HEP Lattice·hep-lat

Mon·Aug 31, 2026Monday·August 31, 2026

8 papers—3 primary·5 cross-listed

01
A different kind of continuum limit for the three-dimensional U(1) gauge theory
Andreas Athenodorou🇨🇾 · Claudio Bonati🇮🇹 · Ivan Soler Calero🇮🇹
In three-dimensional compact U(1) lattice gauge theory color confinement can be understood analytically through the dynamics of magnetic monopoles. However, its continuum limit is pathological, since the ratio of the glueball masses to the square root of the string tension vanishes as the continuum limit is approached. We investigate a simple extension of the Wilson action in which the total number of lattice monopoles is coupled to an additional parameter $μ$ . By tuning $β$ and $μ$ simultaneously, we identify a line of constant physics along which the ratio of the lightest glueball mass to the square root of the string tension remains constant. We further show that the same scaling is satisfied, within numerical uncertainties, by the other low-lying glueball masses considered in this work. Along this trajectory, the string tension in lattice units decreases with increasing $β$ , thus suggesting that the modified lattice action may provide a regularization of three-dimensional compact U(1) gauge theory with a physically well-behaved continuum limit.
hep-latcond-mat.stat-mechhep-th0 citations
02
Renormalization-guided inverse blocking for lattice field generation: construction and validation
Anna Hasenfratz🇺🇸 · Ethan T. Neil🇺🇸 · Letizia Parato🇺🇸 · Noah Schwartz🇺🇸
We propose an algorithm for generating lattice field configurations based on the approximate inversion of a renormalization-group blocking transformation. We optimize the blocking transformation using a ``perfect blocking'' condition so that the blocked lattice distribution is well approximated by a simple coarse action. The blocking is separated into an invertible smoothing transformation followed by decimation. Machine learning, in the form of a conditional normalizing flow, is used to reconstruct the short-distance degrees of freedom removed by the decimation. A short fine-action rethermalization then removes the residual mismatch. Because the coarse ensemble supplies the long-distance modes, the same blocking transformation and conditional flow can be reused recursively on larger lattices, producing a cascade of configurations from an initial small-volume ensemble. We test the method in two-dimensional $ϕ^{4}$ theory with $λ = 1$ at criticality and demonstrate stable cascade upscaling from $1 6^{2}$ to $204 8^{2}$ lattices on local computational resources. Controlled rethermalization tests show that short-distance mismatches relax rapidly, whereas a deliberately introduced mismatch in the relevant thermal direction relaxes much more slowly. The construction uses ingredients that admit natural extensions to higher-dimensional systems and, ultimately, to gauge and fermionic degrees of freedom.
hep-lat1 citation
03
Renormalization-guided cascade upscaling for lattice field generation
Anna Hasenfratz🇺🇸 · Ethan T. Neil🇺🇸 · Letizia Parato🇺🇸 · Noah Schwartz🇺🇸
We introduce a renormalization-group (RG) guided machine-learning algorithm for lattice field generation based on approximate inversion of an RG transformation. A ``perfect blocking'' construction supplies equilibrated long-distance modes, while a conditional normalizing flow reconstructs short-distance details and brief rethermalization removes residual errors. In 2D $ϕ^{4}$ theory at criticality, a flow trained at $L \leq 32$ is reused recursively in cascades reaching $L = 2048$ with correct long-distance physics.
hep-lat1 citation
04
Chern insulator boundary criticality
Benjamin Moy · Eduardo Fradkin
We investigate signatures of chirality at Chern insulator transitions in the presence of a boundary. The transition between a trivial insulator and a Chern insulator with Chern number $C = 1$ is described by a massless Dirac fermion whose parity anomaly gives a critical Hall conductivity $σ_{x y} = \frac{1}{2} \frac{e ^{2}}{h}$ . Using a Dirac mass domain wall construction, we show that the chiral edge mode delocalizes into the bulk at criticality, but the boundary fermion correlation function retains a chiral structure and acquires the scaling dimension of the bulk fermion. We compute current correlation functions and demonstrate that the anomaly of the bulk Hall response is matched by delocalized chiral modes near the boundary. Using only the residual conformal symmetry of a (2+1)d conformal field theory (CFT) in a half-space, we identify parity-odd terms in current and energy-momentum tensor correlation functions that encode these modes and determine their electromagnetic and gravitational anomaly coefficients. Our analysis therefore applies to general time-reversal breaking (2+1)d CFTs, beyond the free Dirac transition. In particular, the analysis of the gravitational anomaly is also applicable to the free Majorana CFT governing the transition between a trivial superconductor and a topological superconductor. We also extend our results to more general Chern number changing transitions and to the transition between a (3+1)d topological insulator and a trivial insulator.
↳ cond-mat.str-elcond-mat.mes-hallhep-lathep-th1 citation
05
Pulling strings in real time: flux tube dynamics in (2+1)-d $Z_{2}$ -Higgs Gauge Theories
Zeno Bacciconi🇮🇹 · Martina Frau🇮🇹 · Luca Tagliacozzo🇪🇸 · Michele Caselle🇮🇹 · Marcello Dalmonte🇮🇹
Understanding real-time flux-tube dynamics in more than one spatial dimension is key to unlocking the non-perturbative physics of confinement, and is now actively pursued by quantum computing and simulation experiments. However, describing such dynamics has proven to be extremely challenging with both experiments and state-of-the-art numerical simulations limited to small volumes and short timescales. Here we investigate flux tube statics and real-time evolution in a genuine two-dimensional $Z_{2}$ Higgs gauge theory at system sizes and timescales order of magnitude beyond present experiments and numerics. The key enabling element is the recently introduced Clifford-augmented matrix product states (CAMPS) framework, which we demonstrate to parametrically reduce the entanglement that must be represented in the matrix product state; both in the pure-gauge limit and in the presence of dynamical matter. We benchmark this capability through stringent tests of effective string theory, including universal spectral features and flux tube roughening properties in presence of matter. We then introduce a string-pull protocol that selectively excites transverse modes and reconstructs their finite-size spectrum in real time. In the rough regime, the response is collective, and our simulations show that this is also well captured by universal effective string theory predictions. Strong confinement instead produces long-lived, lattice-locked local dynamics persisting to times $t J ≳ 100$ . These results provide ab initio evidence that effective string theory captures nonequilibrium string dynamics and reveal a hitherto unexplored long-lived prethermal regime of strongly confined flux tubes, providing a novel angle on how confinement dictates dynamics in more than one spatial dimension.
↳ quant-phcond-mat.stat-mechcond-mat.str-elhep-lat+11 citation
06
Magnetic Moments and Radiative Transitions of the $T_{cc} (3875)^{+}$ and its partner states
Jing Wu🇨🇳 · Yi-Kun Wang🇨🇳 · Kai-Bao Chen🇨🇳 · Yan-Rui Liu🇨🇳 · Jian-Bo Cheng🇨🇳 · Wei-Hua Yang🇨🇳
We systematically investigate the magnetic moments (MMs) and radiative decay widths of S-wave doubly heavy tetraquark states based on chromomagnetic interaction (CMI). They provide a complementary probe to distinguish compact from molecule structures in addition to the mass spectrum and strong decay properties. Using the CMI eigenvectors, we compute the MMs and M1 transition rates for the tetraquarks in the compact configuration. We predict the MM of the observed $T_{cc} (3875)^{+}$ with $I (J^{P}) = 0 (1^{+})$ to be 0.45 $μ_{N}$ when treating it as a compact tetraquark state, whereas the MM of the $0 (1^{+})$ $D D^{*}$ molecule is about $- 0.07 μ_{N}$ . Five radiative transition channels related to the $T_{cc} (3875)^{+}$ are identified with widths ranging from $6.07$ keV to $306.37$ keV. Our results show that the MMs of the $J^{P} = 1^{+}$ $b c q ˉ q ˉ^{'}$ ( $q / q^{'} = u, d, s$ ) and $J^{P} = 1^{+}$ $QQ n ˉ s ˉ$ ( $Q = b, c; n = u, d$ ) states are influenced by the diquark-spin mixing. Through the analyses of radiative transitions between different tetraquark states, we find that such processes in the $QQ n ˉ n ˉ^{'}$ , $QQ s ˉ s ˉ$ , and $b c n ˉ s ˉ$ cases may serve to reveal the tetraquark structures of the initial or final states. We also define the magnetic coupling matrices characterizing the MMs of the tetraquark system with $J^{P} = 1^{+}$ , with which the range of MM can be constrained. The present study provides a valuable reference point for the search of exotic states in future particle physics experiments.
↳ hep-phhep-exhep-latnucl-ex+10 citations
07
Revisiting the $U (1)$ - $C P$ tension in QCD from a 1PI-action perspective
Paolo Di Vecchia🇸🇪 · Francesco Sannino🇮🇹 · Graham M. Shore🇬🇧 · Gabriele Veneziano🇨🇭 · Shimon Yankielowicz🇮🇱
We discuss the tension one encounters in trying to solve, simultaneously, the $U (1)$ and strong- $C P$ problems in QCD with light quarks and a small $θ ˉ$ angle within QCD itself. We do so by considering the low-energy expansion of a $1$ PI effective action $Γ$ , a functional of a properly chosen set of gauge-invariant (composite) operators. After enforcing Ward-identity constraints on $Γ$ , we prove, under minor assumptions, that $C P$ violation at small non-vanishing $θ ˉ$ can be avoided only if the anomaly-induced contribution to the pseudoscalar mass matrix is completely negligible when compared to its non-anomalous counterpart - that is, only if the $U (1)$ problem is not solved. The topological susceptibility in QCD and a precise generalization of the one in pure Yang-Mills theory emerge as the most important players in establishing the above tension and in determining the corrections to various known results at leading order in $θ ˉ$ .
↳ hep-thhep-lathep-ph1 citation
08
Scattering Equations as the lowest order K-identities in the calculation of Stringy Scaling of Hard String Scattering Amplitudes
Sheng-Hong Lai🇹🇼 · Jen-Chi Lee🇹🇼 · Yi Yang🇧🇷
We prove explicitly the n-point K-identities we proposed previously in the calculation of one tensor hard string scattering amplitudes (HSSA). These K-identities were the key to obtain the stringy scaling behavior in the saddle point calculation of the n-point HSSA and, on the other hand, to consistently match with the calculation of decoupling of zero norm states. Moreover, we introduce a G function to generate an infinite set of generalized K-identities (GKI). The lowest order set of these GKI is the scattering equations (SE) used in the calculation of field theory amplitudes in the CHY formalism. The next to leading order set of these GKI is the K-identities used previously in the calculation of one tensor HSSA. We conjecture that the higher order sets of these GKI can be used to calculate higher order HSSA and/or multi-tensor HSSA.
↳ hep-thhep-lathep-phmath-ph+10 citations

Affiliations

first authorsco-authorsvia INSPIRE