We present a systematic analysis of the Higgs signal strengths at 125 GeV and 95 GeV in a non-supersymmetric $ U(1)_X $ model with vector-like fermions ( $ U(1)_X $ VLFM). This framework extends the Standard Model (SM) by introducing an additional $ U(1)_X $ gauge symmetry, three right-handed neutrinos, two singlet Higgs fields ($\textit{ϕ}$ and $\textit{S}$), and one generation of vector-like quarks and leptons. The scalar fields mix in the neutral CP-even sector, yielding two Higgs-like states around 95 GeV and 125 GeV. We perform a $ \chi^2 $ analysis that combines the Higgs signal strength measurements at 125 GeV from ATLAS and CMS, including the $ \gamma\gamma $ , $ WW^* $ , $ ZZ^* $ , $ b\bar{b} $ , and $ \tau\bar{\tau} $ channels, together with the 95 GeV excesses observed in the diphoton and $ b\bar{b} $ final states reported by CMS and LEP. Our results indicate that the $ U(1)_X $ VLFM successfully reproduces the observed signal strengths of the 125 GeV Higgs while simultaneously explaining the 95 GeV excess. The parameters $ g_X $ , $ g_{YX} $ , $ v_S $ , $ v_P $ , and the new Yukawa couplings play a crucial role in achieving this consistency.

China

Rong-Zhi Sun

Shu-Min Zhao

Meng-Zi Cao

Song Gao

Portugal

Xing-Xing Dong

Higgs Bosons at 95 and 125 GeV in the $\textit{U}$(1) $\textit{X}$ VLFM * Supported by National Natural Science Foundation of China (NNSFC) (2075074), Natural Science Foundation of Hebei Province (A2023201040, A2022201022, A2022201017, A2023201041), Natural Science Foundation of Hebei Education Department (QN2022173), the Project of the China Scholarship Council (CSC) (202408130113). This work is also supported by Fundação para a Ciência e a Tecnologia (FCT, Portugal) through the project UID/00777/2025 (https://doi.org/ 10.54499/UID/00777/2025)

We investigate the atmospheric production and subsequent detection of sub-GeV dark mesons within the framework of a confining dark sector coupled to the Standard Model (SM) via a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub></math> vector portal. High-energy cosmic-ray interactions in the atmosphere produce dark quarks through proton bremsstrahlung, rare decays of Standard Model mesons, and Drell-Yan processes, which subsequently hadronize into dark mesons. We adopt a modified quark combination model to describe the nonperturbative dark hadronization process, allowing for a detailed event-level characterization of the dark meson flux. We simulate the flux and the interactions of these relativistic dark mesons in the Jiangmen Underground Neutrino Observatory (JUNO) using the genie generator, considering both elastic scattering off nuclei and deep inelastic scattering channels. Adopting a large-energy-singles-inspired conservative signal definition with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>15</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi><mo>&lt;</mo><msub><mi>E</mi><mrow><mi>vis</mi></mrow></msub><mo>&lt;</mo><mn>100</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math> and vetoing events containing final-state neutrons, we derive projected 90% C.L. sensitivities to the coupling strength between the dark gauge boson and the SM sector for a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>20</mn><mtext> </mtext><mtext> </mtext><mi>kton</mi><mo>·</mo><mi>year</mi></math> exposure. For the representative benchmark masses <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msup><mi>Z</mi><mo>′</mo></msup></msub><mo>=</mo><mn>0.001</mn></math>, 0.01, and 0.1 GeV, the projected JUNO reach corresponds to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>g</mi><mrow><mi>SM</mi></mrow><mn>90</mn></msubsup><mo>=</mo><mn>6.48</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>5</mn></mrow></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>7.75</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>5</mn></mrow></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.37</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>, respectively. This reach is found to be only mildly sensitive to order-one variations of the hadronization parameter, as illustrated by the choices <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>β</mi></msub><mo>=</mo><mn>1</mn><mo>/</mo><mn>3</mn></math>, 1, and 3.

Zirong Chen

Dan Chi

Jinmian Li

Junle Pei

Search for cosmic-ray-produced dark mesons via the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub></math> portal at JUNO

The diurnal modulation in galactic cosmic ray flux observed on the Earth is a widely studied phenomenon. Most of the analyses of this effect have been undertaken with data obtained by neutron monitor stations distributed over the world. The effect may also be seen in muon detectors, although muons are affected in a different way than neutrons. Particularly interesting is a comparison between the data obtained from neutron stations and muon telescopes located in the same region. In this paper we report an investigation of the diurnal modulation of cosmic rays at large latitudes, based on the data collected by three scintillator telescopes of the EEE (Extreme Energy Events) Project, installed at Ny-Ålesund, in the Svalbard archipelago, at $$79^{\circ }$$ N, during the period 2019–2025. Amplitudes and phases of the observed diurnal maximum in the cosmic ray flux were extracted in various periods by a harmonic fit of the averaged daily trend. Muon results were also compared to data collected in the period 2003–2025 by the Barentsburg Neutron Monitor Station, located not far from our detectors. The data, integrated along periods of one year, with a moving average in six months steps, show evidence of a diurnal modulation, with amplitudes of (0.05−0.1) $$\%$$ , smaller, roughly by a factor 2, than for neutrons, and a phase generally close to 12–16 h local time. No sensible differences were observed in the anisotropy parameters between solar nights and days in the polar region. The possible contribution of a second harmonic in the observed diurnal trend was also investigated.

Italy

M. Abbrescia

C. Avanzini

L. Baldini

R. Baldini Ferroli

G. Batignani

M. Battaglieri

E. Bossini

Switzerland

F. Carnesecchi

D. Cavazza

C. Cicalò

L. Cifarelli

F. Coccetti

E. Coccia

A. Corvaglia

A. Caro

D. Gruttola

S. Pasquale

L. Galante

M. Garbini

L. Ghezzer

I. Gnesi

F. Gramegna

Norway

E. Gramstad

S. Grazzi

E. Haland

D. Hatzifotiadou

P. Rocca

R. Liotino

G. Mandaglio

A. Margotti

G. Maron

M. Mazziotta

A. Mulliri

R. Nania

F. Noferini

F. Nozzoli

F. Ould-Saada

F. Palmonari

M. Panareo

M. Panetta

R. Paoletti

C. Pellegrino

L. Perasso

D. Piccolo

O. Pinazza

C. Pinto

S. Pisano

K. Piscicchia

L. Quaglia

M. Rasà

F. Riggi

G. Righini

C. Ripoli

M. Rizzi

B. Sabiu

G. Sartorelli

E. Scapparone

M. Schioppa

G. Scioli

A. Scribano

M. Selvi

M. Taiuti

A. Trifirò

M. Trimarchi

C. Vistoli

L. Votano

M. Williams

A. Zichichi

R. Zuyeuski

Investigation of the diurnal variation of cosmic rays at large latitudes by the detectors of the Extreme Energy Events Project

We study the one-point energy correlator (OPEC) at both the back-to-back and collinear limits in electron-proton and electron-nucleus collisions. We provide the factorization formalism for the two types of OPEC and present phenomenological predictions in the kinematic region relevant for the future Electron-Ion Collider. Focusing on cold nuclear matter effects in electron-nucleus scattering, we demonstrate that the OPEC serves as a powerful probe of the transverse momentum dependent physics and in characterizing the medium-induced transverse momentum broadening in cold nuclear matter.

United States

Yu Fu

Zhong-Bo Kang

Jani Penttala

Yiyu Zhou

Exploring nuclear modification using one-point energy correlator at the electron-ion collider

The paper develops a model to understand the effective quantum geometry of a black hole horizon and the emission of Hawking spectrum in $$2+1$$ dimensions. Using the algebra of Hamiltonian charges on the horizon, we establish that one should view the black hole horizon as formed out of quantised lengths of elementary quanta of value $$8\pi \ell _{P}\, n$$ , where $$n\in \mathbb {N}$$ , and $$\ell _{P}$$ is the Planck length. We determine the black hole entropy using this equidistant length spectrum in the microcanonical ensemble and show that its value is close to the Bekenstein-Hawking entropy. To evaluate the Hawking spectrum, we note that, to an observer near the black hole horizon, the entropy (or length of horizon cross-section) is related to the black hole energy. Hence, one may develop a formulation of length ensemble (similar to the area canonical ensemble of Krasnov) from which the black body spectrum may be obtained directly. This local observer perceives a Hawking spectrum whose temperature is modified by the Tolman factor.

India

Akriti Garg

Ayan Chatterjee

Hawking radiation from black holes in $$2+1$$ dimensions

Some extensions of the Standard Model consider inelastic dark matter (iDM) as an attractive candidate for sub-GeV DM of thermal origin that could be detected at modern accelerators. In the present paper, we calculate the production rate of iDM pairs <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mn>1</mn></msub><msub><mover accent="true"><mi>χ</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msub></math> interacting with the ordinary photon via dipole magnetic moment in the reaction of high-energy electron scattering on nuclei, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>−</mo></msup><mi>N</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>−</mo></msup><mi>N</mi><msub><mi>χ</mi><mn>1</mn></msub><msub><mover accent="true"><mi>χ</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msub></math>, in the NA64e experiment at the CERN Super Proton Synchrotron (SPS). We derive the projected sensitivity of NA64e to such particles assuming <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≃</mo><msup><mn>10</mn><mn>13</mn></msup></math> 100 GeV electrons on target. We also show, that incorporating heavy vector meson decays, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>γ</mi><mo>*</mo></msup><mi>N</mi><mo stretchy="false">→</mo><mi>N</mi><mi>V</mi><mo stretchy="false">(</mo><mo stretchy="false">→</mo><msub><mi>χ</mi><mn>1</mn></msub><msub><mover accent="true"><mi>χ</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msub><mo stretchy="false">)</mo></math>, alongside bremsstrahlunglike emission of inelastic dark matter pairs, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>−</mo></msup><mi>N</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>−</mo></msup><mi>N</mi><msup><mi>γ</mi><mo>*</mo></msup><mo stretchy="false">(</mo><mo stretchy="false">→</mo><msub><mi>χ</mi><mn>1</mn></msub><msub><mover accent="true"><mi>χ</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msub><mo stretchy="false">)</mo></math>, will allow NA64e to probe previously unexplored regions of the iDM parameter space, in particular for modest mass splittings, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><mo>≃</mo><mn>5</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>2</mn></mrow></msup></math>, and relatively light masses, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msub><mi>χ</mi><mn>0</mn></msub></msub><mo>≲</mo><mn>100</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>.

Russia

JINR

Chile

Sergei N. Gninenko

N.V. Krasnikov

I.V. Voronchikhin

D.V. Kirpichnikov

Missing energy signatures of inelastic magnetic dipole DM at NA64e

We investigate whether spontaneous symmetry breaking can persist up to arbitrarily high temperature in ultraviolet-complete quantum field theories in four spacetime dimensions. We focus on completely asymptotically free models with gauge group <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>SU</mi><mo stretchy="false">(</mo><msub><mi>N</mi><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo stretchy="false">)</mo><mo>×</mo><mi>SU</mi><mo stretchy="false">(</mo><msub><mi>N</mi><mrow><mi>c</mi><mn>2</mn></mrow></msub><mo stretchy="false">)</mo></math> and two complex scalar fields, each transforming in the fundamental representation of one gauge factor and singlet under the other. The scalar potential contains quartic self-interactions together with a negative portal coupling between the two sectors. In the Veneziano limit, this class of theories was previously shown to admit fixed-flow trajectories for which one scalar acquires a negative thermal mass at asymptotically large temperature, leading to symmetry nonrestoration. Here we extend that analysis to finite numbers of colors and flavors. We derive the finite-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> fixed-flow equations, compute the leading <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>/</mo><mi>N</mi></math> corrections to the large-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> solutions, and solve the full finite-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> system numerically. We find explicit finite-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> benchmark theories for which the scalar potential remains bounded from below, the gauge sector is asymptotically free, and one scalar thermal mass stays negative at arbitrarily high temperature. This provides an explicit perturbative example of infinite heat order in a four-dimensional ultraviolet-complete quantum field theory with a finite field content.

Slovenia

Borut Bajc

Denmark

Giulia Muco

Francesco Sannino

Sophie Wagner

Infinite heat order in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>3</mn><mo>+</mo><mn>1</mn></mrow></math> dimensions

Si-PIN detectors can be microstructured to achieve angular-selective particle detection capabilities, which we call $\textit{active Transverse Energy Filter}$ (aTEF). The microstructuring consists of a honeycomb structure of deep hexagonally-shaped holes with active silicon side walls, while the bottom of the holes is made insensitive to ionizing radiation. The motivation for this kind of detector arises from the need to distinguish background electrons from signal electrons in a spectrometer of MAC-E filter type. We have demonstrated the angular-dependent detection efficiency of self-fabricated aTEF prototypes in a test setup using an angular-selective photoelectron source to illuminate the detector from various incidence angles.

Germany

S. Schneidewind

K. Gauda

K. Blümer

D. Bonaventura

C. Gönner

V. Hannen

H.W. Ortjohann

W. Pernice

L. Pöllitsch

R. Salomon

M. Stappers

S. Wein

C. Weinheimer

An active transverse energy filter based on microstructured Si-PIN diodes with an angular-selective detection efficiency

We show that the finite energy resolution of a detector does not lead to a correlation between the bins of the observed spectrum unless a correlation is already present in the original spectrum. Our argument not only applies to the energy resolution but more generally to any case in which the probability distribution functions of the event and detector response are a Gaussian (or Poisson) and a multinomial, respectively. This is in contrast with a recent claim that such an effect not only occurs, but also significantly alters the distribution of $$\Delta \chi ^2,$$ the usual test statistic defined as the difference between two $$\chi ^2$$ computed under different hypotheses. We obtain a simple expression for the variance of $$\Delta \chi ^2$$ in the case of non-nested hypotheses, which is valid even if correlations between bins are present. While derived with the mass ordering in mind, our results regarding the distribution of $$\Delta \chi ^2$$ in the presence of (intrinsic) correlations also hold for any simple non-nested hypotheses.

Emilio Ciuffoli

Jarah Evslin

Finite energy resolution, correlations between bins and non-nested hypotheses

Characterizing the correlated behavior of nucleons inside atomic nuclei constitutes a long-standing challenge, both experimentally and theoretically. It has recently been understood that two-particle correlations in the azimuthal distribution of hadrons emitted in the final state of ultra-relativistic ultra-central ion-ion collisions can be used to quantify ground-state two-body correlations. Performing systematic <italic>ab initio</italic> nuclear structure calculations of light nuclei, such an observable is shown to provide a meaningful imaging of angular two-body correlations of various multipolarities in nuclear ground states. This is at variance with the traditional <italic>interpretation</italic> of the low-energy approach relying on Kumar operators that is shown to be inoperative. A future interesting development will consist of targeting specific three-particle correlations to isolate three-nucleon correlations in which additional nuclear structure information of interest leave their fingerprint.

France

Stavros Bofos

Benjamin Bally

Thomas Duguet

Mikael Frosini

Imaging two-body correlations in atomic nuclei via low- and high-energy processes