In this Letter we propose an interpretation of the Hubble tension as an effect of the scale-running of cosmological parameters and fundamental constants, as the Newton’s constant $\textit{G}$ and the cosmological constant $$\Lambda $$ . Namely, the tension between $$H_0$$ measurements by CMB and Supernovae observations would be a consequence of the fact that the value of $$H_0$$ depends (due to the running of $\textit{G}$ and $$\Lambda $$ ) on the scale at which it is measured. Indeed, the two different values of the Hubble parameter $\textit{today}$ correspond to the two different cosmological scales at which Supernovae and CMB measurements probe our universe. We discuss some possible theoretical scenarios in which the running of $\textit{G}$ and $$\Lambda $$ can occur. We stress that one should interpret such a running as a scale-dependence of the cosmological parameters and fundamental constants at the same time rather than a time dependence, as it is usually considered in the literature.

Italy

Fabio Briscese

The Hubble tension as an effect of the renormalization of fundamental constants and cosmological parameters

We investigate the dimuon Higgs decay $\textit{h}$ → $\textit{μ}$ $\textit{μ}$ in the context of an extended Scotogenic model. The model introduces a singlet complex scalar in addition to the standard Scotogenic scalar doublet and singlet fermions, charged under a dark ℤ symmetry. By exploring the one-loop contributions, we show that the model allows for sizable deviations in the Higgs dimuon decay rate, quantified by the quotient $\textit{R}$ = Br($\textit{h}$ → $\textit{μ}$ $\textit{μ}$ )$\textit{/}$Br($\textit{h}$ → $\textit{μ}$ $\textit{μ}$ ) . Crucially, these deviations comply with experimental limits, including those on Br($\textit{μ}$ → $\textit{e}$ $\textit{γ}$) and Br($\textit{h}$ → $\textit{γγ}$). Such deviations can be tested and constrained by future precision measurements at the LHC.

Spain

Pablo Escribano

Víctor Lozano

Chile

Sebastián Norero

Avelino Vicente

Exploring dimuon Higgs decay in an extended Scotogenic model

We consider extending the Standard Model by an anomaly-free and possibly flavour non-universal $\textit{U}$(1) gauge symmetry, whose breaking gives a $\textit{Z′}$ boson that does not affect electroweak precision observables at tree-level or via 1-loop renormalisation group (RG) running. Provided it does not also couple to electrons, such a $\textit{Z′}$ boson would be largely invisible to an electroweak precision machine like FCC-ee or CEPC (up to small finite 1-loop matching contributions that we quantify). We show that, while this class of $\textit{Z′}$ models can also evade tests of quark flavour violation, the constraint of anomaly-cancellation implies that valence quarks, muons, and taus are all charged under $\textit{U}$(1) , with the up quark charge being necessarily large. The conclusion holds even if one augments the SM by three right-handed neutrinos to try and absorb anomalies. This means such $\textit{Z′}$ bosons cannot simultaneously hide below the TeV scale from $\textit{pp}$ → $\textit{ℓℓ}$ Drell–Yan measurements at the LHC and, even if we entertain esoteric models in which the lepton charges are numerically very small, we cannot escape dijet searches at the LHC. For equitable quark and lepton charges, $\textit{pp}$ → $\textit{ℓℓ}$ already excludes such a $\textit{Z′}$ up to $\textit{M/g}$ ≳ 10 TeV, with a reach of 20 TeV expected by the end of the High-Luminosity LHC. The dijet bounds currently sit around 5 TeV, while sensitivity up to 10 TeV could be achieved at HL-LHC. We thus find an excellent complementarity between FCC-ee and HL-LHC in covering all anomaly-free $\textit{Z′}$ bosons up to several TeV.

Switzerland

Joe Davighi

In search of an invisible $\textit{Z′}$

Double field theory (DFT) can be constructed up to third order as the double copy of Yang-Mills theory. In this construction, one starts with Yang-Mills theory on Minkowski space and the resulting DFT action is also defined on Minkowski space. In this work, I extend this double copy procedure to obtain a DFT action on a constant DFT background starting from two Yang-Mills actions constructed around nontrivial background gauge fields on Minkowski space.

Türkiye

Rasim Yilmaz

Double copy map for double field theory on an arbitrary constant background

We present a determination of the strong coupling $$\alpha _s(m_Z)$$ from a global dataset including both fixed-target and collider data from deep-inelastic scattering and a variety of hadronic processes, with a simultaneous determination of parton distribution functions (PDFs) based on the NNPDF4.0 methodology. This determination is performed at NNLO and approximate $${\textrm{N}}^3$$ LO ( $${\textrm{aN}}^3$$ LO) perturbative QCD accuracy, including QED corrections and a photon PDF up to NLO accuracy. We extract $$\alpha _s$$ using two independent methodologies, both of which take into account the cross-correlation between $$\alpha _s$$ and the PDFs. The two methodologies are validated by closure tests that allow us to detect and remove or correct for several sources of bias, and lead to mutually consistent results. We account for all correlated experimental uncertainties, as well as correlated theoretical uncertainties related to missing higher order perturbative corrections (MHOUs). We study the perturbative convergence of our results and the impact of QED corrections. We assess individual sources of uncertainty, specifically MHOUs and the value of the top quark mass. We provide a detailed appraisal of methodological choices, including the choice of input dataset, the form of solution of evolution equation, the treatment of the experimental covariance matrix, and the details of Monte Carlo data generation. We find $$\alpha _s(m_Z)=0.1194^{+0.0007}_{-0.0014}$$ at $${\textrm{aN}}^3$$ $${\textrm{LO}}_{\textrm{QCD}}\otimes {\textrm{NLO}}_{\textrm{QED}}$$ accuracy, consistent with the latest PDG average and with recent lattice results.

United Kingdom

Richard Ball

Andrea Barontini

Juan Cruz-Martinez

Stefano Forte

Finland

Felix Hekhorn

Emanuele Nocera

Netherlands

Juan Rojo

Roy Stegeman

A determination of $$\alpha _s(m_Z)$$ at $${{\textrm{aN}}}^3{{\textrm{LO}}}_{{\textrm{QCD}}}\otimes {{\textrm{NLO}}}_{{\textrm{QED}}}$$ accuracy from a global PDF analysis

Recently, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>P</mi><mi>P</mi></math> decays (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>=</mo><mo stretchy="false">{</mo><msup><mi>B</mi><mn>0</mn></msup><mo>,</mo><msup><mi>B</mi><mo>+</mo></msup><mo>,</mo><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">}</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi><mo>=</mo><mo stretchy="false">{</mo><mi>π</mi><mo>,</mo><mi>K</mi><mo stretchy="false">}</mo></math>) were analyzed under the assumption of flavor SU(3) symmetry (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi></mrow></msub></mrow></math>). Although the individual fits to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><mi>S</mi><mo>=</mo><mn>0</mn></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><mi>S</mi><mo>=</mo><mn>1</mn></math> decays are good, it was found that the combined fit is very poor: there is a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3.6</mn><mi>σ</mi></math> disagreement with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi></mrow></msub></mrow></math> limit of the standard model (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SM</mi></mrow><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi></mrow></msub></mrow></msub></mrow></math>). One can remove this discrepancy by adding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi></mrow></msub></mrow></math>-breaking effects, but 1000% <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi></mrow></msub></mrow></math> breaking is required. In this paper, we extend this analysis to include decays in which there is an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi></math> and/or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>η</mi><mo>′</mo></msup></math> meson in the final state. We now find that the combined fit exhibits a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4.1</mn><mi>σ</mi></math> discrepancy with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SM</mi></mrow><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi></mrow></msub></mrow></msub></mrow></math>, and 1000% <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi></mrow></msub></mrow></math>-breaking effects are still required to explain the data. These results are rigorous, group-theoretically—no theoretical assumptions have been made. But when one adds some theoretical input motivated by QCD factorization, the discrepancy with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SM</mi></mrow><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi></mrow></msub></mrow></msub></mrow></math> grows to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4.9</mn><mi>σ</mi></math>.

United States

Bhubanjyoti Bhattacharya

Canada

Marianne Bouchard

Luke Hudy

Alexandre Jean

David London

Christopher MacKenzie

Anomalies in hadronic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> decays: An update

A search is performed for pairs of light pseudoscalar bosons (a) produced from decays of the 125 GeV Higgs boson (h ). The analysis is based on publicly available data collected in 2016 by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV. The amount of data analyzed corresponds to an integrated luminosity of 16.4 fb . The analysis explores for the first time at the LHC the final state exhibiting two muons and two c-quarks, which originate from flavor-asymmetric decays of the pseudoscalar pair. The search probes the pseudoscalar boson mass interval comprised between 4 and 11 GeV, which represents a region where the light bosons exhibit a considerable Lorentz boost, and thus their decay products overlap. No significant deviation from the standard model expectation is observed. Model-independent upper limits at 95% confidence level are set on the product of the cross section and branching fraction for the $$ {\textrm{h}}_{125}\to \textrm{aa}\to {\mu}^{-}{\mu}^{+}c\overline{c} $$ process relative to the standard model Higgs boson production cross section, reaching a minimum value close to 3$\textit{.}$3 × 10 . The results are interpreted in the context of two Higgs doublets plus singlet models and compared to existing experimental results covering other decay channels. The exclusion limits obtained by this search improve the current constraints set by various LHC searches in scenarios where the coupling of the light boson to up-type quarks is enhanced.

Germany

Danyer Adan

Search for an exotic decay of the 125 GeV Higgs boson to a pair of light pseudoscalars in the final state of two muons and two c-quarks in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV with CMS Open Data

Observation of gamma rays from an exploding black hole would provide strong evidence for primordial black holes, the first direct evidence of Hawking radiation, and definitive information on the particles present in nature. However, indirect constraints suggest that direct observation of an exploding Schwarzschild black hole at current or upcoming gamma ray observatories is implausible. We introduce a dark-QED toy model consisting of a dark photon and a heavy dark electron. In this scenario a population of light primordial black holes charged under the dark <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> symmetry can become quasiextremal, so they survive much longer than if they were uncharged, before discharging and exhibiting a Schwarzschild-like final explosion. We show that the answer is “yes,” in this scenario the probability of observing an exploding black hole over the next 10 years could potentially be over 90%.

Michael J. Baker

Joaquim Iguaz Juan

Aidan Symons

Andrea Thamm

Could We Observe an Exploding Black Hole in the Near Future?

We present a new exact black hole solution of a 5-dimensional Weyl-geometry Gauss-Bonnet theory of gravity. The Euclidean sector defines a fully regular metric coupled to the Weyl vector field. The Euclidean action and entropy are computed, with the latter following the simple <math altimg='si1.svg'><mrow><mi>A</mi><mo linebreak='goodbreak'>/</mo><mn>4</mn></mrow></math> form plus a term linear in the horizon radius, characteristic of Gauss-Bonnet couplings.

Japan

South Korea

Sebastian Bahamonde

Máximo Bañados

An exact five dimensional Weyl-geometry Gauss-Bonnet black hole

We investigate the thermodynamics of asymptotically flat black holes in four-dimensional Einstein-Gauss-Bonnet (4D-EGB) gravity using Rényi entropy as a non-extensive generalization of the Bekenstein-Hawking entropy. The resulting thermodynamic structure, formulated within a restricted phase space-like (RPST-like) framework, reveals a striking resemblance to the thermodynamics of AdS black holes in the standard RPST formalism. In particular, we identify a thermodynamic duality between the Rényi deformation parameter <italic>&#946;</italic> and a conjugate response potential <italic>&#950;</italic>, analogous to the central charge and chemical potential in holographic theories. An extensive thermodynamic analysis in both fixed charge- <math altimg='si1.svg'><mo stretchy='false'>(</mo><mover accent='true'><mrow><mi>Q</mi></mrow><mrow><mo stretchy='false'>&#732;</mo></mrow></mover><mo stretchy='false'>)</mo></math> and fixed potential- <math altimg='si137.svg'><mo stretchy='false'>(</mo><mover accent='true'><mrow><mi mathvariant='normal'>&#934;</mi></mrow><mrow><mo stretchy='false'>&#732;</mo></mrow></mover><mo stretchy='false'>)</mo></math> ensembles reveal Van der Waals-like first-order phase transitions which is an unexpected feature for asymptotically flat black holes. Furthermore, through the formalism of geometrothermodynamics (GTD) and thermodynamic topology. It is shown that the R&#233;nyi modified flat black hole mimics, in both its thermodynamic topology and geometry, the features of its counterparts in the 4D-EGB AdS black hole under RPST, reinforcing the structural similarity between these seemingly different systems. Our findings point to a deeper correspondence between non-extensive entropy and holographic thermodynamics, suggesting that R&#233;nyi entropy may serve as a natural bridge between flat-space black hole thermodynamics and AdS holography.

India

Amijit Bhattacharjee

Prabwal Phukon

Thermodynamics of flat 4D Einstein-Gauss-Bonnet black hole with Rényi entropy: An RPST-like formalism