A Theoretical Study on Charge-parity Symmetry Violation and Quark-lepton Flavor Physics

Charge conjugation & parity (CP) symmetry concern the fundamental symmetry of space and matter,and have been invariably regarded as a key research frontier for particle physics by theoretical physicists in today's world. Because of their discovery of the CP violation, James W. Cronin and Val L. Fitch were honored by the Nobel Prize in physics. Their success lies in revealing the indirect CP violation, caused by either weak interaction or explained by the super-weak interaction. In order to distinguish between the two, it is necessary to investigate the direct CP violation.     

Neutrinos,Large Scientific Facilities and Science Innovation——An Interview with Prof. Arthur B. McDonald

<正>In the middle of May,2017,Professor Ar thur B.McDonald,director of the Sudbury Neutrino Observatory(SNO)in Canada and Nobel Prize Laureate in Physics in 2015,visited the Institute of High Energy Physics(IHEP),Chinese Academy of Sciences(CAS).After a brief visit to the laboratories for particle physics at IHEP,he shared his opinions on the future of neutrino physics,neutr ino exper iments,and other large scienti f ic faci l ities in China and worldwide.     

In Search of Exotic Particles

<正>Looking for"exotic matter"is an important task for high energy physics in the post-Higgs era.Using data from the BEijing Spectrometer(BESIII),researchers have observed a family of particles which contain at least four quarks,providing strong evidence for the existence of unconventional forms of matter.The discovery of Zc particle family For Dr.SHEN Xiaoyan,Dr.YUAN Changzheng and their colleagues at the Institute of High Energy Physics(IHEP),Chinese Academy of Sciences,the year 2013 was     

Confirming of the Higgs Boson

<正>1.Significance of the search for the Higgs boson General relativity and the Standard Model are two major theories in modern physics.General relativity describes space,time and gravity,while the Standard Model is a theory concerning the electromagnetic,weak,and strong nuclear interactions.The Standard Model divides particles into the two categories of fermions(including quarks and leptons)and bosons(including gluons,photons,W and Z bosons and the Higgs boson)according to their spin.According to the Standard Model’s predictions,there are a total of 61 particles in these two categories[1].All the particles but the Higgs boson have been experimentally supported and validated.The Higgs particle is a boson with no spin or electric charge,it has mass     

Prospects of Scientii c Breakthroughs in Dark Matter Particle Detection and Related Research

<正>1.As a key factor of the structure formation of the universe,the existence of dark matter has been widely accepted"Dark matter"refers to a kind of matter in the universe which has gravitational effects,but has no direct interaction with light.It is deemed to be composed of completely new particles beyond the standard model of particle physics,however we know very little about the nature of dark matter.At the beginning of the 20th century,the"two clouds"in physics sky–aether and blackbody radiation–overturned the classical physics theory and gave birth to quantum mechanics and the theory of relativity.Similarly,dark matter,together with dark energy,are called the"two clouds"in the physics sky of the 21st     

Particle and Nuclear Physics

<正>Our understanding of the microscopic universe has gone far beyond the atomic level—now we know even the neutron or proton, once thought to be "elementary particles", can be divided into smaller building blocks, for example quacks. Also known as highenergy physics, particle physics is dedicated to studying the subatomic structure and properties of matter, and understanding how such subnuclear particles interact with each other in high-energy conditions.     

Working together on the Next Big Collider

正High energy physicists in China are completing the conceptual design of a collider,almost four times as big as the Large Hadron Collider in Europe,which will be used to study the details of the Higgs particle and physics beyond the Standard Model."Things are moving forward rapidly,"WANG Yifang,director general of the CAS Institute of High Energy Physics,said at the International Workshop on Circular Electron-Positron Collider(CEPC)in     

Piezotronics and piezo-phototronics: fundamentals and applications

Technology advancement that can provide new solutions and enable augmented capabilities to complementary metal–oxide–semiconductor(CMOS)-based technology,such as active and adaptive interaction between machine and human/ambient,is highly desired.Piezotronic nanodevices and integrated systems exhibit potential in achieving these application goals.Utilizing the gating efect of piezopotential over carrier behaviors in piezoelectric semiconductor materials under externally applied deformation,the piezoelectric and semiconducting properties together with optoelectronic excitation processes can be coupled in these materials for the investigation of novel fundamental physics and the implementation of unprecedented applications.Piezopotential is created by the strain-induced ionic polarization in the piezoelectric semiconducting crystal.Piezotronics deal with the devices fabricated using the piezopotential as a‘gate’voltage to tune/control charge-carrier transport across the metal–semiconductor contact or the p–n junction.Piezo-phototronics is to use the piezopotential for controlling the carrier generation,transport,separation and/or recombination for improving the performance of optoelectronic devices.his review intends to provide an overview of the rapid progress in the emerging ields of piezotronics and piezo-phototronics.he concepts and results presented in this review show promises for implementing novel nano-electromechanical devices and integrating with micro/nano-electromechanical system technology to achieve augmented functionalities to the state-of-the-art CMOS technology that may ind applications in the human–machine interfacing,active lexible/stretchable electronics,sensing,energy harvesting,biomedical diagnosis/therapy,and prosthetics.     

Understanding Heavy Quarkonium and QCD

正Scientists have for the first time calculated the next-to-next-to-leading order(NNLO)radiative correction to the hadronic width of pseudoscalar quarkonium,and conducted a detailed phenomenological study using the latest experimental data.The work,which marks an important progress in heavy quarkonium physics and Quantum Chromodynamics(QCD).was published in the journal Physical Review Letters on December 20,2017.     

A Kavli Institute for Theoretical Physics Established at CAS

On June 18, the launching ceremony for the Kavli Institute for Theoretical Physics China (KITPC) at CAS was held at the campus of the CAS In- stitute of Theoretical Physics in Beijing. Together with the Kavli In- stitute for Astronomy and Astro- physics a…     

S&T Achievements of CAS Members Elected in 2005 (1)

(Division of Mathematics & Physics)CHEN Hesheng, particle physicist, now serves as research professor at the Institute of High Energy Physics (IHEP), CAS. He was born in Hubei Province in 1946 and graduated from the Depart- ment of Technical Physics at Peking University in 1970. In 1984, he obtained his Ph.D. degree of physics from the Massachusetts Institute of Technology, US. He is the director of the IHEP, president of the Chinese Soci- ety of High Energy Physics, and member…     

Neutrino Oscillation Experiments Hopeful to Accelerate the Delivery of Solutions to the “Mystery of Missing Antimatter”

<正>1.Neutrino research occupies an important position in particle physics In 1930,Austrian physicist Pauli[1]proposed the neutrino hypothesis to explain the loss of energy in the process of beta decay.But since neutrinos are uncharged and nearly massless(less than one millionth of the electron mass)and rarely interact with other matter(interact via only the weak force and gravity),they are very diffi cult to detect.For that reason,for a long time,neutrinos only appeared in the equations of theoretical physicists and experiments had failed to confirm their existence.In 1934,Italian physicist Fermi proposed the theory of beta decay that incorporates the neutrino,which was quantitatively consistent with experimental data.In 1941,Chinese physicist WANG     

Debate over Chinese Supercollider Goes Open

正Debates over if China should start building the world’s biggest particle collider went public and have drawn much attention in the past few months.Proposed in 2012 as a "Higgs factory" twice the size of LHC(Large Hadron Collider)and costing at least several billion dollars,the Circular Electron Positron Collider(CEPC)was expected to start construction in 2022 but now came under the question of senior scientists including Nobel laureate Chen-Ning Yang.     

Innovation and culture of team work

<正>Innovation in science is oten associated with the image of a lone scientist at the bench making a ground-breaking discovery,yet many breakthroughs in both basic and applied science critically depend on efective team work.his is best exempliied by major discoveries in high-energy particle physics,for which hundreds of scientists made innovative contributions to interlinked components of the work.On the other hand,most scientists are driven by their individual aspiration and career objec-     

Largest ever photonic ＂Schrodinger cat＂ created

CAS researchers have been successful in their experimental entanglement of six photons in graph states: a "Schr(o)dinger cat" state, and a "cluster" state. By creating two important examples of such states, according to experts, the studies have paved the way for the research into the fundamental issues in quantum computing, quantum error correction and quantum mechanics.     

LU Yongxiang receives honorary doctoral degree from HKU

Together with 1998 Nobel Prize winner in physics Daniel Chee Tsui from Princeton University, CAS President LU Yongxiang was conferred Doctor of Science honoris causa by the University of Hong Kong (HKU) at the congregation held on 24 April.     

Manipulation and Preparation of Five-Particle Entanglement

By making good use of certain quantum physics properties such as entanglement,teleportation and superposition, a quantum computer has the potential to be much more powerful than a classical computer of the same size.Although quantum-mechanical entanglement of three or four particles has been achieved experimentally, and has been used to demonstrate the extreme contradiction between quantum mechanics and local realism, the realization of five-particle entanglement, until recently, remains an experimental challenge. As reported in the July 1 issue of Nature, Prof. Pan Jianwei (Jian-Wei Pan) and his colleagues at the University of Science and Technology of China (USTC) in Hefei have succeeded for the first time in the world in entangling five photons and demonstrating a process called "open-destination teleportation". This is another highlight of Prof. Pan' s work since the periodical published an article on experimental entanglement purification of arbitrary unknown states on May 22 in 2003.     

LU Yongxiang receives honorary doctoral degree from HKU

Together with 1998 Nobel Prize winner in physics Daniel Chee Tsui from Princeton University, CAS Presi- dent LU Yongxiang was conferred Doctor of Science honoris causa by the University of Hong Kong (HKU) at the congregation     

Young Physicist from USTC Receives Fresnel Prize

Dr. CHEN Yu-ao, a young professor from the National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China (USTC), had received the Fresnel Prize for fundamental aspects by European Physical Society (EPS) on May 14 for his "outstanding achievements in the fields of multi-photon entanglement, quantum communication, quantum computation and quantum simulation based on manipulation of photons and atoms".     

Accurate fundamental invariant-neural network representation of ab initio potential energy surfaces

Highly accurate potential energy surfaces are critically important for chemical reaction dynamics. The large number of degrees of freedom and the intricate symmetry adaption pose a big challenge to accurately representing potential energy surfaces(PESs) for polyatomic reactions. Recently, our group has made substantial progress in this direction by developing the fundamental invariant-neural network(FI-NN)approach. Here, we review these advances, demonstrating that the FI-NN approach can represe...