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Symbology of Feynman integrals from twistor geometries

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Science china(physics,Mechanics & Astronomy) 2024年第3期67卷 44-59页

作者： Song He Jiahao Liu Yichao Tang Qinglin Yang School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China cAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China international centre for theoretical physics asia-pacific Beijing 100049 Peng Huanwu center for Fundamental Theory Hefei 230026China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

We study the symbology of planar Feynman integrals in dimensional regularization by considering geometric configurations in momentum twistor space corresponding to their leading singularities(LS). cutting propagators in momentum twistor space amounts to intersecting lines associated with loop and external dual momenta, including the special line associated with the point at infinity, which breaks dual conformal symmetry. We show that cross-ratios of intersection points on these lines, especially those on the infinity line, naturally produce symbol letters for Feynman integrals in D = 4-2∈, which include and generalize their LS. At one loop, we obtain all symbol letters using intersection points from quadruple cuts for integrals up to pentagon kinematics with two massive corners, which agree perfectly with canonical differential equation(cDE) results. We then obtain all two-loop letters, for up to four-mass box and one-mass pentagon kinematics, by considering more intersections arising from two-loop cuts. Finally we comment on how cluster algebras appear from this construction, and importantly how we may extend the method to non-planar integrals.

关键词： Feynman integrals symbol letters twistor geometry

Supermassive black holes triggered by QcD axion bubbles

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communications in theoretical physics 2024年第5期76卷 134-139页

作者： Hai-Jun Li Ying-Quan Peng Wei chao Yu-Feng Zhou Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China center for Advanced Quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China international centre for theoretical physics asia-pacific Beijing/HangzhouChina

Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still unknown.In this paper,we investigate the formation of SMBHs from the quantum chromodynamics(QcD)axion bubbles.In this case,primordial black holes(PBHs)are considered as the seeds of SMBHs,which are generated from the QcD axion bubbles due to an explicit Peccei–Quinn(PQ)symmetry breaking after inflation.The QcD axion bubbles are formed when the QcD axion starts to oscillate during the QcD phase transition.We consider a general case in which the axion bubbles are formed with the bubble effective angle θ_(eff)∈(0,π],leading to the minimum PBH mass∼■(10^(4)−10^(7))M⊙for the axion decay constant f_(a)∼■(10^(16))GeV.The PBHs at this mass region may account for the seeds of SMBHs.

关键词： supermassive black holes primordial black holes quantum chromodynamics axion

Is Yang-Mills theory unitary in fractional spacetime dimensions?

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Science china(physics,Mechanics & Astronomy) 2024年第7期67卷 59-64页

作者： Qingjun Jin Ke Ren Gang Yang Rui Yu Graduate School of china Academy of Engineering physics Beijing 100193China School of physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China cAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China international centre for theoretical physics asia-pacific Hangzhou 310024China School of Physical Science and Technology Inner Mongolia UniversityHohhot 010021China Beijing computational Science Research center Beijing 100193China

We present concrete evidence that Yang-Mills theory exhibits non-unitarity in non-integer spacetime dimensions.This violation of unitarity stems from evanescent operators that,while vanishing in four dimensions,are non-zero in general d dimensions.We demonstrate that these evanescent operators lead to the emergence of both negative-norm states and complex anomalous dimensions.

关键词： gauge field theories field theories in dimensions other than four renormalization

Search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at√s=8 TeV using cMS open data

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chinese physics c 2024年第4期48卷 6-13页

作者： Y.Mahmoud H.Abdallah M.T.Hussein S.Elgammal centre for theoretical physics The British University in EgyptEgypt physics Department Faculty of ScienceCairo UniversityEgypt

In this study,we conducted a search for dark matter using a part of the data recorded by the cMS experiment during run-I of the LHc in 2012 with a center of mass energy of 8 TeV and an integrated luminosity of 11.6 fb−1.These data were gathered from the cMS open data.Dark matter,in the framework of the simplified model(mono-Z′),can be produced from proton-proton collisions in association with a new hypothetical gauge boson,Z′.Thus,the search was conducted in the dimuon plus large missing transverse momentum channel.One benchmark scenario of mono-Z′,which is known as light vector,was used for interpreting the cMS open data.No evidence of dark matter was observed,and exclusion limits were set on the masses of dark matter and Z′at 95%confidence level.

关键词： dark matter large hadron collider cMS open data search for new physics dark fermion

Post-Newtonian binary dynamics in the effective field theory of Horndeskigravity

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chinese physics c 2024年第3期48卷 180-190页

作者：武文浩汤勇 School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyChinese Academy of SciencesHangzhou 310024China international center for theoretical physics asia-pacific Beijing 100049China

General relativity has been very successful since its proposal more than a century ago.However,various cosmological observations and theoretical consistency still motivate us to explore extended gravity theories.Horndeski gravity stands out as one attractive theory by introducing only one scalar field.Here we formulate the post-Newtonian effective field theory of Horndeski gravity and investigate the conservative dynamics of inspiral compact binary systems.We calculate the leading effective Lagrangian for a compact binary and obtain the periastron advance per period.In particular,we apply our analytical calculation to two binary systems,PSR B 1534+12 and PSR J0737-3039,and constrain the relevant model parameters.This theoretical framework can also be systematically extended to higherorders.

关键词： effective field theory modified gravity pulsar

Exploring hidden-charm and hidden-strange hexaquark states from lattice QcD

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Science china(physics,Mechanics & Astronomy) 2024年第1期67卷 30-37页

作者： Hang Liu Jinchen He Liuming Liu Peng Sun Wei Wang Yi-Bo Yang Qi-An Zhang INPAc Key Laboratory for Particle Astrophysics and Cosmology(MOE)Shanghai Key Laboratory for Particle Physics and CosmologySchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Maryland center for Fundamental physics Department of PhysicsUniversity of MarylandCollege ParkMaryland 20742USA Institute of Modern physics Chinese Academy of SciencesLanzhou 730000China University of chinese Academy of Sciences Beijing 100049China Department of physics and Institute of theoretical physics Nanjing Normal UniversityNanjing 210023China Southern center for Nuclear-Science Theory(ScNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou 516000China cAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China international centre for theoretical physics asia-pacific Beijing 100049/Hangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of physics Beihang UniversityBeijing 102206China

Based on five different ensembles of newly generated(2+1)-flavor configurations with pion mass of approximately mπ■(140-310)MeV,we present a lattice analysis of hidden-charm and hidden-strange hexaquarks with the quark content■.The correlation matrices of two types of operators with JPc=0++,0-+,1++and 1--are simulated to extract the masses of the hexaquark candidates,which are subsequently extrapolated to the physical pion mass and continuum limit.The results indicate that ground state masses are below the■threshold and provide a characteristic signal for the experimental discovery of hexaquark candidates,which may enrich the versatile structure of multiquarks;moreover,it is an indispensable step to decipher the nonperturbative nature of the fundamental interactions of quarks and gluons.

关键词： quantum chromodynamics lattice QcD multiquark states

The preface: Interplay of topological and magnetic orders in the Mn-Bi-Te family

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National Science Review 2024年第2期11卷 6-7页

作者： Fu-chun Zhang Hai-Zhou Lu X.c.Xie Kavli Institute for theoretical Sciences University of Chinese Academy of Sciences Department of physics Southern University of Science and Technology (SUSTech) international center for Quantum Materials School of Physics Peking University

The discovery and synthesis of MnBi2Te4in 2013 initially garnered little attention [1]. Yet, the revelation of its topological properties in 2019 [2–6] sparked a surge of research into the MnBiTe family. These extensive studies are primarily driven by two objectives:the realization of a high-temperature quantum anomalous Hall effect （QAHE） and the exploration of exotic phases born from the interplay of topological and magnetic orders,

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Advancing space-based gravitational wave astronomy: Rapid parameter estimation via normalizing flows

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Science china(physics,Mechanics & Astronomy) 2024年第3期67卷 20-33页

作者： Minghui Du Bo Liang He Wang Peng Xu Ziren Luo Yueliang Wu center for Gravitational Wave Experiment National Microgravity LaboratoryInstitute of MechanicsChinese Academy of SciencesBeijing 100190China Key Laboratory of Gravitational Wave Precision Measurement of Zhejiang Province Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China international centre for theoretical physics asia-pacific University of Chinese Academy of SciencesBeijing 100049China Taiji Laboratory for Gravitational Wave Universe(Beijing/Hangzhou) University of Chinese Academy of SciencesBeijing 100049China Lanzhou center of theoretical physics Lanzhou UniversityLanzhou 730000China Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China Institute of theoretical physics Chinese Academy of SciencesBeijing 100190China

Gravitational wave(GW) astronomy is witnessing a transformative shift from terrestrial to space-based detection, with missions like Taiji at the forefront. While the transition brings unprecedented opportunities for exploring massive black hole binaries(MBHBs), it also imposes complex challenges in data analysis, particularly in parameter estimation amidst confusion noise.Addressing this gap, we utilize scalable normalizing flow models to achieve rapid and accurate inference within the Taiji environment. Innovatively, our approach simplifies the data's complexity, employs a transformation mapping to overcome the year-period time-dependent response function, and unveils additional multimodality in the arrival time parameter. Our method estimates MBHBs several orders of magnitude faster than conventional techniques, maintaining high accuracy even in complex backgrounds. These findings significantly enhance the efficiency of GW data analysis, paving the way for rapid detection and alerting systems and enriching our ability to explore the universe through space-based GW observation.

关键词： Taiji program gravitational wave detection parameter estimation machine learning

Phase structures and critical behavior of rational non-linear electrodynamics Anti de Sitter black holes in Rastall gravity

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communications in theoretical physics 2024年第4期76卷 134-152页

作者： Yassine Sekhmani Dhruba Jyoti Gogoi Ratbay Myrzakulov Javlon Rayimbaev Ratbay Myrzakulov Eurasian international centre for theoretical physics Astana 010009Kazakhstan L.N.Gumilyov Eurasian National University Astana 010008Kazakhstan Department of physics Moran CollegeMoranhatCharaideo 785670AssamIndia theoretical physics Division Centre for Atmospheric StudiesDibrugarh UniversityDibrugarh 786004AssamIndia New Uzbekistan University Movarounnahr Str.1Tashkent 100000Uzbekistan University of Tashkent for Applied Sciences Gavhar Str.1Tashkent 100149Uzbekistan National University of Uzbekistan Tashkent 100174Uzbekistan

This research paper presents a black hole solution with a rational nonlinear electrodynamics source within the Rastall gravity framework.The paper analyzes the thermodynamic properties of the solution in normal phase space and explores its critical behavior.The phase structure is examined using the extended first law of thermodynamics,with the cosmological constantΛserving as pressure P.The isotherms exhibit van der Waals behavior at small values of horizon r_(+).The paper also investigates the Gibbs free energy behavior and finds two critical points with two pressures where the re-entrant phase transition occurs and disappears.We also explore the prevalent microstructure of black holes in Ruppeiner geometry,uncovering significant deviations in the nature of particle interactions from conventional practice.Moreover,the thermodynamic geometry is analyzed using the Ruppeiner formalism,with the normalized Ricci scalar indicating possible point-phase transitions of the heat capacity,and the normalized extrinsic curvature having the same sign as the normalized Ricci scalar.The three-phase transitions of the heat capacity are those that we find for the normalized Ruppeiner curvatures.Thus,there is an absolute correspondence.

关键词： Rastall gravity biack hole Phase structures