The interference between amplitudes corresponding to different intermediate resonances plays an important role in generating large CP asymmetries in the phase space in multi-body decays of bottom and charmed mesons. In this study, we examine the CP violation in the decay channel $ {\overline{B}}^{0}\rightarrow K^{-}\pi^{+}\pi^{0} $ in the phase-space region where the intermediate resonances $ \overline{K}^{*}(892)^{0} $ and $ {\overline{K}^{*}_{0}(700)} $ dominate. In particular, the forward-backward asymmetry (FBA) and the CP asymmetry induced by FBA (FB-CPA), which are closely related to the interference effects between the two aforementioned resonances, are investigated. The nontrivial correlation between FBA and FB-CPA is analyzed. The analysis indicates that FB-CPAs around the resonance $ \overline{K}^{*}(892)^{0} $ can be as large as approximately 35%, which can be potentially accessible by Belle and Belle-II collaborations in the near future.

China

Jian-Yu Yang

Yu-Jie Zhao

Jing-Juan Qi

Zhen-Hua Zhang

The forward-backward asymmetry induced CP asymmetry in ${{\overline{B}}^{0}\rightarrow K^{-}\pi^{+}\pi^{0}}$ in phase space around the resonances ${{\overline{K}}^{*}(892)^{0}}$ and ${{\overline{K}}^{*}_{0}(700)}$ * Supported by National Natural Science Foundation of China (12475096, 12405115, 12192261) and Scientific Research Fund of Hunan Provincial Education Department (22A0319)

The Schwinger effect, a non-perturbative mechanism for particle production in strong fields, plays a crucial role in understanding quantum vacuum decay and high-energy phenomena, including heavy-ion collisions (HIC). Although holographic quantum chromodynamics (QCD) models have been widely used to study this effect, most treatments assume isotropy or consider only a single type of anisotropy, neglecting the interplay between spatial and magnetic anisotropies that arise in realistic HIC scenarios. A unified framework accounting for both anisotropies is needed to accurately model particle production. We investigate the Schwinger effect in a twice anisotropic holographic QCD model incorporating both spatial and magnetic anisotropies. Using the anti-de Sitter/conformal field theory correspondence, we compute the total potential of a particle-antiparticle pair to quantify how these anisotropies influence pair production. Our results show that the magnetic field (parameterized by $c_B$ and $q_3$ ) enhances the Schwinger effect by lowering and narrowing the potential barrier, while increasing spatial anisotropy (controlled by $\nu$ ) suppresses the process by raising and widening the barrier. These findings demonstrate that magnetic and spatial anisotropies exert competing effects on particle production, emphasizing the necessity of treating both concurrently in holographic models. This work advances the theoretical description of the Schwinger effect in anisotropic environments, with implications for understanding non-equilibrium dynamics in HIC and other strongly coupled systems.

Wen-Bin Chang

Defu Hou

Schwinger effect in a twice anisotropic holographic model * Defu Hou's research is supported in part by the National Key Research and Development Program of China (2022YFA1604900). Additionally, Defu Hou receives partial support from the National Natural Science Foundation of China (NSFC) (12435009, 12275104). Wen-Bin Chang is supported by the Ph.D. Research Startup Project at Hubei Minzu University (RZ2500000857)

The efficient classification of electromagnetic activity from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mn>0</mn></msup></math> and electrons remains an open problem in the reconstruction of neutrino interactions in liquid argon time projection chamber (LArTPC) detectors. We address this problem using the mathematical framework of optimal transport (OT), which has been successfully employed for event classification in other high energy physics contexts and is ideally suited to the high-resolution calorimetry of LArTPCs. Using a publicly available simulated dataset from the MicroBooNE Collaboration, we show that OT methods achieve state-of-the-art reconstruction performance in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi><mo>/</mo><msup><mi>π</mi><mn>0</mn></msup></math> classification. The success of this first application indicates the broader promise of OT methods for LArTPC-based neutrino experiments.

David Caratelli

Nathaniel Craig

Chuyue Fang

Jessica N. Howard

Optimal transport for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi><mo>/</mo><msup><mi>π</mi><mn>0</mn></msup></math> particle classification in LArTPC neutrino experiments

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 recent years, the resistive cylindrical chamber (RCC) has been introduced as a novel gaseous detector, extending the well-established resistive plate chambers (RPCs) to the case of cylindrical electrode geometry. Preliminary experimental studies, although still limited in number and performed under experimental conditions not always fully controlled, have nevertheless highlighted several promising features of this detector configuration, motivating the need for further systematic investigations of its operation. In contrast, from the simulation perspective, detailed studies of the RCC have not been performed yet, despite the fact that the cylindrical geometry introduces new degrees of freedom – such as cylinder electrodes radii and voltage polarity – which lead to asymmetric behaviour of the avalanche development according to the polarity of the applied voltage between the electrodes. In this work we present a standalone simulation program specifically designed to model avalanche growth and signal induction in both RPC and RCC geometries. The code implements a stepwise transport model for electron multiplication, includes approximate space-charge effects, and evaluates the induced signals on an external electrode. The simulation has been validated against experimental data for planar RPCs and subsequently applied to RCC geometries with the primary goal of investigating the underlying physical features of the cylindrical detector configuration. The results show that key observables such as induced charge and efficiency are well reproduced in the planar case, and they highlight the role of the electric-field asymmetry in shaping avalanche dynamics in the cylindrical geometry. A first comparison with available RCC experimental data is also presented, providing an initial assessment of the model performance in realistic operating conditions.

Italy

M. Abbrescia

United States

S. Colafranceschi

M. Serio

B. Liberti

S. Meola

A. Paoloni

A. Pastore

D. Piccolo

A. Rocchi

G. Saviano

C. Vendittozzi

A standalone simulation program for resistive cylindrical chamber (RCC)

We present the strongest experimental limits to date on the mixing angle, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi></math>, with which a new scalar particle, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>, mixes with the Higgs field in the mass range <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>110</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi><mo>&lt;</mo><msub><mi>m</mi><mi>S</mi></msub><mo>&lt;</mo><mn>155</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>. This result uses the MicroBooNE liquid argon time projection chamber to search for decays of these Higgs-portal scalar particles through the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> channel with the decays of kaons in the NuMI neutrino beam acting as the source of the scalar particles. The analysis uses an exposure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.01</mn><mo>×</mo><msup><mn>10</mn><mn>21</mn></msup></math> protons on target of NuMI beam data including periods when the beam focusing system was configured to focus positively charged hadrons and separate periods when negatively charged hadrons were focused. The analysis searches for scalar particles produced from kaons decaying in flight in the beam’s decay volume and at rest in the target and absorber. At <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>S</mi></msub><mo>=</mo><mn>125</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>S</mi></msub><mo>=</mo><mn>150</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>) we set a limit of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi><mo>&lt;</mo><mn>3.19</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi><mo>&lt;</mo><mn>2.79</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>) at the 95% confidence level.

P. Abratenko

D. Andrade Aldana

L. Arellano

J. Asaadi

A. Ashkenazi

S. Balasubramanian

B. Baller

A. Barnard

G. Barr

D. Barrow

J. Barrow

V. Basque

J. Bateman

O. Benevides Rodrigues

S. Berkman

A. Bhanderi

A. Bhat

M. Bhattacharya

M. Bishai

A. Blake

B. Bogart

T. Bolton

M.B. Brunetti

L. Camilleri

D. Caratelli

F. Cavanna

G. Cerati

A. Chappell

Y. Chen

J.M. Conrad

M. Convery

L. Cooper-Troendle

J.I. Crespo-Anadón

R. Cross

M. Del Tutto

S.R. Dennis

P. Detje

R. Diurba

Z. Djurcic

K. Duffy

S. Dytman

B. Eberly

P. Englezos

A. Ereditato

J.J. Evans

C. Fang

W. Foreman

B.T. Fleming

D. Franco

A.P. Furmanski

F. Gao

D. Garcia-Gamez

S. Gardiner

G. Ge

S. Gollapinni

E. Gramellini

P. Green

H. Greenlee

L. Gu

W. Gu

R. Guenette

P. Guzowski

L. Hagaman

M.D. Handley

O. Hen

C. Hilgenberg

G.A. Horton-Smith

B. Irwin

M.S. Ismail

C. James

X. Ji

J.H. Jo

R.A. Johnson

Y.J. Jwa

D. Kalra

G. Karagiorgi

W. Ketchum

M. Kirby

T. Kobilarcik

N. Lane

J.Y. Li

Y. Li

K. Lin

B.R. Littlejohn

L. Liu

W.C. Louis

X. Luo

T. Mahmud

C. Mariani

D. Marsden

J. Marshall

N. Martinez

D.A. Martinez Caicedo

S. Martynenko

A. Mastbaum

I. Mawby

N. McConkey

L. Mellet

J. Mendez

J. Micallef

Search for the production of Higgs-portal scalar bosons in the NuMI beam using the MicroBooNE detector

We analyze the decay of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo stretchy="false">→</mo><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>−</mo></msup><mo stretchy="false">(</mo><mo>ℓ</mo><mo>=</mo><mi>e</mi><mo>,</mo><mi>μ</mi><mo stretchy="false">)</mo></math> via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>γ</mi><msup><mi>η</mi><mo>′</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>η</mi><mo>′</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><mi>η</mi></math>, based on (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>10087</mn><mo>±</mo><mn>44</mn></math>) <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>×</mo><mrow><msup><mrow><mn>10</mn></mrow><mrow><mn>6</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math> events collected with the BESIII detector at the BEPCII storage rings. The branching fraction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo stretchy="false">→</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math> is measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>5.8</mn><mo>±</mo><msub><mn>1.0</mn><mrow><mi>stat</mi></mrow></msub><mo>±</mo><msub><mn>0.2</mn><mrow><mi>syst</mi></mrow></msub><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup></math>, which is consistent with the previous measurements and theoretical expectations. In addition, no significant <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> signal is observed in the <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> invariant mass spectrum, and an improved upper limit of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>η</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">)</mo><mo>&lt;</mo><mn>2.2</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>7</mn></mrow></msup></math> is set at 90% confidence level.

M. Ablikim

M.N. Achasov

P. Adlarson

X.C. Ai

R. Aliberti

A. Amoroso

Q. An

Y. Bai

O. Bakina

Y. Ban

H.R. Bao

V. Batozskaya

K. Begzsuren

N. Berger

M. Berlowski

M. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

R.A. Briere

A. Brueggemann

H. Cai

M.H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

S.A. Cetin

X.Y. Chai

J.F. Chang

G.R. Che

Y.Z. Che

C.H. Chen

Chao Chen

G. Chen

H.S. Chen

H.Y. Chen

M.L. Chen

S.J. Chen

S.L. Chen

S.M. Chen

T. Chen

X.R. Chen

X.T. Chen

X.Y. Chen

Y.B. Chen

Y.Q. Chen

Z. Chen

Z.J. Chen

Z.K. Chen

J.C. Cheng

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

J. Cottee-Meldrum

J.J. Cui

H.L. Dai

Measurement of the branching fraction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo stretchy="false">→</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math> and search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math>