Journal of High Energy Physics最新文献

Electronic excitations in atomic, molecular, and crystal targets are at the forefront of the ongoing search for light, sub-GeV dark matter (DM). In many light DM-electron interactions the energy and momentum deposited is much smaller than the electron mass, motivating a non-relativistic (NR) description of the electron. Thus, for any target, light DM-electron phenomenology relies on understanding the interactions between the DM and electron in the NR limit. In this work we derive the NR effective field theory (EFT) of general DM-electron interactions from a top-down perspective, starting from general high-energy DM-electron interaction Lagrangians. This provides an explicit connection between high-energy theories and their low-energy phenomenology in electron excitation based experiments. Furthermore, we derive Feynman rules for the DM-electron NR EFT, allowing observables to be computed diagrammatically, which can systematically explain the presence of in-medium screening effects in general DM models. We use these Feynman rules to compute absorption, scattering, and dark Thomson scattering rates for a wide variety of high-energy DM models.

pp → W^±h, Zh processes at the LHC are studied in the framework of the inert doublet model (IDM). To quantify the effects of the IDM and their observability in these processes we revisit the NLO (QCD and EW) predictions in the Standard Model (SM) and their uncertainty. Taking all available current constraints on the parameter space of the IDM, we consider both the case of the IDM providing a good Dark Matter (DM) candidate within the freeze-out mechanism as well as when the DM restrictions are relaxed. In the former, deviations from the SM of only a few per mil in these cross sections at the LHC are found and may not be measured. In the latter, the deviations can reach a few percents and should be observable. Smaller discrepancies in this case require that the theoretical uncertainties be improved, in particular those arising from the parton distribution functions (PDFs). We stress the importance of the photon-induced real corrections and the need for further improvement in the extraction of the photon PDF. The analysis also showcases the development and exploitation of our automated tool for the computation of one-loop electroweak and QCD corrections for a New Physics model with internal tests such as those concerning the soft and collinear parts provided through both dipole subtraction and phase space slicing besides tests for ultra-violet finiteness and gauge-parameter independence.

We address nonperturbative dynamics of the two-dimensional bosonic and supersymmetric CP^N−1 models for general N by developing new tools directly on R². The analysis starts with a new formulation of instantons that is consistent with the existence of the classical moduli space, classical dipole-dipole type interactions of instanton-anti-instanton pairs, and vanishing interaction of instanton-instanton pairs. The classical consistency is achieved via a representation of the instanton as a collection of N pointlike constituents carrying pair of real and imaginary charges valued in the weight lattice of SU(N). The constituents interact via a generalized Coulomb interaction and do not violate the fact that instanton is a single lump with integer topological charge. By developing the appropriate Gibbs distribution, we show that the vacuum can be captured by a statistical field theory of these constituents, and their cluster expansion. Contrary to the common belief that instantons do not capture the vacuum structure and non-perturbation properties of such theories, our refined analysis is able to produce properties such as mass gap, theta dependence, and confinement of the theory on R². In supersymmetric theory, our construction gives a new derivation of the mirror symmetry between the sigma model and the dual Landau-Ginzburg model by Hori and Vafa. Our construction also demonstrates that there is absolutely no conflict between large N and instantons.

Plebanski’s second heavenly equation reduces the problem of finding a self-dual Einstein metric to solving a non-linear second-order PDE for a single function. Plebanski’s original equation is for self-dual metrics obtained as perturbations of the flat metric. Recently, a version of this equation was discovered for self-dual metrics arising as perturbations around a constant curvature background. We provide a new simple derivation of both versions of the Plebanski second heavenly equation. Our derivation relies on the “pure connection” description of self-dual gravity. Our results also suggest a new interpretation to the kinematic algebra of self-dual Yang-Mills theory, as the Lie algebra of (0, 1) vector fields on a ℝ⁴ endowed with a complex structure.

Recent research has leveraged the tractability of ( Toverline{T} ) style deformations to formulate timelike-bounded patches of three-dimensional bulk spacetimes including dS₃. This proceeds by breaking the problem into two parts: a solvable theory that captures the most entropic energy bands, and a tuning algorithm to treat additional effects and fine structure. We point out that the method extends readily to higher dimensions, and in particular does not require factorization of the full T ² operator (the higher dimensional analogue of ( Toverline{T} ) defined in [1]). Focusing on dS₄, we first define a solvable theory at finite N via a restricted T ² deformation of the CFT₃ on S² × ℝ, in which T is replaced by the form it would take in symmetric homogeneous states, containing only diagonal energy density E/V and pressure (-dE/dV) components. This explicitly defines a finite-N solvable sector of dS₄/deformed-CFT₃, capturing the radial geometry and count of the entropically dominant energy band, reproducing the Gibbons-Hawking entropy as a state count. To accurately capture local bulk excitations of dS₄ including gravitons, we build a deformation algorithm in direct analogy to the case of dS₃ with bulk matter recently proposed in [2]. This starts with an infinitesimal stint of the solvable deformation as a regulator. The full microscopic theory is built by adding renormalized versions of T ² and other operators at each step, defined by matching to bulk local calculations when they apply, including an uplift from AdS₄/CFT₃ to dS₄ (as is available in hyperbolic compactifications of M theory). The details of the bulk-local algorithm depend on the choice of boundary conditions; we summarize the status of these in GR and beyond, illustrating our method for the case of the cylindrical Dirichlet condition which can be UV completed by our finite quantum theory.

We consider codimension-one defects in the theory of d compact scalars on a two-dimensional worldsheet, acting linearly by mixing the scalars and their duals. By requiring that the defects are topological, we find that they correspond to a non-Abelian zero-form symmetry acting on the fields as elements of O(d; ℝ) × O(d; ℝ), and on momentum and winding charges as elements of O(d, d; ℝ). When the latter action is rational, we prove that it can be realized by combining gauging of non-anomalous discrete subgroups of the momentum and winding U(1) symmetries, and elements of the O(d, d; ℤ) duality group, such that the couplings of the theory are left invariant. Generically, these defects map local operators into non-genuine operators attached to lines, thus corresponding to a non-invertible symmetry. We confirm our results within a Lagrangian description of the non-invertible topological defects associated to the O(d, d; ℚ) action on charges, giving a natural explanation of the rationality conditions. Finally, we apply our findings to toroidal compactifications of bosonic string theory. In the simplest non-trivial case, we discuss the selection rules of these non-invertible symmetries, verifying explicitly that they are satisfied on a worldsheet of higher genus.

Carrollian amplitudes are flat space amplitudes written in position space at null infinity which can be re-interpreted as correlators in a putative dual Carrollian CFT. We argue that these amplitudes are the natural objects obtained in the flat space limit of AdS Lorentzian boundary correlators. The flat limit is taken entirely in position space by introducing Bondi coordinates in the bulk. From the bulk perspective, this procedure makes it manifest that the flat limit of any Witten diagram is the corresponding flat space Feynman diagram. It also makes explicit the fact that the flat limit in the bulk is implemented by a Carrollian limit at the boundary. We systematically analyse tree-level two, three and four-point correlators. Familiar features such as the distributional nature of Carrollian amplitudes and the presence of a bulk point singularity arise naturally as a consequence of requiring a finite and non-trivial Carrollian limit.

M-theory geometric engineering on non-compact Calabi-Yau fourfolds (CY4) produces 3d theories with 4 supercharges. Carefully establishing a dictionary between the geometry of the CY4 and the QFT in the transverse directions remains, to a large extent, an unresolved challenge, complicated by subtleties arising from M5-brane instanton corrections. Such difficulties can be circumvented in the restricted and yet controlled setting offered by CY4 with terminal singularities, as they do not admit crepant resolutions with compact exceptional divisors. After a general review of their properties and partial classifications, we focus on a subclass of terminal CY4 constructed as deformed Du Val singularities, that admit crepant resolutions with at most exceptional 2-cycles. We extract the corresponding 3d ( mathcal{N} ) = 2 supersymmetric theory descendant in an unambiguous fashion, as the absence of compact 4-cycles leaves no room for a choice of background G₄ flux. These turn out to be theories of chiral multiplets with no gauge group and at most abelian flavor factors: we argue that they serve as the simplest building blocks to substantiate a rigorous CY4/3d QFT geometric engineering mapping.

It has been recently proposed that the naive semiclassical prediction of non-unitary black hole evaporation can be understood in the fundamental description of the black hole as a consequence of ignorance of high-complexity information. Validity of this conjecture implies that any algorithm which is polynomially bounded in computational complexity cannot accurately reconstruct the black hole dynamics. In this work, we prove that such bounded quantum algorithms cannot accurately predict (pseudo)random unitary dynamics, even if they are given access to an arbitrary set of polynomially complex observables under this time evolution; this shows that “learning” a (pseudo)random unitary is computationally hard. We use the common simplification of modeling black holes and more generally chaotic systems via (pseudo)random dynamics. The quantum algorithms that we consider are completely general, and their attempted guess for the time evolution of black holes is likewise unconstrained: it need not be a linear operator, and may be as general as an arbitrary (e.g. decohering) quantum channel.

The Higgs boson decay into bottom quarks is the dominant decay channel contributing to its total decay width, which can be used to measure the bottom quark Yukawa coupling and mass. This decay width has been computed up to ( mathcal{O}left({alpha}_s^4right) ) for the process induced by the bottom quark Yukawa coupling, assuming massless final states, and the corresponding corrections beyond ( mathcal{O}left({alpha}_s^2right) ) are found to be less than 0.2%. We present an analytical result for the decay into massive bottom quarks at ( mathcal{O}left({alpha}_s^3right) ) that includes the contribution from the top quark Yukawa coupling induced process. We have made use of the optical theorem, canonical differential equations and the regular basis in the calculation and expressed the result in terms of multiple polylogarithms and elliptic functions. We propose a systematic and unified procedure to derive the ϵ-factorized differential equation for the three-loop kite integral family, which includes the three-loop banana integrals as a sub-sector. We find that the ( mathcal{O}left({alpha}_s^3right) ) corrections increase the decay width, relative to the result up to ( mathcal{O}left({alpha}_s^2right) ), by 1% due to the large logarithms ( {log}^ileft({m}_H^2/{m}_b^2right) ) with 1 ≤ i ≤ 4 in the small bottom quark mass limit. The coefficient of the double logarithm is proportional to C_A – C_F, which is the typical color structure in the resummation of soft quark contributions at subleading power.