In this work, we present a systematic study of the event characteristics and underlying physics relevant to neutrino-antineutrino discrimination in atmospheric neutrino charged-current interactions in large liquid scintillator detectors. This study encompasses the primary neutrino interactions, the subsequent secondary interactions of final-state particles, and the ensuing neutron captures. We investigate in detail the properties of final-state charged leptons and hadrons, deriving distinct distributions of inelasticity and neutron-capture multiplicity for both neutrino and antineutrino interactions. These distributions are used to quantify the performance of neutrino-antineutrino discrimination. Our findings lay the groundwork for atmospheric neutrino oscillation studies in large liquid scintillator detectors, particularly for determining the neutrino mass ordering.

China

Xinhai He

Gao-song Li

Yu-Feng Li

Wuming Luo

Liang-jian Wen

Atmospheric neutrino charged-current interactions at large liquid- scintillator detectors: I. physics of neutrino-antineutrino discrimination * Supported in part by the National Natural Science Foundation of China (12125506, 12075255), and the CAS Project for Young Scientists in Basic Research (YSBR-099)

We study oscillon/<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>I</mi></mrow></math>-ball solutions in a real scalar version of the Friedberg-Lee-Sirlin model. Using the multiple-scale analysis, we derive the conditions for oscillon solutions and explore multifield oscillon configurations. In these configurations, the two fields form colocated oscillons that oscillate with frequencies set by their respective masses. These multifield oscillons can be viewed as a bound state of two oscillons due to attractive interactions between the fields. We confirm these analytical predictions through numerical lattice calculations. This work extends the standard picture of single-field oscillons and may be relevant for cosmological scenarios involving multiple interacting real scalar fields.

Japan

Kai Murai

Tatsuya Ogawa

Fuminobu Takahashi

Multifield oscillons/<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>I</mi></mrow></math>-balls in the Friedberg-Lee-Sirlin model

Null strings, strings with Carrollian worldsheets, are traditionally described by the Isberg-Lindström-Sundborg-Theodoridis (ILST) action, which is obtained via a tensionless limit of standard tensile strings. In a recent work [1], we observed that the ILST action enjoys an overlooked partial-gauge symmetry whose existence calls into question the consistency of standard null-string analyses found in the literature. In this paper, we show that the Carrollian geometry provides us with two Weyl scaling options, in contrast to a single Weyl scaling available for the ordinary tensile string worldsheet. Defining the null string theory by the action that realizes the two Carroll-Weyl scalings as well as the 2D diffeomorphisms as local (gauge) symmetries, we construct the new null string action. We show that the ILST action is obtained after fixing one of the two Carroll-Weyl scalings of the action that we construct, and that the residual part of this symmetry is precisely the overlooked partial-gauge symmetry discussed in [1]. We hence clarify the Carroll-geometric origin of the overlooked symmetry and pave the way for a consistent quantization of null strings.

Iran

M.M. Sheikh-Jabbari

H. Yavartanoo

Null strings gauged and reloaded, I: Null strings have Carroll-Weyl gauge symmetry

We develop the theoretical framework for semi-inclusive deep-inelastic scattering on a polarized spin-1 target and apply it to scattering on the polarized deuteron with spectator nucleon tagging. In Part I (this article) we present the general form of the semi-inclusive cross section and polarization observables for the spin-1 target. A relativistically covariant formulation in terms of four-vectors and invariant polarization parameters is employed. The target polarization is described by a spin density matrix with vector and tensor polarization. The spin and azimuthal angle dependence of the semi-inclusive cross section is derived and parametrized in terms of invariant structure functions. To validate the result, the structure functions are expressed as photon-target helicity amplitudes with known symmetry properties. The expressions presented here are kinematic (no assumptions about particle production dynamics) and valid in all regions of the deep-inelastic final state (current and target fragmentation regions). In Part II (following article), we consider deep-inelastic scattering on the polarized deuteron with spectator nucleon tagging as a special case of target fragmentation. The semi-inclusive structure functions are computed by separating nuclear and hadronic structure, and the polarization observables are explored as functions of the tagged nucleon momentum.

United States

W. Cosyn

C. Weiss

Semi-inclusive deep-inelastic scattering on a polarized spin-1 target. I. Cross section and spin observables

We study in the bottom-up framework the possibility to generate the quark mass hierarchies without severe fine-tuning, the quark mixing and CP-violation (CPV) in a flavour model with $$S^\prime _4$$ modular symmetry having minimal number of parameters. The model is considered in the vicinity of the fixed point $$\tau _\text {T}= i\infty $$ , $$\tau _\text {vev} \sim \tau _\text {T}$$ , $$\tau _\text {vev}$$ being the vacuum expectation value (VEV) of the modulus $$\tau $$ , which allows to explain the hierarchies of the quark masses. The ten quark observables are described effectively by nine real parameters. The CP-symmetry is broken explicitly since, as is well known, reproducing the observed CPV in the quark sector in the case of spontaneous breaking of CP-symmetry by $$\tau _\text {vev}$$ is highly problematic in the class of minimal modular quark flavour models (explaining the quark mass hierarchies without fine-tuning) of the type we consider. We perform a statistical analysis of the model and show that it is phenomenologically viable and consistent, in particular, with the “inclusive” decay data on the $$|V_{ub}|$$ and $$|V_{cb}|$$ elements of the CKM matrix and, in the case of a very high scale of supersymmetry breaking, with the current “average” experimental values of $$|V_{ub}|$$ and $$|V_{cb}|$$ .

Italy

S. Petcov

M. Tanimoto

$$S^\prime _4$$ quark flavour model in the vicinity of the fixed point $$\tau = i\infty $$

We investigate the polarization properties of the direct images of a geometrically and optically thin accretion disk around fully self-consistent models of Kerr black holes with synchronized scalar hair. The presence of a massive scalar field alters the geodesic structure of the spacetime and thus leaves an imprint on the polarization of radiation emitted near the black hole horizon. To study this effect, we employ a simple analytical model of a geometrically thin accretion disk, orbiting in the equatorial plane and emitting synchrotron radiation. The main deviation from a corresponding Kerr black hole in general relativity is found to be a dephasing in the twist of the polarization vector, which is surprisingly larger for the least scalarized solutions we consider. This behavior suggests that polarization observables are primarily sensitive to local geometric and transport effects along photon trajectories rather than to the overall scalar field strength. Furthermore, our results demonstrate that while equatorial magnetic fields produce qualitatively similar polarization patterns to Kerr black holes in general relativity, vertical magnetic fields at high observer inclinations can lead to a characteristic reversal of the twist direction of the polarization vector.

Bulgaria

Valentin Deliyski

Galin Gyulchev

Germany

Spain

Daniela Doneva

Petya Nedkova

Stoytcho Yazadjiev

Polarized equatorial emission around Kerr black holes with synchronized scalar hair. I. direct images

We demonstrate that simple feed-forward neural networks (NNs) can accurately compute correlation functions of conformal field theories (CFTs) on a line. Strikingly, by optimising a NN solely on crossing symmetry and providing only the scaling dimension of the leading non-trivial operator and the correlator’s value at a single “anchor point”, we can reconstruct target physical correlators to within a few percent. We establish the robustness of this minimal-data approach across a broad class of theories and dimensions, including generalised free fields, contact and one-loop Witten diagrams in AdS <inf>2</inf>, unitary and non-unitary 2d minimal models, the 3d Ising model, and half-BPS correlators in 4d <math altimg='si40.svg'><mrow><mi mathvariant='script'>N</mi><mo linebreak='goodbreak'>=</mo><mn>4</mn></mrow></math> super-Yang&#8211;Mills theory, together with several thermal two-point functions, notably including those of the 3d Ising model. We argue that this remarkable alignment between NNs and CFTs stems from the spectral bias of gradient-based training, which heavily favours smooth functions. To ground this connection, we analyse the smoothness of conformal correlators using fractional Sobolev semi-norms, Chebyshev spectral decompositions, and a measure based on curvature. Finally, we establish the broader reconstructive power of this technique by extending it beyond the diagonal kinematics of the line.

United Kingdom

Kausik Ghosh

Sidhaarth Kumar

Greece

Vasilis Niarchos

Andreas Stergiou

Neural spectral bias and conformal correlators I introduction and applications

The origin of the finite dip in the curvature power spectrum of instantaneous Slow-Roll (SR)-Ulta-Slow-Roll (USR)-SR inflation remains controversial at linear order, and its full spectral features still lack a complete asymptotic analytical description. We revisit linear perturbation dynamics in this framework. Using the junction method and asymptotic expansions of Hankel functions, we for the first time derive accurate and simple asymptotic expressions for mode evolution and the resulting power spectrum, based on three systematic rules for dominant-term identification across transitions. We find the finite dip arises from cancellation between two growing modes within linear perturbation theory, rather than between constant and growing terms as previously suggested. We also provide analytical descriptions of the amplitude enhancement and the two oscillatory patterns observed in the spectrum. All asypmtotic analytical results are validated by numerical calculations with the reconstructed SR-USR-SR inflationary potential.

Wen Li

Chao Chen

Evolution of linear perturbations under time-dependent hubble friction I: SR-USR-SR inflation

We perform three T-dualities on classical $$ \mathcal{N} $$ = 1 scale-separated AdS solutions of massive type IIA supergravity. These solutions arose from a compactification on a toroidal $\textit{G}$ -holonomy space with smeared O2 and O6/D6 sources. The T-dual backgrounds are classical $$ \mathcal{N} $$ = 1 AdS solutions of type IIB supergravity with O5/D5 and O9/D9 sources (type I) compactified on a space with $\textit{G}$ -structure and non-vanishing Ricci scalar. We generalize the original solutions in IIA in the T-dual picture and present on the type IIB side fully classical solutions with parametric control, scale separation, and integer conformal dimensions for the dual operators in the corresponding CFT. We also obtain strongly coupled solutions with the same properties. These are S-dual to parametrically controlled classical solutions of the heterotic SO(32) string theory.

Zheng Miao

Muthusamy Rajaguru

George Tringas

Timm Wrase

T-dualities and scale-separated AdS3 in type I

In this paper, pair production of standard model (SM)-like Higgs bosons, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi><mi>h</mi></math>, is studied through <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>γ</mi></math> scattering at future electron-positron colliders, in the framework of the inert doublet model with two active doublets—i.e., the I(<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mo>+</mo><mn>2</mn></mrow></math>)HDM for short. The relevance of the process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>γ</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi></math> for such a beyond-the-SM (BSM) scenario stems from the fact that it is a one-loop process at lowest order, wherein inert charged states <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mo>±</mo></msup></math> contribute alongside <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>W</mi><mo>±</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>H</mi><mo>±</mo></msup></math>, and heavy fermions (primarily, bottom and top quarks), crucially, at the same perturbative order. Given that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mo>±</mo></msup><mo>/</mo><msup><mi>H</mi><mo>±</mo></msup></math> masses and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi><msup><mi>S</mi><mo>+</mo></msup><msup><mi>S</mi><mo>−</mo></msup></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>S</mi><mo>±</mo></msup><mo>=</mo><msup><mi>χ</mi><mo>±</mo></msup><mo>,</mo><msup><mi>H</mi><mo>±</mo></msup></math>) couplings are very mildly constrained, there exist regions of the parameter space of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">I</mi><mo stretchy="false">(</mo><mrow><mn>1</mn><mo>+</mo><mn>2</mn></mrow><mo stretchy="false">)</mo><mi>HDM</mi></math> where the former can be rather light and the latter rather large. After imposing up-to-date theoretical and experimental constraints on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">I</mi><mo stretchy="false">(</mo><mrow><mn>1</mn><mo>+</mo><mn>2</mn></mrow><mo stretchy="false">)</mo><mi>HDM</mi></math>, it is found that the production rates of such processes at future <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>γ</mi></math> machines can be enhanced by up to a factor of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≈</mo><mn>50</mn></math> with respect to the SM, significantly exceeding typical yields of conventional two-Higgs-doublet models (2HDMs). Further, thanks to the level of control that one can attain at such facilities on the photon kinematics, leading to excellent invariant mass resolution of the incoming photon pairs, we show how it is possible to extract from this process the value of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mo>±</mo></msup></math> mass (along with those of the active <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>H</mi><mo>±</mo></msup></math> states) with high precision, and whichever of the decays of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi><mi>h</mi></math> pair, both with and without beam polarization.

France

Morocco

Abdesslam Arhrib

Ayoub Hmissou

Sweden

Stefano Moretti

Larbi Rahili

Probing standard-model-like di-Higgs production at photon-photon colliders in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">I</mi><mo stretchy="false">(</mo><mrow><mn>1</mn><mo>+</mo><mn>2</mn></mrow><mo stretchy="false">)</mo><mi>HDM</mi></mrow></math> type-I