Sheffield Responsive RA for exploitation of ADMX, ATLAS, LZ, T2K

本提案是关于4个响应性RA职位，以协助开发我们参与的实验，ADMX， ATLAS， LZ和T2K，并在附件中提供了完整的细节。目标是招募新的博士后研究人员，合同期限为2.5年。这些职位的长度对于刚毕业的博士生来说是理想的，可以进一步发展他们在粒子物理领域的职业生涯，并成为独立的研究人员。RAs将参加小组活动，并有机会参加和组织小组研讨会和期刊俱乐部，以及与硕士和博士级别的研究生一起工作。(1)利用ATLAS探测器改进UPC碰撞中光子诱导过程的测量这篇文章的重点是利用ATLAS实验扩展可通过电子和光子访问的相空间，并利用这些光子诱导过程测量的新发展，建立在Anastopoulos和Lohwasser的重要专业知识的基础上。具体来说，这篇文章将导致smg - b>过程的可达基准截面翻倍，并将允许扩展到更低的质量和改进光子诱导过程中BSM物理的限制。这将通过发展超越最先进的电子和光子重建、识别和校准算法来实现，这一努力需要大量的专业知识和事先参与。(2)利用T2K远端探测器上的钆载荷来提高对CP违反的灵敏度这篇文章的重点是利用最近对T2K远端探测器的升级来最大限度地提高对狄拉克相CP违反参数δ (CP)的灵敏度。T2K用于实现对该参数的灵敏度的主要处理是将其中微子模式（“正向角电流”）的振荡结果与从其反中微子模式（“反向角电流”）的数据获得的振荡结果进行比较。目前，这种灵敏度的一个主要限制因素是，在反向角电流（RHC）模式下收集的数据含有“错误符号”中微子的严重污染（约20%）。提高T2K搜索CP违逆的物理范围需要提高区分中微子相互作用和反中微子相互作用的能力。(3) LZ中子诱导多重散射重建、识别和测量的新技术。本文主要对LUX-ZEPLIN （LZ）实验数据进行了分析。LZ中的一个主要问题是由中子散射产生的wimp诱导的NR信号的不可还原性核后坐力（NR）背景水平。该职位将开发和应用变革性的新技术来重建、识别和测量中子诱导的多重散射（MS） NR事件。这些事件将用于在FlameNEST框架内实现的剖面似然比（PLR）拟合，以估计WIMP感兴趣搜索区域（ROI）中中子诱导的单散射（SS） NR事件的总体。这将首次使WIMP暗物质NR信号能够在LZ数据中被确定。(4) ADMX轴子搜索利用在不断提高的灵敏度水平上对wimp的加速器和直接搜索的无效结果导致对轴子暗物质的兴趣迅速增加。Daw是美国轴子暗物质实验（ADMX）合作项目的唯一英国成员，该项目在QCD轴子的灵敏度方面领先世界。谢菲尔德PDRA专注于ADMX数据分析，将使谢菲尔德能够领导ADMX数据分析的下一阶段，进一步加强英国与ADMX的合作，并促进由拟议的PDRA组成的ADMX/QSHS联合分析工作组的形成。

This proposal is for 4 responsive RA positions to assist in the exploitation of the experiments we areinvolved in, ADMX, ATLAS, LZ and T2K, with full details given in the case for support attached. The goal is to recruit new postdoctoral researchers for a 2.5 years contract. The length of theposts is ideal for newly graduated PhD students to further their careers in particle physics and developas independent researchers. RAs will join the group activities and will be given the chance to join andorganise the group seminars and journal clubs, as well to work with research students both at the Mastersand PhD level.(1) Improving the measurement of Photon- Induced Processes in UPC collisions with the ATLAS detectorThis post is focused on extending the phase space accessible via electrons and photons with the ATLAS experiment and the exploitation of these new developments in measurements of photon-induced pro- cesses, building up on the significant expertise of Anastopoulos and Lohwasser. Specifically, the post will lead to a doubling of the accessible fiducial cross-section for the SM gg -> gg, process and will allow for extension to lower masses and improvement of the limits on BSM physics in photon-induced processes. This will be achieved by developing beyond the state-of-the-art electron and photon reconstruction, identification and calibration algorithms, an endeavour that requires significant expertise and prior involvement. (2) Exploitation of the gadolinium loading at the T2K far detector to improve sensitivity to CP violationThis post is focused on exploiting recent upgrades to the T2K far detector to maximise sensitivity to the Dirac-phase CP violation parameter, delta(CP). The main handle that T2K uses to achieve sensitivity to this parameter is to compare oscillation results from its neutrino mode ("Forward Horn Current") to those obtained from data in its antineutrino mode ("Reverse Horn Current"). At present, a major limiting factor in this sensitivity is that face that data collected in Reverse Horn Current (RHC) mode contain significant contamination (about 20%) from 'wrong-sign' neutrinos. Improving the physics reach of the T2K search for CP violation requires enhancing the ability to distinguish neutrino interactions from antineutrino interactions. (3) New techniques for reconstructing, identifying and measuring neutron-induced multiple scatter in LZThis post is focused on analysis of data from the LUX-ZEPLIN (LZ) experiment. A major concern in LZ is the level of irreducible nuclear recoil (NR) background to WIMP-induced NR signals generated by neutron scattering. This post will develop and apply transformative new techniques for reconstructing, identifying and measuring neutron-induced multiple scatter (MS) NR events. These events will be used in a profile-likelihood ratio (PLR) fit, implemented within the FlameNEST framework, to estimate the population of neutron-induced single scatter (SS) NR events in the WIMP search region of interest (ROI). This will, for the first time, enable a WIMP dark matter NR signal to be identified with confidence in LZ data. (4) ADMX Axion Search ExploitationNull results from accelerator and direct searches for WIMPs at ever-increasing sensitivity levels have led to rapidly increasing interest in axion dark matter. Daw is the sole UK member of the US Axion Dark Matter eXperiment (ADMX) collaboration, which leads the world in sensitivity for the QCD axion. A Sheffield PDRA focused on ADMX data analysis would allow Sheffield to lead the next phase of ADMX data analysis, further reinforce UK collaboration with ADMX, and facilitate the formation of a joint ADMX/QSHS analysis taskforce consisting of the proposed PDRA,