摘要
The Beijing Spectrometer(BESⅢ)experiment,which has been studying particle collisions produced by the Beijing Electron Positron Collider(BEPCⅡ)since 2009,has so far discovered a total of 26 new particle candidates(Fig.1).The particles,all strongly-interacting hadrons,are thought to be composed of quarks(q),antiquarks(q),and gluons(g)bound together by the strong force in a surprising variety of configurations.Elucidating their properties provides new insight into the complex nature of nuclear interactions and has been one of the central goals of the BESIII Collaboration,which consists of an international team of more than 600 scientists.While several of the newly discovered hadrons are consistent with the conventional two-quark picture of mesons(qq)or the three-quark picture of baryons(qqq),and were expected,others are more surprising and have exotic configurations,such as tetraquarks(qqqq),meson molecules(qq()qq()),glueballs(gg),or hybrid mesons(qgq).They have led to new advances in our theoretical understanding of the strong force,for example through the development of new approaches in quantum field theory[1]or understanding the importance of hadron molecules[2],and have initiated intense experimental effort[3].In the following,we briefly tour the 26 new hadrons,roughly from the heaviest to the lightest.Their names appear in boldface the first time they are mentioned.
作者
刘智青
Ryan E.Mitchell
Zhiqing Liu;Ryan E.Mitchell(Institute of Frontier and Interdisciplinary Science,Shandong University,Jinan 250100,China;Department of Physics,Indiana University,Bloomington IN 47401,USA)
