5 pages, 4 figures; extracted from the proceedings of the 4th International Workshop on Transverse Polarization Phenomena in Hard Processes (Transversity 2014), 9-13 June 2014, Chia (Cagliari - Italy); EPJ Web of Conferences LaTeX style
We present preliminary results for an updated extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. Data for proton and deuteron targets by HERMES and COMPASS allow for a flavor separation of the valence components of transversity, while di-hadron fragmentation functions are taken from the semi-inclusive production of two pion pairs in back-to-back jets in $e^+ e^-$ annihilation. The latter data from Belle have been reanalyzed using the replica method and a more realistic estimate of the uncertainties on the chiral-odd interference fragmentation function has been obtained. After encoding this piece of information into the deep-inelastic scattering cross section, the transversity has been re-extracted by using the most recent and more precise COMPASS data for proton target. This picture represents the current most realistic estimate of the uncertainties on our knowledge of transversity. The preliminary results indicate that the valence up component seems smaller and with a narrower error band than in previous extraction.
Impact of Future Dihadron Production Measurements on the Transversity Distributions and Tensor Charges of the Nucleon
Temple University（天普大学）；College of William & Mary（威廉玛丽学院）；Duke University（杜克大学）；Lebanon Valley College（黎巴谷学院）；Penn State University Berks（宾夕法尼亚州立大学伯克斯分校）；Jefferson Lab（杰斐逊实验室）
Simplified approach to extracting nucleon transversity in collinear factorization using near-side energy-energy correlators
University of California, Los Angeles（加州大学洛杉矶分校）；Mani L. Bhaumik Institute for Theoretical Physics, University of California, Los Angeles（加州大学洛杉矶分校马尼·L·巴乌米克理论物理研究所）；Center for Frontiers in Nuclear Science, Stony Brook University（石溪大学核科学前沿中心）；Temple University（天普大学）；Lebanon Valley College（黎巴嫩谷学院）
Transverse-spin dependent energy-energy correlators in proton-proton collisions within the dihadron fragmentation framework
University of California, Los Angeles（加州大学洛杉矶分校）；Mani L. Bhaumik Institute for Theoretical Physics, University of California, Los Angeles（加州大学洛杉矶分校马尼·L·布海米克理论物理研究所）；Center for Frontiers in Nuclear Science, Stony Brook University（纽约州立大学石溪分校核科学前沿中心）；Temple University（天普大学）；Lebanon Valley College（黎巴嫩谷学院）
Evolution of the parton dihadron fragmentation functions
研究了e+e-湮灭过程中夸克和胶子部分子双强子碎裂函数及其演化。我们提供了这样的双强子碎裂函数的部分子矩阵元素的定义，并推导出动量和规则及其连接到单强子碎裂函数。我们将Lund Monte Carlo模型JETSET的结果作为Q_0^2=2 GeV^2部分子双强子碎裂函数的初始条件。数值求解了夸克和胶子碎裂函数的演化方程，在不同的高尺度Q^2下的结果与JETSET的结果符合得很好。从单一的碎片功能的输入的重要性指出。
Probing Gluon Linear Polarization with Dihadron Fragmentation in $χ_b$ Decays
Beijing University of Chemical Technology（北京化工大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；China Center of Advanced Science and Technology（中国科学技术中心）；Center for High Energy Physics, Peking University（北京大学高能物理中心）
Dihadron fragmentation framework for near-side energy-energy correlators
University of California, Los Angeles（加州大学洛杉矶分校）；Mani L. Bhaumik Institute for Theoretical Physics, University of California, Los Angeles（加州大学洛杉矶分校马尼·L·巴乌米克理论物理研究所）；Stony Brook University（石溪大学）；Temple University（天普大学）；Lebanon Valley College（黎巴嫩谷学院）
Unveiling Light-Quark Yukawa Flavor Structure via Dihadron Fragmentation at Lepton Colliders
School of Physics, Peking University（北京大学物理学院）；School of Physics, Zhengzhou University（郑州大学物理学院）；Center for High Energy Physics, Peking University（北京大学高能物理中心）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；China Center of Advanced Science and Technology（中国高等科学技术中心）
Azimuthal Correlations in the Structure Functions of polarized Dihadron Semi-Inclusive Deep Inelastic Scattering
讨论了非极化轻子与横极化核子深度非弹性散射中两个强子产生的方位角关联。具体地说，一个简单的方法来访问对应于Sivers效应和横向诱导的单自旋方位角不对称性的结构函数的非极化结构函数的比率。然后将这种方法应用于由包括Sivers效应的LEPTO Monte Carlo事件发生器的修改版本生成的样本伪数据。利用这些数据，它示出，方位角的相关性在Sivers的结构功能和非极化结构功能是显着不同的。在一个双强子样品中的柯林斯一样的单强子不对称性也进行了讨论，其中的实验结果最近提出的COMPASS合作。
Probing the Color-Octet Mechanism via Dihadron Fragmentation in $χ_b$ Decays
Beijing University of Chemical Technology（北京化工大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；China Center of Advanced Science and Technology（中国高等科学技术中心）；Center for High Energy Physics, Peking University（北京大学高能物理中心）
Extraction of Quark Transversity Distribution and Collins Fragmentation Functions with QCD Evolution
研究了$e^+e^-$湮灭和半包含强子产生过程中柯林斯方位角不对称性的横动量相关演化。所有相关系数的计算精度均达到次首对数（NLL）阶精度。本文采用Collins-Soper-Sterman（CSS）近似NLL阶的TMD演化方法，通过对BELLE和BABAR合作组测量的$u$湮灭中背靠背双强子产生的Collins不对称性以及来自HERMES，COMPASS，JLab HALL A实验演化效应和相关的理论不确定性的影响进行了讨论。我们进一步讨论了结果的TMD解释，给出了非极化夸克分布、横动量分布、非极化夸克碎裂和Collins碎裂函数随横动量和硬动量标度的变化.我们对未来的实验进行了详细的预测，并讨论了它们的影响。
