北大高能系列: Exotic states from π + π − /π ± /η + quarkonium

by Dr Xiaolong Wang (IHEP)

Thursday 30 Nov 2017, 10:30 → 11:30 Asia/Shanghai

B105 (CHEP)

王小龙，复旦大学青年研究员，长期从事Belle和Belle II实验研究。2010年博士毕业于高能所，2010-2012为高能所博士后。2012-2016年在美国弗吉尼亚理工大学做博士后研究助理；2016-2017年为日本KEK研究员。2017年8月，作为院聘关键人才，被复旦大学引进开展粒子物理实验研究。 王博士在物理分析和硬件方面都做了重要工作。其中，物理分析方面，发现的Y(4660)新粒子是第一个由中国科学家发现，并且被PDG收录的粒子。硬件工作方面，在弗吉尼亚理工大学四年期间，负责了KLM的绝大部分硬件工作，是主要负责人之一；在KEK工作期间，推动完成时间刻度Time-Base-Correction的30皮秒时间分辨，现在是这一刻度工作的负责人。王博士获得了2010年中科院院长奖以及2014年北京市科学技术奖二等奖。 王博士目前正在复旦大学全面开展Belle II实验，包括物理分析与硬件工作等各个方面。 “What is the structure of a hadron?” is a key question of Particle Physics. The well known Quark Model had been working well for tens year, even the Quantum chromodynamics allows much more types of hadrons. In searching for the excited quarkonium states about the open-charm (D-Dbar) or open-bottom (B-Bbar) threshold via hadronic transitions by Belle, BaBar and BESIII, dozens of new structures have been observed. This number is well above the prediction of Quark Model, while the nature of most of the states are still undercover and they are called ‘exotic states’. Emitting π + π − or η are the first two channels in the hadronic transitions of quarkonium states, therefore, couples of exotic states were discovered in these hadronic transitions, such as Y (4260), Y (4360), Z(3900), Z(4430) and Z_b(10610/10650). This talk will review the exotic states observed in the systems of a quarkonium and a pair of π + π − , a charged π ± , or an η. The similar properties of π + π − /π ± /η from the transitions of the exotic states are helpful to figure out the nature of the exotic states. However, the statistics of currents experiments such as Belle and BESIII are still limited for most of the exotic states. The new intensity frontier experiment Belle II will start data taking in 2018 with the e + e − luminosity increases by 50 times, eight years after the shut down of the KEKB accelerator at KEK, Japan. There will be a unique Belle II data sample for exotic states soon, and the question of the structures of hadrons should be explored to be much clear with this data sample.

Slides

• IMG_20171130_103325.jpg
• IMG_20171130_115548.jpg
• seminar_PKU_wxl_v1.pdf