Upcoming space-based gravitational-wave detectors will be sensitive to millions and resolve tens of thousands of stellar-mass binary systems at mHz frequencies. The vast majority of these will be double white dwarfs in our Galaxy. The greatest part will remain unresolved, forming an incoherent stochastic foreground signal. Using state-of-the-art galactic models for the formation and evolution of binary white dwarfs and accurate LISA simulated signals, we introduce a test for foreground Gaussianity and stationarity, building on methods available for ground-based detectors. We explain the observed non-stationarity with a new analytical modulation induced by the LISA constellation motion and the intrinsic anisotropy of the source distribution. By demodulating the foreground signal, we reveal a deviation from Gaussianity in the 2–10 mHz frequency band. Our finding is crucial to design faithful data models: the proposed method serves as a diagnostic and estimation tool to flag and model deviations, respectively. Neglecting them would introduce systematic biases on individual sources and astrophysical foregrounds parameter estimation, ultimately leading to inaccurate interpretation of the LISA data.

Italy

United Kingdom

Riccardo Buscicchio

Antoine Klein

Germany

Valeriya Korol

France

Francesco Renzo

Christopher Moore

Davide Gerosa

Alessandro Carzaniga

Test for LISA foreground Gaussianity and stationarity: galactic white-dwarf binaries

A search for a pseudoscalar $\textit{a}$ produced in association with a top-quark pair, or in association with a single top quark plus a $\textit{W}$ boson, with the pseudoscalar decaying into $\textit{b}$-quarks ( $$a\rightarrow b\bar{b}$$ ), is performed using the full Run 2 data sample using a dileptonic decay mode signature. The search covers pseudoscalar boson masses between 12 and 100 GeV and involves both the kinematic regime where the decay products of the pseudoscalar are reconstructed as two standard $\textit{b}$-tagged small-radius jets, or merged into a large-radius jet due to its Lorentz boost. No significant excess relative to expectations is observed. Assuming a branching ratio $$\text {BR}(a\rightarrow b\bar{b})=100\% $$ , the range of pseudoscalar masses between 50 and 80 GeV is excluded at 95% confidence level for a coupling of the pseudoscalar to the top quark of 0.5, while a coupling of 1.0 is excluded at 95% confidence level for the masses considered, with the coupling defined as the strength modifier of the Standard Model Yukawa coupling.

G. Aad

Norway

E. Aakvaag

United States

B. Abbott

United Arab Emirates

S. Abdelhameed

K. Abeling

N.J. Abicht

S. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Y. Abulaiti

B. Acharya

A. Ackermann

C. Bourdarios

Poland

L. Adamczyk

S. Addepalli

M. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A. Affolder

Y. Afik

Spain

M. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

Azerbaijan

F. Ahmadov

S. Ahuja

China

X. Ai

G. Aielli

A. Aikot

M. Tamlihat

B. Aitbenchikh

M. Akbiyik

Sweden

T. Åkesson

A. Akimov

Japan

D. Akiyama

N. Akolkar

S. Aktas

G. Alberghi

Canada

J. Albert

P. Albicocco

G. Albouy

S. Alderweireldt

Z. Alegria

Switzerland

M. Aleksa

I. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

Saudi Arabia

H. Ali

S. Ali

S. Alibocus

South Africa

M. Aliev

G. Alimonti

W. Alkakhi

C. Allaire

B. Allbrooke

J. Allen

P. Allport

A. Aloisio

Argentina

F. Alonso

C. Alpigiani

Z. Alsolami

A. Alvarez Fernandez

M. Alves Cardoso

M. Alviggi

M. Aly

Brazil

Y. Amaral Coutinho

A. Ambler

C. Amelung

M. Amerl

C. Ames

T. Amezza

D. Amidei

B. Amini

K. Amirie

A. Amirkhanov

Portugal

S. Amor Dos Santos

K. Amos

D. Amperiadou

S. An

C. Anastopoulos

T. Andeen

J. Anders

A. Anderson

A. Andreazza

S. Angelidakis

A. Angerami

A. Anisenkov

A. Annovi

C. Antel

E. Antipov

M. Antonelli

F. Anulli

M. Aoki

T. Aoki

Search for a new pseudoscalar decaying into a pair of bottom and antibottom quarks in top-associated production in $$\sqrt{s}=13$$ TeV proton–proton collisions with the ATLAS detector

We present an automatic renormalization group equations (RGEs) solver, D7RGESolver, designed for the precise numerical solution of one-loop RGEs of dimension-7 (dim-7) operators within the standard model effective field theory (SMEFT). This tool is capable of calculating the RGE effects of dim-5 and dim-7 SMEFT operators between any two scales above the electroweak scale. We take the nuclear neutrinoless double beta (0$\textit{νββ}$) decay process as an example to appreciate the importance of the running effects in phenomenological studies. Our analysis demonstrates that 0$\textit{νββ}$ decay can constrain nearly all dim-7 SMEFT operators involving first-generation leptons that violate lepton number by two units, after accounting for RGE effects. Specifically, we have placed meaningful constraints on 55 dim-7 Wilson coefficients, compared to only 10 from a simple tree-level analysis. Certain operators exhibit much stricter constraints when RGE effects are included, especially for the operators that mix with neutrino mass operators. We provide a complete code documentation for D7RGESolver, along with examples of its usage and interfacing with external automated codes for calculating 0$\textit{νββ}$ decay. The D7RGESolver code is available at:

Yi Liao

Xiao-Dong Ma

Hao-Lin Wang

Xiang Zhao

RGE solver for the complete dim-7 SMEFT interactions and its application to 0$\textit{νββ}$ decay

The $\textit{B}$-Mesogenesis model explains the matter-antimatter asymmetry and leads to the right amount of dark matter in the Universe. In particular, this model predicts new decay channels of the $\textit{b}$ quark. We investigate the modification of inclusive $\textit{b}$-hadron decay rates and of the lifetimes of different $\textit{B}$ mesons due to these new decay channels and compare our results with available predictions for exclusive $\textit{B}$ meson decays. We find that for the specific decay channel $\textit{b}$ → $\textit{duψ}$, only a small region of parameter space remains viable after applying current experimental constraints. This surviving region is highly constrained but not yet fully excluded. We further investigate the individual sensitivities and complementarity of the different constraints from inclusive branching ratios and lifetimes.

Alexander Lenz

Ali Mohamed

Zachary Wüthrich

Constraining $\textit{B}$-mesogenesis models with inclusive and exclusive decays

We construct and analyse infinite classes of regular supergravity backgrounds dual to four-dimensional superconformal field theories (SCFTs) compactified on a circle with a supersymmetry-preserving twist. These flows lead to three-dimensional gapped QFTs preserving four supercharges. The solutions arise in Type IIB, Type IIA, and eleven-dimensional supergravity, and generalise known constructions by incorporating deformations that avoid typical singularities associated with the holographic description of the Coulomb branch of the CFT. We examine several observables: Wilson loops, holographic central charges, and complexity. We show they exhibit a universal factorisation, with each observable decomposing into a UV-CFT contribution times a flow-dependent factor. We also explore the parameter regimes where higher-curvature corrections become relevant, affecting the physical interpretation of certain observables. Our findings provide new insights into universal features of holographic RG flows and resolve a puzzle related to complexity in these systems.

Dimitrios Chatzis

Madison Hammond

Georgios Itsios

Carlos Nunez

Dimitrios Zoakos

Universal observables, SUSY RG-flows and holography

We consider the supersymmetric Wess-Zumino model at large $\textit{N}$ in (2 + 1) dimension. We introduce a chemical potential($\textit{μ}$) at finite temperature($\textit{T}$). The non-trivial fixed point of this model is described by a pair of coupled gap equations. This fixed point behaves as a thermal CFT for all values of the coupling. We find that at large chemical potential these coupled equations simplify and solutions become analytically tractable. We solve them analytically for all values of the coupling at this limit. The solutions admit a systematic series expansion in $$ \frac{T}{\mu } $$ . Thus, using the solutions of the gap equation at large chemical potential we can evaluate the analytic form of the partition function, stress tensor and spin-1 current as a perturbative expansion in orders of $$ \frac{T}{\mu } $$ . Applying the OPE inversion formula on the scalar and fermion two point functions of the theory, we compute higher spin currents at large $\textit{μ}$.

India

Srijan Kumar

Large $\textit{N}$ Wess-Zumino model at finite temperature and large chemical potential in 3$\textit{d}$

We present the results of our lattice QCD computation of the hadronic matrix elements relevant to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>c</mi></msub><mi>γ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>b</mi></msub><mi>γ</mi></math> decays by using the gauge configurations produced by the Extended Twisted Mass Collaboration with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>f</mi></msub><mo>=</mo><mn>2</mn><mo>+</mo><mn>1</mn><mo>+</mo><mn>1</mn></math> dynamical Wilson-Clover twisted mass fermions at five different lattice spacings with physical dynamical <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>u</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>d</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi></math> quark masses (except for the coarsest lattice for which the lightest sea quark corresponds to a pion with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>π</mi></msub><mo>≃</mo><mn>175</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>). While the hadronic matrix element for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>c</mi></msub><mi>γ</mi></math> is obtained directly, the one relevant to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>b</mi></msub><mi>γ</mi></math> is reached by working with heavy quark masses <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>m</mi><mi>H</mi><mrow><mo stretchy="false">(</mo><mi>n</mi><mo stretchy="false">)</mo></mrow></msubsup><mo>=</mo><msup><mi>λ</mi><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msup><msub><mi>m</mi><mi>c</mi></msub></math>, with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi><mo>∼</mo><mn>1.24</mn></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi><mo>=</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mo>…</mo><mo>,</mo><mn>6</mn></math>, and then extrapolated to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>b</mi></msub></math> by several judicious Ansätze. In the continuum limit we obtain <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><msub><mi>h</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>c</mi></msub><mi>γ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0.604</mn><mo stretchy="false">(</mo><mn>24</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>, which is by a factor of 2.3 more accurate than the previous lattice estimates, and in good agreement with the experimental measurement. In the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-quark case we obtain <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><msub><mi>h</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>b</mi></msub><mi>γ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>46.0</mn><mo stretchy="false">(</mo><mn>4.8</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>keV</mi></math>.

D. Bečirević

R. Di Palma

R. Frezzotti

G. Gagliardi

V. Lubicz

F. Sanfilippo

N. Tantalo

Lattice QCD determination of the radiative decay rates <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>c</mi></msub><mi>γ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>b</mi></msub><mi>γ</mi></math>

Quantum contextuality refers to the impossibility of assigning a predefined, intrinsic value to a physical property of a system independently of the context in which the property is measured. It is, perhaps, the most fundamental feature of quantum mechanics. The many states with different spin that particle physics provides are the ideal setting for testing contextuality. We verify that the polarization states of single spin-1 massive particles produced at colliders are contextual. We test <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>W</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math> gauge bosons produced in top-quark decays, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>*</mo></msup><mo stretchy="false">(</mo><mn>892</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math> mesons in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math>-meson decays and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ϕ</mi></math> mesons in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>χ</mi><mi>c</mi><mn>0</mn></msubsup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>χ</mi><mi>c</mi><mn>1</mn></msubsup></math> charmonium decays by reinterpreting the data and the analyses of the ATLAS, LHCb, Belle II and BESIII experimental collaborations, respectively. The polarization states of these four particles show contextuality with a significance larger than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math>. We also discuss the presence of quantum contextuality in spin states of bipartite systems formed by spin-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math> particles. We test <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi></math> baryons reinterpreting two BESIII data analyses, and pairs of top quarks utilizing a recent analysis of the CMS Collaboration. Quantum contextuality is present with a significance exceeding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math> also in these cases. In addition, we study the feasibility of testing quantum contextuality by means of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> boson production in association with the Higgs boson, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math> bosons pairs created in Higgs boson decays and with pairs of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> leptons. For the latter, we use Monte Carlo simulations that mimic the settings of SuperKEKB and of future lepton colliders. Experiments at high energies, though not designed for the purpose, perform surprisingly well in testing for quantum contextuality.

M. Fabbrichesi

R. Floreanini

Estonia

E. Gabrielli

L. Marzola

Tests of quantum contextuality in particle physics

A new method was proposed recently to investigate the location of the putative critical point of strongly interacting matter, governed by quantum chromodynamics. By approximating contours of constant entropy density at finite baryon chemical potential, the conditions for the existence of a critical point are solved. In this work, we analyze this method in the hadron resonance gas and Nambu–Jona-Lasinio models. We demonstrate that the prediction of the critical point in the HRG model is solely due to mesonic and baryonic degrees of freedom, and thus is not necessarily a signal of a critical point. We argue that such an expansion leads to a physically meaningful prediction only when applied near the critical point.

Michał Marczenko

Michał Szymański

Hungary

Győző Kovács

Challenges in locating the QCD critical point via constant entropy density contours

Inverse decays are an interesting avenue for producing dark matter in the early Universe. We study in detail various phases of dark matter parameter space where inverse decays control its abundance, expanding on our work of inverse decay (INDY) dark matter and going beyond. The role of initial conditions and the impact of departure from kinetic equilibrium are investigated as well. We show how these inverse decay phases can arise in theories of a kinetically mixed dark photon and dark Higgs, with promising prospects for detection at upcoming experiments.