Improving sensitivity to the unitarity triangle angle gamma with CLEO-c CP-tagged D0 decays. (Project proposal for Responsive RA call)

使用 CLEO-c CP 标记的 D0 衰减提高对酉三角角伽马的灵敏度。

• 批准号: PP/F000650/1
• 负责人: Jonas Rademacker
• 金额: $ 27.84万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=PP%2FF000650%2F1
• 关键词: Improving; sensitivity; unitarity; triangle; angle

Precision measurements of CP violation in B mesons shed light on fundamental parameters of the Standard Model of particle physics, related to areas such as the generation of fermion masses and the predominance of matter over antimatter in the universe, and probe the Standard Model description of CP violation with a high sensitivity to New Physics. Arguably the most important goal of CP-violation measurements over the next decade will be a precise determination of the CP-violation parameter gamma. The LHCb experiment at the LHC at CERN will, for the first time, be able to perform such precision measurements. Measuring gamma will also be central to the programme of a possible Super-B factory. One of the most promising classes of gamma measurements involves the decay B+ -> DK+. In this decay chain, the D is unstable and decays further, for example to Ks pi pi. There are many intermediary states via which the D can decay to the same final state. These different decay paths interfere with each other, causing an interference pattern that can, for 3-body decays, be visualised in a 2-dimensional Dalitz plot. For 4-body decays, the visualisation is more difficult, but the same principles apply. For D mesons that originate from B+/- decays, the interference patterns are sensitive to decay parameters of the B, in particular the parameter gamma. Due to CP violation, those patterns look different depending whether the D originated from a B+ decay or a B- decay. Analysing those patterns allows in principle a very precise determination of gamma. This however requires a thorough understanding of D meson decays and the corresponding interference patterns before any B decay parameters enter. This is expected to be the limiting factor in the precision on gamma with this method. Understanding the D-decays fully requires two pieces of information for each point in the Dalitz plot: the amplitude and the phase. Usually, only one parameter can be measured, the intensity. Understanding the intensity pattern in terms of amplitudes and phases requires the use of a model for those D decays. The parameters of this model are then fitted to the intensity distribution. However, there is a dependency on the choice of model. This is the largest systematic uncertainty for the aforementioned gamma measurements. At its present value, this uncertainty will limit the use of the data accumulated at LHCb and any future Super-B facility. The CLEO-c experiment operating at Cornell University, NY, USA produces pairs of D mesons in a quantum correlated state, which is not the case at the e+e- B factories or the LHC. This data set allows, for the same final state, two independent measurements of the decay patterns of the Dalitz plot, 'CP tagged' and 'flavour tagged'. This makes it possible, in principle, to directly extract both amplitude and phase for each point in Dalitz space, without any model dependence. Even for channels where event numbers are not sufficient for a completely model-independent approach, the existing models will benefit greatly from the unique constraints imposed by the quantum-correlated data. This will significantly reduce the systematic error associated with our understanding of D decays in gamma measurement with B->DK at LHCb and elsewhere. CLEO-c however is a collaboration with very limited resources and at present there is not enough manpower to analyse many of the channels that are most important for gamma measurements at B-physics experiments. We therefore propose to join the Dalitz analysis group of CLEO-c to spearhead these studies, joining CLEO-c well before the end of data taking in spring 2008. This will put us in a position in 2008/09 to fully exploit the entire CLEO-c dataset for the proposed measurements. Our project concludes with the application of the results to gamma measurements at LHCb.

B Meson中CP违规的精确测量揭示了粒子物理标准模型的基本参数，该模型与诸如Fermion块的产生以及物质在宇宙中的物质占主导地位有关，并探究了CP侵犯CP的标准模型描述，对新物理学的敏感性很高。可以说，在接下来的十年中，CP侵略测量的最重要目标是对CP侵略参数伽马的精确确定。在CERN的LHC进行的LHCB实验将首次能够执行此类精度测量。测量伽玛也将是可能的超级-B工厂计划的核心。最有前途的伽马测量结果之一涉及衰减B+ - > dk+。在这个衰减链中，D是不稳定的，并且会进一步腐烂，例如KS Pi Pi。在许多中间状态下，d可以腐烂到同一最终状态。这些不同的衰减路径彼此干扰，导致干扰模式，对于三体衰减，可以在二维Dalitz图中可视化。对于四体衰减，可视化更加困难，但是相同的原理适用。对于起源于B +/-衰减的D媒介，干扰模式对B的衰减参数敏感，尤其是参数γ。由于违反了CP，这些模式看起来不同于D起源于B+衰减还是B-衰减。分析这些模式原则上可以非常精确地确定伽马。但是，这需要对D梅森腐烂和任何B衰减参数输入之前的相应干扰模式有深入的了解。通过这种方法，这预计将是伽马伽马精确度的限制因素。理解d-Decays在Dalitz图中的每个点需要两个信息：振幅和相位。通常，只能测量一个参数，即强度。了解幅度和阶段的强度模式需要用于这些D衰变的模型。然后将该模型的参数拟合到强度分布。但是，对模型的选择有依赖性。这是上述伽马测量值最大的系统不确定性。以目前的价值，这种不确定性将限制在LHCB和任何未来的Super-B设施中累积的数据的使用。在美国纽约州康奈尔大学运营的CLEO-C实验产生了量子相关状态的成对的D膜，在E+E-e-e-b工厂或LHC中并非如此。对于同一最终状态，该数据集允许对达利兹图的衰减模式进行两个独立的测量，即“标记为CP”和“风味标记”。从原则上讲，这使得无需任何模型依赖性即可直接在达利兹空间中直接提取幅度和相位。即使对于事件编号不足以完全独立于模型的方法不足以使现有模型也将从量子相关数据施加的独特约束中受益。这将显着减少与我们对LHCB和其他地方B-> dk伽马测量中D衰变相关的系统错误。但是，Cleo-C是一项与非常有限的资源的合作，目前没有足够的人力来分析许多对于B物理实验中伽马测量最重要的渠道。因此，我们建议将Cleo-C的Dalitz分析组加入这些研究，并在2008年春季收集数据结束之前就加入了Cleo-C。这将使我们在2008/09年处于一个位置，以完全利用整个CLEO-C数据集进行拟议的测量结果。我们的项目以LHCB的伽马测量结果应用于伽马测量结果。

项目成果

Higher-order multipole amplitudes in charmonium radiative transitions

• DOI: 10.1103/physrevd.80.112003
• 发表时间: 2009-10
• 期刊: Physical Review D
• 影响因子: 5
• 作者: M. Artuso;E. al.

Amplitude analysis of D 0 ? K + K - p + p -

D 0 的幅度分析？

• DOI: 10.1103/physrevd.85.122002
• 发表时间: 2012
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Artuso M

Observation of J/psi-->3gamma.

• DOI: 10.1103/physrevlett.101.101801
• 发表时间: 2008-06
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: G. Adams;M. Anderson;J. Cummings;I. Dankó;D. Hu;B. Moziak;J. Napolitano;Q. He;J. Insler;H. Muramatsu;C. S. Park;E. Thorndike;F. Yang;M. Artuso;S. Blusk;S. Khalil;J. Li;R. Mountain;S. Nisar;K. Randrianarivony;N. Sultana;T. Skwarnicki;S. Stone;J. Wang;L. Zhang;G. Bonvicini;D. Cinabro;M. Dubrovin;A. Lincoln;P. Naik;J. Rademacker;D. Asner;K. W. Edwards;J. Reed;R. Briere;T. Ferguson;J. Ma;G. Tatishvili;H. Vogel;M. E. Watkins;J. Rosner;J. Alexander;D. Cassel;J. Duboscq;R. Ehrlich;L. Fields;R. Galik;L. Gibbons;R. Gray;S. Gray;D. Hartill;B. Heltsley;D. Hertz;J. Hunt;J. Kandaswamy;D. Kreinick;V. Kuznetsov;J. Ledoux;H. Mahlke-Krüger;D. Mohapatra;P. Onyisi;J. Patterson;D. Peterson;D. Riley;A. Ryd;A. Sadoff;X. Shi;S. Stroiney;W. Sun;T. Wilksen;S. Athar;R. Patel;J. Yelton;P. Rubin;B. Eisenstein;I. Karliner;S. Mehrabyan;N. Lowrey;M. Selen;E. White;J. Wiss;R. Mitchell;M. Shepherd;D. Besson;T. Pedlar;D. Cronin-Hennessy;K. Gao;J. Hietala;Y. Kubota;T. Klein;B. Lang;R. Poling;A. Scott;P. Zweber;S. Dobbs;Z. Metreveli;K. Seth;A. Tomaradze;J. Libby;A. Powell;G. Wilkinson;K. Ecklund;W. Love;V. Savinov;H. Mendez;J. Ge;D. Miller;I. Shipsey;B. Xin

Study of ? ( 2 S ) decays to ? p p ¯ , p 0 p p ¯ , and ? p p ¯ , and search for p p ¯ threshold enhancements

研究？

• DOI: 10.1103/physrevd.82.092002
• 发表时间: 2010
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Alexander J

Measurement of absolute branching fractions of inclusive semileptonic decays of charm and charmed-strange mesons

• DOI: 10.1103/physrevd.81.052007
• 发表时间: 2009-12
• 期刊: Physical Review D
• 影响因子: 5
• 作者: The Cleo Collaboration