PaperPanorama

HEP Lattice·hep-lat

Mon·Oct 5, 2026

7 papers—5 primary·2 cross-listed

All7Primary5Cross-lists2
  1. 01

    All-mode approach for general tensor renormalization group method

    Katsumasa Nakayama · Shinji Takeda

    We apply the stochastic all-mode technique to general coarse-graining schemes of the tensor renormalization group (TRG) approach. The technique possesses a notable characteristic of being entirely free from systematic errors which can potentially arise in the coarse-graining step, while it has statistical errors caused by random noise. The key element in our generalization is employing a method called squeezer, and the all-mode technique can be used when it is constructed. Since many TRG methods can be described in terms of the squeezers, our approach can be applicable in all such cases. In this work, we demonstrate the new method with higher-order TRG in the two- and three-dimensional Ising model.

    hep-lat
  2. 02

    Towards Precision-Controlled Partonic Structures from First Principles

    Jinchen He

    The internal structure of hadrons is governed by nonperturbative Quantum Chromodynamics (QCD). This dissertation presents first-principles calculations of partonic observables using lattice QCD and effective field theory, with controlled systematic uncertainties, advancing from collinear structure to transverse-momentum-dependent distributions (TMDs) that encode the three-dimensional partonic structure of hadrons. Within the large momentum effective theory (LaMET) framework, this work presents state-of-the-art calculations of pion distribution amplitudes and systematic studies of nucleon parton distributions, with control of renormalization, excited-state contamination, Fourier-transform systematics, and power corrections. A Coulomb-gauge formulation of quasi-distributions simplifies ultraviolet structure by avoiding Wilson-line related linear divergences, with Gribov-copy effects found to be negligible at current statistical precision. Building on these developments, this dissertation reports lattice determinations of nucleon TMD parton distributions, the Collins-Soper kernel, the intrinsic soft function, and pion TMD observables. These results provide nonperturbative inputs for global QCD analyses and the precision hadron-structure program, including the Electron-Ion Collider. In parallel, this work explores machine-learning acceleration of lattice gauge simulations through neural field transformations embedded in Hybrid Monte Carlo. In two-dimensional U(1) tests, the method reduces autocorrelation and improves performance toward finer lattice spacing, suggesting potential applications to more efficient lattice QCD simulations.

    hep-lathep-ph
  3. 03

    Critical coupling and in three-dimensional theory

    Stephan Durr · Tolga S. H. Kiel

    We consider the theory with in three Euclidean dimensions. For a variety of self-couplings , the critical (bare) parameter is determined where the lattice-regulated system changes from the symmetric phase to the broken phase. Next, we send the box volume to infinity and switch to a universal scheme; this yields for each simulated . Finally, a continuum extrapolation gives , and we find . In addition, is determined in the combined continuum and infinite-volume limit.

    hep-latcond-mat.stat-mech
  4. 04

    Looking at radiative corrections to the semileptonic decay-rate ratio

    Constantia Alexandrou · Simone Bacchio · Antonio Evangelista · Andreas Konstantinou · Nazario Tantalo

    We investigate the impact of radiative corrections on the ratio of the semileptonic decay rates . Phenomenological analyses point to sizable radiative effects on the experimentally measured ratio. From a theoretical perspective, this observable is particularly appealing because several hadronic and electroweak contributions partially cancel in the ratio, providing a cleaner probe of electromagnetic effects. We identify the dominant contributions to the radiative corrections and develop the framework for a dedicated calculation. This represents a first step toward a precise theoretical description of baryon semileptonic decays, helping to assess their potential as precision tests of the Standard Model.

    hep-lat
  5. 05

    Complex-momentum form factors from lattice QCD

    Maxwell T. Hansen · Gurtej Kanwar

    We demonstrate that form factors evaluated at complex-valued momenta can be directly accessed from position-space Euclidean correlators without analytically continuing the latter and without solving an inverse problem. The approach directly applies a bilateral Laplace transform to the lattice data, which provides the analytically continued form factor wherever it converges. Focusing on the pion form factor in Quantum Chromodynamics (QCD), this gives access to the observable as a function of invariant \(Q^2\) throughout an extended analytic domain consisting of all complex \(Q^2\) with real part larger than \(-4m_\pi^2\). This could, for example, be used to improve charge-radius determinations or provide more complete data for fits based on conformal mapping of the data. After developing the approach for infinite-volume correlators, we discuss various options for finite-volume estimators suitable for realistic calculations, including position-space fits or application of a spatial chemical potential represented by boundary conditions with an imaginary twist angle. Finally, we test the method in the two-dimensional \(O(3)\) nonlinear sigma model using Monte Carlo data.

    hep-lathep-th
  6. 06

    Blackened BPS: the end of the thermal BMN branch

    Jorge E. Santos

    We study the thermodynamics of the BMN matrix model at large and strong coupling, using its dual black holes in eleven-dimensional supergravity. Within the consistent truncation to two-dimensional gauged supergravity, the static -invariant black holes solve ordinary differential equations, which we solve to high precision. We formulate holographic renormalisation for this truncation and fix the finite counterterms using a supersymmetric solution. This gives the energy, the entropy and the response to the BMN mass independently, and we verify the first law and the Smarr relation along the branch. The thermal branch ends at a critical value of , which power-law fits place at with an estimated uncertainty below . The first-order transition inferred in earlier work, where the free energy was reconstructed from the entropy, does not survive, and an independent eleven-dimensional calculation agrees with ours over the range it covers. Instead, the free energy, the entropy and the mass response approach their values in the confined phase continuously at the end of the branch, where the solutions become singular. If this branch remains the dominant one up to its end point, the transition therefore coincides with the singularity. Near the end of the branch, the scalar fields follow a solution of the supersymmetric first-order equations, while the metric carries a nontrivial blackening factor. The horizon develops a neck whose profile is universal, with radii growing as the power of the distance from the pinch. Within the range we resolve, the geometry is not that of the Ricci-flat double cone which governs mergers of vacuum black holes.

    ↳ hep-thhep-lat
  7. 07

    A Polynomial-Scaling PDE Solver with Entanglement-Basis Tensor Networks

    Abhijatmedhi Chotrattanapituk · Michael J. Landry · Chu-Liang Fu · Mingda Li

    We develop a finite element method (FEM) for partial differential equation (PDE) solver based on the entanglement-basis representation introduced in our companion work. By lifting non-linear finite-element equations into an augmented coefficient space, the governing PDE together with boundary, initial, and inter-element constraints can be expressed through a unified quadratic residual minimization. Although this augmented space grows exponentially with the number of elements, its tensor-product structure allows it to be represented efficiently using tensor networks. Using the matrix product state (MPS) as a concrete example, we show that density matrix renormalization group (DMRG) sweeps enable element-by-element optimization without explicitly constructing the full augmented space. For bounded bond dimension, the resulting computational cost scales polynomially with the number of finite elements. We extend the framework to time-dependent problems through implicit temporal discretization and demonstrate convergence under both mesh and polynomial refinement using diffusion equations.

    ↳ math.NAcond-mat.othercs.NAhep-lat+1