Understanding near-threshold strong interactions is essential for disentangling hadronic molecules and compact multiquark states in heavy-flavor spectroscopy. In this context, the doubly charmed tetraquark candidate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo stretchy="false">(</mo><mn>3875</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup></math> serves as a critical benchmark because it lies very close to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><mo>−</mo><mi>D</mi></math> thresholds. Motivated by the interaction ambiguity reported recently [<a href="http://dx.doi.org/10.1103/kd4s-9rzr">Phys. Rev. D 113, L031505 (2026)</a>], we evaluate the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><mo>−</mo><mi>D</mi></math> scattering lengths and femtoscopic correlation functions for the molecular and molecule-compact admixture assignments of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo stretchy="false">(</mo><mn>3875</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup></math>. We show that, although these scenarios yield similar invariant-mass line shapes, their corresponding femtoscopic correlation functions differ markedly and remain clearly distinguishable for typical particle-emitting sources created at the LHC. Our results indicate that femtoscopy can serve as a sensitive and complementary probe of the near-threshold dynamics of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo stretchy="false">(</mo><mn>3875</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup></math>, providing vital theoretical references for future LHC femtoscopy measurements.

China

Duo-Lun Ge

Zhi-Wei Liu

Li-Sheng Geng

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>D</mi><msup><mrow><mi>D</mi></mrow><mrow><mo>*</mo></mrow></msup></mrow></math> correlation functions in deciphering the nature of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo stretchy="false">(</mo><mn>3875</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup></math>

We present results from the first lattice QCD calculation of the two-pion contributions to the light-quark connected vector-current correlation function obtained from staggered-quark operators. We employ the MILC Collaboration’s gauge-field ensemble with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mo>+</mo><mn>1</mn><mo>+</mo><mn>1</mn></math> flavors of highly improved staggered sea quarks at a lattice spacing of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>a</mi><mo>≈</mo><mn>0.15</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></math> with a light sea-quark mass at its physical value. The two-pion contributions allow for a refined determination of the noisy long-distance tail of the vector-current correlation function, which we use to compute the light-quark connected contribution to hadronic vacuum polarization (HVP) with improved statistical precision. We compare our results with traditional noise-reduction techniques used in lattice QCD calculations of the light-quark connected HVP, namely, the so-called fit and bounding methods. We observe a factor of roughly 3 improvement in the statistical precision in the determination of the HVP contribution to the muon’s anomalous magnetic moment over these approaches. We also lay the group theoretical groundwork for extending this calculation to finer lattice spacings with increased numbers of staggered two-pion taste states.

United States

Shaun Lahert

Carleton DeTar

Aida X. El-Khadra

Steven Gottlieb

Andreas S. Kronfeld

Ruth S. Van de Water

Two-pion contribution to the hadronic vacuum polarization with staggered quarks

We investigate the holographic realization of topological operators for continuous non-Abelian symmetries in quantum field theories. As a concrete case study, we focus on type IIB string theory on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>AdS</mi><mn>5</mn></msub><mo>×</mo><msup><mi>S</mi><mn>5</mn></msup></math> which admits an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>O</mi><mo stretchy="false">(</mo><mn>6</mn><mo stretchy="false">)</mo></math> isometry, dual to the R-symmetry in 4D <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> super-Yang-Mills theory. We argue that symmetry operators for continuous symmetries are generally realized by bound states of D5-branes and Kaluza-Klein (KK) monopoles hanging from the conformal boundary. Together they account for the contributions to Gauss’s law constraints from the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mn>5</mn></msub></math> flux and the Einstein-Hilbert term respectively. We also demonstrate how the D5-KK bound state measures the representation of the end point of Wilson lines constructed by D3-branes.

Ibrahima Bah

Spain

Federico Bonetti

Mufaro Chitoto

Germany

Enoch Leung

Non-Abelian symmetry operators from hanging branes in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>AdS</mi><mn>5</mn></msub><mo>×</mo><msup><mi>S</mi><mn>5</mn></msup></math>

The superconformal field theory (SCFT)/vertex-operator algebra (VOA) correspondence provides a powerful framework for studying 4d <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></mrow></math> SCFTs through the mathematical machinery of 2d VOAs. It captures the Schur operators of the underlying SCFT, whose spectrum is encoded by the Schur index and its refinement, the Macdonald index. While the Schur index is identified with the vacuum character of the associated VOA, a general VOA-based derivation of the Macdonald index has remained elusive. In this letter, we propose a novel and intrinsic method for recovering a special non-Schur limit of the Macdonald index directly from the VOA. The construction requires no additional assumptions and applies whenever the underlying 4d theory is unitary. We test the proposal in a variety of examples, and further extend it to the case with surface defects, suggesting a notion of graded unitarity in the presence of defects. Our method also introduces a new class of series for general VOAs, analogous to but distinct from the conventional character, and potentially useful in broader contexts.

Hongliang Jiang

Macdonald index from vertex-operator algebras and graded unitarity

We examine decoherence in neutrino oscillations induced by an ultralight scalar field coupled to neutrinos. The scalar induces time- and position-dependent shifts in the neutrino mass matrix. Neutrinos sample different field configurations throughout an experimental data-taking period, which leads to damping effects in the oscillation pattern in the form of decoherence. By recasting the neutrino-scalar dynamics within the open quantum systems framework, we establish a mapping between a complete model and phenomenological decoherence approaches. We find that the parameter driving decoherence scales as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>/</mo><msup><mrow><mi>E</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>L</mi></math> is the baseline and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>E</mi></math> is the neutrino energy, as opposed to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>L</mi><mo>/</mo><mi>E</mi></math> typically assumed in phenomenological studies of open system approaches to neutrino oscillations.

Brazil

Lua F.T. Airoldi

Gustavo F.S. Alves

Pedro A.N. Machado

Peter Vander Griend

Open system approach to neutrinos propagating in an ultralight scalar background

The NUCLEUS experiment aims to measure coherent elastic neutrino–nucleus scattering (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math>) at unprecedentedly low nuclear recoil energies using gram-scale cryogenic calorimeters operated at the Chooz nuclear power plant in France. Access to recoil energies at the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mn>10</mn><mtext> </mtext><mtext> </mtext><mi>eV</mi><mo stretchy="false">)</mo></math> scale enables <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> studies at extremely low momentum transfer and provides enhanced sensitivity to new physics. In this work, we present sensitivity projections for the upcoming NUCLEUS technical and physics runs, incorporating a data-driven treatment of the low-energy excess (LEE) observed during commissioning. We develop a likelihood framework that exploits reactor-power variation to disentangle signal and background in a low signal-to-background regime and to assess the impact of the dominant systematic uncertainties. For the Technical Run with a 7 g <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>CaWO</mi><mn>4</mn></msub></math> target, we find competitive sensitivity to several scenarios beyond the Standard Model, which do not require a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> observation. For the Physics Run, assuming complete suppression of the LEE, we project a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4.7</mn><mi>σ</mi></math> observation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> with a statistical precision of about 20% in 1 year, enabling a determination of the weak mixing angle at the lowest momentum transfer probed to date with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> and leading <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math>-based constraints on the neutrino charge radius and new mediator models.

Austria

H. Abele

G. Angloher

B. Arnold

Italy

M. Atzori Corona

A. Bento

France

E. Bossio

F. Buchsteiner

J. Burkhart

F. Cappella

M. Cappelli

N. Casali

R. Cerulli

A. Cruciani

G. Del Castello

M. del Gallo Roccagiovine

S. Dorer

A. Erhart

M. Friedl

S. Fichtinger

V.M. Ghete

M. Giammei

C. Goupy

J. Hakenmüller

D. Hauff

F. Jeanneau

E. Jericha

M. Kaznacheeva

H. Kluck

A. Langenkämper

T. Lasserre

D. Lhuillier

M. Mancuso

R. Martin

B. Mauri

A. Mazzolari

L. McCallin

H. Neyrial

C. Nones

L. Oberauer

L. Peters

F. Petricca

W. Potzel

F. Pröbst

F. Pucci

F. Reindl

M. Romagnoni

J. Rothe

N. Schermer

J. Schieck

S. Schönert

C. Schwertner

L. Scola

G. Soum-Sidikov

L. Stodolsky

A. Schröder

R. Strauss

R. Thalmeier

C. Tomei

L. Valla

M. Vignati

M. Vivier

A. Wallach

P. Wasser

A. Wex

L. Wienke

Prospect of the NUCLEUS experiment at Chooz for coherent elastic neutrino-nucleus scattering and new physics searches

In the present work, we have studied the spacelike baryon Sachs form factors in the isospin asymmetric nuclear medium using the vector-meson dominance (VMD) model. The in-medium effects are incorporated through the medium-modified masses of vector mesons which are calculated using the QCD sum rule approach, taking density-dependent scalar quark and gluon condensates as inputs from chiral SU(3) quark mean-field (CQMF) model. The effective magnetic moments of the baryons are also calculated in the CQMF model. In the framework of the VMD model, the photon couples to the nucleons through intermediary vector mesons with the same quantum number as that of a photon. This coupling leads to the relation of isoscalar and isovector Dirac and Pauli form factors which are then used to calculate the Sachs electric and magnetic form factors, which provide physically measurable quantities that represent the electric and magnetic distributions of the baryons. The present work aims to study the effects of asymmetric nuclear matter at finite temperature on the Sachs form factors of baryons in the spacelike region. The electric and magnetic charge radii have also been calculated for the baryons in free space and dense asymmetric nuclear matter. The results obtained have been compared with other available phenomenological models, lattice simulations, and experimental data.

India

Ekta Rawat

Navpreet Kaur

Harleen Dahiya

Arvind Kumar

Suneel Dutt

Spacelike Sachs electric and magnetic form factors of the baryons in the asymmetric nuclear medium

The observation of resonant di-Higgs production, which would strongly suggest the existence of a new heavy neutral scalar <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi></math>, has been searched for extensively at the LHC. In the two-Higgs doublet model (2HDM) with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>H</mi></msub><mo>≫</mo><msub><mi>m</mi><mi>h</mi></msub></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi></math> is the Higgs boson of mass 125 GeV observed at the LHC, we show that a direct correlation emerges between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Br</mi><mo stretchy="false">(</mo><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Br</mi><mo stretchy="false">(</mo><mi>H</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi><mo stretchy="false">)</mo></math>, with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>V</mi><mo>=</mo><mi>Z</mi></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>W</mi></mrow></math>, which depends only on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>H</mi></msub></math> (and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>V</mi></msub></math>). In particular, for heavy scalar masses between 500 GeV and 1 TeV, we find that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Br</mi><mo stretchy="false">(</mo><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi><mo stretchy="false">)</mo><mo>/</mo><mi>Br</mi><mo stretchy="false">(</mo><mi>H</mi><mo stretchy="false">→</mo><mi>Z</mi><mi>Z</mi><mo stretchy="false">)</mo><mo>≈</mo><mn>9.4</mn><mo>±</mo><mn>0.25</mn></mrow></math>. Moreover, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi></math> is a dominant decay mode over a significant region of the parameter space and serves as the primary probe for a heavy scalar resonance at current and future hadron colliders. The origin of these predictions is most transparent in the Higgs basis, where the term in the scalar potential proportional to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">H</mi><mn>1</mn><mi>†</mi></msubsup><msub><mi mathvariant="script">H</mi><mn>1</mn></msub><msubsup><mi mathvariant="script">H</mi><mn>1</mn><mi>†</mi></msubsup><msub><mi mathvariant="script">H</mi><mn>2</mn></msub></math> (and its Hermitian conjugate) generates the leading contributions to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>h</mi><mi>h</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>h</mi><mi>h</mi><mi>h</mi></math> couplings in the decoupling limit of the 2HDM. Additionally, the latter coupling governs the resonant prompt tri-Higgs production via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi><mi>h</mi></math>, which is also directly correlated to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi></math> (and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi></math>), and can yield rates large enough to be measured at the High-Luminosity LHC.

Guglielmo Coloretti

Andreas Crivellin

Howard E. Haber

Correlating resonant di-Higgs and tri-Higgs production to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi></math> in the two-Higgs-doublet model

The photon hologram of a one-particle density matrix of a photon gas is derived including the case where the energy of a probe photon is above the electron-positron pair creation threshold. The explicit expressions for the holograms of a photon gas with one-particle density matrix in the form of a single Gaussian and of coherent and incoherent lattices of Gaussians are obtained. The conditions for resonant cones of coherent scattering by coherent and incoherent lattices are found. These conditions turn out to be different. The explicit expressions for the dielectric susceptibility tensor of a photon gas and of a single photon prepared in arbitrary quantum states are derived on the probe-photon mass shell. It is established that a photon gas and a single photon behave in coherent photon scattering as a medium with linear and circular birefringence. This medium is transparent below the electron-positron pair creation threshold and is absorbing otherwise. In the high-energy limit, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>≫</mo><mn>2</mn><mi>m</mi></math>, it has the dielectric susceptibility tensor of a birefringent plasma except for a slow logarithmic scaling. It is shown that, for the probe photon energies of order 1 GeV and higher, the energies of target photons of order 1 eV and higher, and the photon gas density such that the classical intensity parameter is of order unity, the hologram of the photon gas can be measured with existing experimental facilities.

Russia

P.O. Kazinski

A.A. Sokolov

High-energy photon hologram of a photon gas

We introduce a learning method for recovering action parameters in lattice field theories. Our method is based on the minimization of a convex loss function constructed using the Schwinger-Dyson relations. We show that score matching, a popular learning method, is a special case of our construction of an infinite family of valid loss functions. Importantly, our general Schwinger-Dyson-based construction applies to gauge theories and models with Grassmann-valued fields used to represent dynamical fermions. In particular, we extend our method to realistic lattice field theories including quantum chromodynamics.