In double charmonium production, a long-standing challenge is that the theoretical predictions are not consistent with the measurements at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> factories. Within the Non-Relativistic Quantum Chromodynamics (NRQCD) framework, the next-to-leading order calculation has proved its power to cut down the discrepancy between theory and experiments. To further clarify this puzzle, we have performed the next-to-next-to-leading order calculation. The amplitude is obtained as an analytical asymptotic expansion in the ratio of the squared charm-quark mass over the squared center-of-mass energy, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>m</mi><mi>c</mi><mn>2</mn></msubsup><mo>/</mo><mi>s</mi></math>. We investigate the origin of the leading logarithms by performing a region analysis, revealing the intricate factorization structure in this process. We provide numerical predictions on the total cross sections of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>+</mo><msub><mi>η</mi><mi>c</mi></msub></math> production, which agree with the experimental results. Extension of our computation to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">ϒ</mi><mo>+</mo><msub><mi>η</mi><mi>b</mi></msub></math> production is also discussed.

Xiang Chen

Xin Guan

Chuan-Qi He

Yan-Qing Ma

Jian Wang

Da-Jiang Zhang

Analytical two-loop amplitudes of <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><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>+</mo><msub><mi>η</mi><mi>c</mi></msub></math> at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> factories

We systematically investigate the quasinormal modes of thick branes in $\textit{f}$($\textit{R}$) gravity by numerically solving the Schrödinger-like perturbation equation of gravitational perturbations. To ensure reliability of the results, we employ three complementary methods: the asymptotic iteration method, direct integration of the wave equation, and time-domain numerical evolution. We analyze how model parameters influence the shape of the effective potential of gravitational perturbations and find that the structure of the potential barrier plays a significant role in shaping the quasinormal frequency spectrum. The results obtained from the three methods exhibit strong consistency, thereby ensuring the reliability of the calculations. In particular, real parts of the quasinormal frequencies exhibit an approximately arithmetic progression, suggesting that quasi-localized states can be understood as resonances between the barriers.

China

Yu-Peng E.

Chun-Chun Zhu

Yu-Xiao Liu

Quasinormal modes of thick branes in $\textit{f}$($\textit{R}$) gravity

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

In the experiment to study 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><mo stretchy="false">→</mo><mi>n</mi><mover accent="true"><mi>n</mi><mo stretchy="false">¯</mo></mover></math> process at the VEPP-2000 <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> collider, the ratio <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>G</mi><mi>E</mi></msub><mo stretchy="false">|</mo><mo>/</mo><mo stretchy="false">|</mo><msub><mi>G</mi><mi>M</mi></msub><mo stretchy="false">|</mo></math> of the neutron timelike electric and magnetic form factors has been measured. The experiment was carried out with the SND detector in the center-of-mass energy range 1890–2000 MeV in eight energy points with an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>83</mn><mtext> </mtext><mtext> </mtext><msup><mi>pb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>G</mi><mi>E</mi></msub><mo stretchy="false">|</mo><mo>/</mo><mo stretchy="false">|</mo><msub><mi>G</mi><mi>M</mi></msub><mo stretchy="false">|</mo></math> ratio is determined by the analyzing the distribution of the polar angle of the produced antineutron. The measured <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>G</mi><mi>E</mi></msub><mo stretchy="false">|</mo><mo>/</mo><mo stretchy="false">|</mo><msub><mi>G</mi><mi>M</mi></msub><mo stretchy="false">|</mo></math> value in the energy range under study is between 1.0 and 1.5 with an average value of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1.21</mn><mo>±</mo><mn>0.13</mn></math>.

M.N. Achasov

A.E. Alizzi

A. Yu. Barnyakov

E.V. Bedarev

K.I. Beloborodov

A.V. Berdyugin

A.G. Bogdanchikov

A.A. Botov

T.V. Dimova

V.P. Druzhinin

R.A. Efremov

V.N. Zhabin

V.V. Zhulanov

P.V. Zhulanova

L.V. Kardapoltsev

A.S. Kasaev

A.A. Kattsin

D.P. Kovrizhin

I.A. Koop

A.A. Korol

A.S. Kupich

A.P. Kryukov

N.A. Melnikova

N. Yu. Muchnoi

A.E. Obrazovsky

A.A. Oorzhak

I.V. Ovtin

E.V. Pakhtusova

I.A. Polomoshnov

K.V. Pugachev

S.A. Rastigeev

Yu. A. Rogovsky

A.I. Senchenko

S.I. Serednyakov

Z.K. Silagadze

K.D. Sungurov

I.K. Surin

Yu. V. Usov

A.G. Kharlamov

D.E. Chistyakov

D.A. Shtol

Measurement of the neutron timelike electric and magnetic form factor ratio at the VEPP-2000 <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> collider

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

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

J.P. Dai

A. Dbeyssi

R.E. de Boer

D. Dedovich

C.Q. Deng

Z.Y. Deng

A. Denig

I. Denysenko

M. Destefanis

F. De Mori

B. Ding

X.X. Ding

Y. Ding

Y.X. Ding

J. Dong

L.Y. Dong

M.Y. Dong

X. Dong

M.C. Du

S.X. Du

Y.Y. Duan

Z.H. Duan

P. Egorov

G.F. Fan

J.J. Fan

Y.H. Fan

J. Fang

S.S. Fang

W.X. Fang

Y.Q. Fang

L. Fava

F. Feldbauer

G. Felici

C.Q. Feng

J.H. Feng

L. Feng

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>

We theoretically investigate the transfer of quantum coherence and entanglement in a tripartite system arising from the weak scattering process <math altimg='si12.svg'><mrow><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>&#8722;</mo></msup><mspace width='-0.16em' /><mo>&#8594;</mo><mspace width='-0.16em' /><msup><mi>&#956;</mi><mo>+</mo></msup><msup><mi>&#956;</mi><mo>&#8722;</mo></msup></mrow></math> mediated by <italic>Z</italic>-boson exchange. Our setup involves an electron&#8211;positron collision in which the incoming positron is initially entangled with a muon acting as a spectator that does not directly participate in the scattering process. Using a quantum-information framework, we track the evolution of bipartite entanglement and non-local coherence during the interaction, employing logarithmic negativity and the <italic>l</italic> <inf>1</inf>-norm of correlated coherence as quantitative measures. Restricting the analysis to the kinematically allowed region, we show that the scattering induces a redistribution of quantum correlations, transferring entanglement from the initial positron&#8211;spectator pair to the produced <math altimg='si13.svg'><mrow><msup><mi>&#956;</mi><mo>+</mo></msup><msup><mi>&#956;</mi><mo>&#8722;</mo></msup></mrow></math> pair and to spectator&#8211;(produced muon) bipartitions. The process can also generate entanglement between one of the produced muons and the distant spectator, despite the absence of any direct interaction between them, illustrating a non-local transfer of quantum resources. At the same time, local coherence exhibits a more limited variation and is progressively reduced as the electron momentum in the center-of-mass frame increases, indicating that the observed behavior is predominantly governed by non-local correlations. These results demonstrate how weak scattering processes can serve as a platform for exploring the dynamics of quantum correlations in high-energy physics.

Morocco

Yassine Oussarhan

Fouad Essaadi

Said Mouslih

Mohamed Ouhammou

Mohamed Jakha

Souad Taj

Bouzid Manaut

Transfer of quantum coherence and entanglement in weak <math altimg='si11.svg'><mrow><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>&#8722;</mo></msup><mo>&#10230;</mo><msup><mi>&#956;</mi><mo>+</mo></msup><msup><mi>&#956;</mi><mo>&#8722;</mo></msup></mrow></math> scattering through <italic>Z</italic>-boson exchange

Neutral triple gauge couplings (nTGCs) first arise from the dimension-8 operators of the Standard Model effective field theory (SMEFT), rather than the dimension-4 SM Lagrangian and dimension-6 SMEFT operators, opening up a unique window for probing new physics at the dimension-8 level. In this work, we formulate the nTGC form factors of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi><msup><mi>V</mi><mo>*</mo></msup></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>V</mi><mo>=</mo><mi>Z</mi></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>γ</mi></mrow></math>) that are compatible with the spontaneous breaking of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo><mo stretchy="false">⊗</mo><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></math> electroweak gauge symmetry and consistently match the dimension-8 nTGC operators in the broken phase. We study the sensitivities for probing both the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi><msup><mi>V</mi><mo>*</mo></msup></math> form factors and the corresponding new physics scales through <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi></math> production (with visible/invisible fermionic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> decays) at high energy <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> colliders including CEPC, FCC-ee, LCF, ILC, and CLIC. In particular, we identify the dimension-8 operator that contributes to the pure triple <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> boson coupling <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi><msup><mi>Z</mi><mo>*</mo></msup></math> alone, but not the mixed <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi><msup><mi>γ</mi><mo>*</mo></msup></math> coupling. We further study the correlations between probes of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi><msup><mi>Z</mi><mo>*</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi><msup><mi>γ</mi><mo>*</mo></msup></math> couplings. Using machine learning, we show that angular distributions of the final-state fermions can play key roles in suppressing the SM backgrounds. The sensitivities can be further improved by using polarized <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>∓</mo></msup></math> beams, and we find that the optimal sensitivity bounds on the nTGC correlations are given by the mixed setting including both the unpolarized operation and the follow-up polarized operation. We demonstrate that machine learning is advantageous for handling the 4-body final states from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi></math> decays and improves significantly the sensitivity reaches of probes of nTGCs in <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> collisions. We find that nTGC new physics scales can be probed up to the multi-TeV scale at the proposed <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> colliders.

John Ellis

Hong-Jian He

Rui-Qing Xiao

Shi-Ping Zeng

Probing neutral triple gauge couplings via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi></math> production at <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> colliders with machine learning

The $ e^+e^- $ annihilation of unpolarized beams is free from initial hadron states or initial anisotropy around the azimuthal angle. Hence, it is ideal for studying the correlations of dynamical origin via final state jets. We investigate the planar properties of multi-jet events employing the relevant event-shape observables at next-to-next-to-leading order ( $ {\cal{O}} $ ( $ \alpha_{s}^{3} $ )) in perturbative Quantum Chromodynamics (QCD). In particular, the azimuthal angle correlations on the long pseudo-rapidity (polar angle) range (Ridge correlation) between the inclusive jet momenta are calculated. We demonstrate that the significant planar properties and the strong correlations as the consequence are natural results of the energy-momentum conservation of the perturbative QCD radiation dynamics. Our study provides benchmarks of a hard strong interaction background for investigating the collective and/or thermal effects via the Ridge-like correlation observables for various scattering processes.

Xuan Chen

Yuesheng Dai

Shi-Yuan Li

Zong-Guo Si

Huiting Sun

Planar property and long-range azimuthal correlation in $\textit{e}$ $^{+}$ $\textit{e}$ $^{–}$ annihilation * Supported by the National Science Foundation of China (NSFC) (12475085, 12275157, 12321005, 12235008)

We present MicroBooNE’s first search for dark sector <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> explanations of the long-standing MiniBooNE anomaly. The MiniBooNE anomaly has garnered significant attention over the past 20 years including previous MicroBooNE investigations into both anomalous electron and photon excesses, but its origin still remains unclear. In this Letter, we provide the first direct test of dark sector models in which dark neutrinos, produced through neutrino-induced scattering, decay into missing energy and visible <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> pairs comprising the MiniBooNE anomaly. Many such models have recently gained traction as a viable solution to the anomaly while evading past bounds. Using an exposure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>6.87</mn><mo>×</mo><msup><mn>10</mn><mn>20</mn></msup></math> protons-on-target in the Booster Neutrino Beam, we implement a selection targeting forward-going, coherently produced <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> events. After unblinding, we observe 95 events, which we compare with the constrained background-only prediction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>69.7</mn><mo>±</mo><mn>17.3</mn></math>. This analysis sets the world’s first direct limits on these dark sector models and, at the 95% confidence level, excludes the entirety of the single dark neutrino and majority of the dual dark neutrino, parameter space that is viable as a solution to the MiniBooNE anomaly.

A.M. Abdullahi

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. Bhat

First Search for Dark Sector <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> Explanations of the MiniBooNE Anomaly at MicroBooNE