Research in Theoretical Hadronic Physics and Related Topics

我们打算研究的课题包括：硬π介子的电产生。我们将计算高横动量半排介子的电产生，特别是考虑高扭曲过程，其中π介子是直接产生的，并且看起来是运动学孤立的，但包括主扭转（其中π介子是由部分子碎裂产生的，并作为喷流的一部分出现）和软亲核的估计，cesses。直接和领先的扭曲过程允许数据产生关于目标中夸克和胶子分布的信息。两个特别的新项目是做电产生而不是光产生，并包括初态部分子横动量，一个应用是看高扭曲过程是否与爱马仕的数据有关，可能与Je .erson实验室的Hall B数据有关，在那里有相当大的兴趣结果。爱马仕测量了极化靶的极化光子光生双介子，首次确定了质子中胶子的极化。发表的结果很大程度上依赖于理论分析，而理论分析又很大程度上依赖于调整到更高能量的程序包。我们提出了我们认为是必要的独立计算各种过程的贡献（光子-胶子融合，QCD Compton，矢量介子优势（VMD）），特别是观察结果对不同碎裂模型，初态横动量和VMD贡献的不同估计的敏感性。在微扰QCD计算中，我们发现，对于近似的氘核形状因子，我们的计算值远低于实际值，但却忽略了提供隐色态的短程波函数.我们最近发展了一种方法来处理模拟这些组分的6-夸克团波函数.我们提出用包含隐色组分的波函数来计算近似的氘核形状因子，用微扰QCD来研究低动量传递。我们将研究Breit和光锋螺旋度振幅之间关系的形式和应用方面，这些振幅的高动量传递行为的次主导功率修正，以及离散对称性对光锋振幅的应用。形式结果可以允许，例如，找到次主导螺旋度振幅近似必须遵守的约束（这在文献中并不总是实现）。更积极的是，我们可以看到正式的结果，以指导调查如何非领导权力可以参数化，并再次看到，例如，如何和在哪里N。（1232）跃迁的结果可以接近微扰QCD的结果。非对易场论的唯象学。在早期的研究道路上，我们想完成费曼规则的洛伦兹守恒非共通性变场理论和非对易时空的特征.除了fAfA弹性散射外，我们还想考虑用算子代数来做洛伦兹守恒的非对易场理论，除了我们迄今为止所做的收缩Snyder代数外.NSF评论的搜索.建议活动的智力价值：大多数活动是在现代强子物理学的前沿，其余的是在粒子物理学的一个有趣的方向的现象学的前沿。这些项目将导致许多出版物在领先的参考期刊。建议活动的更广泛的影响：这些项目将有助于弥合强子理论与观察到的现象之间的差距，并加深对强子反应机制的理解。它们还将培训包括本科生在内的新生。PI已经有两名成功的女博士生。学生，目前的项目可能会扩大妇女进入老年人的机会。PI定期在杰森实验室和弥合大学和国家实验室之间的差距，以及数据和理论之间。

We propose to investigate a n mber of topics,including:Hard Pion Electroproduction. We will calculate high transverse momentum semi-exclusivepion electroproduction,considering especially the higher twist process where the pions are pro-duced directly and appear kinematically isolated,but including leading twist (where the pionsare produced by parton fragmentation and appear as part of a jet)and estimates of soft pro-cesses.The direct and leading twist processes allow data to yield information about the quarkand gluon distributions in the target.Two particular new items are to do electroproductionrather than photoproduction and to include initial state parton transverse momentum.An ap-plication is to see if the higher twist process are relevant to data from HERMES,and possiblyHall B data from Je .erson Lab,where there is considerable interest in the result.Dipions and the Polarization of Gluons. HERMES has measured dipions photoproducedwith polarized photons o .polarized targets,which has given the .rst determination of the po-larization of gluons in the proton.The published result depends heavily upon the theoreticalanalysis,in turn heavily based on program packages that are tuned to higher energies.Wepropose what we believe is a necessary independent calculation the contributions of the vari-ous processes (photon-gluon fusion,QCD Compton,and vector meson dominance (VMD)),inparticular to see the sensitivity of the results to di .ering fragmentation models,initial statetransverse momentum,and di .ering estimates of the VMD contribution.The Deuteron Form Factor. The only perturbative QCD calculation of the asymptoticdeuteron form factor lies well below the data,but strikingly omits the short range wave functionsthat provide for hidden color states.We have recently developed ways to manipulate 6-quarkcluster wave functions that model these components.We propose to calculate the asymptoticform factor with wave functions including a hidden color component,to see the e .ect of thehidden color components upon the magnitude of the result.Bringing Perturbative QCD to Lower Momentum Transfers. We will study formal andapplied aspects of relations between the Breit and light-front helicity amplitudes,next-to-leadingpower corrections to the high momentum transfer behavior of those amplitudes,and applicationof discrete symmetries to light-front amplitudes.The formal results can allow s,for example,to.nd constraints that approximations to the subdominant helicity amplitudes must obey (whichare not always realized in the literature).More positively,we can se the formal results to guideinvestigation of how non-leading powers can be parameterized and see,again for example,howand where the N .(1232)transition may approach the perturbative QCD results.Phenomenology of Noncommutative Field Theory. Following up on an earlier researchpath,we would like to complete the set of Feynman rules for the Lorentz conserving noncom-mutative .eld theory and .nd the signatures of noncommutative spacetime for a selection ofprocesses in addition to fAfA elastic scattering.Also we would like to consider ways to do Lorentzconserving noncommutative .eld theory with operator algebras in addition to the contractedSnyder algebra we have worked out so far.NSF Review Criteria. Intellectual merit of the proposed activity:Most of the activity is atthe forefront of modern hadronic physics,and the rest is at the forefront of the phenomenologyof an interesting direction in particle physics.The projects will lead to many publicationsin the leading refereed journals.Broader impacts of the proposed activity:The projects willhelp bridge the gap between hadronic theory and observed phenomena,and lead to greaterunderstanding of the mechanisms of hadronic reactions.They will also train new students,including undergraduates.The PI has had two successful women Ph.D.students,and thepresent project may extend opportunities for women entering the .eld.The PI is regularly atthe Je .erson Laboratory and bridging the gap between university and national lab as well asbetween data and theory.