We determine the scaling dimensions in the boundary CFT corresponding to the O($\textit{N}$) model in EAdS . The CFT data accessible to the 4-point boundary correlator of fundamental fields are extracted in $\textit{d}$ = 2 and $\textit{d}$ = 4, at a finite coupling, and to the leading nontrivial order in the 1$\textit{/N}$ expansion. We focus on the non-singlet sectors, namely the anti-symmetric and symmetric traceless irreducible representations of the O($\textit{N}$) group, extending the previous results that considered only the singlet sector. Studying the non-singlet sector requires an understanding of the crossed-channel diagram contributions to the $\textit{s}$-channel conformal block decomposition. Building upon an existing computation, we present general formulas in $\textit{d}$ = 2 and $\textit{d}$ = 4 for the contribution of a $\textit{t}$-channel conformal block to the anomalous dimensions of $\textit{s}$-channel double-twist operators, derived for external scalar operators with equal scaling dimensions. Up to some technical details, this eventually leads to the complete picture of 1$\textit{/N}$ corrections to the CFT data in the interacting theory.

Czechia

Jonáš Dujava

Petr Vaško

Finite-coupling spectrum of O($\textit{N}$) model in AdS

We present predictions for the zero-temperature equation of state at finite isospin density using the Nambu-Jona-Lasinio (NJL) model within the medium separation scheme (MSS)—a scheme that explicitly disentangles medium effects from the ultraviolet divergent vacuum terms. Recent lattice QCD results reveal a nonmonotonic speed of sound (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>c</mi><mi>s</mi><mn>2</mn></msubsup></math>) as a function of isospin chemical potential (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>μ</mi><mi>I</mi></msub></math>), exhibiting explicit violation of the conformal bound <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>c</mi><mi>s</mi><mn>2</mn></msubsup><mo>=</mo><mn>1</mn><mo>/</mo><mn>3</mn></math>. These findings have attracted significant theoretical interest, as established models—including the NJL model—failed to anticipate this behavior prior to lattice simulations. Conventional NJL implementations yield unphysical artifacts, often attributed to regularization scale sensitivity stemming from nonrenormalizability. However, in this work, we demonstrate that the standard NJL framework combined with MSS quantitatively reproduces state-of-the-art lattice data for isospin QCD.

Brazil

Bruno S. Lopes

Dyana C. Duarte

Ricardo L.S. Farias

Rudnei O. Ramos

Speed of sound peak in isospin QCD: A natural prediction of the medium separation scheme

We have studied an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>O</mi><mo stretchy="false">(</mo><mn>4</mn><mo stretchy="false">)</mo></math> gauged <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>O</mi><mo stretchy="false">(</mo><mn>5</mn><mo stretchy="false">)</mo></math> Skyrmion on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi mathvariant="normal">I</mi><mspace depth="0.0ex" height="0.0ex" width="-0.2em"></mspace><mi mathvariant="normal">R</mi></mrow><mrow><mn>4</mn></mrow></msup></mrow></math>, which can be seen as a static soliton in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4</mn><mo>+</mo><mn>1</mn></math> dimensions. This is a sequel of the known <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>O</mi><mo stretchy="false">(</mo><mi>D</mi><mo stretchy="false">)</mo></math> gauged <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>O</mi><mo stretchy="false">(</mo><mi>D</mi><mo>+</mo><mn>1</mn><mo stretchy="false">)</mo></math> Skyrmions on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi mathvariant="normal">I</mi><mspace depth="0.0ex" height="0.0ex" width="-0.2em"></mspace><mi mathvariant="normal">R</mi></mrow><mrow><mi>D</mi></mrow></msup></mrow></math> in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo>=</mo><mn>2</mn></math> and in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo>=</mo><mn>3</mn></math>, which are likewise localized to an absolute scale and topologically stable, their energies being bounded below by the winding number. In the absence of an analytic proof of existence, some such solutions are constructed numerically. Two families of solutions are found, of which only one possesses a gauge decoupling limit. The curvatures of both of these solutions decay as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>r</mi><mrow><mo>−</mo><mn>3</mn></mrow></msup></math>, a property they share with the Yang-Mills instantons on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi mathvariant="normal">I</mi><mspace depth="0.0ex" height="0.0ex" width="-0.2em"></mspace><mi mathvariant="normal">R</mi></mrow><mrow><mn>4</mn></mrow></msup></mrow></math>.

Spain

Francisco Navarro-Lérida

Ireland

D.H. Tchrakian

SO(4) gauged O(5) Skyrmion on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">R</mi><mn>4</mn></msup></math>

We introduce a novel method to compute gravitational wave amplitudes within the framework of effective field theory. By reinterpreting the Feynman diagram expansion as a Born series, our method offers several key advantages. It directly yields partial wave amplitudes, streamlining the matching with black hole perturbation theory. Long-distance gravitational interactions are unambiguously factorized from short-distance tidal effects, including dissipation, which are systematically incorporated via an in-in worldline effective action. Crucially, at every order in perturbation theory, integrals are expressed in terms of harmonic polylogarithms, enabling an end-to-end computation scalable to arbitrary orders. We illustrate the method with new predictions for scalar black hole Love numbers and their renormalization group equations to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><msup><mrow><mi>G</mi></mrow><mrow><mn>7</mn></mrow></msup><mo stretchy="false">)</mo></mrow></math>.

Canada

Simon Caron-Huot

Miguel Correia

United States

Giulia Isabella

Mikhail Solon

Gravitational Wave Scattering via the Born Series: Scalar Tidal Matching to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><msup><mrow><mi>G</mi></mrow><mrow><mn>7</mn></mrow></msup><mo stretchy="false">)</mo></mrow></math> and Beyond

We present predictions for centrality-dependent charged-hadron production in <italic>p</italic>-O collisions at top LHC energies based on a nonequilibrium-statistical relativistic diffusion model. Colour-glass condensate initial conditions are used in a three-sources momentum-space model for gluon-gluon, quark-gluon and gluon-quark sources. Our results are to be compared with forthcoming Run 3 pseudorapidity distributions for <math altimg='si2.svg'><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo linebreak='goodbreak'>=</mo><mn>9.618</mn></mrow></math> TeV <italic>p</italic>-O collisions.

Germany

L. Konrad

P. Schulz

G. Wolschin

Predictions for charged-hadron production in <italic>p</italic>-O collisions at LHC energies

We consider the three-loop mixed strong-electroweak $$\left(\mathcal{O}\left(\alpha {\alpha }_{s}^{2}\right)\right)$$ corrections to the quark form factor. We compute the master integrals which are appearing in the Feynman diagrams containing a single massive boson in the loop. We use the state-of-the-art method of differential equations to compute all 303 of them, expressing the results in terms of generalized polylogarithms. We encounter multiple square roots that cannot be simultaneously rationalized using a single transformation. Applying concurrent transformations allows us to express the results through generalized polylogarithms with a simple alphabet, but with multiple interdependent arguments.

India

Tanmoy Pati

Narayan Rana

Three loop master integrals for $$\mathcal{O}\left(\alpha {\alpha }_{s}^{2}\right)$$ corrections to quark form factor

We present the perturbative results of the discretization errors proportional to the quark mass [<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mi>a</mi><mi>m</mi><mo stretchy="false">)</mo></math>] on the QCD running coupling within lattice perturbation theory. Our analysis involves calculating the two-loop renormalization factor <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mi>g</mi></msub></math> using improved lattice actions for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><msub><mi>N</mi><mi>c</mi></msub><mo stretchy="false">)</mo></math> gauge group and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>f</mi></msub></math> multiplets of fermions with a finite quark mass. We employ the background field method to compute <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mi>g</mi></msub></math>, by calculating quantum corrections on both the background and quantum gluon propagator, respecting the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo></math> improvement. This allows us to evaluate the perturbative <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mi>a</mi><mi>m</mi><mo stretchy="false">)</mo></math> lattice errors which affect the determination of the running coupling. Eliminating these <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mi>a</mi><mi>m</mi><mo stretchy="false">)</mo></math> effects is crucial for the nonperturbative studies of precision determinations of the strong coupling constant using lattice field theory.

Cyprus

M. Costa

D. Gavriel

H. Panagopoulos

G. Spanoudes

Perturbative determination of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mi>a</mi><mi>m</mi><mo stretchy="false">)</mo></math> improvement on the QCD running coupling

We investigate a chirally imbalanced medium in the context of the two-flavor Nambu-Jona-Lasinio model using both the large-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>c</mi></msub></math> (LN) and beyond large-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>c</mi></msub></math> (BLN) approximations. To incorporate BLN effects, we consider the optimized perturbation theory (OPT) to the first nontrivial order, which includes two-loop (exchange) contributions. This procedure allows us to explicitly explore how finite <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>c</mi></msub></math> corrections affect the thermodynamics as well as the phase diagram of chirally imbalanced quark matter. We then compare the results obtained with a sharp three-dimensional cutoff—generically referred to as the traditional regularization scheme—and with an alternative procedure called the medium separation scheme (MSS). In the first case, we observe that the pseudocritical temperature decreases as the chiral chemical potential increases, an effect dubbed inverse chiral catalysis. On the other hand, when considering the MSS regularization, which properly isolates the medium contributions from the vacuum, we find the opposite result. We show that the results obtained with MSS are consistent with well-established lattice quantum chromodynamics data in both the LN and BLN approximations. Finally, we suggest that to cope with the high-density limit, the standard OPT interpolation prescription must be modified with the inclusion of an extra variational parameter.

André G. da Silva

France

Marcus Benghi Pinto

William R. Tavares

Two-flavor chirally imbalanced quark matter beyond large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math>

In this paper, we explore a new class of integrable sigma models, which we refer to as the “dual regime” of Yang-Baxter (YB) deformed O(2$\textit{N}$) sigma models. This dual regime manifests itself in the conformal perturbation approach. Namely, it is well known that conventional YB-deformed O($\textit{N}$) sigma models are described in the UV by a collection of free bosonic fields perturbed by some relevant operators. The holomorphic parts of these operators play the role of screening operators which define certain integrable systems in the free theory. All of these integrable systems depend on a continuous parameter $\textit{b}$, which parametrizes the central charge, and are known to possess the duality under $\textit{b}$ ↔ −1 −$\textit{b}$ . Although O(2$\textit{N}$ + 1) integrable systems are self-dual, O(2$\textit{N}$) systems are not. In particular, the O(2$\textit{N}$) integrable systems provide new perturbations of the sigma model type. We identify the corresponding one-loop metric and $\textit{B}$-field and show that they solve the generalized Ricci flow equation.

Russia

Alexey Bychkov

Alexey Litvinov

On dual regime in Yang-Baxter deformed O(2$\textit{N}$) sigma models

The quarkonium production in association with a heavy-quark pair of the same flavor was found to play an important role in various production schemes and provide a distinctive signature that could be studied in experiment. Within the nonrelativistic QCD framework, we perform the first complete calculation of the hadroproduction process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mi>g</mi><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>+</mo><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover></math> at the next-to-leading order (NLO) in the expansion of strong coupling constant <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>α</mi><mi>s</mi></msub></math>. The result tells us that the NLO corrections substantially enhance the color-singlet yield and alter the predicted polarization patterns and, hence, lead to a better agreement with experimental data across the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub></math> spectrum. In contrast to charm-quark fragmentation, the fixed-order <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"><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover></math> associated production channel displays a markedly different kinematic behavior. While the inclusion of this process greatly reduces the discrepancy between color-singlet theoretical prediction and experimental measurement, a residual gap of approximately 1 order of magnitude still remains.

China

Qi-Ming Feng

Cong-Feng Qiao

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math> polarization and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub></math> distribution in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover></math> associated hadroproduction at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><msubsup><mi>α</mi><mi>s</mi><mn>5</mn></msubsup><mo stretchy="false">)</mo></math>