the existence of vertex operators carrying different ghost numbers. A recent no-go theorem demonstrated the impossibility of constructing a ghost number zero vertex operator consistent with 11D supergravity in the minimal pure spinor formalism. In this letter, we overcome this obstruction by working in the non-minimal formulation of the 11D pure spinor superparticle. We construct, for the first time, a ghost number zero vertex operator with a remarkably compact structure when expressed in terms of physical operators. We further verify that it satisfies the expected descent relation with the ghost number one vertex operator, and that its commutator with the ghost number three single-particle vertex reproduces the two-particle superfield recently introduced in the literature.

Orbifold CFTs contain twist operators that can join and split copies of the CFT. In this paper, we study the effects of four twist-2 operators on two copies of a single free boson. A recent study analyzed their effects on the vacuum, finding a nontrivial left-right mixing that arises from the fact that the covering surface is a torus, while the effects of one or two twist-2 operators do not produce such mixing. Here, we extend this analysis to excited states and find a similar left-right mixing. Furthermore, we explore the continuum, or high-energy, limit and show that the left-right mixing becomes negligible in this limit.

We discuss a basis for the nonperturbative Hilbert space of quantum gravity with one asymptotic boundary. We use this basis to show that the Hilbert space for gravity with two disconnected boundaries factorizes into a product of two copies of the single boundary Hilbert space.

We investigate the problem of bulk metric reconstruction in holography by leveraging the inverse scattering framework applied to boundary two-point correlation functions. We generalize our previous work of scalar field and show that reconstruction can be achieved using a single operator rather than a pair. We also apply this method into reconstruction of static homogeneous anisotropic black holes and the reconstruction using correlation function of gauge field. In addition, we analyze the method’s robustness under measurement noise and propose filtering strategies to improve reconstruction accuracy. This work advances data-driven bulk reconstruction by providing a concrete, experimentally viable pathway to recover spacetime geometry from field-theoretic observables.

Instanton contributions in 2d string theory are known to include subtle numerical factors ζ_n closely related to a contour prescription in multi-instanton string amplitudes. Both ingredients appear to be ambiguous due to a degeneracy between (1, n)-ZZ instantons and n (1,1)-ZZ instantons in the linear dilaton background. We resolve this ambiguity using insights from the dual matrix quantum mechanics where the multipliers ζ_n can be derived from an integral representation of the scattering phase and follow from the median resummation prescribed by resurgence theory. We evaluate multi-instanton string amplitudes in the theory compactified on a circle of finite radius for arbitrary number of instantons and show that they reproduce the matrix model predictions provided the Lorentzian contour prescription is used for their evaluation. We also show that the non-perturbative free energy matches the structure of the D-instanton induced string field theory effective action, which suggests the vanishing of contributions from worldsheet topologies of negative Euler number.

The current work involves augmenting the ∆(54) discrete flavor model by incorporating two Standard Model Higgs particles into the Inverse Seesaw mechanism. We introduced Weyl fermions and Vector like fermions, which are gauge singlets in the Standard Model and produces Majorana mass terms in our Lagrangian. The resulting mass matrix produces a non-zero reactor angle (θ₁₃). We have determined the effective Majorana neutrino mass, which is the parameter of relevance in neutrinoless double beta decay investigations. We additionally investigate the possibility of baryogenesis in the proposed framework via resonant leptogenesis. We have the non-zero value for resonantly enhanced CP asymmetry originating from the decay of right-handed neutrinos at the TeV scale, accounting for flavor effects. The evolution of lepton asymmetry is systematically analyzed by numerically solving a set of Boltzmann equations, leading to the determination of the baryon asymmetry with a magnitude of |η_B| ≈ 6 × 10⁻¹⁰. This outcome is achieved by selecting specific values for the right-handed neutrino mass M₁ = 10 TeV and mass splitting, d ≈ 10⁻⁸.

Axion models generically suffer from a severe quality problem when coupled to gravity. In this article we provide a very simple model with a high quality axion. The axion is a pseudo-Nambu-Goldstone boson of the baryon number symmetry, U(1)_B, of a new composite sector that breaks U(1)_B spontaneously when it confines. A controlled example is a supersymmetric QCD (SQCD) with N_c = N_f. The axion shift symmetry is automatically protected due to the high dimension of the gauge-invariant baryon operator, with the Peccei-Quinn breaking operators arising at dimension N_c + 2. The standard model gauge group is embedded as a subgroup of the flavor symmetry group of SQCD that has an anomaly with U(1)_B, generating the standard coupling with gluons.

The free energy, or equivalently the ground state energy in finite volume, may be calculated from forward scattering amplitudes using a formula due to Dashen, Ma, and Bernstein [1]. However a naive treatment leads to singularities when considering the scattering of three or more particles. It is shown in detail how the approach can be applied to multi-particle scattering in various massive scalar theories in 1+1d, with or without integrability. The results for the sinh-Gordon, Lieb-Liniger, and O(N) non-linear sigma models are compared to exact results. It is shown how bound states can be considered in this approach by considering the attractive Lieb-Liniger model.