Research Program in Intermediate Energy Physics

中间能源物理研究项目

• 批准号: 0402151
• 负责人: Richard Jones
• 金额: $ 8.53万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0402151&HistoricalAwards=false
• 关键词: Research; Program; Intermediate; Energy; Physics

Experiments in meson spectroscopy test critical aspects of the standardtheory of the strong nuclear force. Although they only live for a shorttime before they decay, mesons provide a unique laboratory for the studyof the strong force because they are the simplest quark configuration,just a one quark and one antiquark. The GlueX experiment is a major newinitiative being undertaken at Jefferson Lab in Newport News, Virginiausing polarized photons from the CEBAF electron accelerator to searchfor a new class of excitations known as exotic mesons. Although exoticswere predicted based upon the standard theory over 20 years ago,conclusive experimental evidence for their existence has not yet beenestablished. The P.I. is a member of the governing board of the GlueXexperiment and has specific responsibility in the design andconstruction of the polarized photon source. A preliminary step towardsthe larger goals of GlueX was the Radphi experiment was constructedstudy the decays of a known meson, the phi(1020). The phi itself is notexotic, but some evidence pointed to the possible exotic nature of twoother mesons at around the same mass, the a0(980) and the f0(980). Radiative decays of the phi to these scalars provide an important testof this hypothesis. The experiment collected its data during a 60-dayrun in summer 2000, and is in the final stages of data analysis. TheP.I. is also involved in the Qweak experiment at Jefferson Lab, whichundertakes a precise measurement of the weak charge of the proton as asearch for physics beyond the Standard Model. In this project he hasshared responsibility for the Compton-backscatter electron polarimeter.

介子光谱实验检验了强核力标准理论的关键方面。虽然介子在衰变前只存在很短的时间，但它们为研究强作用力提供了一个独特的实验室，因为它们是最简单的夸克构型，只有一个夸克和一个反夸克。GlueX实验是弗吉尼亚州纽波特纽斯的杰斐逊实验室进行的一项重大创新，它利用CEBAF电子加速器的偏振光子来寻找一种被称为外来介子的新激发。虽然20多年前就根据标准理论预测了外来物种，但它们存在的确凿实验证据尚未建立。P.I.是GlueXexperiment管理委员会的成员，在偏振光子源的设计和构建中负有特定的责任。为了实现GlueX更大的目标，Radphi实验是为了研究已知介子的衰变而建立的。π本身并不是奇异的，但是一些证据指出了具有相同质量的另外两个介子——a0（980）和f0（980）——可能具有奇异的性质。对这些标量的辐射衰减为这个假设提供了一个重要的检验。该实验于2000年夏季进行了60天的实验，收集了数据，目前已进入数据分析的最后阶段。TheP.I。他还参与了杰斐逊实验室的Qweak实验，该实验负责对质子的弱电荷进行精确测量，以寻找超越标准模型的物理。在这个项目中，他共同负责康普顿后向散射电子偏振计。