Isospin violation is driven through the light quark mass difference and electromagnetic effects.I review recent progress in extracting the light quark mass difference and tests of the chiral dynamics of Quantum Chromo...Isospin violation is driven through the light quark mass difference and electromagnetic effects.I review recent progress in extracting the light quark mass difference and tests of the chiral dynamics of Quantum Chromodynamics in various reactions involving light as well as heavy quarks.展开更多
We perform calculations for the Bs0→ J/ψπ0f0（980） and Bs0 → J/ψπ0a0（980） reactions, showing that the first is isospin-suppressed while the second is isospin-allowed. The reaction proceeds via a triangle mech...We perform calculations for the Bs0→ J/ψπ0f0（980） and Bs0 → J/ψπ0a0（980） reactions, showing that the first is isospin-suppressed while the second is isospin-allowed. The reaction proceeds via a triangle mechanism, with Bs0 →J/ψK＊ K ＋c.c., followed by the decay K＊ →Kπ and a further fusion of KK into the f0（980） or a0（980）. We show that the mechanism develops a singularity around the π0 f0（980） or π0a0（980） invariant mass of 1420 MeV, where the π0f0 and π0a0 decay modes are magnified and also the ratio of π0f0 to π0a0 production. Using experimental information for the Bs0 → J/ψK＊K ＋c.c. decay, we are able to obtain absolute values for the reactions studied which fall into the experimentally accessible range. The reactions proposed and the observables evaluated, when contrasted with actual experiments, should be very valuable to obtain information on the nature of the low lying scalar mesons.展开更多
We analyze the φ meson production in e^＋e^- →ωπ^0 as a probe for studying the isospin violation mechanisms. By clarifying the dynamic sources causing the isospin violation, we succeed in quantifying those mechani...We analyze the φ meson production in e^＋e^- →ωπ^0 as a probe for studying the isospin violation mechanisms. By clarifying the dynamic sources causing the isospin violation, we succeed in quantifying those mechanisms with the help of the recent KLOE data. Hence, the φ→ωπ^0 branching ratio is extracted. We find that apart from the electromagnetic （EM） transitions, the strong transition via intermediate kaon loops plays an important role in understanding the cross section and its lineshape.展开更多
We study the ■_(s)^(0)→J/ψf_(0)(980) and ■_(s)^(0)→J/ψa_(0)(980) reactions,and pay attention to the different sources of iso spin violation and mixing of f_(0)(980) and a_(0)(980) resonances where these resonanc...We study the ■_(s)^(0)→J/ψf_(0)(980) and ■_(s)^(0)→J/ψa_(0)(980) reactions,and pay attention to the different sources of iso spin violation and mixing of f_(0)(980) and a_(0)(980) resonances where these resonances are dynamically generated from meson-meson interactions.We find that the main cause of isospin violation is isospin breaking in the meson-meson transition T matrices,and the other source is that the loops involving kaons in the production mechanism do not cancel due to the different masses of charged and neutral kaons.We obtain a branching ratio for a_(0)(980)production of the order of 5×10^(-6).Future experiments can address this problem,and the production rate and shape of the π^(0)η mass distribution will definitely help to better understand the nature of scalar resonances.展开更多
基金Supported by DFG (SFB/TR-16)EU FP7 HadronPhysics2,HGF VH-VI-231BMBF (grant 06BN9006)
文摘Isospin violation is driven through the light quark mass difference and electromagnetic effects.I review recent progress in extracting the light quark mass difference and tests of the chiral dynamics of Quantum Chromodynamics in various reactions involving light as well as heavy quarks.
基金Supported by National Natural Science Foundation of China(11565007,11747307,11647309,11735003,11475227)the Youth Innovation Promotion Association CAS(2016367)+1 种基金partly supported by the Spanish Ministerio de Economiay Competitividad and European FEDER funds(FIS2011-28853-C02-01,FIS2011-28853-C02-02,FIS2014-57026-REDT,FIS2014-51948-C2-1-P,FIS2014-51948-C2-2-P)the Generalitat Valenciana in the program Prometeo(II-2014/068)
文摘We perform calculations for the Bs0→ J/ψπ0f0（980） and Bs0 → J/ψπ0a0（980） reactions, showing that the first is isospin-suppressed while the second is isospin-allowed. The reaction proceeds via a triangle mechanism, with Bs0 →J/ψK＊ K ＋c.c., followed by the decay K＊ →Kπ and a further fusion of KK into the f0（980） or a0（980）. We show that the mechanism develops a singularity around the π0 f0（980） or π0a0（980） invariant mass of 1420 MeV, where the π0f0 and π0a0 decay modes are magnified and also the ratio of π0f0 to π0a0 production. Using experimental information for the Bs0 → J/ψK＊K ＋c.c. decay, we are able to obtain absolute values for the reactions studied which fall into the experimentally accessible range. The reactions proposed and the observables evaluated, when contrasted with actual experiments, should be very valuable to obtain information on the nature of the low lying scalar mesons.
基金Supported by National Natural Science Foundation of China (10675131,10491306,10435080,10521003)Chinese Academy of Sciences (KJCX3-SYW-N2)the Ministry of Science and Technology of China (2009CB825200)
文摘We analyze the φ meson production in e^＋e^- →ωπ^0 as a probe for studying the isospin violation mechanisms. By clarifying the dynamic sources causing the isospin violation, we succeed in quantifying those mechanisms with the help of the recent KLOE data. Hence, the φ→ωπ^0 branching ratio is extracted. We find that apart from the electromagnetic （EM） transitions, the strong transition via intermediate kaon loops plays an important role in understanding the cross section and its lineshape.
基金partly supported by the National Natural Science Foundation of China (11975083,12147211)partly supported by the Spanish Ministerio de Economia y Competitividad and European FEDER funds (FIS2017-84038-C2-1-P B)+1 种基金Generalitat Valenciana (PROMETEO/2020/023)funding from the European Unions Horizon 2020 research and innovation programme (824093) for the"STRONG-2020"project。
文摘We study the ■_(s)^(0)→J/ψf_(0)(980) and ■_(s)^(0)→J/ψa_(0)(980) reactions,and pay attention to the different sources of iso spin violation and mixing of f_(0)(980) and a_(0)(980) resonances where these resonances are dynamically generated from meson-meson interactions.We find that the main cause of isospin violation is isospin breaking in the meson-meson transition T matrices,and the other source is that the loops involving kaons in the production mechanism do not cancel due to the different masses of charged and neutral kaons.We obtain a branching ratio for a_(0)(980)production of the order of 5×10^(-6).Future experiments can address this problem,and the production rate and shape of the π^(0)η mass distribution will definitely help to better understand the nature of scalar resonances.
