We study the equation of state (EoS) of QCD matter in a bottom-up holographic setup that combines an Einstein-Maxwell-dilaton (EMD) sector with an improved Karch-Katz-Son-Stephanov (KKSS) flavor action. In the probe approximation, we perform an inverse reconstruction of the model functions by parameterizing them with neural networks and solving the EMD equations via a differentiable ODE solver (a neural ODE framework), calibrating the model to a reference thermodynamic table for $(2+1)$ -flavor QCD at finite temperature and finite baryon chemical potential. The reconstructed model functions are then parameterized and kept fixed across thermodynamic states. Next, viewing the EMD sector as an effective description of pure Yang-Mills theory, we fix its parameters by fitting the $\mu_B=0$ lattice pure-glue EoS using a hybrid optimization strategy. Finally, we go beyond the probe limit and solve the coupled EMD+KKSS equations with back-reaction, using the pure-glue-calibrated EMD sector as a fixed input and varying the KKSS couplings to compare with the $\mu_B=0$ two-flavor lattice EoS. We find a visible mismatch and a high-temperature behavior in which the back-reacted dimensionless ratios approach a nearly $\beta_1$ -insensitive plateau close to the pure-glue baseline, providing a simple structural diagnostic for the present flavor-sector truncation.

China

Yutian Deng

Mei Huang

Lin Zhang

Holographic QCD equation of state constrained by lattice QCD: neural-ODE for probe-limit and a back-reaction test * Start-up funding from Sun Yat-sen University (SYSU) (Y. Deng and L. Zhang); National Natural Science Foundation of China (NSFC) (12235016) (L. Zhang and M. Huang) and 12221005 (M. Huang)

AdS × S × S solutions warped over a Riemann surface, Σ, are indexed by a parameter, $\textit{γ}$, that defines the superconformal algebra, $\textit{D}$(2, 1; $\textit{γ}$) ⨁ $\textit{D}$(2, 1; $\textit{γ}$) they preserve. We show that these solutions come from multiple back-reacted M2-M5 spikes, and that different values of $\textit{γ}$ correspond to different scaling limits of the same M2-M5 solutions. We find that when $\textit{γ}$ switches from positive to negative, the infrared region of the AdS switches from the tip of spikes, far from the M5 branes, to the bottom of the spikes, far from the M2 branes. We also explain how the bubbling negative-$\textit{γ}$ solutions emerge from the geometric transition of multiple M2-M5 spikes.

France

Iosif Bena

Israel

Raphaël Dulac

Dimitrios Toulikas

United States

Nicholas Warner

Effervescent spikes in M-theory

We present constraints on the sum of neutrino masses ∑ <italic>m<inf>&#957;</inf></italic> from a dataset incorporating the full SPT-3G 2018 TT/TE/EE+lensing spectra together with Planck PR4 lensing and low-&#8467; parts of the Planck PR3 spectra. Using it together with the DESI DR2 BAO measurements, we arrive at a 95% upper limit of &#8721; <italic>m<inf>&#957;</inf></italic>&#8239;&lt;&#8239;0.11&#8201;eV, relaxing the tension between &#923;CDM and lower bounds on &#8721; <italic>m<inf>&#957;</inf></italic> based on neutrino oscillation experiments as compared to the <monospace>Planck+DESI</monospace> constraint. When including DES Y1 weak lensing information and the Pantheon+ SNIa catalog, the limit is further loosened to &#8721; <italic>m<inf>&#957;</inf></italic>&#8239;&lt;&#8239;0.138&#8201;eV with a slight preference for &#8721; <italic>m<inf>&#957;</inf></italic>&#8239;&gt;&#8239;0. By contrast, replacing SPT-3G 2018 primary CMB and lensing spectra with ones from the SPT-3G 2019-2020 (D1) release tightens the overall constraint to &#8239;&lt;&#8239;0.082&#8201;eV and pushes the &#8721; <italic>m<inf>&#957;</inf></italic> posterior mode value to zero, indicating a preference for quasi-negative neutrino masses in line with the D1 analysis. This is a curious shift within SPT-3G measurements of the same field taken in 2018 and in 2019-2020 and processed with different analysis pipelines.

Russia

Dmitry Gorbunov

Nikita Nedelko

Changing constraints on ∑ <italic>m<inf>&#957;</inf></italic> from SPT-3G 2018 to D1 in the context of DESI DR2

In this work, Static wormhole models are examined within the framework of curvature-based <math altimg='si17.svg'><mrow><mi mathvariant='italic'>f</mi><mo>(</mo><mi mathvariant='fraktur'>R</mi><mo>,</mo><msub><mi mathvariant='fraktur'>L</mi><mi mathvariant='fraktur'>m</mi></msub><mo>,</mo><mi mathvariant='italic'>T</mi><mo>)</mo></mrow></math> gravity theory. A relationship between the matter energy density and pressure is proposed for the Morris-Thorne wormhole geometry with a constant redshift function. By incorporating a gradient-dependent equation of state ( <math altimg='si18.svg'><mrow><msub><mi>P</mi><mi>r</mi></msub><mo linebreak='goodbreak'>=</mo><msub><mi>P</mi><mi>r</mi></msub><mrow><mo>(</mo><mi>&#961;</mi><mo>,</mo><msup><mi>&#961;</mi><mo>&#8242;</mo></msup><mo>)</mo></mrow></mrow></math> and <math altimg='si19.svg'><mrow><msub><mi>P</mi><mi>t</mi></msub><mo linebreak='goodbreak'>=</mo><msub><mi>P</mi><mi>t</mi></msub><mrow><mo>(</mo><msub><mi>P</mi><mi>r</mi></msub><mo>,</mo><msubsup><mi>P</mi><mi>r</mi><mo>&#8242;</mo></msubsup><mo>)</mo></mrow></mrow></math>), we derive exact wormhole solutions for two representative cases. Our analysis shows that exact wormhole models can admit null energy condition violations localized at the throat, while preserving a non-negative matter energy density. The stability analysis is performed via the Tolman&#8211;Oppenheimer-Volkoff equation under hydrostatic equilibrium, demonstrating that the balance among anisotropic and hydrostatic forces sustains the wormhole&#8217;s stable configuration. For positive and negative values of <italic>&#950;</italic>, the energy flux attains a pronounced negative magnitude, inducing an outward flux that supports the stability of the wormhole throat. The geometric characteristics of the wormhole are examined through embedding diagrams, and the total exotic matter required to maintain the configuration is evaluated using the volume integral quantifier. Simultaneously, the effective potential demonstrates enhanced photon confinement and increased stability of particle orbits.

India

Sweeti Kiroriwal

Azerbaijan

Oman

S.K. Maurya

Jitendra Kumar

Wormholes generated by a density-gradient dependent equation of state in <math altimg='si17.svg'><mrow><mi mathvariant='italic'>f</mi><mo>(</mo><mi mathvariant='fraktur'>R</mi><mo>,</mo><msub><mi mathvariant='fraktur'>L</mi><mi mathvariant='fraktur'>m</mi></msub><mo>,</mo><mi mathvariant='italic'>T</mi><mo>)</mo></mrow></math> gravity

We consider complex, supersymmetric, non-extremal Euclidean black holes that are asymptotically locally AdS , with $\textit{S}$ × $\textit{M}$ conformal boundary. We study field theory backgrounds consisting of various $\textit{M}$ , and explicitly construct Killing spinors that are anti-periodic around the Euclidean time circle. Focussing on elliptically/biaxially squashed three-spheres and Lens spaces, we compute the supersymmetric index of the 𝒩 = 4 SYM in a Cardy-like limit. While such black holes have not been constructed for general $\textit{M}$ , we demonstrate that the supersymmetric indices can be recovered from gravity computations using equivariant localization, by extending the boundary Killing spinors to the bulk. We show that this involves gluing the black hole geometry with a supersymmetric, horizonless AlAdS geometry, chosen such that the Casimir energy is removed from the supersymmetric partition function.

United Kingdom

Jaeha Park

Localizing AlAdS5 black holes and the SUSY index on $\textit{S}$ 1 $\textit{× M}$ 3

We consider M-theory on the backgrounds $$ {\mathrm{AdS}}_4\times {S}^7/{\mathbb{Z}}_{N_f} $$ and AdS × $\textit{S}$ /ℤ , which have fixed point loci AdS × $\textit{S}$ for $\textit{d}$ = 3, 6. These theories are holographically dual to certain CFTs in $\textit{d}$ = 3, 6 with eight supercharges. We compute the bulk cubic couplings between graviton KK modes and gluon KK modes living on the fixed points of these theories, which are generically extremal. We use these couplings to compute the graviton exchange term that appears in the strong coupling expansion of holographic correlators of gluon KK modes 〈22$\textit{pp}$〉 in these theories, and check that it matches the expected flat space limit. We express the answer in terms of a new reduced correlator solution to the superconformal Ward identities, which we derive for all CFTs with eight supercharges in 3 ≤ $\textit{d}$ ≤ 6.

Shai Chester

Rishi Mouland

Jesse Muiden

Clément Virally

Extremal couplings and gluon scattering in M-theory

The existence of a large extra dimension in which only gravity propagates would have spectacular consequences for cosmology and laboratory experiments. In the strong coupling limit of the $\textit{E}$ × $\textit{E}$ heterotic string theory, the gauge and matter fields live at the end of the eleventh dimension, which becomes a natural candidate for a micron-size $\textit{dark dimension}$. In this work, however, we show that the length of the M-theory interval is severely constrained by proton decay searches. Our results indicate that in such constructions the size of the eleventh dimension is $\textit{R}$ ≲ 𝒪(10 ) meters.

Switzerland

Mario Reig

Ignacio Ruiz

The dark dimension, proton decay, and the length of the M-theory interval

Using data samples collected by the Belle and Belle II experiments at the Υ(4$\textit{S}$) resonance with integrated luminosities of 571 fb and 365 fb , respectively, we measure the pseudoscalar $\textit{B}$-meson mass difference to be $\textit{m}$($\textit{B}$ ) − $\textit{m}$($\textit{B}$ ) = (0$\textit{.}$495 ± 0$\textit{.}$024 ± 0$\textit{.}$005) MeV/$\textit{c}$ . The results are based on a simultaneous fit to the variable $${\overline{M} }_{bc}$$ , which is related to the $\textit{B}$ momentum, for $\textit{B}$ and $\textit{B}$ candidates; and to the energy dependence of $$\mathcal{R}=\sigma ({e}^{+}{e}^{-}\to {B}^{0}{\overline{B} }^{0}) / \sigma ({e}^{+}{e}^{-}\to {B}^{+}{B}^{-})$$ , which is measured using changes in the average center-of-mass energy over the data taking periods. The phase-space hypothesis $$\mathcal{R}={({p}_{{B}^{0}} /{p}_{{B}^{+}})}^{3}$$ , upon which previous measurements rely, is strongly disfavored by our fit; the measured mass-difference value for the phase-space hypothesis also differs significantly from our measurement. We constrain $$\mathcal{R}$$ in a broader energy range than covered by the direct measurement and extract the energy dependence of $$\mathcal{R}$$ in the range from the $$B\overline{B }$$ threshold up to 10.59 GeV. We interpret the results using a phenomenological model and constrain the parameters of the $$B\overline{B }$$ potential in the isovector channel.

M. Abumusabh

I. Adachi

L. Aggarwal

H. Ahmed

Y. Ahn

H. Aihara

N. Akopov

S. Alghamdi

M. Alhakami

A. Aloisio

N. Althubiti

K. Amos

N. Anh Ky

C. Antonioli

D. Asner

H. Atmacan

T. Aushev

R. Ayad

V. Babu

N. Baghel

S. Bahinipati

P. Bambade

Sw. Banerjee

M. Barrett

M. Bartl

J. Baudot

A. Beaubien

F. Becherer

J. Becker

J. Bennett

F. Bernlochner

V. Bertacchi

M. Bertemes

E. Bertholet

M. Bessner

S. Bettarini

V. Bhardwaj

F. Bianchi

T. Bilka

D. Biswas

D. Bodrov

A. Bondar

G. Bonvicini

J. Borah

A. Boschetti

A. Bozek

M. Bračko

P. Branchini

R. Briere

T. Browder

A. Budano

S. Bussino

Q. Campagna

M. Campajola

G. Casarosa

C. Cecchi

P. Chang

P. Cheema

L. Chen

B. Cheon

C. Cheshta

H. Chetri

K. Chilikin

J. Chin

K. Chirapatpimol

H.E. Cho

K. Cho

S.J. Cho

S.K. Choi

S. Choudhury

S. Chutia

J. Colorado-Caicedo

I. Consigny

L. Corona

J. Cui

E. Cruz-Burelo

S. Motte

G. Marino

G. Nardo

G. Pietro

R. Sangro

M. Destefanis

S. Dey

A. Canto

Z. Doležal

I. Domínguez Jiménez

T. Dong

X. Dong

M. Dorigo

G. Dujany

P. Ecker

J. Eppelt

R. Farkas

P. Feichtinger

T. Ferber

T. Fillinger

C. Finck

G. Finocchiaro

F. Forti

B. Fulsom

Measurements of the mass difference $\textit{m}$($\textit{B}$ 0) $\textit{− m}$($\textit{B}$ +) and the energy dependence of the cross-section ratio $$\sigma ({e}^{+}{e}^{-}\to {B}^{0}{\overline{B} }^{0})/\sigma ({e}^{+}{e}^{-}\to {B}^{+}{B}^{-})$$ at Belle and Belle II

Starting from the most general effective |∆$\textit{B}$| = 1 Hamiltonian describing non-leptonic $\textit{b}$-quark decays $$ b\to {q}_1{\overline{q}}_2{q}_3 $$ , we compute analytic expressions for all matching coefficients of the two-quark operator contributions in the heavy quark expansion (HQE) of a $\textit{B}$ meson, up to mass-dimension-six. In addition, we calculate the weak-annihilation contributions, which enter the matching of four-quark operators in the HQE at dimension-six and were previously missing. Our results complete the calculation of beyond Standard Model (BSM) effects in non-leptonic, tree-level, $\textit{b}$-quark decays relevant for $\textit{B}$ meson lifetimes and lifetime ratios such as $$ \tau \left({B}_s^0\right)/\tau \left({B}_d^0\right) $$ . Such BSM contributions naturally arise in generic extensions of the Standard Model (SM) that aim to address the observed tensions between experimental measurements and theoretical predictions based on QCD factorisation in several colour-allowed non-leptonic $\textit{B}$-meson decays. As a by-product of our calculation, we also determine the matching coefficients in the HQE induced by the QCD-penguin operators within the SM, including both the interference between current-current and penguin operators and the contributions quadratic in the penguin operators. Owing to the suppression of the QCD-penguin Wilson coefficients within the SM, these effects are typically regarded as corrections of order $\textit{α}$ and $$ {\alpha}_s^2 $$ in the strong coupling, respectively. Our results reproduce the known expressions at dimension-three and provide new results for the coefficients of the chromomagnetic operator at dimension-five and of the Darwin operator at dimension-six.

Germany

Martin Lang

Alexander Lenz

Ali Mohamed

Netherlands

Maria Piscopo

Aleksey Rusov

$\textit{B}$-meson decay width up to $$ 1/{m}_b^3 $$ corrections within and beyond the Standard Model

We continue the investigation of symmetries and anomalies of $\textit{T}$[$\textit{M}$] theories obtained by compactifying 6d SCFTs on an internal manifold $\textit{M}$. We extend the notion of “polarizations on a manifold $\textit{M}$” to cases where $\textit{M}$ may have boundaries or defects. Through examples with $\textit{M}$ of dimension two, three, and four, we illustrate recurring themes in compactifications — for instance, the important roles played by Kaluza-Klein modes, and how the generalized symmetries (including higher-group and non-invertible ones) of $\textit{T}$[$\textit{M}$], together with their anomalies, arise from non-trivial combinations of the parent 6d symmetries and the geometric structures of the internal manifold. For each dimension, we also focus on several topics that are especially interesting in that setting. These include: for 2-manifolds, the geometry of the “full moduli space” of $\textit{T}$[$\textit{M}$ ] and its interaction with polarizations and symmetries; for 3-manifolds, the effect of torsion in homology on the spectrum of line operators in $\textit{T}$[$\textit{M}$ ], together with applications to the study of quantum invariants such as $$ {\hat{Z}}_a\left({M}_3,q\right) $$ ; and for 4-manifolds, predictions for VOA[$\textit{M}$ ] following from symmetries of $\textit{T}$[$\textit{M}$ ], as well as the construction of a new invariant of 4-manifolds that depends on two “$\textit{q}$-parameters.” Along the way, we discuss a range of topics that are of independent interest, such as how non-invertible symmetries in higher dimensions can become invertible under compactification, how to classify defects in quantum field theory via their response to a change of framing, and the interplay between $$ {\hat{Z}}_a $$ and volume conjectures.

Sergei Gukov

Po-Shen Hsin

Denmark

Du Pei

Sunghyuk Park

Generalized global symmetries of $\textit{T}$[$\textit{M}$] theories. Part II