{"title":"COMPASS光介子的自由等压线分析","authors":"F. Krinner","doi":"10.1142/9789811219313_0078","DOIUrl":null,"url":null,"abstract":"Modern hadron-spectroscopy experiments such as COMPASS collect data samples of unprecedented size, so that novel analysis techniques become possible and necessary. One such technique is the freed-isobar partial-wave analysis (PWA). In this approach, fixed parametrizations for the amplitudes of intermediate states commonly modeled using Breit-Wigner shapes are replaced by sets of step-like functions that are determined from the data. This approach not only reduces the model dependence of partial-wave analyses, but also allows us to study the amplitudes of the intermediate states and their dependence on the parent system. \nWe will also present results of a freed-isobar PWA performed on the large data set on diffractive production of three charged pions collected by the COMPASS experiment, which consists of $46\\times10^6$ exclusive events. We will focus on results for the wave with spin-exotic quantum numbers $J^{PC}=1^{-+}$, in particular on its decay into $\\rho(770)\\pi$. Here, the freed-isobar PWA method provides insight into the interplay of three- and two-particle dynamics and confirms the decay of the spin-exotic $\\pi_1(1600)$ resonance to $\\rho(770)\\pi$ in a model-independent way.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2019-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Freed-isobar analysis of light mesons at COMPASS\",\"authors\":\"F. Krinner\",\"doi\":\"10.1142/9789811219313_0078\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Modern hadron-spectroscopy experiments such as COMPASS collect data samples of unprecedented size, so that novel analysis techniques become possible and necessary. One such technique is the freed-isobar partial-wave analysis (PWA). In this approach, fixed parametrizations for the amplitudes of intermediate states commonly modeled using Breit-Wigner shapes are replaced by sets of step-like functions that are determined from the data. This approach not only reduces the model dependence of partial-wave analyses, but also allows us to study the amplitudes of the intermediate states and their dependence on the parent system. \\nWe will also present results of a freed-isobar PWA performed on the large data set on diffractive production of three charged pions collected by the COMPASS experiment, which consists of $46\\\\times10^6$ exclusive events. We will focus on results for the wave with spin-exotic quantum numbers $J^{PC}=1^{-+}$, in particular on its decay into $\\\\rho(770)\\\\pi$. Here, the freed-isobar PWA method provides insight into the interplay of three- and two-particle dynamics and confirms the decay of the spin-exotic $\\\\pi_1(1600)$ resonance to $\\\\rho(770)\\\\pi$ in a model-independent way.\",\"PeriodicalId\":8429,\"journal\":{\"name\":\"arXiv: High Energy Physics - Experiment\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2019-11-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv: High Energy Physics - Experiment\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1142/9789811219313_0078\",\"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/10.1142/9789811219313_0078","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Modern hadron-spectroscopy experiments such as COMPASS collect data samples of unprecedented size, so that novel analysis techniques become possible and necessary. One such technique is the freed-isobar partial-wave analysis (PWA). In this approach, fixed parametrizations for the amplitudes of intermediate states commonly modeled using Breit-Wigner shapes are replaced by sets of step-like functions that are determined from the data. This approach not only reduces the model dependence of partial-wave analyses, but also allows us to study the amplitudes of the intermediate states and their dependence on the parent system.
We will also present results of a freed-isobar PWA performed on the large data set on diffractive production of three charged pions collected by the COMPASS experiment, which consists of $46\times10^6$ exclusive events. We will focus on results for the wave with spin-exotic quantum numbers $J^{PC}=1^{-+}$, in particular on its decay into $\rho(770)\pi$. Here, the freed-isobar PWA method provides insight into the interplay of three- and two-particle dynamics and confirms the decay of the spin-exotic $\pi_1(1600)$ resonance to $\rho(770)\pi$ in a model-independent way.