The inverse seesaw mechanism provides a concise scenario to produce tiny neutrino masses. Here we investigate the Majoron dark matter arising from the $$\mathrm{U(1)_L}$$ symmetry spontaneous breaking and matter–antimatter asymmetry in the framework of a high scale inverse seesaw mechanism. Due to the existence of a lepton-number-violating mass term, the Majoron gets its mass from radiative corrections. On the other hand, the Noether’s theorem indicates that the Majoron can obtain a non-zero initial velocity in the early universe, and then generates the relic abundance via kinetic misalignment mechanism. With the same initial Majoron velocity, the observed baryon asymmetry can also be explained through the so-called spontanous bayogenensis mechanism.

China

Ying-Quan Peng

Xiu-Fei Li

Cogenesis of Majoron dark matter and baryon asymmetry from a high scale inverse seesaw mechanism

We present an analytic calculation of the integrated double-emission eikonal function of a massive and a massless emitter whose momenta are at an arbitrary angle to each other. This quantity provides one of the required ingredients for extending the nested soft-collinear subtraction scheme to processes with massive final-state particles. To calculate it, we use the standard methodology involving reverse unitarity and its extension to cases with Heaviside functions, integration-by-parts technology and reduction to master integrals, and differential equations. In addition, we also describe a semi-numerical method based on the subtraction of infra-red and collinear singularities from the eikonal function, allowing us to extract divergences of the integrated eikonal function analytically, and to derive a simple integral representation for the finite remainder.

Germany

Dennis Horstmann

Kirill Melnikov

Ming-Ming Long

Andrey Pikelner

Integral of the double-emission eikonal function for a massive and a massless emitter at an arbitrary angle

Conformal higher-spin gravity is the log-divergent part of the effective action of the scalar field coupled to background fields via higher-spin currents, as was defined by Segal and Tseytlin, which can be worked out over the flat space background. We revisit the problem of the scalar field in a higher-spin background and propose a manifestly covariant version thereof. The construction utilizes the Fedosov quantization of the cotangent bundle and the action is written with the help of the trace on a curved phase space that is provided by the Feigin-Felder-Shoikhet cocycle. The same construction allows one to formulate quantum mechanics on a curved space, the phase space being the cotangent bundle.

Belgium

Thomas Basile

Shailesh Dhasmana

Evgeny Skvortsov

Scalar field on a higher-spin background via Fedosov quantization

The photoproduction of <math altimg='si1.svg'><mi>J</mi><mo stretchy='false'>/</mo><mi>&#968;</mi></math> meson off the nucleon is investigated using a dynamical model based on a Hamiltonian that describes the reaction mechanisms involving meson-exchange and direct <math altimg='si1.svg'><mi>J</mi><mo stretchy='false'>/</mo><mi>&#968;</mi></math>-radiation terms. Pomeron exchange is also included to account for the monotonically increasing high-energy behavior of the cross section. To explore the low-energy mechanism, we scrutinize the role of light-meson [ <math altimg='si2.svg'><msup><mrow><mi>&#960;</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy='false'>(</mo><mn>135</mn><mo stretchy='false'>)</mo></math>, <math altimg='si3.svg'><mi>&#951;</mi><mo stretchy='false'>(</mo><mn>548</mn><mo stretchy='false'>)</mo></math>, <math altimg='si4.svg'><msup><mrow><mi>&#951;</mi></mrow><mrow><mo>&#8242;</mo></mrow></msup><mo stretchy='false'>(</mo><mn>958</mn><mo stretchy='false'>)</mo></math>, <math altimg='si5.svg'><msub><mrow><mi>f</mi></mrow><mrow><mn>1</mn></mrow></msub><mo stretchy='false'>(</mo><mn>1285</mn><mo stretchy='false'>)</mo></math>] and charmonium-meson [ <math altimg='si27.svg'><msub><mrow><mi>&#951;</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy='false'>(</mo><mn>1</mn><mi>S</mi><mo stretchy='false'>)</mo></math>, <math altimg='si28.svg'><msub><mrow><mi>&#967;</mi></mrow><mrow><mi>c</mi><mn>0</mn></mrow></msub><mo stretchy='false'>(</mo><mn>1</mn><mi>P</mi><mo stretchy='false'>)</mo></math>, <math altimg='si29.svg'><msub><mrow><mi>&#967;</mi></mrow><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo stretchy='false'>(</mo><mn>1</mn><mi>P</mi><mo stretchy='false'>)</mo></math>, <math altimg='si30.svg'><msub><mrow><mi>&#951;</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy='false'>(</mo><mn>2</mn><mi>S</mi><mo stretchy='false'>)</mo></math>, <math altimg='si10.svg'><msub><mrow><mi>&#967;</mi></mrow><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3872</mn><mo stretchy='false'>)</mo></math>] exchanges in the <italic>t</italic>-channel diagram. Most of the coupling constants are determined from the radiative decays of the <math altimg='si1.svg'><mi>J</mi><mo stretchy='false'>/</mo><mi>&#968;</mi></math> or the relevant charmonium mesons. The final <math altimg='si1.svg'><mi>J</mi><mo stretchy='false'>/</mo><mi>&#968;</mi></math>- <italic>N</italic> interaction is described by gluon-exchange and direct <math altimg='si11.svg'><mi>J</mi><mo stretchy='false'>/</mo><mi>&#968;</mi><mi>N</mi></math> coupling. The parameters of the Hamiltonian are fitted using the latest GlueX and <math altimg='si1.svg'><mi>J</mi><mo stretchy='false'>/</mo><mi>&#968;</mi></math>-007 experiments at the Jefferson Laboratory (JLab). We find that among the meson-exchange terms, the light mesons <math altimg='si3.svg'><mi>&#951;</mi><mo stretchy='false'>(</mo><mn>548</mn><mo stretchy='false'>)</mo></math> and <math altimg='si4.svg'><msup><mrow><mi>&#951;</mi></mrow><mrow><mo>&#8242;</mo></mrow></msup><mo stretchy='false'>(</mo><mn>958</mn><mo stretchy='false'>)</mo></math> make the most significant contributions to <math altimg='si12.svg'><mi>&#947;</mi><mi>p</mi><mo stretchy='false'>&#8594;</mo><mi>J</mi><mo stretchy='false'>/</mo><mi>&#968;</mi><mi>p</mi></math>, while the effect of charmonium mesons is relatively minor. The final-state interaction (FSI) contribution is found to be 1 - 2 orders of magnitude smaller than that of the Born term, but becomes significant near the threshold when a Yukawa-type potential is employed for the charmonium-nucleon interaction. The resulting total and <italic>t</italic>-dependent differential cross sections show good agreement with the JLab data. High-precision angular measurements near the threshold energy ( <math altimg='si13.svg'><msub><mrow><mi>E</mi></mrow><mrow><mi>&#947;</mi></mrow></msub><mo>&#10877;</mo><mn>8.9</mn></math> GeV) are highly desirable to clarify the role of the FSI term.

South Korea

Sang-Ho Kim

<italic>J</italic>/ <italic>&#968;</italic>-meson photoproduction off the nucleon in a dynamical model

We explore constraints that arise from associating an entanglement wedge (EW) to subregions of a cutoff boundary at a finite distance in AdS/CFT, using a subcritical end-of-the-world (ETW) brane acting as a cutoff.

United States

Krishan Saraswat

Constraints from entanglement wedge nesting for holography at a finite cutoff

Cosmic strings are powerful witnesses to cosmic events including any period of early matter domination. If such a period of matter domination was catalyzed by metastable, long-lived particles, then there will be complementary signals to ascertain the nature of the dark sector in experiments detecting primordial features in the gravitational wave (GW) power spectrum and laboratory searches for long-lived particles. We give explicit examples of global and local <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> gauge extended dark sectors to demonstrate such a complementarity as the union of the two experiments reveals more information about the dark sector than either experiment. Demanding that Higgs-portal long-lived scalar be looked for, in various experiments such as DUNE, FASER, FASER-II, MATHUSLA, and SHiP, we identify the parameter space that leads to complementary observables for GW detectors such as the Laser Interferometer Space Antenna and Einstein Telescope.

Satyabrata Datta

India

Ambar Ghosal

Poland

Anish Ghoshal

United Kingdom

Graham White

Complementarity between cosmic string gravitational waves and long-lived particle searches in a laboratory

Addressing the fermion flavor structures using modular invariance is a challenging task in the framework of quark-lepton unification. Building on recent applications of modular symmetry in nonsupersymmetric models, we propose the first renormalizable <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>5</mn><mo stretchy="false">)</mo></math> grand unified theory incorporating level 3 nonholomorphic modular symmetry, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Γ</mi><mn>3</mn></msub><mo>≃</mo><msub><mi>A</mi><mn>4</mn></msub></math>. This framework constrains Yukawa couplings to polyharmonic Maaß forms, significantly reducing the number of free parameters while enhancing the predictive power of the models. We present a comprehensive analysis of fermion masses and mixing while tackling key grand unified theory (GUT) queries such as gauge coupling unification and proton decay. Beyond the minimal <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>5</mn><mo stretchy="false">)</mo></math> framework, the Higgs sector incorporates the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4</mn><msub><mn>5</mn><mi>H</mi></msub></math> dimensional Higgs field crucial in differentiating the masses of down quarks and charged leptons, and the fermion sector is extended with three right-handed neutrinos enabling neutrino masses via the type-I seesaw mechanism. We analyze two benchmark models with distinct modular weight and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>A</mi><mn>4</mn></msub></math> charge assignments. The predicted effective Majorana mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mrow><mi>β</mi><mi>β</mi></mrow></msub></math> values align with current neutrinoless double-beta decay experiments, and the effective neutrino mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>β</mi></msub></math> is within the reach of future beta decay searches. The predicted sum of neutrino masses, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>∑</mo><msub><mi>m</mi><mi>i</mi></msub></math>, satisfies the upper bound set by recent cosmological observations. The gauge coupling unification is achieved through a light scalar triplet <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>3</mn></msub><mo>∼</mo><mo stretchy="false">(</mo><mn>3</mn><mo>,</mo><mn>3</mn><mo>,</mo><mo>−</mo><mn>1</mn><mo>/</mo><mn>3</mn><mo stretchy="false">)</mo></math> and a scalar octet <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>5</mn></msub><mo>∼</mo><mo stretchy="false">(</mo><mn>8</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>1</mn><mo>/</mo><mn>2</mn><mo stretchy="false">)</mo></math> belonging to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4</mn><msub><mn>5</mn><mi>H</mi></msub></math> Higgs, while proton decay constraints require that the contribution of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4</mn><msub><mn>5</mn><mi>H</mi></msub></math> Higgs to the up-quark mass matrix remains highly suppressed.

United Arab Emirates

Mohamed Amin Loualidi

Morocco

Mohamed Miskaoui

Salah Nasri

Nonholomorphic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>A</mi><mn>4</mn></msub></math> modular invariance for fermion masses and mixing in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>5</mn><mo stretchy="false">)</mo></math> GUT

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>) is a key process for probing Standard Model and beyond the Standard Model (BSM) properties. Following its first detection by the COHERENT Collaboration, recent reactor-based experiments provide a unique opportunity to refine our current understanding. In particular, the high-precision data from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CONUS</mi><mo>+</mo></mrow></math>, combined with the strong bounds from TEXONO, not only validate the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> process at low energies but also provide improved constraints on the weak mixing angle, neutrino electromagnetic properties (including the charge radius, millicharge, and magnetic moment), and nonstandard interactions and light mediators. We also examine the role of elastic neutrino-electron scattering, which gains significance in certain BSM scenarios and allows us to obtain the best limit for the millicharge of the electron neutrinos. By combining reactor and higher-energy spallation neutron source measurements, this work strengthens <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> as a precision tool for testing the Standard Model and beyond.

Italy

M. Atzori Corona

M. Cadeddu

N. Cargioli

F. Dordei

C. Giunti

Reactor antineutrinos <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> on germanium: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CONUS</mi><mo>+</mo></mrow></math> and TEXONO as a new gateway to SM and BSM physics

It is well-known that the momentum spectra of particles confined to finite spatial volumes deviate from the continuous spectra used for unconfined particles. In this article, we consider real scalar particles confined to finite volumes with periodic boundary conditions, such that the particles’ spectra are discrete. We directly compute the density matrices describing the decay processes $$\phi \rightarrow \varphi ^2$$ and $$\phi \rightarrow \varphi \chi \nu $$ , and subsequently derive expressions for the decay probabilities both for confined and unconfined particles. The latter decay process is used as a rough toy model for a neutron decaying into a proton, an electron, and an anti-electron neutrino. We propose that finite volume effects can have an impact on the outcomes of experiments measuring the neutron lifetime. In addition, our findings at the toy model level suggest that taking into account possible initial correlations between neutrons and their daughter particles might be relevant as well.

Austria

Christian Käding

Particles in finite volumes and a toy model of decaying neutrons

Extensive air showers produce high-energy muons that can be utilized to probe hadronic interaction models in cosmic ray interactions. Most muons originate from pion and kaon decays, called $\textit{conventional}$ muons, while a smaller fraction, referred to as $\textit{prompt}$ muons, arises from the decay of heavier, short-lived hadrons. The option of the air shower simulation tool is used in this work to investigate the prompt and conventional muon flux in the energy range of $${100}\,\hbox {TeV}$$ – $${100}\,\hbox {PeV}$$ , utilizing the newly developed open-source python software . Identifying the muon parent particles allows for scaling the contribution of prompt particles, which can be leveraged by future experimental analyses to measure the normalization of the prompt muon flux. Obtained prompt muon spectra from are compared to results. The relevance to large-volume neutrino detectors, such as IceCube and KM3NeT, and the connection to hadronic interaction models is discussed.

Sweden

Ludwig Neste

Pascal Gutjahr

Mirco Hünnefeld

Jean-Marco Alameddine

Wolfgang Rhode

Julia Tjus

Felix Riehn

Kevin Kröninger

Johannes Albrecht

Prompt and conventional high-energy muon spectra from a full Monte Carlo simulation via