Elucidating the fundamental nature of hadrons with Particle Identification Detector

用粒子识别探测器阐明强子的基本性质

• 批准号: ST/W005433/1
• 负责人: Mikhail Bashkanov
• 金额: $ 3.02万
• 依托单位: University of York
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FW005433%2F1
• 关键词: Elucidating; fundamental; nature; hadrons; Particle; Elucidating; fundamental; nature; hadrons; Particle

In this application we request a timely and cost-effective UK equipment contribution to next generation science programmes with the CrystalBall@MAMI. This new research landscape is enabled by the commissioning of a new high-rate time projection chamber (TPC) which can operate with intense, energetic photon beams. The TPC will be constructed by the end of 2022 with experiments running in 2023. The TPC will provide charged particle tracking with exquisite accuracy and, for the first time, will allow us to detect low energy recoiling nuclei (protons, deuterons, heavier species) following photoreactions. The latter aspect opens up exciting scientific possibilities for the UK at MAMI and this new capability aligns well with our highest impact research goals. The measurement programme will provide key information on the fundamental properties of the new d* hexaquark particle. Additionally, with the TPC there are new and exciting prospects to study in detail the in-medium interaction of the d*, using the dominant and clean d* resonance peaks accessible with nuclear recoil tagging.As we recently showed, hexaquarks might also coexist inside neutron stars effectively restricting the maximum allowed neutron star size at exactly the value determined by LIGO and NICER. We have also shown that primordinary produced hexaquark condensate might play a role of dark-matter particles. To elaborate this concept, one needs to investigate hexaquark behaviour inside the nuclear medium. It can be done in a laboratory environment, and then apply the results to the nuclear equation of state (EoS) of neutron stars.York leads a major CB@MAMI programme aiming to accurately determine the size and shape of neutron skins, using the method of coherent pion photoproduction. Accurate skin determinations are a powerful discriminator for nuclear theories; DFT and ab-initio predictions predict widely varying skin thicknesses, highlighting how accurate measurements will provide crucial missing information for nuclear science. The neutron skin also correlates with the most poorly constrained and elusive parameter in the EoS for nucleonic matter, the density dependence of the symmetry energy (L). The TPC allows measurement of momentum transfer to the nuclear recoil with greatly reduced systematics, enables much improved separation of coherent and incoherent processes, opens up new target possibilities (e.g. noble gases like Xenon) and for subsequent gamma spectroscopy on the recoil nuclei can veto unwanted backgrounds from nuclear breakup.

在此应用程序中，我们要求使用Crystalball@Mami及时且具有成本效益的英国设备为下一代科学计划做出贡献。这一新的研究环境是通过新的高速时间投影室（TPC）的调试来实现的，该室可以用激烈，充满活力的光子束运行。 TPC将在2022年底之前构建，在2023年运行的实验。TPC将以精确的精度提供带电的粒子跟踪，并且首次将使我们能够在光反应后检测到低能量后退核（质子，迪特龙，较重的物种）。后一个方面为英国在MAMI中打开了令人兴奋的科学可能性，而这一新能力与我们最大的影响研究目标吻合。测量计划将提供有关新D* Hexaquark粒子基本属性的关键信息。此外，使用TPC，还有一些新的令人兴奋的前景可以详细研究D*的中等内部相互作用，使用主要和干净的D*共振峰可以带有核后坐力标记。正如我们最近显示的那样，Hexaquarks可能还可以在Neutron中共存，在中子恒星内有效地限制了最大的限制Neutron Star sige the Neutron Star sige ticlemon Star sige ticles sige the Ligo和Nicer nicer and Nicer and Nicer。我们还表明，原始产生的Hexaquark冷凝物可能起着深色 - 物质颗粒的作用。为了阐述这一概念，需要研究核培养基内的六夸克行为。它可以在实验室环境中完成，然后将结果应用于中子星的核方程（EOS）。York带领一个主要的CB@MAMI计划，旨在使用相干胎胎光照射的方法准确地确定中子皮的大小和形状。准确的皮肤测定是核理论的强大歧视者。 DFT和AB-Initio预测预测了较大的皮肤厚度，突出了准确的测量将如何为核科学提供关键的缺失信息。中子皮肤还与EOS在核次物质（对称能量的密度依赖性（L）的密度依赖性（L）中，EOS中最糟糕和难以捉摸的参数相关。 TPC允许通过系统学大大减少的动量转移到核后坐力的测量，可以大大改善相干和不连贯的过程的分离，从而打开了新的目标可能性（例如，Xenon等新目标），并在后续的γ光谱中，在后退的后甲基核心上可以使核核与不需要的核核分类进行ver虫。