In the presence of a strong electric field, the vacuum is unstable to the production of pairs of charged particles—the Schwinger effect. The created pairs extract energy from the electric field, resulting in nontrivial backreaction. In this paper, we study <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mo>+</mo><mn>1</mn><mi mathvariant="normal">D</mi></mrow></math> massive QED subject to strong external electric fields in a self-consistent and fully quantum manner. We use the bosonized version of the theory, which attains a cosine interaction term in the presence of nonzero fermion mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>m</mi></math>. However, the assumption of a strong electric field justifies a perturbative treatment of the cosine interaction, i.e., an expansion in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>m</mi></math>. We calculate the vacuum expectation value of the electric field to first order in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>m</mi></math> and show that—surprisingly—it satisfies a classical nonlinear partial differential equation (related to the sine-Gordon equation). We show that the electric field exhibits dissipation-free oscillations (analogous to ordinary plasma oscillations) and calculate the plasma frequency analytically. We also compare to the semiclassical approximation commonly used to study backreaction, showing that it fails to capture the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>O</mi><mo stretchy="false">(</mo><mi>m</mi><mo stretchy="false">)</mo></math> shift in the plasma frequency.

Samuel E. Gralla

Morifumi Mizuno

Schwinger effect with backreaction in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mo>+</mo><mn>1</mn><mi mathvariant="normal">D</mi></mrow></math> massive QED with a strong external field

Our understanding of high-lying states within the charmonium family remains incomplete, particularly in light of recent observations of charmonium states at energies around 4 GeV. In this study, we investigate the spectroscopic properties of several high-lying charmonia, focusing on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>D</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>F</mi></math> states. A mass spectrum analysis is conducted, incorporating the unquenched effects. We then present a detailed study of the strong decay properties, including partial decay widths for two-body strong decays permitted by the Okubo-Zweig-Iizuka rule. Additionally, we explore the primary radiative decay channels associated with these states. Finally, we discuss the radiative transitions of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>D</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>F</mi></math> states via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> annihilation. Theoretical predictions provided here aim to guide future experimental searches for high-lying charmonium states at facilities such as BESIII, Belle II, LHCb, and the future Super <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math>–Charm Facility.

Cheng-Xi Liu

Zi-Long Man

Tian-Le Gao

Xiang Liu

Prospects for observing the missing <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>D</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>F</mi></math> charmonium states around 4 GeV

In all previous calculations of the nonlocal subleading contribution to the inclusive penguin decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><msub><mi>X</mi><mi>s</mi></msub><mi>γ</mi></math> due to the interference of the electroweak operators <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">O</mi><mn>1</mn><mi>c</mi></msubsup><mo>−</mo><msub><mi mathvariant="script">O</mi><mrow><mn>7</mn><mi>γ</mi></mrow></msub></math> the local Voloshin term was subtracted. In view of the ongoing analysis at order <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>α</mi><mi>s</mi></msub></math>, we present a calculation of the complete nonlocal contribution which takes into account the high correlation between the uncertainties of the local Voloshin and the nonlocal term of the previous analyses. The new calculation has a high impact on the range of the nonlocal contribution.

Michael Benzke

Maria Vittoria Garzelli

Tobias Hurth

Addendum to “Resolved <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>/</mo><msub><mi>m</mi><mi>b</mi></msub></math> contributions to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><msub><mi>X</mi><mrow><mi>s</mi><mo>,</mo><mi>d</mi></mrow></msub><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>−</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><msub><mi>X</mi><mi>s</mi></msub><mi>γ</mi></math>”

Particle identification (PID) is essential for future particle physics experiments such as the Circular Electron-Positron Collider (CEPC) and the Future Circular Collider. A high-granularity Time Projection Chamber (TPC) not only provides precise tracking but also enables d$\textit{N}$/d$\textit{x}$ measurements for PID. The d$\textit{N}$/d$\textit{x}$ method estimates the number of primary ionization electrons, offering significant improvements in PID performance. However, accurate reconstruction remains a major challenge for this approach. In this paper, we introduce a deep learning model, the Graph Point Transformer (GraphPT), for d$\textit{N}$/d$\textit{x}$ reconstruction. In our approach, TPC data are represented as point clouds. The network backbone adopts a U-Net architecture built upon graph neural networks, incorporating an attention mechanism for node aggregation specifically optimized for point cloud processing. The proposed GraphPT model surpasses the traditional truncated mean method in PID performance. In particular, for the CEPC baseline TPC, the $\textit{K/π}$ separation power improves by approximately 10% to 20% in the momentum interval from 5 to 20 GeV/$\textit{c}$.

China

Guang Zhao

Yue Chang

Jinxian Zhang

Linghui Wu

Huirong Qi

Xin She

Mingyi Dong

Shengsen Sun

Jianchun Wang

Yifang Wang

Chunxu Yu

d$\textit{N}$/d$\textit{x}$ reconstruction with deep learning for high-granularity TPCs

We derive the general form of the effective equations governing black hole dynamics in the limit of a large number of dimensions $\textit{D}$. These split into a universal $\textit{soap-bubble}$ embedding condition for stationary configurations and a set of nonlinear dynamical evolution equations describing near-horizon fluctuations of $\textit{O}$(1/$\textit{D}$) amplitude over horizon scales of $$ O\left(1/\sqrt{D}\right) $$ . We obtain these equations in full generality, including arbitrary asymptotic sources in the near-horizon region, and we show that they form a parabolic system with a well-posed initial value problem. To connect the various approaches to large-$\textit{D}$ black hole dynamics, we also show that both the embedding and dynamical equations can be derived from the covariant membrane formalism. We clarify the intrinsic scope of the large-$\textit{D}$ approach, emphasizing that it yields a well-posed dynamical evolution only on horizon scales of $$ O\left(1/\sqrt{D}\right) $$ , which is the range where the most relevant horizon dynamics occur. Our results highlight the versatility of these effective theories for studying a wide class of black hole phenomena.

Spain

Roberto Emparan

Jordi Rafecas-Ventosa

United States

Benson Way

General effective theories of black holes in the large $\textit{D}$ limit

We present a set of <math altimg='si2.svg'><mrow><mi>&#8467;</mi><mo linebreak='goodbreak'>+</mo><mn>3</mn></mrow></math> simple differential operators and prove that they annihilate an &#8467;-loop generic mass banana integral in dimensional regularization. We study the singular locus of the ideal generated by these operators and show that it is contained in the set of Landau singularities of the first and second type. Through the Macaulay matrix method, we calculate the corresponding holonomic rank up to <math altimg='si3.svg'><mrow><mi>&#8467;</mi><mo linebreak='goodbreak'>=</mo><mn>8</mn></mrow></math>, obtaining <math altimg='si4.svg'><mrow><msup><mn>2</mn><mrow><mi>&#8467;</mi><mo>+</mo><mn>1</mn></mrow></msup><mo linebreak='goodbreak'>&#8722;</mo><mn>1</mn></mrow></math>, which agrees with the number of master integrals for the generic mass banana integrals. Based on these findings, we conjecture that the proposed operators generate the annihilating ideal for the generic mass banana integrals in dimensional regularization.

Italy

Wojciech Flieger

D-ideal of generic mass banana integrals in dimensional regularization

We apply the light-cone QCD sum rules with chiral currents to compute transition form factors of the semileptonic decay of the charmed and bottom scalar mesons <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo>/</mo><mi>B</mi></math> to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo><msup><mi>l</mi><mo>+</mo></msup><msub><mi>ν</mi><mi>l</mi></msub></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mi>l</mi><mo>=</mo><mi>e</mi><mo>,</mo><mi>μ</mi><mo stretchy="false">)</mo></mrow></math>, where the scalar meson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></math> are firstly regarded as two quark states, and contributions from the tetraquark component are then added via proper modulation of four distribution amplitudes considered. The obtained transition form factors and branching fraction are free of the contribution from the light-cone distribution amplitudes at the level of twist-three and two simple relations connecting their form factors are obtained. Our computations indicates that the decay branch fractions are on the margin of the measurements reported by the Beijing Spectrometer III in the pure two-quark scenario and are in good agreement with observations when tetraquark component is considered.

Di Gao

JiangShan Lan

Duojie Jia

Xingbo Zhao

Yanjun Sun

Transition form factors for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo>/</mo><mi>B</mi></math> to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></math> from light-cone QCD sum rules

We consider an $$\mathcal{N}=1$$ nonrenormalizable supersymmetric gauge theory with the superpotential quartic in the chiral matter superfields. With the help of the Slavnov’s higher covariant derivative regularization it is demonstrated that (in the lowest nontrivial order) the leading power divergent quantum correction to the gauge coupling constant is given by an integral of double total derivatives with respect to the loop momenta. The result obtained after calculating this integral turned out to be proportional to the corresponding quantum correction to the kinetic term of the matter superfields. More exactly, in the considered approximation the quadratically divergent contributions to the gauge coupling and to the kinetic term of the chiral matter superfields are related by an equation analogous to the exact NSVZ $$\beta $$ -function for the renormalizable case.

France

Ali Lakhal

Russia

Konstantin Stepanyantz

Relation between leading divergences in nonrenormalizable 4$\textit{D}$ supersymmetric theories

A new model based on the relativistic Boltzmann equation in the isotropization time approximation is developed to investigate the collective behavior of the quark-gluon plasma produced in high-energy heavy-ion collisions. The equation is solved in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>(</mo><mn>2</mn><mo>+</mo><mn>2</mn><mo>)</mo><mi mathvariant="normal">D</mi></mrow></math> (two spatial and two momentum-space dimensions). This framework couples preequilibrium dynamics with hydrodynamic evolution to simulate the dynamics of quasiparticle evolution. A numerical scheme based on the method of characteristics enables the evolution to begin from a specified initial Boltzmann distribution. In this work, the spatial structure of the initial distribution is modeled using the Trento framework. Our results show that a medium initialized at <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>τ</mi><mn>0</mn></msub></math> on the order of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>1</mn><mspace width="0.16em"></mspace><mi>fm</mi><mo>/</mo><mi>c</mi></mrow></math> with a small shear viscosity to entropy density ratio (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>η</mi><mo>/</mo><mi>s</mi><mo>=</mo><mn>0.008</mn></mrow></math>) evolves consistently with hydrodynamic simulations, such as those performed using the vish2+1 code, while discrepancies arise for a medium with <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>η</mi><mo>/</mo><mi>s</mi><mo>=</mo><mn>0.8</mn></mrow></math>. Furthermore, when initialized with a highly anisotropic momentum distribution in the longitudinal direction at early times, the system exhibits spatially nonuniform thermalization in the transverse plane, leading to the emergence of a nontrivial hypersurface that marks the onset of hydrodynamic applicability. Finally, we compute the <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>T</mi></msub></math>-spectra for a nonfluctuating initial condition using the hybrid version of CoMBolt-ITA. In this hybrid setup, the description is switched from quasiparticles to hadrons, and UrQMD is used to model the hadron gas dynamics. We compare these results with those obtained from the hybrid vish2+1 initialized within the same setup. For a small shear viscosity, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>η</mi><mo>/</mo><mi>s</mi><mo>=</mo><mn>0.08</mn></mrow></math>, the two results show a good level of consistency, whereas for a larger value, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>η</mi><mo>/</mo><mi>s</mi><mo>=</mo><mn>0.8</mn></mrow></math>, a noticeable discrepancy emerges.

Germany

S.F. Taghavi

Iran

S.M.A. Tabatabaee Mehr

F. Taghinavaz

<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>(</mo><mn>2</mn><mo>+</mo><mn>2</mn><mo>)</mo><mi mathvariant="normal">D</mi></mrow></math> collective model based on a relativistic Boltzmann equation in the isotropization-time approximation: CoMBolt-ITA

The capability of the ALICE@LHC and STAR@RHIC experiments to reconstruct <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math> mesons has enabled femtoscopic correlation measurements of open-charm mesons in both small and large systems. In this work, we present a theoretical calculation of the correlation functions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover></math> mesons with nucleons, based on the Koonin-Pratt formalism. We employ an effective Lagrangian to model the interaction between charmed mesons and baryons and apply the TROY formalism to obtain the off-shell <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math>-matrix in coupled channels, incorporating the effect of the Coulomb interaction when the pair involves two charged particles. The resulting full coupled-channel wave function is inserted into the Koonin-Pratt equation with channel weights derived from a thermal model. Additionally, we compute the correlation functions using the Lednický-Lyuboshitz approximation with low-energy scattering parameters extracted from the unitarized amplitudes. We compare these two approaches and provide predictions for different correlated pairs. Our results can be tested against current and future experimental data from the ALICE and STAR Collaborations in both proton-proton and heavy-ion collisions.

Mikel F. Barbat

Juan M. Torres-Rincon

Àngels Ramos

Laura Tolos

Femtoscopy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>D</mi><mi>N</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mi>N</mi></math> systems