We study two-body scattering as an SU(N)-equivariant map acting on tensor-product representation spaces and analyze the entanglement generated by the $\textit{S}$-matrix. This representation-theoretic perspective separates group structure from dynamics: the decomposition of $\textit{R}$⊗$\textit{R}$′ fixes the invariant operator algebra and therefore the qualitative entangling power of the process. For particles in the fundamental representation, End ($\textit{N}$⊗$\textit{N}$) = Span{𝕀, 𝕊}, so only the identity and swap directions preserve separability, whereas generic combinations generate entanglement. Adjoint-adjoint scattering involves a larger invariant algebra involving $\textit{d}$-tensors and is intrinsically entangling. In Yang-Mills theory one can use color-kinematics duality to show that the color kernel lies on a fixed ray of this operator space, yielding a universal maximum of the outgoing entanglement for scattering at right angles, $$ {E}_{\star}^{(2)}=\frac{3}{4} $$ for SU(2) and $$ {E}_{\star}^{(3)}\simeq 0.91 $$ , independent of kinematics. Dimension-six operators preserve this universality, while dimension-eight deformations populate new color sectors and shift $$ {E}_{\star}^{(N)} $$ , suggesting that entanglement in color space functions as a tomographic probe of effective operators. In helicity space, requiring maximally entangled inputs to scatter into maximally entangled outputs uniquely selects the Yang-Mills quartic coupling and enforces the color Jacobi identity, restating the on-shell Ward constraints as conditions on entanglement preservation. Our results suggest that the information-theoretic viewpoint unifies algebraic, geometric, and dynamical aspects of scattering.

United States

Kun-Feng Lyu

Rahul Muraleedharan

Kuver Sinha

Entanglement, Yang-Mills, and the scattering matrix as an SU(N)-equivariant kernel

Italy

Alexander Kamenshchik

Polina Petriakova

Erratum: IR finite correlation functions in de Sitter space, a smooth massless limit, and an autonomous equation

Photon-graviton conversion in an electromagnetic field is a well-known prediction of Einstein-Maxwell theory. First discussed at tree-level by Gertsenshtein in 1962, more recently it has been shown to lead to magnetic dichroism starting from one-loop. While previously only two diagrams were assumed to contribute to this one-loop photon-graviton amplitude in a constant electromagnetic field, here we point out the existence of a third one involving a tadpole subdiagram. As shown by H. Gies and one of the authors in 2016 for the pure QED case, such diagrams cannot be omitted in general even though the tadpole formally vanishes. After a short review of the calculation of one-loop photon-graviton amplitudes in the worldline formalism, we use this formalism for a unified calculation of all three diagrams. Although phenomenologically this amplitude is mainly of interest for the case of the spinor loop in a magnetic field, here we will also include the scalar loop and the electric field component, since the computational effort is essentially the same. We show that the tadpole diagram, although contributing to the amplitude, does not contribute to the magnetic dichroism. The gravitational Ward identity provides a useful check.

Germany

N. Ahmadiniaz

F. Bastianelli

F. Karbstein

Mexico

C. Schubert

One loop photon-graviton mixing in an electromagnetic field: part 3

<p>Dark matter detection experiments using liquid argon rely on a precise characterization of the ionization response to nuclear recoils, especially in the keV energy range relevant for light dark matter interactions. In this work, we present a comprehensive analysis that combines new measurements from the ReD setup, part of the DarkSide experimental program, with calibration data from DarkSide-50, as well as results from the ARIS and SCENE experiments. These combined datasets enable improved constraints on atomic screening effects in the modeling of the ionization response of liquid argon to nuclear recoils. The analysis is performed within the Thomas-Imel recombination framework adopted in previous DarkSide studies, and is here further constrained by the inclusion of ReD data, which allow the screening function to be determined from calibration measurements. By including the updated ionization model into the DarkSide-50 analysis framework, we obtain stronger exclusion limits on low-mass weakly interacting massive particle (WIMP) interactions, setting new world-leading constraints in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mi>–</mi><mn>3</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>/</mo><msup><mrow><mi mathvariant="normal">c</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> WIMP mass range. Finally, we recast the sensitivity projections for the upcoming DarkSide-20k detector, demonstrating a significantly enhanced discovery potential for low-mass dark matter candidates.</p>

F. Acerbi

Canada

P. Adhikari

P. Agnes

Poland

I. Ahmad

S. Albergo

Brazil

I.F. Albuquerque

T. Alexander

A.K. Alton

P. Amaudruz

M. Angiolilli

E. Aprile

M. Atzori Corona

D.J. Auty

M. Ave

Russia

I.C. Avetisov

O. Azzolini

H.O. Back

Z. Balmforth

Spain

A.I. Barrado Olmedo

France

P. Barrillon

G. Batignani

S. Bharat

United Kingdom

P. Bhowmick

S. Blua

V. Bocci

W. Bonivento

B. Bottino

M.G. Boulay

T. Braun

A. Buchowicz

S. Bussino

J. Busto

M. Cadeddu

R. Calabrese

V. Camillo

A. Caminata

N. Canci

M. Caravati

M. Cárdenas-Montes

N. Cargioli

M. Carlini

P. Cavalcante

S. Cebrian

S. Chashin

A. Chepurnov

S. Choudhary

L. Cifarelli

B. Cleveland

Y. Coadou

I. Coarasa

V. Cocco

E. Conde Vilda

L. Consiglio

A.F.V. Cortez

B.S. Costa

M. Czubak

S. D’Auria

M.D. Da Rocha Rolo

A. Dainty

G. Darbo

S. Davini

R. de Asmundis

S. De Cecco

M. De Napoli

G. Dellacasa

A.V. Derbin

L. Di Noto

P. Di Stefano

L.K. Dias

D. Díaz Mairena

C. Dionisi

G. Dolganov

F. Dordei

V. Dronik

A. Elersich

T. Erjavec

N. Fearon

M. Fernández Díaz

L. Ferro

A. Ficorella

G. Fiorillo

D. Fleming

P. Franchini

D. Franco

H. Frandini Gatti

E. Frolov

F. Gabriele

D. Gahan

C. Galbiati

G. Galiński

G. Gallina

M. Garbini

P. Garcia Abia

A. Gawdzik

G.K. Giovanetti

V. Goicoechea Casanueva

A. Gola

L. Grandi

G. Grauso

G. Grilli di Cortona

Sensitivity to low-mass WIMPs with an improved liquid argon ionization response model within the DarkSide program

<p>In view of the recent theoretical developments in the fixed center approximation for the scattering of a particle with a a two-body cluster, implementing elastic unitarity on the standard fixed center formalism, and the imminent availability of ALICE data on the correlation function of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mtext> </mtext><msub><mi>f</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mn>1285</mn><mo stretchy="false">)</mo></math> system, we update the results of a previous work for this correlation function and the low-energy scattering observables. The new results show appreciable changes in some observables and should provide valuable input for comparison with the forthcoming experimental data. Such a comparison is expected to yield relevant information on the nature of the axial-vector meson states.</p>

P. Encarnación

A. Feijoo

China

E. Oset

Scattering observables and correlation function for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mn>1285</mn><mo stretchy="false">)</mo></math> revisited

We suggest a new duality between a pair of 3d $$ \mathcal{N} $$ = 5 SCFTs, one of ABJ type and one based on the exceptional superalgebra $\textit{F}$ (4). Our main evidence for the proposed duality is the matching of the superconformal index. In addition to the intrinsic interest in dualities between strongly coupled field theories, the result can also be useful in the classification of 3d $$ \mathcal{N} $$ = 5 SCFTs.

Israel

Ki-Hong Lee

Belal Nazzal

Gabi Zafrir

A note on dualities of F(4) type 3d $$ \mathcal{N} $$ = 5 SCFTs

We study the existence and limitations of hyperinvariant tensor networks incorporating a local SU(2) symmetry. As discrete implementations of the anti de-Sitter/conformal field theory (AdS/CFT) correspondence, such networks have created bridges between the fields of quantum information theory and quantum gravity. Adding SU(2) symmetry to the tensor network allows a direct connection to spin network states, a basis of the kinematic Hilbert space of loop quantum gravity (LQG). We consider a particular situation where the states can be interpreted as kinematic quantum states for three-dimensional quantum gravity. We demonstrate an entanglement-geometry correspondence realized in certain quantum states of the gravitational field in LQG, showing that models similar to the ones introduced by [F. Pastawski et al., JHEP 06, 149 (2015)] can be obtained as quantum gravitational models from first principles. We provide examples of hyperinvariant tensor networks, but also prove constraints on their existence in the form of no-go theorems that exclude absolutely maximally entangled states as well as general holographic codes from local SU(2)-invariance, as long as the logical index also transforms covariantly under the gauge group. We calculate surface areas as expectation values of the LQG area operator and discuss further possible constraints as a consequence of a decay of correlations on the boundary.

Fynn Otto

Austria

Refik Mansuroglu

Norbert Schuch

Otfried Gühne

Hanno Sahlmann

Hyperinvariant spin network states — an AdS/CFT model from first principles

We investigate families of 3d $$ \mathcal{N} $$ = 2 chiral quiver gauge theories conjectured to be dual to M2-branes probing toric SE singularities. Geometrically, these families correspond to toric diagrams without internal points. At the field theory level, the models are constructed via an un-higgsing procedure applied to non-chiral quivers. While the moduli space of these theories was shown to match M-theory expectations, determining the $\textit{N}$ scaling of the free energy remained an open problem for over a decade, with positive results emerging only very recently. In this work, we address this challenge by reformulating the three-sphere partition function as a hyperbolic hypergeometric integral. Using exact integral identities, we show that the free energy reduces at leading order in $\textit{N}$ to that of non-chiral quivers with chiral flavors, for which the $\textit{N}$ scaling is already established. Physically, this mathematical identity corresponds to the equivalence of three-sphere partition functions under a generalization of Giveon-Kutasov duality to chiral quivers.

Antonio Amariti

Giulia Lanzetti

$\textit{N}$ 3/2 scaling from 3d $$ \mathcal{N} $$ = 2 dualities: an alternative approach to chiral quivers

We propose a correction to one of the elliptic blocks in the NS sector of 2d $$ \mathcal{N} $$ = 1 superconformal field theories. We analyze the 4-point block in the pillow geometry to demonstrate the necessity of the correction and verify the formula by numerically checking the crossing symmetries in the $$ \mathcal{N} $$ = 1 super Liouville theory, as well as directly comparing the $\textit{c}$-recursion and $\textit{h}$-recursion results.

Kangning Liu

Corrections of an elliptic block in the NS sector

We present a complete analytic and semi-analytic study of gravitational collapse and primordial black hole (PBH) formation in the quadratic $\textit{f}$($\textit{R}$) model $$f(R)=R+\alpha R^2$$ . We first derive the perturbative expansion around General Relativity (GR), working to first order in the small parameter $$\alpha $$ . For a collapsing flat FLRW dust interior we compute the explicit first-order corrections to the scale factor, the stellar radius, and the horizon formation time. We then use these results to infer the expected trend in the PBH formation threshold $$\delta _c$$ , rather than a direct quantitative determination. Within this perturbative framework, the quadratic correction modifies the dust collapse dynamics at first order, while the flat radiation-dominated background does not receive a nontrivial correction at the same order. As result, any modification of PBH formation in the radiation era must arise from nonlinear or non-perturbative effects. The perturbative analysis therefore provides qualitative insight into how curvature corrections influence collapse, particularly in high-curvature regimes. To access this regime we reformulate the theory in the Einstein frame, where the model becomes GR plus the scalaron field $$\phi $$ with the Starobinsky potential. We provide the complete ODE system governing both the cosmological background and the evolution of an overdense closed FLRW patch. This system can be numerically integrated to obtain the critical overdensity $$\delta _c(k)$$ for PBH formation near the end of inflation.

Egypt

G. Nashed

Saudi Arabia

A. Eid

Primordial black hole formation in $$f(R)=R+\alpha R^2$$ gravity: perturbative and non-perturbative analysis