Stephen Olsen, "The Curious History of the Kobayashi-Maskawa Six-Quark Mixing Matrix"

Wednesday 24 Jan 2024, 15:00 → 16:00 Asia/Shanghai

122 Multidisciplinary Building

ABSTRACT:  

The 1973 Kobayashi Maskawa paper proposed a compelling link between Cabibbo’s flavor mixing scheme and CP violation but, since it required the existence of six quarks at a time when the physics community was happy with only three, it received zero attention. However, two years after the paper appeared---at which time it had received a grand total of two citations---the charmed quark was discovered and it finally got some notice and acceptance. After this stumbling start, it subsequently emerged as the focal point of a huge amount of experimental and theoretical research activity. Some curious facts:

• Kobayashi and Maskawa (and other Japanese physicists) were aware of the existence of the charmed quark nearly three years before its “discovery” at Brookhaven and SLAC;
• The matrix provided in their seminal 1973 paper was mathematically incorrect, as were other versions that were commonly used for the next twelve years;
• The CKM matrix CP phase -and CP violations in general- are only measurable because of the very specific, fine-tuned hierarchies of the flavor mixing angles and meson masses;
• Similarly, the neutrino mixing discovery, and the PMNS matrix measurability were only possible because of the favorable values of the neutrino mass differences and mixing angles.

In this talk, I will review some of the less well-known events that occurred during the 50-year history of the KM matrix and, time permitting, add some speculations about what may be in store for the future.    

 

About the speaker:    

Stephen Olsen教授在强子谱学和B物理方面取得卓越的成就。Olsen教授在位于日本的Belle实验上担任多年的领导岗位，并主导发现了首个奇异重味强子态X(3872)，在国际上引起巨大反响，文章引用率超过1300次；Olsen教授在Belle实验上的其他重要研究成果包括首次发现中性B介子中的CP破坏、发现桑偶素粒子eta_c(2S)、发现Y(3940)奇异态、发现Z(4430)四夸克候选粒子等；自1992年起开始参与中国北京的BES实验，历经BESI/BESII/BESIII三代实验，均发挥重要作用，包括推动精确测量tau轻子质量和2-5GeV区域的R值测量、发现X(ppbar)阈值增强结构和Zc(3885)+四夸克候选粒子等。以上这些亮点工作的物理文章引用率超3300次。鉴于Olsen教授在高能物理实验方向上的突出成就，2016年获得高能物理实验领域最高奖项一粒子物理实验潘诺夫斯基奖。Olsen教授受邀撰写多篇强子谱学和B介子方面的综述文章，在高能物理领域具有很大影响力。

 

Zoom meeting:

Meeting ID 会议号: 96687553276

Meeting URL 会议链接:: https://zoom.us/j/96687553276?pwd=OFAzVFM3KzV1MEpabDBjTklEUTBPdz09

Password 会议密码: 123456

 

IHEP-UCAS-seminar-2024_CKM-history_solsen-final.pptx

poster_2024Jan24.JPG