We clarify the origin of magic angles in twisted multilayered graphene using Yang-Mills flows in two dimensions. We relate the effective Hamiltonian describing the electrons in the multilayered graphene to the $$ {\overline{\partial}}_A $$ operator on a two dimensional torus coupled to an SU($\textit{N}$) gauge field. Despite the absence of a characteristic class such as $\textit{c}$ relevant for the quantum Hall effect, we show that there are topological invariants associated with the zero modes occuring in a family of Hamiltonians. The flatbands in the spectrum of the effective Hamiltonian are associated with Yang-Mills connections, studied by M. Atiyah and R. Bott long time ago. The emergent U(1) magnetic field with nonzero flux is presumably responsible for the observed Hall effect in the absence of (external) magnetic field. We provide a numeric algorithm transforming the original single-particle Hamiltonian to the direct sum of $$ {\overline{\partial}}_A $$ operators coupled to abelian gauge fields with non-zero $\textit{c}$ ’s. Our gradient flow perspective gives a simple bound for magic angles: if the gauge field $\textit{A}$($\textit{α}$) is such that the YM energy $$ {\int}_{{\mathbbm{T}}^2} $$ tr $$ {F}_{A\left(\alpha \right)}^2 $$ is smaller than that of U(1) magnetic flux embedded into SU(2), then $\textit{α}$ is not magic.

United States

Vasilii Iugov

Nikita Nekrasov

Yang-Mills flows for multilayered graphene

<p>We apply the variational Monte Carlo method based on neural network quantum states, using a neural autoregressive flow architecture as our ansatz, to determine the ground state wave function of the bosonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SU</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math> Yang-Mills-type two-matrix model at strong coupling. Previous literature hinted at the inaccuracy of such an approach at strong coupling. In this work, the accuracy of the results is tested using lattice Monte Carlo simulations: we benchmark the expectation value of the energy of the ground state for system sizes <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> that are beyond brute-force exact diagonalization methods. We observe that the variational method with neural network states reproduces the right ground state energy when the width of the network employed in this work is sufficiently large. We confirm that the correct result is obtained for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo>=</mo><mn>2</mn></math> and 3, while obtaining a precise value for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo>=</mo><mn>4</mn></math> requires more resources than the amount available for this work.</p>

Germany

Norbert Bodendorfer

Türkiye

Onur Oktay

United Kingdom

Vaibhav Gautam

Masanori Hanada

Japan

Enrico Rinaldi

Variational Monte Carlo with neural network quantum states for a Yang-Mills matrix model

We construct defect networks in pure Yang-Mills theory in two dimensions using a refinement of the lattice approach. The refinement preserves the locality properties of individual defects, and is compatible with solvability of the theory via subdivision invariance. We explicitly demonstrate closure of the building blocks under fusion.

Italy

Luca Griguolo

Elisa Marieni

Itamar Yaakov

Lattice defect networks in 2d Yang-Mills

We propose that chiral two-dimensional Yang-Mills theory on a Riemann surface is dual to a deformed stationary subsector of the Gromov-Witten theory of that surface. Firstly, we argue that the algebraic structure that underlies the large $\textit{N}$ limit of the chiral gauge theory is a partial permutation algebra of observables which codes covering maps of all degrees simultaneously. Secondly, we exploit the Gromov-Witten/Hurwitz correspondence to interpret chiral Yang-Mills theory as a finite deformation of a Gromov-Witten theory by an area-dependent transposition interaction and an operator that codes a compactification of Hurwitz space. The proposed string dual manifestly includes an integral over the moduli space of Riemann surfaces as well as the identification of closed string states as completed cycles.

France

Lior Benizri

Jan Troost

The string dual to two-dimensional Yang-Mills theory

Searches for pair-produced long-lived particles (LLPs) at the LHC commonly operate under the assumption that the two LLPs are identical. In this paper we entertain the possibility that the targeted final states are, instead, induced by a LLP pair with different masses and/or lifetimes. We propose a simple and intuitively-parametrised toy model in order to study such asymmetric production of LLPs. Using the recasting material of a recent search for displaced jets by the ATLAS collaboration, we demonstrate that we can set constraints on the production cross-section times branching fraction into jets for a variety of asymmetric LLP and mediator mass combinations.

Thomas Chehab

Louie Corpe

Andreas Goudelis

Abdelhamid Haddad

Louise Millot

Constraints on asymmetric production of long-lived scalars at the Large Hadron Collider

In this study, we investigate the gravitational collapses of rotating stellar systems accounting for gamma-ray burst jet progenitors. Based on the virial theorem of hadron collisional relaxations and Newtonian slow-rotating approximation, we analyze the conversion of gravitational binding energy into kinetic energy of hadrons, whose collisions produce photons and electron-positron pairs forming fireballs. Our qualitative analysis implies that rotation effects collimated and spinning fireballs with nontrivial angular momenta along the propagating direction, thus making ultra-relativistic jets. Results reveal the possible trends that the fireball becomes more collimated and the jet angle decreases as the total angular momentum and mass ratio $\textit{J}$/$\textit{M}$ of the slow-rotating collapsing core increases. Discussing the extrapolation of these trends to fast-rotating collapsing systems, we speculate that the ratio $\textit{J}$/$\textit{M}$ should be a key quantity for differentiating long bursts (massive core collapses) from short bursts (binary coalescence). We derive the intrinsic correlations of collimated fireball quantities that should be imprinted on a large sample of observed GRB data as empirical correlations.

China

She-Sheng Xue

Collimated and spinning fireballs for ultra-relativistic jets: long vs short gamma-ray bursts by angular momentum and mass ratio

We perform a detailed computation of key quantities across the first-order deconfinement phase transition of the SU(3) Yang-Mills theory. Specifically, we calculate the entropy density, <math altimg='si1.svg'><mi>s</mi><mo stretchy='false'>(</mo><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy='false'>)</mo><mo stretchy='false'>/</mo><msubsup><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow><mrow><mn>3</mn></mrow></msubsup></math>, on both sides of the transition and determine the latent heat <italic>h</italic>. The calculations are carried out in the lattice regularization with the Wilson action, employing shifted boundary conditions in the temporal direction. Our simulations are performed at five different values of the lattice spacing in order to extrapolate the results to the continuum limit. The latent heat can be measured also as the discontinuity in the trace anomaly of the energy-momentum tensor: our result using the entropy density is compatible with the one obtained from the trace anomaly, giving a combined estimate <math altimg='si2.svg'><mi>h</mi><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>1.175</mn><mo stretchy='false'>(</mo><mn>10</mn><mo stretchy='false'>)</mo></math>. Additionally, we determine the critical temperature <math altimg='si3.svg'><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math> in physical units with permille accuracy, yielding <math altimg='si4.svg'><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub><msqrt><mrow><msub><mrow><mi>t</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></msqrt><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>0.24915</mn><mo stretchy='false'>(</mo><mn>29</mn><mo stretchy='false'>)</mo></math>. These results allow to connect with precision the confined and the deconfined phases and we present an improved computation of the Equation of State across the deconfinement transition for <italic>T</italic> between 0 and <math altimg='si5.svg'><mn>3.4</mn><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math>.

Leonardo Giusti

Mitsuaki Hirasawa

Michele Pepe

Luca Virzì

A precise study of the thermodynamic properties of the SU(3) Yang-Mills theory across the deconfinement transition

We use a loop truncated Jevicki-Sakita effective collective field Hamiltonian to obtain, over a very large range of values of 't Hooft's coupling, and directly in the large <italic>N</italic> limit, the large <italic>N</italic> (planar) ground state energy, the planar ground state expectation values of invariant correlators, and the <math altimg='si1.svg'><mn>1</mn><mo stretchy='false'>/</mo><mi>N</mi></math> spectrum of the quantum mechanical system of three massless Yang-Mills coupled matrices. This captures the dynamics of the (residual) gauge invariant sector of the spatially reduced <math altimg='si2.svg'><mn>3</mn><mo linebreak='goodbreak' linebreakstyle='after'>+</mo><mn>1</mn></math> dimensional pure Yang-Mills theory, in the large <italic>N</italic> limit. The large <italic>N</italic> loop space constraints are handled by the use of master variables. As is the case for two matrices, the method is highly efficient directly in the massless limit, and it reproduces to a very high precision the scaling dependence of physical quantities, determined by their dimensions, on the dimensionful 't Hooft coupling. We obtain the bound state masses of &#8220;glueballs&#8221;, their quantum numbers and ensuing degeneracies.

South Africa

João P. Rodrigues

“Glueballs” in the quantum mechanics of three large massless Yang-Mills coupled matrices

We revisit the path integral formulation of bosonic string theory in locally-AdS spacetimes. Through a careful analysis of the worldsheet sigma model, we write down an effective theory of long strings living near the boundary of AdS . By directly computing the partition function of the long-string sector, we find that the worldsheet path integral naturally organizes itself into the Coulomb-gas expansion of a 2D conformal field theory on the asymptotic boundary, with the number of coulomb integrals being dual to the dimension of the moduli space of worldsheet instantons on the boundary of AdS . As such, we provide a derivation of the CFT dual of long strings in AdS for completely generic spacetime and worldsheet topologies.

Bob Knighton

Deriving the long-string CFT in AdS

We propose a novel collider signature for neutral long-lived particles (LLPs): the emerging photon jet in the hadronic calorimeter (HCAL). This signature arises when a neutral LLP decays into photons within the HCAL, producing an electromagnetic shower without associated charged tracks or energy deposits in the electromagnetic calorimeter (ECAL). To demonstrate the viability of this approach, we consider the fermiophobic Higgs boson <math altimg='si1.svg'><msub><mrow><mi>h</mi></mrow><mrow><mi mathvariant='normal'>f</mi></mrow></msub></math> in the Type-I two-Higgs-doublet model as a representative scenario. In the ultralight regime ( <math altimg='si2.svg'><msub><mrow><mi>m</mi></mrow><mrow><msub><mrow><mi>h</mi></mrow><mrow><mi mathvariant='normal'>f</mi></mrow></msub></mrow></msub><mo linebreak='goodbreak' linebreakstyle='after'>&lt;</mo><mn>1</mn></math> GeV), <math altimg='si1.svg'><msub><mrow><mi>h</mi></mrow><mrow><mi mathvariant='normal'>f</mi></mrow></msub></math> decays exclusively into a photon pair via loop-induced processes, resulting in a suppressed width and consequently a long lifetime. Focusing on the golden channel <math altimg='si3.svg'><mi>p</mi><mi>p</mi><mo stretchy='false'>&#8594;</mo><msup><mrow><mi>H</mi></mrow><mrow><mo>&#177;</mo></mrow></msup><msub><mrow><mi>h</mi></mrow><mrow><mi mathvariant='normal'>f</mi></mrow></msub><mo stretchy='false'>&#8594;</mo><msup><mrow><mi>W</mi></mrow><mrow><mo>&#177;</mo></mrow></msup><msub><mrow><mi>h</mi></mrow><mrow><mi mathvariant='normal'>f</mi></mrow></msub><msub><mrow><mi>h</mi></mrow><mrow><mi mathvariant='normal'>f</mi></mrow></msub></math>, we analyze the exotic final state in which one <math altimg='si1.svg'><msub><mrow><mi>h</mi></mrow><mrow><mi mathvariant='normal'>f</mi></mrow></msub></math> decays in the ECAL and appears as a highly collimated photon jet (reconstructed as a single photon), while the other decays within the HCAL, producing an emerging photon jet. Through a detailed signal-to-background analysis incorporating realistic detector effects via fast simulation, we demonstrate that this signature achieves discovery-level sensitivity at the HL-LHC across a broad region of parameter space consistent with theoretical and experimental constraints. While our study focuses on the fermiophobic Higgs, the emerging photon jet in the HCAL constitutes a broadly applicable and previously unexplored strategy for detecting neutral LLPs decaying into photons, opening a new avenue in LLP searches at colliders.

South Korea

Jinheung Kim

Dongjoo Kim

Soojin Lee

Jeonghyeon Song

Emerging photon jets in the hadronic calorimeter: A novel signature of neutral long-lived particles at the LHC