A search is performed for dark matter produced in association with bottom quarks and a pair of electrons or muons in data collected with the CMS detector at the LHC, corresponding to 138 fb of integrated luminosity of proton-proton collisions at a center-of-mass energy of 13 TeV. For the first time at the LHC, the associated production of a bottom quark-antiquark pair and a new heavy neutral Higgs boson (H) that subsequently decays into a leptonically decaying Z boson and a pseudoscalar (a) is explored. The latter acts as a dark matter mediator in the context of the two Higgs doublet model plus a pseudoscalar (2HDM+a). Multivariate techniques that target a wide range of mass configurations for the H and a particles are used. The observations are consistent with the expectations from standard model processes. Upper limits at 95% confidence level are set on the product of cross section and branching fraction of the new particles, ranging from 10 pb for an H mass of 400 GeV to 10 pb for an H mass of 2000 GeV. Constraints on the parameter space of a benchmark 2HDM+a model are derived and compared with expectations in the context of cosmological predictions.

Armenia

V. Chekhovsky

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J. Andrejkovic

L. Benato

T. Bergauer

K. Damanakis

M. Dragicevic

C. Giordano

P. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

D. Schwarz

R. Schöfbeck

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

T. Laer

P. Mechelen

J. Bierkens

N. Breugelmans

J. D’Hondt

S. Dansana

A. Moor

M. Delcourt

F. Heyen

Y. Hong

S. Lowette

I. Makarenko

D. Müller

S. Tavernier

M. Tytgat

G. Onsem

S. Putte

D. Vannerom

B. Bilin

B. Clerbaux

A. Das

I. Bruyn

G. Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F. Khan

A. Malara

M. Shahzad

L. Thomas

M. Bemden

C. Vander Velde

P. Vanlaer

F. Zhang

M. Coen

D. Dobur

G. Gokbulut

J. Knolle

L. Lambrecht

D. Marckx

K. Skovpen

N. Bossche

J. Linden

J. Vandenbroeck

L. Wezenbeek

S. Bein

A. Benecke

A. Bethani

G. Bruno

A. Cappati

J. De Favereau De Jeneret

C. Delaere

A. Giammanco

A. Guzel

Sa. Jain

V. Lemaitre

J. Lidrych

P. Mastrapasqua

S. Turkcapar

Brazil

G. Alves

E. Coelho

G. Correia Silva

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E. Tonelli Manganote

A. Vilela Pereira

W. Aldá Júnior

M. Barroso Ferreira Filho

H. Brandao Malbouisson

W. Carvalho

J. Chinellato

Search for dark matter production in association with bottom quarks and a lepton pair in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

We present an investigation of the structural properties of heavy-light ( $$D, D_s, B, B_s$$ ) and heavy-heavy ( $$B_c$$ ) mesons by incorporating the $\textit{V}$-scheme strong coupling constant $$\alpha _V$$ up to the third-loop order ( $$N^3$$ LO). The inclusion of three-loop radiative corrections is critical to achieving perturbative convergence and effectively canceling renormalon-induced instabilities. A central feature of this work is the rigorous calibration of the string tension $\textit{b}$ using the universal scaling ratio $$R_{n_f} = \Lambda _{\overline{\text {MS}}}^{(n_f)}/\sqrt{b}$$ , matched to the non-perturbative Sommer scale $$r_0$$ from FLAG 2024 averages. By integrating these flavor-dependent $$N^3$$ LO refinements ( $$b \approx 0.1951 \pm 0.0369$$ GeV $$^2$$ ) into a variational Cornell potential framework, we demonstrate a systematic“stiffening”of the internal structure and a physical spatial contraction across successive loop orders. Our $$N^3$$ LO results for root-mean-square (RMS) matter radii and charge radii exhibit remarkable agreement with established benchmarks: specifically, the $$B_c$$ charge radius (0.191 fm) and matter radius (0.2967 fm) align closely with light-front predictions and relativistic quark model studies. Evaluation of the Isgur–Wise function reveals that while higher-order corrections primarily reshape the light-quark spectator cloud, the heavy core localization remains dominated by the constituent mass scale.

India

Rishan Choudhury

Pritom Nath

Jugal Lahkar

Variationally improved structure of heavy-light mesons at $$N^3$$ LO: stiffening effects and universal form factors in the $\textit{V}$-scheme

We present BSkG5, the latest entry in the Brussels-Skyrme-on-a-Grid (BSkG) series and the first large-scale nuclear structure model based on next-to-next-to-leading order (N2LO) Skyrme energy density functional (EDF). By extending the traditional Skyrme EDF ansatz with central terms containing up to four gradients, we are able to combine an excellent global description of nuclear ground state properties with a stiff equation of state for pure neutron matter that is consistent with astronomical observations of neutron stars. More precisely, the new model matches the accuracy of earlier BSkG models but with two parameters less: we achieve root-mean-square deviations of 0.649 MeV for 2457 atomic masses, 0.0267 fm for 810 charge radii, and 0.43 MeV for 45 primary fission barriers of actinide nuclei. We demonstrate that the complexities of N2LO EDFs are not insurmountable, even for demanding many-body calculations.

Germany

G. Grams

W. Ryssens

A. Sánchez-Fernández

N.N. Shchechilin

L. González-Miret Zaragoza

P. Demol

N. Chamel

S. Goriely

France

M. Bender

Skyrme-Hartree-Fock-Bogoliubov mass models on a 3D mesh: V. The N2LO extension of the Skyrme EDF

The results of a search for the production of two scalar bosons in final states with two photons and two tau leptons are presented. The search considers both nonresonant production of a Higgs boson pair, HH, and resonant production via a new boson X which decays either to HH or to H and a new scalar Y. The analysis uses up to 138 fb of proton-proton collision data, recorded between 2016 and 2018 by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV. No evidence for signal is found in the data. For the nonresonant production, the observed (expected) upper limit at 95% confidence level (CL) on the HH production cross section is set at 930 (740) fb, corresponding to 33 (26) times the standard model prediction. At 95% CL, HH production is observed (expected) to be excluded for values of $\textit{κ}$ outside the range between −12 (−9.4) and 17 (15). Observed (expected) upper limits at 95% CL for the X → HH cross section are found to be within 160 to 2200 (200 to 1800) fb, depending on the mass of X. In the X → Y(ττ)H(γγ) search, the observed (expected) upper limits on the product of the production cross section and decay branching fractions vary between 0.059–1.2 fb (0.087–0.68 fb). For the X → Y(γγ)H(ττ) search the observed (expected) upper limits on the product of the production cross section and Y → γγ branching fraction vary between 0.69–15 fb (0.73–8.3 fb) in the low Y mass search, tightening constraints on the next-to-minimal supersymmetric standard model, and between 0.64–10 fb (0.70–7.6 fb) in the high Y mass search.

S. Chatterjee

J. Jaramillo

K. Lee

K. Mota Amarilo

C. Caputo

I. Donertas

T. Tran

E. Costa

Search for the nonresonant and resonant production of a Higgs boson in association with an additional scalar boson in the $\textit{γγττ}$ final state in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

Differential top quark pair production cross sections are measured in the dilepton final states e e , μ μ , and e μ , as a function of kinematic variables of the two-neutrino system: the transverse momentum $$ {p}_{\textrm{T}}^{\nu \nu} $$ of the dineutrino system, the minimum distance in azimuthal angle between $$ {\overrightarrow{p}}_{\textrm{T}}^{\nu \nu} $$ and leptons, and in two dimensions in bins of both observables. The measurements are performed using CERN LHC proton-proton collisions at $$ \sqrt{s}=13 $$ TeV, recorded by the CMS detector between 2016 and 2018, corresponding to an integrated luminosity of 138 fb . The measured cross sections are unfolded to the particle level using an unregularized least squares method. Results are compared with predictions by the standard model of particle physics, and found to be in agreement with theoretical calculations as well as Monte Carlo simulations.

G. Silveira

Measurement of the dineutrino system kinematic variables in dileptonic top quark pair production in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

<p>A novel machine-learning-based flavor-tagging algorithm combining same-side and opposite-side tagging is used to obtain the equivalent of 27 500 tagged <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo stretchy="false">/</mo><mi>ψ</mi><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></math> decays from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, collected by the CMS experiment and corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>96.5</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. A time- and flavor-dependent angular analysis of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mrow><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math> final state, consistent with a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></mrow><mo stretchy="false">→</mo><mrow><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math> decay, is used to measure parameters of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo>−</mo><msubsup><mover accent="true"><mi>B</mi><mo accent="true" stretchy="false">¯</mo></mover><mi>s</mi><mn>0</mn></msubsup></math> system. The weak phase is measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mi mathvariant="normal">s</mi></mrow></msub><mo>=</mo><mrow><mo>−</mo><mn>73</mn></mrow><mo>±</mo><mn>22</mn><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow><mo>±</mo><mn>10</mn><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow><mtext> </mtext><mtext> </mtext><mi>mrad</mi></mrow></math>, which, combined with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>8</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math> CMS result, gives <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mi mathvariant="normal">s</mi></mrow></msub><mo>=</mo><mrow><mo>−</mo><mn>75</mn></mrow><mo>±</mo><mn>23</mn><mtext> </mtext><mtext> </mtext><mi>mrad</mi></mrow></math>. This value differs from zero by 3.2 standard deviations, providing the first evidence for mixing-induced <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo stretchy="false">/</mo><mi>ψ</mi><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></math> decays. All measured physics parameters are found to agree with standard model predictions where available.</p>

J.W. Andrejkovic

P.S. Hussain

T. Van Laer

P. Van Mechelen

A. De Moor

G.P. Van Onsem

S. Van Putte

A.K. Das

I. De Bruyn

G. De Lentdecker

F.A. Khan

S. Paredes

M.A. Shahzad

M. Vanden Bemden

M. De Coen

N. Van Den Bossche

J. van der Linden

I.S. Donertas

A.O. Guzel

T.T. Tran

G.A. Alves

W.L. Aldá Júnior

E.M. Da Costa

G.G. Da Silveira

D. De Jesus Damiao

First Evidence for Mixing-Induced <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> Violation in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></math> Decays in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> Collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math>

We develop a covariant formulation of Andreev reflection at a normal-metal–superconductor (N-S) interface embedded in a static curved spacetime and specialize to the Schwarzschild exterior. The construction rests on the Bogoliubov–de Gennes (BdG) equations formulated intrinsically on a static hypersurface Σ <inf><italic>t</italic></inf>, with the superconducting gap &#916; treated as a local order parameter and quasiparticle transport encoded in a conserved probability current whose hypersurface flux defines the conductance for an observer at infinity. Using the timelike Killing field to relate proper and asymptotic observables, we derive a gravitationally redshifted Blonder&#8211;Tinkham&#8211;Klapwijk (BTK) formula in which the asymptotic differential conductance depends on the ratio <italic>E</italic> <inf>&#8734;</inf>/&#916; <inf>&#8734;</inf>, where &#916; <inf>&#8734;</inf>&#8239;&#8801;&#8239; <italic>&#945;</italic>&#8201;&#916; <inf>proper</inf> and <math altimg='si37.svg'><mrow><mi>&#945;</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><msqrt><mrow><mn>1</mn><mo linebreak='badbreak'>&#8722;</mo><msub><mi>r</mi><mi>s</mi></msub><mo linebreak='badbreak'>/</mo><mi>r</mi></mrow></msqrt></mrow></math> is the Schwarzschild lapse. For a transparent interface, the zero-bias conductance doubling that signals Andreev processes survives at all radii, but the energy window over which it operates is compressed by the lapse. Under asymptotic voltage bias, the conductance spectrum retains its flat-space form when expressed in redshifted variables; under local proper bias, the spectrum is reshaped by <italic>&#945;</italic>. In the near-horizon (Rindler) limit, the effective gap seen at infinity vanishes linearly with proper distance, &#916; <inf>&#8734;</inf>&#8733; <italic>&#954;&#961;</italic>, producing a gapless conductance profile reminiscent of a normal-metal junction&#8212;gravity mimics gap suppression. We analyze the excess current, the thermal conductance, the shot noise Fano factor, and the Wiedemann&#8211;Franz ratio, showing that each acquires a definite <italic>&#945;</italic>-scaling that disentangles local constitutive physics from kinematic redshift. Dimensionless transport ratios&#8212;the normalized conductance, the Fano factor, and the Wiedemann&#8211;Franz number&#8212;are shown to be redshift-invariant. The results are gauge- and coordinate-invariant, operationally stated for both proper and asymptotic observers, and remain analytic from the weak-field regime to the near-horizon limit.

Türkiye

İzzet Sakallı

Andreev reflection and the BTK conductance in Schwarzschild spacetime

A measurement of the substructure of bottom quark jets (b jets) in proton-proton (pp) collisions is presented. The measurement uses data collected in pp collisions at $$ \sqrt{s}=5.02 $$ TeV, with a low number of simultaneous interactions per bunch crossing, recorded by the CMS experiment in 2017, corresponding to an integrated luminosity of 301 pb . An algorithm to identify and cluster the charged decay daughters of b hadrons is developed for this analysis, which facilitates the exposure of the gluon radiation pattern of b jets using iterative Cambridge-Aachen declustering. The soft-drop-groomed jet radius, $\textit{R}$ , and momentum balance, $\textit{z}$ , of b quark jets are presented. These observables can be used to test perturbative quantum chromodynamics predictions that account for mass effects. Because the b hadron is partially reconstructed from its charged decay daughters, only charged particles are used for the jet substructure studies. In addition, a jet fragmentation function, $\textit{z}$ , is measured, which is defined as the distribution of the ratio of the transverse momentum ($\textit{p}$ ) of the partially reconstructed b hadron with respect to the charged-particle component of the jet $\textit{p}$ . The substructure variable distributions are unfolded to the charged-particle level. The b jet substructure is compared to the substructure of jets in an inclusive jet sample that is dominated by light-quark and gluon jets in order to assess the role of the b quark mass. A strong suppression of emissions at small $\textit{R}$ values is observed for b jets when compared to inclusive jets, consistent with the dead-cone effect. The measurement is also compared with theoretical predictions from Monte Carlo event generators. This is the first substructure measurement of b jets that clusters together the b hadron decay daughters independent of the b hadron species and decay channel.

Jet fragmentation function and groomed substructure of bottom quark jets in proton-proton collisions at 5.02 TeV

A search for a pair of light pseudoscalar bosons (a ) produced in the decay of the 125 GeV Higgs boson is presented. The analysis examines decay modes where one a decays into a pair of tau leptons and the other decays into either another pair of tau leptons or a pair of muons. The a boson mass probed in this study ranges from 4 to 15 GeV. The data sample was recorded by the CMS experiment in proton-proton collisions at a center-of-mass energy of 13 TeV and corresponds to an integrated luminosity of 138 fb . No excess above standard model (SM) expectations is observed. The study combines the 4τ and 2μ2τ channels to set upper limits at 95% confidence level (CL) on the product of the Higgs boson production cross section and the branching fraction to the 4τ final state, relative to the Higgs boson production cross section predicted by the SM. In this interpretation, the a boson is assumed to have Yukawa-like couplings to fermions, with coupling strengths proportional to the respective fermion masses. The observed (expected) upper limits range between 0.007 (0.011) and 0.079 (0.066) across the mass range considered. The results are also interpreted in the context of models with two Higgs doublets and an additional complex singlet field (2HD+S). The tightest constraints are obtained for the Type III 2HD+S model. In this case, assuming the Higgs boson production cross section equals the SM prediction, values of the branching ratio for the Higgs boson decay into a pair of a bosons exceeding 16% are excluded at 95% CL for a boson masses between 5 and 15 GeV and tan $\textit{β >}$ 2, with the exception of scenarios in which the a boson mixes with charm or bottom quark-antiquark bound states.

Search for light pseudoscalar boson pairs produced from Higgs boson decays using the 4τ and 2μ2τ final states in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

We study correlation numbers in Virasoro minimal string [ ]. Using analytic properties of correlation functions in spacelike and timelike Liouville theories, we verify exact expressions for correlation numbers for the four punctured sphere and the once punctured torus conjectured in [ (2024) 057 ].

Russia

Dmitry Khromov

Alexey Litvinov

On correlation numbers $\textit{V}$ 0$\textit{,}$4 and $\textit{V}$ 1$\textit{,}$1 in Virasoro minimal string theory