This study investigates the ultraviolet realization of semileptonic four-fermion operator $ O_{ledq}^{\alpha \beta 11} $ that incorporates Majorana dark matter (DM) in both lepton-flavor-conserving (LFC) and lepton-flavor-violating (LFV) scenarios at the one-loop level via box diagram, thereby effectively alleviating the lower bounds on the new physics scale. In addition, we investigate the interplay between model-independent constraints on the Wilson coefficients and DM direct detection, relic density, and collider searches in the context of fermion portal DM model with two mediators. We found that both the projected future constraint on the LFC Wilson coefficient $ C_{ledq}^{2211}/\Lambda^2 \lt $ $ (12.3\; \text{TeV})^{-2} $ from the measurements of neutrino non-standard interaction in the next-generation neutrino oscillation experiments, and the LFV constraint $ C_{ledq}^{1211}/\Lambda^2 \lt \left(2.2\times 10^3\; \text{TeV} \right)^{-2} $ from ongoing charged-lepton-flavor-violation searches, provide a complementary exploration of the parameter space encompassing the DM and scalar masses. With a colored mediator mass of approximately $ 2\; \text{TeV} $ , the sensitivity of the indirect constraints on the four-fermion operator can surpass those of collider searches and DM direct detection, in scenarios where the masses of the DM and scalar are close. By ensuring the correct DM relic density, however, we find that the collider searches and DM direct detection are more sensitive to the electroweak-scale DM and scalar than indirect constraints.

China

Yuxuan He

Gang Li

Jia Liu

Xiao-Ping Wang

Xiang Zhao

Lepton flavor of four-fermion operator and fermion portal dark matter * Gang Li and Xiang Zhao are supported by the National Natural Science Foundation of China (12347105, 12505127), the Guangdong Basic and Applied Basic Research Foundation (2024A1515012668). The work of Jia Liu is supported by the National Science Foundation of China (12235001, 12475103) and State Key Laboratory of Nuclear Physics and Technology (NPT2025ZX11). The work of Xiao-Ping Wang is supported by National Science Foundation of China (12375095) and the Fundamental Research Funds for the Central Universities

This contribution reviews recent progress in the low-lying scalar mesons and glueballs. We propose a new classification for the scalar nonet that includes $f_0(980)$ and $a_0(980)$ as the lowest states, while we identify $f_0(1500)$ as a primary glueball candidate. We demonstrate that the production yields of these states in heavy-ion collisions are mutually consistent across statistical, coalescence, and S-matrix frameworks. To investigate their internal structure, we move beyond standard phenomenology by describing glueballs as topological solitons. This approach yields an energy spectrum in excellent agreement with lattice QCD and experimental data, while interpreting $f_0(2470)$ as a tightly bound glueballonium to explain its anomalously long lifetime. This non-perturbative framework provides a predictive basis for the future experimental verification of exotic scalar states. Abstract Published by the Jagiellonian University 2026 authors

Poland

C. Sasaki

Selected Topics in Quark–Hadron Physics: From Scalar Nonets to Topological Glueballs

We introduce a lattice QCD mixed action approach that employs Wilson-type quarks in the sea and valence sectors. The sea sector is based on gauge ensembles with $$N_\mathrm {\scriptstyle f}=2+1$$ flavours of non-perturbatively O($\textit{a}$)-improved Wilson fermions generated by the Coordinated Lattice Simulations (CLS) initiative. The parameter space of the considered ensembles encompasses five values of the lattice spacing, a range of pion masses extending down to the physical point, and large physical volumes. In the valence sector, we employ Wilson twisted-mass fermions at maximal twist, using the same massless Wilson-Dirac operator in both the sea and valence sectors. We describe the strategy applied for the required matching of the sea and valence quark masses along the target renormalised chiral trajectory. A precise universality test is then conducted by comparing the continuum-limit results of the mixed-action approach and of the unitary setup, in which the same Wilson fermion regularisation is employed in the sea and in the valence. As a key application, we conduct a scale setting procedure based on lattice determinations of the masses and decay constants of the pion and kaon, as well as the gradient flow scale $$t_0$$ . The scale setting can consequently be performed in three distinct ways, utilising the unitary setup, the mixed action approach, and their combination. We observe that the latter combination results in enhanced control of the systematic uncertainties, thereby yielding a precise determination of the physical value of $$t_0$$ .

Germany

Andrea Bussone

Alessandro Conigli

Julien Frison

Spain

Gregorio Herdoíza

Carlos Pena

Italy

David Preti

José Romero

Alejandro Sáez

Javier Ugarrio

Hadronic physics from a Wilson fermion mixed-action approach: setup and scale setting

In recent years, the complete set of cross sections for Large Hadron Collider (LHC) processes ending with three resolved final states consisting of either photons or jets has been evaluated at next-to-next-to-leading order in QCD and leading order in QED. Results for three photons or three jets have only been obtained using the leading-color approximation of the virtual two-loop amplitudes. In the meantime, the required amplitudes have become available without recourse to the color expansion. In the present publication, we quantify the effects of the subleading-color contributions, and show that they do not exceed 2% for most of the previously published results. The one exception is the ratio of three- to two-jet cross sections, where subleading-color effects can reach up to 5%. Furthermore, we show that these conclusions hold for both popular infrared renormalization schemes, i.e. minimal subtraction and a scheme based on Catani’s magic formula for infrared divergences of two-loop amplitudes. The size of the effects is usually overshadowed by the size of the remaining uncertainty due to the truncation of the perturbation series. This is particularly important in the case of three-jet distributions that have already been used for the extraction of the strong-coupling constant at the very high energies available at the LHC.

Michał Czakon

Rene Poncelet

How much color do we really need? Two-loop subleading-color effects in photon and jet physics

This work presents a proof of concept for MUSIC, a multi-purpose detector conceived for high-precision and ultra-high-energy physics studies in the challenging environment of $$\sqrt{s}=10$$ TeV muon–antimuon collisions. The detector features a central tracking system, electromagnetic and hadronic calorimeters, and dedicated muon detectors. This paper outlines the main design elements of each subdetector, with an emphasis on the effects of machine-induced backgrounds and the reconstruction strategies employed for key physics objects. Performance results for electrons, photons, muons, and jets are reported, and studies of jet flavour identification are discussed.

Paolo Andreetto

Nazar Bartosik

Andrea Bersani

Switzerland

Daniele Calzolari

Massimo Casarsa

Vittoria Ciccarella

Elisa Meco

Ruben Gargiulo

Alessio Gianelle

Carlo Giraldin

United Kingdom

Karol Krizka

Anton Lechner

Luigi Longo

Donatella Lucchesi

Leonardo Palombini

Nadia Pastrone

Ivano Sarra

Lorenzo Sestini

Rosamaria Venditti

Davide Zuliani

Music: a multi-purpose detector concept for physics at the 10 TeV muon collider

In the Standard Model, partial unification of the non-Abelian running gauge couplings is achieved at the scale <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>μ</mi><mn>32</mn><mrow><mi>SM</mi></mrow></msubsup><mo>≈</mo><mn>2.8</mn><mo>×</mo><msup><mn>10</mn><mn>16</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. Elaborating on this fact, we discuss a simple general parametrization for the new physics corrections leading to full unification at some scale <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><mi>X</mi></msub></math>. We show that for any new physics model such that the corrections to the non-Abelian couplings are equal (or nearly so), <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><mi>X</mi></msub></math> is equal (or close to) the partial unification scale <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>μ</mi><mn>32</mn><mrow><mi>SM</mi></mrow></msubsup></math>; the latter scales could be disentangled only if the corrections to the non-Abelian couplings are significantly different. We explore how the parametrization works for some relevant models with new physics below <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><mi>X</mi></msub></math>, as low-energy supersymmetry, split supersymmetry, etc. As for models with a desert up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><mi>X</mi></msub></math>, we explore, in particular, how the parametrization works for string-inspired corrections; we find a phenomenologically remarkable possibility for unification at about 100 TeV, suggesting a low string scale, in addition to the more conservative possibility for unification at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>μ</mi><mn>32</mn><mrow><mi>SM</mi></mrow></msubsup></math>; for models with power-law running/threshold corrections, we also outline an interesting connection with the number of fermion families propagating in the bulk.

Isabella Masina

Mariano Quirós

Standard model partial unification scale as a guide to new physics model building

The recently developed “imaging-by-smashing” technique has emerged as a powerful approach to connect final-state collective flow phenomena in ultra-relativistic nuclear collisions with the intrinsic structure of the colliding nuclei. While most efforts have focused on constraining nuclear shape properties such as deformation and triaxiality, less attention has been given to the neutron skin, primarily in heavy nuclei such as $$^{208}$$ Pb. In this work, a novel study of the neutron-skin thickness in $$^{48}$$ Ca is presented, based on comparative analyses of $$^{48}$$ Ca+ $$^{48}$$ Ca and $$^{40}$$ Ca+ $$^{40}$$ Ca collisions at $$\sqrt{s_\textrm{NN}}=5.02$$ TeV. Simulations within the AMPT framework are employed to investigate the impact of varying neutron-skin thicknesses $$\Delta r_{np}$$ for $$^{48}$$ Ca on collective flow observables, including anisotropic flow coefficients and mean transverse momentum ( $$[p_\textrm{T}]$$ ) fluctuations. The triangular flow $$v_3$$ , quadrangular flow $$v_4$$ , as well as the variance and skewness of $$[p_\textrm{T}]$$ fluctuations, display notable sensitivity to $$\Delta r_{np}$$ . These findings indicate that calcium-isotope runs at the LHC could provide an independent and complementary approach to constraining $$\Delta r_{np}$$ , with the potential to help resolve the current tension between PREX and CREX measurements.

Denmark

Andreas Vitsos

Leonora Soranzo

Emil Nielsen

You Zhou

Characterizing the neutron skin of $$^{48}$$ Ca through collective flow at the CERN large hadron collider

Extracting accurate results from neutrino oscillation and cross section experiments requires accurate simulation of the neutrino-nucleus interaction. The rescattering of outgoing hadrons (final state interactions) by the rest of the nucleus is an important component of these interactions. We present a new measurement of proton transparency (defined as the fraction of outgoing protons that emerge without significant rescattering) using electron-nucleus scattering data recorded by the CLAS detector at Jefferson Laboratory on helium, carbon, and iron targets. This analysis uses a new data-driven method to extract the transparency. It defines transparency as the ratio of electron-scattering events with a detected proton to quasi-elastic electron-scattering events where a proton should have been knocked out. Our results are consistent with previous measurements that determined the transparency from the ratio of measured events to theoretically predicted events. We find that the GENIE event generator, which is widely used by oscillation experiments to simulate neutrino-nucleus interactions, needs to better describe both the nuclear ground state and proton rescattering in order to reproduce our measured transparency ratios, especially at lower proton momenta.

United States

S. Dytman

M. Betancourt

N. Steinberg

L.B. Weinstein

Israel

A. Ashkenazi

J. Tena-Vidal

A. Papadopoulou

G. Chambers-Wall

J. Smith

P. Achenbach

France

J.S. Alvarado

M.J. Amaryan

H. Atac

Saudi Arabia

L. Baashen

N.A. Baltzell

L. Barion

M. Bashkanov

M. Battaglieri

F. Benmokhtar

A. Bianconi

A.S. Biselli

M. Bondi

F. Bossù

S. Boiarinov

K.-Th. Brinkmann

W.J. Briscoe

Chile

W.K. Brooks

S. Bueltmann

V.D. Burkert

T. Cao

R. Capobianco

D.S. Carman

J.C. Carvajal

P. Chatagnon

Russia

V. Chesnokov

H. Chinchay

G. Ciullo

P.L. Cole

M. Contalbrigo

A. D’Angelo

Armenia

N. Dashyan

R. De Vita

M. Defurne

A. Deur

S. Diehl

C. Djalali

R. Dupre

H. Egiyan

A. El Alaoui

L. El Fassi

L. Elouadrhiri

M. Farooq

S. Fegan

I.P. Fernando

A. Filippi

G. Gavalian

G.P. Gilfoyle

R.W. Gothe

L. Guo

K. Hafidi

H. Hakobyan

M. Hattawy

F. Hauenstein

T.B. Hayward

D. Heddle

A. Hobart

M. Holtrop

Yu-Chun Hung

Y. Ilieva

D.G. Ireland

E.L. Isupov

H. Jiang

South Korea

H.S. Jo

S. Joosten

M. Khandaker

A. Kim

W. Kim

F.J. Klein

V. Klimenko

A. Kripko

V. Kubarovsky

S.E. Kuhn

L. Lanza

P. Lenisa

D. Marchand

V. Mascagna

D. Matamoros

B. McKinnon

T. Mineeva

M. Mirazita

V. Mokeev

C. Munoz Camacho

P. Nadel-Turonski

T. Nagorna

K. Neupane

D. Nguyen

S. Niccolai

M. Osipenko

L.L. Pappalardo

R. Paremuzyan

Proton transparency and neutrino physics: New methods and modeling

Brazil

Níckolas Aguiar Alves

Lectures on the Bondi–Metzner–Sachs Group and related topics in infrared physics

We study the processes <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>τ</mi></msub><mi>n</mi><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><msup><mi>τ</mi><mo>−</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mo>−</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub><mi>p</mi><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>τ</mi><mo>+</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mo>+</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub><mo stretchy="false">)</mo></math>, with particular emphasis on the pion energy and angular distributions, as a possible signal for lepton flavor universality violation, and in general of physics beyond the Standard Model (SM), as well as a sensitive probe of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> polarization vector. We work within an effective low-energy extension of the SM with all dimension-six four-fermion operators. In this framework, complex Wilson coefficients which encode new physics can generate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-violating contributions. We propose an observable that provides a genuine <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-odd signal due to its sensitivity to particular transverse components of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> polarization vector. Namely, we show that the asymmetry in the azimuthal-angle distribution of the pion in the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>τ</mi><mo>±</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>±</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub></math> constitutes a smoking-gun prediction of such a beyond the SM scenario. We estimate the strength of this effect extrapolating nucleon-hyperon form factors recently obtained from lattice QCD calculations.

E. Hernández

J. Nieves

Sweden

J.E. Sobczyk

Probing new physics and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>τ</mi></msub><mi>n</mi><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><msup><mi>τ</mi><mo>−</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mo>−</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub><mi>p</mi><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>τ</mi><mo>+</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mo>+</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub><mo stretchy="false">)</mo></math>