In the context of Monte Carlo (MC) generators with parton showers that have next-to-leading-logarithmic (NLL) precision, the cutoff $\textit{Q}$ terminating the shower evolution should be viewed as an infrared factorization scale so that parameters or non-perturbative effects of the MC generator may have a field theoretic interpretation with a controllable scheme dependence. This implies that the generator’s parton level should be carefully defined within QCD perturbation theory with subleading order precision. Furthermore, it entails that the shower cut $\textit{Q}$ is not treated as one of the generator’s tuning parameters, but that the tuning can be carried out reliably for a range of $\textit{Q}$ values and that the hadron level description is $\textit{Q}$ -invariant. This in turn imposes non-trival constraints on the behavior of the generator’s hadronization model, so that its parameters can adapt accordingly when the $\textit{Q}$ value is changed. We investigate these features using the angular ordered parton shower and the cluster hadronization model implemented in the H 7.2 MC generator focusing in particular on the $\textit{e}$ $\textit{e}$ 2-jettiness distribution, where the shower is known to be NLL precise and where QCD factorization imposes stringent constraints on the hadronization corrections. We show that the H default cluster hadronization model does not exhibit these features or consistency with QCD factorization with a satisfying precision. We design a modification of the cluster hadronization model, where some dynamical parton shower aspects are added that are missing in the default model. For this novel dynamical cluster hadronization model these features and consistency with QCD factorization are realized much more accurately.

Austria

André Hoang

Oliver Jin

Simon Plätzer

Daniel Samitz

Matching hadronization and perturbative evolution: the cluster model in light of infrared shower cutoff dependence

The Gallium anomaly is an unexplained deficit in the neutrinos observed during the calibration of GALLEX and SAGE using a Cr radioactive source and recently confirmed by BEST. The possible explanations for this deficit include an overestimation of the neutrino absorption cross section in Ga, an incorrect measurement of the source activity or the existence of sterile neutrinos. However, as this deficit has only been observed in Ga detectors, it has not been possible to distinguish among various proposals. Therefore, we propose an experiment using the same radioactive source but with a different detection method, electron-neutrino scattering. We discuss potential locations for such an experiment, estimating the main backgrounds and expected event rates, considering various target masses and source positions. Even if the anomaly does not result from the detection method, such an experiment can provide an independent determination of the branching ratio of the Cr decay by using the spectral information or observing the scattering angle. It is also sensitive to an eventual baseline dependence of the anomaly, as is predicted in sterile neutrino models.

China

Emilio Ciuffoli

Jarah Evslin

Ruixuan Gao

Haixing Lin

Jian Tang

Testing the Gallium anomaly using electron-neutrino scattering

We consider quantum gravity with zero cosmological constant in three dimensions. First, we show that pure quantum gravity can be written as a magnetic Carrollian theory living on null infinity, described by Schwarzian-like degrees of freedom. Next, we couple quantum gravity to massless matter. Transition amplitudes exhibit several features that resemble soft graviton physics in four dimensions, despite the absence of a propagating graviton. As in four dimensions, we find three equivalent results: a soft graviton theorem, an infinite-dimensional BMS asymptotic symmetry, and a gravitational memory effect. We also resolve some extant puzzles concerning the partition function and Hilbert space of pure 3d gravity with zero cosmological constant.

United States

Jordan Cotler

Canada

Kristan Jensen

Stefan Prohazka

Max Riegler

Belgium

Jakob Salzer

Soft gravitons in three dimensions

We develop methods for computing the effective action at infinite momentum for 1 + 1$\textit{d}$ QFTs at finite volume which do not rely on the theory having a Lagrangian description. We do this by taking the infinite momentum limit of equal-time quantization and integrating out all except for the chiral modes of the theory. Our main application of this method is to the Ising Field Theory (IFT), with an energy and magnetic deformation, where we compute the effective lightcone Hamiltonian numerically and check it against results from TCSA. Remarkably, in the low-temperature phase, the Lorentz invariant effective Hamiltonian at infinite momentum takes a very compact form and depends on the volume only through the finite volume vacuum expectation value of ⟨$\textit{σ}$⟩, the spin operator.

Hongbin Chen

A. Fitzpatrick

Emanuel Katz

Yuan Xin

Large momentum EFT and lightcone quantization

In analogy with the non-Abelian gauge helicities conserved in time for “null fields”, that we have defined previously, in this paper we first define non-Abelian fluid helicities and then total non-Abelian helicities for combined non-Abelian fluid and gauge fields. For a U(N) group the helicities considered are for both gluonic-type fluids, composed of particles in the adjoint representation, and quark-type fluids, in the $\textit{N}$-dimensional Cartan subalgebra. We write down various Lagrangian formulations for the uncoupled and coupled systems. In each case we determine the equations of motion, symmetries, and a Hamiltonian formulation. Taking the velocity of the fluid in the adjoint representation, we find that in the case of the gluonic fluid, we can write a non-Abelian gluonic fluid Euler-Yang-Mills equation that conserves the defined helicities, and comes from a Lagrangian.

Brazil

Horatiu Nastase

Israel

Jacob Sonnenschein

Nonabelian fluids and helicities

We consider the $$ \mathcal{N} $$ = 2 quiver gauge theory arising from a $\textit{ℤ}$ orbifold of $$ \mathcal{N} $$ = 4 Super Yang-Mills theory. Over the years, exploiting supersymmetric localization, exact expressions for several observables have been derived in the planar limit of this theory. In particular, some of these can be expressed as Fredholm determinants of semi-infinite matrices and their strong coupling expansions in inverse powers of the ’t Hooft coupling have been calculated analytically to any desired order. On the other hand, there are also observables that cannot be rewritten in such a closed form, therefore extracting information at strong coupling is more complicated and almost no results are known beyond the leading order. In this work we focus on two observables of this type: the correlators of $\textit{n}$ coincident Wilson loops and the integrated correlators of two Higgs branch operators in the presence of a Wilson line. We introduce an analytic method to evaluate the first terms of their strong coupling expansions. We also outline a numerical algorithm that serves as an independent check of the analytical results and provides predictions in cases where analytical techniques are currently not known.

Pieter-Jan Smet

Germany

Alessandro Pini

Italy

Paolo Vallarino

Analytical and numerical routes to strong coupling in $$ \mathcal{N} $$ = 2 SCFTs

We study defects in symmetry breaking phases, such as domain walls, vortices, and hedgehogs. In particular, we focus on the localized gapless excitations which sometimes occur at the cores of these objects. These are topologically protected by an ’t Hooft anomaly. We classify different symmetry breaking phases in terms of the anomalies of these defects, and relate them to the anomaly of the broken symmetry by an anomaly-matching formula. We also derive the obstruction to the existence of a symmetry breaking phase with a local defect. We obtain these results using a long exact sequence of groups of invertible field theories, which we call the “symmetry breaking long exact sequence” (SBLES). The mathematical backbone of the SBLES is studied in a companion paper [1]. Our work further develops the theory of higher Berry phase and its bulk-boundary correspondence, and serves as a new computational tool for classifying symmetry protected topological phases.

Arun Debray

Sanath Devalapurkar

Cameron Krulewski

Yu Liu

Natalia Pacheco-Tallaj

Ryan Thorngren

A long exact sequence in symmetry breaking: order parameter constraints, defect anomaly-matching, and higher Berry phases

We develop a novel way to probe subgalactic-scale matter distribution with diffractive lensing on gravitational waves. Five-year observations from Einstein Telescope and DECIGO are expected to probe $\textit{k}$ = 10 ∼ 10 Mpc down to $\textit{P}$ ($\textit{k}$) = 10 ∼ 10 Mpc level. These results can be interpreted in terms of primordial black holes in the range $\textit{M}$ ≳ 10 $\textit{M}$ down to $\textit{f}$ = 10 level, or QCD axion minihalos in the range $\textit{m}$ = 10 ∼ 10 eV. A key result of the paper is the approximate relation between the scale $\textit{k}$ and the gravitational wave frequency $\textit{f}$, derived in an ensemble of ‘multi-lensing’ events. This relation enables direct measurement of the power spectrum at specific scales, with sensitivities characterized by model-independent kernels $\textit{δP}$ ($\textit{k}$). Additionally, we delineate the statistical properties of ‘multi-lensing’ based on the ‘Fresnel number’ $\textit{N}$ . When $\textit{N}$ ≳ $$ \mathcal{O}(1) $$ , the statistical significance can be approximately calculated by Variance of lensing effects, which is directly related to the power spectrum among other moments of matter distribution.

South Korea

Sungjung Kim

Han Choi

Sunghoon Jung

Probing small-scale power spectrum with gravitational-wave diffractive lensing

In our earlier work [1], we introduced a lattice Hamiltonian for Adjoint QCD using staggered Majorana fermions. We found the gauge invariant space of states explicitly for the gauge group SU(2) and used them for numerical calculations of observables, such as the spectrum and the expectation value of the fermion bilinear. In this paper, we carry out a more in-depth study of our lattice model, extending it to any compact and simply-connected gauge group $\textit{G}$. We show how to find the gauge invariant space of states and use it to study various observables. We also use the lattice model to calculate the mixed ’t Hooft anomalies of Adjoint QCD for arbitrary $\textit{G}$. We show that the matrix elements of the lattice Hamiltonian can be expressed in terms of the Wigner 6$\textit{j}$-symbols of $\textit{G}$. For $\textit{G}$ = SU(3), we perform exact diagonalization for lattices of up to six sites and study the low-lying spectrum, the fermion bilinear condensate, and the string tension. We also show how to write the lattice strong coupling expansion for ground state energies and operator expectation values in terms of the Wigner 6$\textit{j}$-symbols. For SU(3) we carry this out explicitly and find good agreement with the exact diagonalizations, and for SU(4) we give expansions that can be compared with future numerical studies.

Ross Dempsey

Silviu Pufu

Benjamin Søgaard

Igor Klebanov

More about the lattice Hamiltonian for Adjoint QCD

Thermal light dark matter (LDM) with particle masses in the 1 MeV–1 GeV range could successfully explain the observed dark matter abundance as a relic from the primordial Universe. In this picture, a new feeble interaction acts as a “portal” between the Standard Model and LDM particles, allowing for the exploration of this paradigm at accelerator experiments. In the last years, the “missing energy” experiment NA64$\textit{e}$ at CERN SPS (Super Proton Synchrotron) has set world-leading constraints in the vector-mediated LDM parameter space, by exploiting a 100 GeV electron beam impinging on an electromagnetic calorimeter, acting as an active target. In this paper, we report a detailed description of the analysis of a preliminary measurement with a 70 GeV/c positron beam at NA64$\textit{e}$, performed during summer 2023 with an accumulated statistics of 1$\textit{.}$596 × 10 positrons on target (hereafter referred to as $\textit{e}$ OT). This data set was analyzed with the primary aim of evaluating the performance of the NA64$\textit{e}$ detector with a lower energy positron beam, towards the realization of the post-LS3 program. The analysis results, other than additionally probing unexplored regions in the LDM parameter space, provide valuable information towards the future NA64$\textit{e}$ positron campaign.

Yu. Andreev

A. Antonov

Chile

M. Ayala Torres

Switzerland

D. Banerjee

B. Banto Oberhauser

V. Bautin

J. Bernhard

P. Bisio

M. Bondì

A. Celentano

N. Charitonidis

P. Crivelli

A. Dermenev

S. Donskov

R. Dusaev

T. Enik

V. Frolov

S. Gertsenberger

S. Girod

S. Gninenko

M. Hösgen

Y. Kambar

A. Karneyeu

G. Kekelidze

B. Ketzer

D. Kirpichnikov

M. Kirsanov

V. Kramarenko

L. Kravchuk

N. Krasnikov

S. Kuleshov

V. Lyubovitskij

V. Lysan

A. Marini

L. Marsicano

V. Matveev

R. Mena Fredes

R. Mena Yanssen

Spain

L. Molina Bueno

M. Mongillo

D. Peshekhonov

V. Polyakov

B. Radics

K. Salamatin

V. Samoylenko

H. Sieber

D. Shchukin

O. Soto

V. Tikhomirov

I. Tlisova

A. Toropin

M. Tuzi

P. Volkov

I. Voronchikhin

J. Zamora-Saá

A. Zhevlakov

Proof of principle for a light dark matter search with low-energy positron beams at NA64