In this work, we investigate the resonance structures in the $ \Sigma(1/2^-) $ system from both three-quark and five-quark perspectives within the framework of the chiral quark model. An accurate few-body computational approach, the Gaussian expansion method, is employed to construct the orbital wave functions of multiquark states. To reduce the model dependence on parameters, we fit two sets of parameters to check the stability of the results. The calculations show that our results remain stable despite changes in the parameters. In the three-quark calculations, two $ \Sigma(1/2^-) $ states are obtained with energies around 1.8 GeV, which are good candidates for the experimentally observed $ \Sigma(1750) $ and $ \Sigma(1900) $ . In the five-quark configuration, several stable resonance states are identified, including $ \Sigma \pi $ , $ N \bar{K} $ , and $ N \bar{K}^{*} $ . These resonance states survive the channel-coupling calculations under the complex-scaling framework and manifest as stable structures. Our results support the existence of a two-pole structure for the $ \Sigma(1/2^-) $ system, predominantly composed of $ \Sigma \pi $ and $ N \bar{K} $ configurations, analogous to the well-known $ \Lambda(1380) $ - $ \Lambda(1405) $ ( $ \Sigma \pi $ - $ N \bar{K} $ ) system. On the other hand, although the energy of the $ N \bar{K}^{*} $ configuration is close to that of $ \Sigma(1750) $ and $ \Sigma(1900) $ , the obtained width is not consistent with the experimental values. This suggests that the $ N \bar{K}^{*} $ state needs to mix with three-quark components to better explain the experimental $ \Sigma(1750) $ and $ \Sigma(1900) $ states. According to our decay width calculations, the predicted two resonance states are primarily composed of $ \Sigma \pi $ and $ N \bar{K} $ , with their main decay channel being $ \Lambda \pi $ . Therefore, we encourage experimental groups to search for the predicted two-pole structure of the $ \Sigma(1/2^-) $ system in the invariant mass spectrum of $ \Lambda \pi $ .

China

Yu Yao

Xuejie Liu

Xiaoyun Chen

Yuheng Wu

Jialun Ping

Yue Tan

Qi Huang

Investigation of resonances in the Σ(1/2$^{–}$) system based on the chiral quark model * Supported partly by the National Science Foundation of China (12205249, 12305087). Yue Tan is supported by the Funding for School-Level Research Projects of Yancheng Institute of Technology (xjr2022039) and the Qinglan Project Fund of Jiangsu Province. Qi Huang is supported by the Start-up Funds of Nanjing Normal University (184080H201B20)

We present the analysis techniques developed to explore the keV-scale energy region of the Cryogenic Underground Observatory for Rare Events (CUORE) experiment, based on more than 2 metric ton yr of data collected over five years. By prioritizing a stricter selection over a larger exposure, we are able to optimize data selection for thresholds at 10 keV and 3 keV with 691 kg yr and 11 kg yr of data, respectively. We study how the performance varies among the 988-detector array with different detector characteristics and data-taking conditions. We achieve an average baseline resolution of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.54</mn><mo>±</mo><mn>0.14</mn><mtext> </mtext><mtext> </mtext><mi>keV</mi></math> FWHM and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1.18</mn><mo>±</mo><mn>0.02</mn><mtext> </mtext><mtext> </mtext><mi>keV</mi></math> FWHM for the data selection at 10 keV and 3 keV, respectively. The analysis methods employed reduce the overall background by about an order of magnitude, reaching <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2.06</mn><mo>±</mo><mn>0.05</mn><mtext> </mtext><mtext> </mtext><mi>counts</mi><mo>/</mo><mo stretchy="false">(</mo><mi>keV</mi><mtext> </mtext><mi>kg</mi><mtext> </mtext><mi>days</mi><mo stretchy="false">)</mo></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>16</mn><mo>±</mo><mn>2</mn><mtext> </mtext><mtext> </mtext><mi>counts</mi><mo>/</mo><mo stretchy="false">(</mo><mi>keV</mi><mtext> </mtext><mi>kg</mi><mtext> </mtext><mi>days</mi><mo stretchy="false">)</mo></mrow></math> at the thresholds of 10 keV and 3 keV. We evaluate for the first time the near-threshold reconstruction efficiencies of the CUORE experiment, and find these to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>50</mn><mo>±</mo><mn>2</mn><mo>%</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>26</mn><mo>±</mo><mn>4</mn><mo>%</mo></math> at 10 keV and 3 keV, respectively. This analysis provides crucial insights into rare decay studies, new physics searches, and keV-scale background modeling with CUORE. We demonstrate that ton-scale cryogenic calorimeters can operate across a wide energy range, from keV to MeV, establishing their scalability as versatile detectors for rare event and dark matter physics. These findings also inform the optimization of future large mass cryogenic calorimeters to enhance the sensitivity to low-energy phenomena.

United States

D.Q. Adams

C. Alduino

K. Alfonso

A. Armatol

F.T. Avignone

Italy

O. Azzolini

G. Bari

F. Bellini

G. Benato

M. Beretta

M. Biassoni

A. Branca

C. Brofferio

C. Bucci

J. Camilleri

A. Caminata

A. Campani

J. Cao

C. Capelli

S. Capelli

L. Cappelli

L. Cardani

P. Carniti

N. Casali

E. Celi

D. Chiesa

M. Clemenza

S. Copello

A. Cosoli

O. Cremonesi

R.J. Creswick

A. D’Addabbo

I. Dafinei

S. Dell’Oro

S. Di Domizio

S. Di Lorenzo

France

T. Dixon

D.Q. Fang

M. Faverzani

E. Ferri

F. Ferroni

E. Fiorini

M.A. Franceschi

S.J. Freedman

S.H. Fu

B.K. Fujikawa

S. Ghislandi

A. Giachero

M. Girola

L. Gironi

A. Giuliani

P. Gorla

C. Gotti

P.V. Guillaumon

T.D. Gutierrez

K. Han

E.V. Hansen

K.M. Heeger

D.L. Helis

H.Z. Huang

M.T. Hurst

G. Keppel

Yu. G. Kolomensky

R. Kowalski

R. Liu

L. Ma

Y.G. Ma

L. Marini

R.H. Maruyama

D. Mayer

Y. Mei

M.N. Moore

T. Napolitano

M. Nastasi

C. Nones

E.B. Norman

A. Nucciotti

I. Nutini

T. O’Donnell

M. Olmi

B.T. Oregui

S. Pagan

C.E. Pagliarone

L. Pagnanini

M. Pallavicini

L. Pattavina

M. Pavan

G. Pessina

V. Pettinacci

C. Pira

S. Pirro

E.G. Pottebaum

S. Pozzi

E. Previtali

A. Puiu

S. Quitadamo

A. Ressa

C. Rosenfeld

B. Schmidt

R. Serino

Exploring the keV-scale physics potential of CUORE

Driven by the increasing volume of recorded data, the demand for simulation from experiments based at the Large Hadron Collider will rise sharply in the coming years. Addressing this demand solely with existing computationally intensive workflows is not feasible. This paper introduces a new fast simulation tool designed to address this demand at the LHCb experiment. This tool emulates the detector response to arbitrary multibody decay topologies at the LHCb. Rather than memorizing specific decay channels, the model learns generalizable patterns within the response, allowing it to interpolate to channels not present in the training data. Novel heterogeneous graph neural network architectures are employed that are designed to embed the physical characteristics of the task directly into the network structure. We demonstrate the performance of the tool across a range of decay topologies, showing that the networks can correctly model the relationships between complex variables. The architectures and methods presented are generic and could readily be adapted to emulate workflows at other simulation-intensive particle physics experiments.

Switzerland

G. Hijano

United Kingdom

D. Lancierini

A. Marshall

A. Mauri

P. Owen

M. Patel

K. Petridis

S.R. Qasim

N. Serra

W. Sutcliffe

H. Tilquin

Towards replacing detector simulations with heterogeneous graph neural networks in flavor physics analyses

Rare decays of the kind $\textit{B}$ → $\textit{K}$ $\textit{μ}$ $\textit{μ}$ and $\textit{B}$ → $\textit{ϕμ}$ $\textit{μ}$ are key players for testing the Standard Model. The current experimental data for their decay rates and angular observables show tensions with the theoretical predictions that may be indications of New Physics. We present a strategy to extract the relevant short-distance coefficients in the presence of new sources of CP violation from a minimal set of observables, utilizing the synergy between the rare modes with vector meson final states and $\textit{B}$ → $\textit{Kμ}$ $\textit{μ}$ decays. Using the current data as a guideline, we illustrate the new method to determine the complex coefficients $$ {C}_9^{\left(\prime \right)} $$ and $$ {C}_{10}^{\left(\prime \right)} $$ using only four angular observables. Interestingly, the current experimental picture leaves significant room for CP-violating New Physics. We discuss also the link to leptonic $$ {B}_s^0\to {\mu}^{+}{\mu}^{-} $$ decays. Our strategy complements global fit efforts and could also help to disentangle long-distance QCD dynamics from possible new CP-violating interactions.

Netherlands

Robert Fleischer

Martijn Hamersveld

Tim Kortekaas

Anders Rehult

K. Vos

Probing new physics through CP violation in $\textit{B}$

We study inclusive semileptonic $$\overline{B}\to {X }_{c}{\ell}\overline{\nu }$$ decays ($\textit{ℓ}$ = $\textit{e}$, $\textit{μ}$) in the presence of generic physics Beyond the Standard Model (BSM) that is heavy compared to the $\textit{b}$-quark mass. Its effect is encoded in the Wilson coefficients of dimension-six operators of the Weak Effective Theory (WET). We compute the resulting BSM contributions to the experimentally measured kinematic moments and the total decay rate through order $$\mathcal{O}\left({\Lambda}_{\text{QCD}}^{3}/{m}_{b}^{3}\right)$$ in the Heavy Quark Expansion, as well as the $$\mathcal{O}\left({\alpha }_{s}\right)$$ corrections for the right-handed vector current. We then perform fits to the full set of available inclusive measurements in several single-mediator scenarios and in the full WET basis. We find qualitatively new bounds in several of these scenarios, complementary to and competitive with constraints from exclusive decays.

Alexandre Carvunis

Gael Finauri

Paolo Gambino

Martin Jung

Sandro Mächler

New Physics in inclusive semileptonic $\textit{B}$ decays

Due to the success of the Standard Model (SM), it is reasonable to anticipate that the signal of new physics (NP) beyond the SM is small. Consequently, future searches for NP and precision tests of the SM will require high luminosity collider experiments. Moreover, as precision tests advance, rare processes with many final-state particles require consideration which demands the analysis of a vast number of observables. The high luminosity produces a large amount of experimental data spanning a large observable space, posing a significant data-processing challenge. In recent years, quantum machine learning has emerged as a promising approach for processing large amounts of complex data on a quantum computer. In this study, we propose quantum searching neighbor (QSN) and variational QSN (VQSN) algorithms to search for NP. The QSN is a classification algorithm. The VQSN introduces variation to the QSN to process classical data. As applications, we apply the (V) QSN in the phenomenological study of the NP at the Large Hadron Collider and muon colliders. Examples are implemented on a real quantum hardware, which confirms reliable performance under noisy conditions. The results indicate that the VQSN demonstrates superior efficiency in the sense of computational complexity to a classical counterpart k-nearest neighbor algorithm, even when dealing with classical data.

Ji-Chong Yang

Shuai Zhang

Chong-Xing Yue

A quantum machine learning classifier to search for new physics

Is field space infinite? If not, it either loops back on itself or ends altogether. Periodic boundary conditions are of course familiar, but field space endpoints—which appear in real-world systems—are far less explored. In this paper we argue that boundaries in field space are generic, radiatively stable structures that allow for new physics at very low scales not ruled out by experiment. Such boundaries are delocalized in field space from the vacuum, so they can only be accessed by coherent fields or high multiplicity processes, both of which are weakly constrained observationally. Low multiplicity interactions do not detect the boundary and instead perceive a “mirage cutoff” that is parametrically higher than the true cutoff of the theory. Hence, field space boundaries are deformations of the standard model that are Lorentz invariant, local, unitary at low energies, and experimentally unconstrained. We comment on the possibility of field space boundaries on the long-range force carriers and the Higgs, as well as possible implications for the hierarchy problem.

Clifford Cheung

Ira Z. Rothstein

Hiding new physics at the end of field space

Based on $ (10087\pm 44)\times10^{6} $ $ J/\psi $ events collected with the BESIII detector, we search for the lepton number violating decay $ J/\psi \to K^+K^+e^-e^- + c.c. $ for the first time. The upper limit on the branching fraction of this decay is set to $ 2.1 \times 10^{-9} $ at the 90% confidence level with a frequentist method. This is the first search for $ J/\psi $ decays with a lepton number change by two, offering valuable insights into the underlying physical processes.

M. Ablikim

Russia

M.N. Achasov

Sweden

P. Adlarson

X.C. Ai

Germany

R. Aliberti

A. Amoroso

Q. An

Y. Bai

O. Bakina

Y. Ban

H.R. Bao

Poland

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M.B. 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

Türkiye

S.A. Cetin

X.Y. Chai

J.F. Chang

T.T. Chang

G.R. Che

Y.Z. Che

C.H. Chen

Chao Chen

G. Chen

H.S. Chen

H.Y. Chen

Search for the lepton number violating process ${{\boldsymbol J}/{\boldsymbol\psi }{\bf\to}{\boldsymbol K}^{\bf +}{\boldsymbol K}^{\bf +}{\boldsymbol e}^{\bf -}{\boldsymbol e}^{\bf -}{\bf +}{\boldsymbol {c.c.}}}$ * This work is supported in part by National Key R&D Program of China under Contracts Nos. 2023YFA1606000, 2023YFA1606704; National Natural Science Foundation of China (NSFC) under Contracts Nos. 12035009, 11635010, 11935015, 11935016, 11935018, 12025502, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12361141819; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; CAS under Contract No. YSBR-101; 100 Talents Program of CAS; The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; German Research Foundation DFG under Contract No. FOR5327; Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation under Contracts Nos. 2021.0174, 2021.0299; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Research Foundation of Korea under Contract No. NRF-2022R1A2C1092335; National Science and Technology fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand under Contract No. B50G670107; Polish National Science Centre under Contract No. 2024/53/B/ST2/00975; Swedish Research Council under Contract No. 2019.04595; U. S. Department of Energy under Contract No. DE-FG02-05ER41374