{"title":"在COMPASS生产的外来谐音","authors":"A. Guskov","doi":"10.22323/1.310.0125","DOIUrl":null,"url":null,"abstract":"Exotic charmonium-like states have been targeted by various experiments in the last 15 years, but their nature still is unknown. Photo-(muo)production is a new promising instrument to study them. COMPASS, a fixed target experiment at CERN, analyzed the full set of the data collected with a muon beam between 2002 and 2011, covering the range from 7 GeV to 19 GeV in the centre-of-mass energy of the (virtual)photon-nucleon system. Production of the X(3872) state in the reaction $\\mu^+~N \\rightarrow \\mu^+(J/\\psi\\pi^+\\pi^- )\\pi^{\\pm} N'$ has been observed with a statistical significance of around 5 $\\sigma$. The shape of the $\\pi^+\\pi^-$ mass distribution from the decay $X(3872)\\rightarrow J/\\psi\\pi^+\\pi^-$ shows disagreement with previous observations. The product of the cross section and the branching fraction of the $X(3872)$ decay into $J/\\psi\\pi\\pi$ is estimated as 71$\\pm$28(stat)$\\pm$39(syst) pb. The results obtained for the production of the $Z_c^{\\pm}(3900)$ are also reported as well as future perspectives.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2017-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"Muoproduction of exotic charmonia at COMPASS\",\"authors\":\"A. Guskov\",\"doi\":\"10.22323/1.310.0125\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Exotic charmonium-like states have been targeted by various experiments in the last 15 years, but their nature still is unknown. Photo-(muo)production is a new promising instrument to study them. COMPASS, a fixed target experiment at CERN, analyzed the full set of the data collected with a muon beam between 2002 and 2011, covering the range from 7 GeV to 19 GeV in the centre-of-mass energy of the (virtual)photon-nucleon system. Production of the X(3872) state in the reaction $\\\\mu^+~N \\\\rightarrow \\\\mu^+(J/\\\\psi\\\\pi^+\\\\pi^- )\\\\pi^{\\\\pm} N'$ has been observed with a statistical significance of around 5 $\\\\sigma$. The shape of the $\\\\pi^+\\\\pi^-$ mass distribution from the decay $X(3872)\\\\rightarrow J/\\\\psi\\\\pi^+\\\\pi^-$ shows disagreement with previous observations. The product of the cross section and the branching fraction of the $X(3872)$ decay into $J/\\\\psi\\\\pi\\\\pi$ is estimated as 71$\\\\pm$28(stat)$\\\\pm$39(syst) pb. The results obtained for the production of the $Z_c^{\\\\pm}(3900)$ are also reported as well as future perspectives.\",\"PeriodicalId\":8429,\"journal\":{\"name\":\"arXiv: High Energy Physics - Experiment\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2017-12-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv: High Energy Physics - Experiment\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.22323/1.310.0125\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv: High Energy Physics - Experiment","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.22323/1.310.0125","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Exotic charmonium-like states have been targeted by various experiments in the last 15 years, but their nature still is unknown. Photo-(muo)production is a new promising instrument to study them. COMPASS, a fixed target experiment at CERN, analyzed the full set of the data collected with a muon beam between 2002 and 2011, covering the range from 7 GeV to 19 GeV in the centre-of-mass energy of the (virtual)photon-nucleon system. Production of the X(3872) state in the reaction $\mu^+~N \rightarrow \mu^+(J/\psi\pi^+\pi^- )\pi^{\pm} N'$ has been observed with a statistical significance of around 5 $\sigma$. The shape of the $\pi^+\pi^-$ mass distribution from the decay $X(3872)\rightarrow J/\psi\pi^+\pi^-$ shows disagreement with previous observations. The product of the cross section and the branching fraction of the $X(3872)$ decay into $J/\psi\pi\pi$ is estimated as 71$\pm$28(stat)$\pm$39(syst) pb. The results obtained for the production of the $Z_c^{\pm}(3900)$ are also reported as well as future perspectives.