China

Xuewei Liu

Wei Dou

Japan

Benda Xu

Hanwen Wang

Guofu Cao

Erratum to: First-principle event reconstruction by time-charge readouts for TAO

The production of heavy-quark (HQ) jets is a new area that addresses the mass effect of jet quenching in heavy-ion physics. This paper presents a theoretical study of HQ jet yield suppression in Pb+Pb collisions at the Large Hadron Collider (LHC) and focuses on the energy loss of HQ jets produced by different mechanisms. The $\textit{p+p}$ baseline is provided by the generator simulation of high-energy reactions of particles (SHERPA), and the jet-medium interactions are described by the SHELL transport model, which considers the elastic and inelastic partonic energy loss in the quark-gluon plasma (QGP). In $\textit{p+p}$ collisions, our numerical results indicate that the HQ jets from gluon splitting ( $ g \rightarrow Q $ -jet) are the dominant contribution at high $ p_T $ , displaying more dispersive structures than the HQ-initiated ( $ Q \rightarrow Q $ -jet). In nucleus-nucleus collisions, our calculations were consistent with the inclusive and b-jet $ R_{AA} $ recently measured by the ATLAS collaboration, revealing a remarkable manifestation of the mass effect of jet energy loss. As a result of the dispersive substructure, the $ g \rightarrow Q $ -jet loses more energy than the $ Q \rightarrow Q $ -jet in the QGP. Due to the significant contribution of $ g \rightarrow c $ -jet, the $ R_{AA} $ of $\textit{c}$-jet is comparable or even smaller than that of inclusive jet. To experimentally distinguish the $ g \rightarrow Q $ -jet and $ Q \rightarrow Q $ -jet, we propose event selection strategies based on their topological features and test their performances. By isolating the $ c \rightarrow c $ -jet, $ b \rightarrow b $ -jet, and the jets initiated by heavy quarks, we predicted that the order of their $ R_{AA} $ are in line with the mass hierarchy of energy loss. Future measurements on the $ R_{AA} $ of $ Q \rightarrow Q $ -jet and $ g \rightarrow Q $ -jet will provide a unique opportunity for testing the flavor/mass dependence of energy loss at the jet level.

Sa Wang

Shuang Li

Yao Li

Ben-Wei Zhang

Enke Wang

Probing the mass effect of heavy quark jets in high-energy nuclear collisions * Supported by the MajorProject of Basic and Applied Basic Research of Guangdong Province, China (2020B0301030008, 2023A1515011460), and the National Natural Science Foundation of China (11935007, 12035007, 12247127, 12375137). Sa Wang is supported by the Open Foundation of Key Laboratory of Quark and Lepton Physics (MOE) (QLPL2023P01) and the Talent Scientific Star-up Foundation of the China Three Gorges University, China (CTGU) (2024RCKJ013)

The Taishan Antineutrino Observatory (TAO) is a liquid-scintillator satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO) to measure the reference reactor neutrino spectrum with unprecedented energy resolution. We use inhomogeneous Poisson process and Tweedie generalized linear model (GLM) to characterize the detector response and the charge distribution of a SiPM. We develop a pure probabilistic model for time and charge of SiPMs from first principles to reconstruct point-like events in the TAO central detector. Thanks to our precise model and the high photo-coverage and quantum efficiency of the SiPM tiles at TAO, we achieve vertex position resolution better than $$20\,\hbox {mm}$$ , energy resolution of about $$2\%$$ at $$1\,\hbox {MeV}$$ and $$<0.5\%$$ non-uniformity, marking the world’s best performance of liquid scintillator detectors. With such resolution, we perceive $$\hbox {MeV}$$ events to exhibit track effects. It opens up an exciting possibility of computed tracking calorimeter for unsegmented liquid scintillator detector like TAO. Our methodology is applicable to other experiments that utilize PMTs for time and charge readouts.

First-principle event reconstruction by time-charge readouts for TAO

Using the recently proposed covariant framework of general relativistic stochastic mechanics and stochastic thermodynamics, we proved the detailed and integral fluctuation theorems in curved spacetime. The time-reversal transformation is described as a transformation from the perspective of future-directed observer to that of the corresponding past-directed observer, which enables us to maintain general covariance throughout the construction.

Yifan Cai

Tao Wang

Liu Zhao

General relativistic fluctuation theorems

Levitated ferromagnets act as ultraprecise magnetometers, which can exhibit high quality factors due to their excellent isolation from the environment. These instruments can be utilized in searches for ultralight dark matter candidates, such as axionlike dark matter or dark-photon dark matter. In addition to being sensitive to an axion-photon coupling or kinetic mixing, which produce physical magnetic fields, ferromagnets are also sensitive to the effective magnetic field (or “axion wind”) produced by an axion-electron coupling. While the dynamics of a levitated ferromagnet in response to a dc magnetic field have been well studied, all of these couplings would produce ac fields. In this work, we study the response of a ferromagnet to an applied ac magnetic field and use these results to project their sensitivity to axion and dark-photon dark matter. We pay special attention to the direction of motion induced by an applied ac field, in particular, whether it precesses around the applied field (similar to an electron spin) or librates in the plane of the field (similar to a compass needle). We show that existing levitated ferromagnet setups can already have comparable sensitivity to an axion-electron coupling as comagnetometer or torsion balance experiments. In addition, future setups can become sensitive probes of axion-electron coupling, dark-photon kinetic mixing, and axion-photon coupling, for ultralight dark matter masses <math><mrow><msub><mrow><mi>m</mi></mrow><mrow><mi>DM</mi></mrow></msub><mo>≲</mo><mi>feV</mi></mrow></math>.

United States

Saarik Kalia

Germany

Dmitry Budker

Derek F. Jackson Kimball

Wei Ji

Zhen Liu

Alexander O. Sushkov

United Kingdom

Chris Timberlake

Hendrik Ulbricht

Italy

Andrea Vinante

Singapore

Ultralight dark matter detection with levitated ferromagnets

In this study, we compute the electromagnetic and hadronic decay widths of the S-wave fully heavy tetraquark <math><msub><mi>T</mi><mrow><mn>4</mn><mi>Q</mi></mrow></msub></math> (<math><mi>Q</mi><mo>=</mo><mi>c</mi></math> or <math><mi>b</mi></math>) at lowest order in <math><msub><mi>α</mi><mi>s</mi></msub></math> and <math><mi>v</mi></math>, in the framework of nonrelativistic QCD. The short-distance coefficients are determined through the standard procedure of matching. The nonperturbative long-distance matrix elements are related to the phenomenological four-body Schrödinger wave functions at the origin, whose values are taken from literature. The branching fractions are predicted to be around <math><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math> and <math><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup></math> for the <math><msub><mi>T</mi><mrow><mn>4</mn><mi>c</mi></mrow></msub></math> hadronic decay and electromagnetic decay, respectively. Combining our results with the <math><msub><mi>T</mi><mrow><mn>4</mn><mi>c</mi></mrow></msub></math> production cross sections at the LHC, we also predict the event numbers for various decay channels. With integrated luminosity <math><mi>L</mi><mo>=</mo><mn>100</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, it is expected that the event numbers can reach <math><mrow><msup><mrow><mn>10</mn></mrow><mrow><mn>3</mn></mrow></msup><mi>–</mi><msup><mrow><mn>10</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math> for <math><msub><mi>T</mi><mrow><mn>4</mn><mi>c</mi></mrow></msub><mo>→</mo><mi>γ</mi><mi>γ</mi></math>, and <math><mrow><msup><mrow><mn>10</mn></mrow><mrow><mn>5</mn></mrow></msup><mi>–</mi><msup><mrow><mn>10</mn></mrow><mrow><mn>6</mn></mrow></msup></mrow></math> for <math><msub><mi>T</mi><mrow><mn>4</mn><mi>c</mi></mrow></msub><mo>→</mo><mi>LH</mi></math>, at the LHC. The detecting prospect is promising. In addition, the decay widths of <math><msub><mi>T</mi><mrow><mn>4</mn><mi>b</mi></mrow></msub></math> are estimated based on simple dimensional analysis as well as velocity scaling rule.

Wen-Long Sang

Yu-Dong Zhang

Feng Feng

Electromagnetic and hadronic decay of fully heavy tetraquarks

The thermodynamics of charged topological black holes (TBHs) with different horizon geometries in d-dimensional Einstein-Maxwell and 4-dimensional conformal gravities is revisited using the restricted phase space formalism. The concept of subsystems for black holes is introduced, which enables a precise description for the thermodynamic behaviors of (non-compact) black holes with infinitely large horizon area. The concrete behaviors can be different for TBHs in the same underlying theory but with different horizon geometries, or for those with the same horizon geometry but from different underlying theories. The high and low temperature limits of the TBHs are also considered, and the high temperature limits behave universally as low temperature phonon gases. Finally, using the concept of subsystems, some conceptual issues in the description for thermal fluctuations in black hole systems are clarified, and the relative thermal fluctuations for finite subsystems are also analyzed in some detail.

Zhiqiang Zhang

Xiangqing Kong

Topological black holes in Einstein-Maxwell and 4D conformal gravities revisited

We report a precise match between the high temperature <math><mo>(</mo><mi>D</mi><mo>+</mo><mn>2</mn><mo>)</mo></math>-dimensional Tangherlini-AdS black hole and the low temperature quantum phonon gas in D-dimensional nonmetallic crystals residing in <math><mo>(</mo><mi>D</mi><mo>+</mo><mn>1</mn><mo>)</mo></math>-dimensional flat spacetime. The match is realized by use of the recently proposed restricted phase space formalism for black hole thermodynamics, and the result can be viewed as a novel contribution to the AdS/CMT correspondence on a quantitative level.

High temperature AdS black holes are low temperature quantum phonon gases

The Taishan Antineutrino Observatory (TAO or JUNO-TAO) is a satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). Located near a reactor of the Taishan Nuclear Power Plant, TAO will measure the reactor antineutrino energy spectrum with an unprecedented energy resolution of  $$&lt;2\%$$  <math> <mrow> <mo>&lt;</mo> <mn>2</mn> <mo>%</mo> </mrow> </math>   at 1 MeV. Energy calibration is critical to achieve such a high energy resolution. Using the Automated Calibration Unit (ACU) and the Cable Loop System (CLS), multiple radioactive sources are deployed to various positions in the TAO detector for energy calibration. The residual non-uniformity can be controlled within 0.2%. The energy resolution degradation and energy bias caused by the residual non-uniformity can be controlled within 0.05% and 0.3%, respectively. The uncertainty of the non-linear energy response can be controlled within 0.6% with the radioactive sources of various energies, and could be further improved with cosmogenic  $$^{12}{\textrm{B}}$$  <math> <mrow> <msup> <mrow></mrow> <mn>12</mn> </msup> <mtext>B</mtext> </mrow> </math>   which is produced by the interaction of cosmic muon in the liquid scintillator. The stability of other detector parameters, e.g., the gain of each Silicon Photo-multiplier, will be monitored with an ultraviolet LED calibration system.

Hangkun Xu

Chile

Angel Abusleme

JINR

Nikolay Anfimov

France

Stéphane Callier

Agustin Campeny

Jun Cao

Cedric Cerna

Yu Chen

Russia

Alexander Chepurnov

Yayun Ding

Frederic Druillole

Andrea Fabbri

Zhengyong Fei

Maxim Gromov

Miao He

Wei He

Yuanqiang He

Joseph Hor

Shaojing Hou

Jianrun Hu

Jun Hu

Cédric Huss

Xiaolu Ji

Tao Jiang

Xiaoshan Jiang

Cécile Jolliet

Daozheng Li

Min Li

Ruhui Li

Yichen Li

Caimei Liu

Mengchao Liu

Yunzhe Liu

Claudio Lombardo

Selma Lorenzo

Peizhi Lu

Guang Luo

Stefano Mari

Xiaoyan Ma

Paolo Montini

Juan Ochoa-Ricoux

Yatian Pei

Frédéric Perrot

Fabrizio Petrucci

Xiaohui Qian

Abdel Rebii

Czechia

Bedr̆ich Roskovec

Arsenij Rybnikov

Hans Steiger

Xilei Sun

Pablo Walker

Derun Wang

Meifen Wang

Wei Wang

Zhimin Wang

Diru Wu

Xiang Xiao

Yuguang Xie

Zhangquan Xie

Wenqi Yan

Huan Yang

Haifeng Yao

Mei Ye

Chengzhuo Yuan

Kirill Zamogilnyi

Liang Zhan

Jie Zhang

Shuihan Zhang

Rong Zhao

Calibration strategy of the JUNO-TAO experiment

We study the sensitivity of JUNO and TAO to the oscillations induced by two well-motivated scenarios beyond the standard model: large extra dimensions (LEDs) and light sterile neutrinos in the context of <math><mrow><mn>3</mn><mo>+</mo><mn>1</mn></mrow></math> neutrino mixing. We find that <math><mrow><mi>JUNO</mi><mo>+</mo><mi>TAO</mi></mrow></math> can set competitive bounds on the parameter space of each scenario. In particular, we find that <math><mrow><mi>JUNO</mi><mo>+</mo><mi>TAO</mi></mrow></math> can be competitive with MINOS, DUNE, or KATRIN in the context of LED. If LEDs are present in nature, we show that the parameters could be measured with a similar precision as the standard oscillation parameters. We also show that <math><mrow><mi>JUNO</mi><mo>+</mo><mi>TAO</mi></mrow></math> can test nearly all of the parameter space preferred by gallium experiments in the context of <math><mrow><mn>3</mn><mo>+</mo><mn>1</mn></mrow></math> mixing. Finally, we discuss the possibility to distinguish the two scenarios from each other.