Studies in Experimental Nuclear Physics at Indiana University

印第安纳大学实验核物理研究

• 批准号: 0100348
• 负责人: Steven Vigdor
• 金额: $ 800.7万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-12-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0100348&HistoricalAwards=false
• 关键词: Studies; Experimental; Nuclear; Physics; Indiana

The Indiana nuclear physics group plans to assume a leading role in theinvestigation of the following critical questions in nuclear physics.The spin of the proton is an essential property that determines thestructure of matter, yet we know that only a small part of the spincomes from the three quarks that form the proton. The STAR-SPIN groupwould definitively measure the contribution from the gluons, theshort-lived particles that hold the quarks together and which accountfor much of its mass to see if that is where the missing spinresides.The measurement of the gluon contribution to the proton spinwill be carried out by adding a special detector for high energy gammarays to the STAR detector located at the Relativistic Heavy IonCollider. The detector is now being built using separate NSFconstruction funds. The force between pairs of neutrons and protons cannot, by itself,account for the strength that binds the nucleus together. New,three-body forces are needed, but their form is almost unknown. Bymanipulating the neutron and proton spins when three of them cometogether, the PINTEX collaboration would produce a map to guide a theoryof such three-body force. . FY2002 will be the last year of data takingusing the intense beams and unique capabilities of the IndianaUniversity Cooler Facility to study these three-body forces. The weak force between nucleons, which can change the form of matter, is still poorly understood. By making a measurement accurate to one part in a billion on the formation of a deuteron from a neutron and a proton, the IU neutron group would measure the longest-range part of the weak force . The Indiana group would support studies of the weak force and other effects accessible using cold neutrons at NIST and LANSCE and byproviding crucial parts of the experimental apparatus. There is mounting evidence that neutrinos, one of the most ubiquitousparticles in the universe, may have mass, thus changing our most eleganttheories of matter and how it controls the expansion of the universe. The neutrino group would check a recent observation from LANL of a fewcases where neutrinos, because they have mass, spontaneously change fromone neutrino type into another by collecting a large enough data sampleto settle this issue. A key component of the Indiana program will be the training of studentsto become the next generation of researchers. This effort includes theinvolvement of post-doctoral associates in critical experimental roles,guiding the research of graduate students, involving undergraduatesthrough the NSF-funded REU summer program and part-time employment, andreaching out to make the community aware of our scientific mission.

印第安纳州核物理小组计划在研究核物理中的下列关键问题方面发挥主导作用。质子的自旋是决定物质结构的基本性质，但我们知道，自旋中只有一小部分来自形成质子的三个夸克。恒星自旋小组将明确测量胶子的贡献，胶子是将夸克聚集在一起的短生命粒子，它占了夸克质量的很大一部分，以确定丢失的脊椎是否位于胶子。胶子对质子自旋的贡献的测量将通过在相对论重离子对撞机的恒星探测器上增加一个专门的高能伽马探测器来实现。探测器现在正在使用单独的NSF建设基金建造。中子和质子对之间的作用力本身不能解释将原子核结合在一起的强度。需要新的三体力，但它们的形式几乎是未知的。通过操纵中子和质子的自转，当它们中的三个结合在一起时，PINTEX的合作将产生一张地图来指导这样的三体力理论。。2002财年将是利用强流光束和印第安纳大学冷却器设备的独特能力来研究这些三体力的最后一年。核子之间的弱作用力可以改变物质的形式，但人们仍然知之甚少。通过使一个中子和一个质子形成氚的测量精确到十亿分之一，IU中子组将测量最远距离的弱作用力部分。印第安纳小组将通过提供实验仪器的关键部件，支持使用NIST和LANSCE的冷中子来研究弱力和其他效应。越来越多的证据表明，中微子--宇宙中最普遍的粒子之一--可能具有质量，从而改变了我们关于物质及其控制宇宙膨胀的最优雅的理论。中微子小组将检查LANL最近观察到的几个案例，在这些案例中，中微子由于具有质量，通过收集足够大的数据样本来解决这个问题，自发地从一种中微子类型转换为另一种中微子类型。印第安纳州项目的一个关键组成部分将是培养学生成为下一代研究人员。这一努力包括让博士后助理参与关键的实验角色，指导研究生的研究，通过NSF资助的REU暑期项目和兼职工作让本科生参与进来，并向社会伸出援手，让他们了解我们的科学使命。