⚛️ high-energy experiments

First Observation of an Exotic Reggeon

本文基于新的高统计量 COMPASS 测量结果和非分箱高质量分析，报告了在 $\eta\pi^-$ 和 $\eta^\prime\pi^-$ 对的外围产生过程中，首次高显著性地观测到一种可能与 $\pi_1(1600)$ 相关的奇异 Reggeon。

原作者： G. D. Alexeev (for JPAC Collaboration), M. G. Alexeev (for JPAC Collaboration), C. Alice (for JPAC Collaboration), A. Amoroso (for JPAC Collaboration), V. Andrieux (for JPAC Collaboration), V. Anosov G. D. Alexeev (for JPAC Collaboration), M. G. Alexeev (for JPAC Collaboration), C. Alice (for JPAC Collaboration), A. Amoroso (for JPAC Collaboration), V. Andrieux (for JPAC Collaboration), V. Anosov (for JPAC Collaboration), K. Augsten (for JPAC Collaboration), W. Augustyniak (for JPAC Collaboration), C. D. R. Azevedo (for JPAC Collaboration), B. Badelek (for JPAC Collaboration), R. Beck (for JPAC Collaboration), J. Beckers (for JPAC Collaboration), Y. Bedfer (for JPAC Collaboration), J. Bernhard (for JPAC Collaboration), F. Bradamante (for JPAC Collaboration), A. Bressan (for JPAC Collaboration), W. -C. Chang (for JPAC Collaboration), C. Chatterjee (for JPAC Collaboration), M. Chiosso (for JPAC Collaboration), S. -U. Chung (for JPAC Collaboration), A. Cicuttin (for JPAC Collaboration), M. L. Crespo (for JPAC Collaboration), D. D'Ago (for JPAC Collaboration), S. Dalla Torre (for JPAC Collaboration), S. S. Dasgupta (for JPAC Collaboration), S. Dasgupta (for JPAC Collaboration), F. Delcarro (for JPAC Collaboration), I. Denisenko (for JPAC Collaboration), O. Yu. Denisov (for JPAC Collaboration), S. V. Donskov (for JPAC Collaboration), N. Doshita (for JPAC Collaboration), Ch. Dreisbach (for JPAC Collaboration), W. Dunnweber (for JPAC Collaboration), R. R. Dusaev (for JPAC Collaboration), D. Ecker (for JPAC Collaboration), P. Faccioli (for JPAC Collaboration), M. Faessler (for JPAC Collaboration), M. Finger (for JPAC Collaboration), M. jr Finger (for JPAC Collaboration), H. Fischer (for JPAC Collaboration), K. J. Flothner (for JPAC Collaboration), W. Florian (for JPAC Collaboration), J. M. Friedrich (for JPAC Collaboration), V. Frolov (for JPAC Collaboration), L. G. Garcia Ordonez (for JPAC Collaboration), O. P. Gavrichtchouk (for JPAC Collaboration), S. Gerassimov (for JPAC Collaboration), J. Giarra (for JPAC Collaboration), D. Giordano (for JPAC Collaboration), A. Grasso (for JPAC Collaboration), A. Gridin (for JPAC Collaboration), M. Grosse Perdekamp (for JPAC Collaboration), B. Grube (for JPAC Collaboration), M. Gruner (for JPAC Collaboration), A. Guskov (for JPAC Collaboration), P. Haas (for JPAC Collaboration), D. von Harrach (for JPAC Collaboration), M. Hoffmann (for JPAC Collaboration), N. d'Hose (for JPAC Collaboration), C. -Y. Hsieh (for JPAC Collaboration), S. Ishimoto (for JPAC Collaboration), A. Ivanov (for JPAC Collaboration), T. Iwata (for JPAC Collaboration), V. Jary (for JPAC Collaboration), R. Joosten (for JPAC Collaboration), E. Kabuss (for JPAC Collaboration), F. Kaspar (for JPAC Collaboration), A. Kerbizi (for JPAC Collaboration), B. Ketzer (for JPAC Collaboration), G. V. Khaustov (for JPAC Collaboration), J. H. Koivuniemi (for JPAC Collaboration), V. N. Kolosov (for JPAC Collaboration), K. Kondo Horikawa (for JPAC Collaboration), I. Konorov (for JPAC Collaboration), A. Yu. Korzenev (for JPAC Collaboration), A. M. Kotzinian (for JPAC Collaboration), O. M. Kouznetsov (for JPAC Collaboration), A. Koval (for JPAC Collaboration), F. Kunne (for JPAC Collaboration), K. Kurek (for JPAC Collaboration), R. P. Kurjata (for JPAC Collaboration), G. Kurten (for JPAC Collaboration), A. Kveton (for JPAC Collaboration), K. Lavickova (for JPAC Collaboration), S. Levorato (for JPAC Collaboration), Y. -S. Lian (for JPAC Collaboration), J. Lichtenstadt (for JPAC Collaboration), P. -J. Lin (for JPAC Collaboration), R. Longo (for JPAC Collaboration), V. E. Lyubovitskij (for JPAC Collaboration), A. Maggiora (for JPAC Collaboration), N. Makke (for JPAC Collaboration), G. K. Mallot (for JPAC Collaboration), A. Maltsev (for JPAC Collaboration), A. Martin (for JPAC Collaboration), J. Marzec (for JPAC Collaboration), J. Matousek (for JPAC Collaboration), T. Matsuda (for JPAC Collaboration), C. Menezes Pires (for JPAC Collaboration), F. Metzger (for JPAC Collaboration), W. Meyer (for JPAC Collaboration), M. Mikhasenko (for JPAC Collaboration), E. Mitrofanov (for JPAC Collaboration), D. Miura (for JPAC Collaboration), Y. Miyachi (for JPAC Collaboration), R. Molina (for JPAC Collaboration), A. Moretti (for JPAC Collaboration), A. Nagaytsev (for JPAC Collaboration), D. Neyret (for JPAC Collaboration), M. Niemiec (for JPAC Collaboration), J. Novy (for JPAC Collaboration), W. -D. Nowak (for JPAC Collaboration), G. Nukazuka (for JPAC Collaboration), A. G. Olshevsky (for JPAC Collaboration), M. Ostrick (for JPAC Collaboration), D. Panzieri (for JPAC Collaboration), B. Parsamyan (for JPAC Collaboration), S. Paul (for JPAC Collaboration), H. Pekeler (for JPAC Collaboration), J. -C. Peng (for JPAC Collaboration), M. Pesek (for JPAC Collaboration), D. V. Peshekhonov (for JPAC Collaboration), M. Peskova (for JPAC Collaboration), S. Platchkov (for JPAC Collaboration), J. Pochodzalla (for JPAC Collaboration), V. A. Polyakov (for JPAC Collaboration), C. Quintans (for JPAC Collaboration), G. Reicherz (for JPAC Collaboration), C. Riedl (for JPAC Collaboration), D. I. Ryabchikov (for JPAC Collaboration), A. Rychter (for JPAC Collaboration), A. Rymbekova (for JPAC Collaboration), V. D. Samoylenko (for JPAC Collaboration), A. Sandacz (for JPAC Collaboration), S. Sarkar (for JPAC Collaboration), I. A. Savin (for JPAC Collaboration), G. Sbrizzai (for JPAC Collaboration), H. Schmieden (for JPAC Collaboration), A. Selyunin (for JPAC Collaboration), S. Seriubin (for JPAC Collaboration), L. Sinha (for JPAC Collaboration), D. Spulbeck (for JPAC Collaboration), A. Srnka (for JPAC Collaboration), M. Stolarski (for JPAC Collaboration), M. Sulc (for JPAC Collaboration), H. Suzuki (for JPAC Collaboration), S. Tessaro (for JPAC Collaboration), F. Tessarotto (for JPAC Collaboration), A. Thiel (for JPAC Collaboration), F. Tosello (for JPAC Collaboration), A. Townsend (for JPAC Collaboration), V. Tskhay (for JPAC Collaboration), B. Valinoti (for JPAC Collaboration), B. M. Veit (for JPAC Collaboration), J. F. C. A. Veloso (for JPAC Collaboration), A. Vijayakumar (for JPAC Collaboration), M. Virius (for JPAC Collaboration), M. Wagner (for JPAC Collaboration), S. Wallner (for JPAC Collaboration), K. Zaremba (for JPAC Collaboration), M. Zavertyaev (for JPAC Collaboration), M. Zemko (for JPAC Collaboration), E. Zemlyanichkina (for JPAC Collaboration), M. Ziembicki (for JPAC Collaboration), for the COMPASS Collaboration (for JPAC Collaboration), C. Fernandez-Ramirez (for JPAC Collaboration), M. Mikhasenko (for JPAC Collaboration), L. Bibrzycki (for JPAC Collaboration), G. Foti (for JPAC Collaboration), N. Hammoud (for JPAC Collaboration), V. Mathieu (for JPAC Collaboration), G. Montana (for JPAC Collaboration), R. J. Perry (for JPAC Collaboration), A. Pilloni (for JPAC Collaboration), A. Rodas (for JPAC Collaboration), V. Shastry (for JPAC Collaboration), W. A. Smith (for JPAC Collaboration), A. P. Szczepaniak (for JPAC Collaboration), D. Winney (for JPAC Collaboration)

发布于 2026-07-21

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CC BY 4.0

原作者： G. D. Alexeev (for JPAC Collaboration), M. G. Alexeev (for JPAC Collaboration), C. Alice (for JPAC Collaboration), A. Amoroso (for JPAC Collaboration), V. Andrieux (for JPAC Collaboration), V. Anosov (for JPAC Collaboration), K. Augsten (for JPAC Collaboration), W. Augustyniak (for JPAC Collaboration), C. D. R. Azevedo (for JPAC Collaboration), B. Badelek (for JPAC Collaboration), R. Beck (for JPAC Collaboration), J. Beckers (for JPAC Collaboration), Y. Bedfer (for JPAC Collaboration), J. Bernhard (for JPAC Collaboration), F. Bradamante (for JPAC Collaboration), A. Bressan (for JPAC Collaboration), W. -C. Chang (for JPAC Collaboration), C. Chatterjee (for JPAC Collaboration), M. Chiosso (for JPAC Collaboration), S. -U. Chung (for JPAC Collaboration), A. Cicuttin (for JPAC Collaboration), M. L. Crespo (for JPAC Collaboration), D. D'Ago (for JPAC Collaboration), S. Dalla Torre (for JPAC Collaboration), S. S. Dasgupta (for JPAC Collaboration), S. Dasgupta (for JPAC Collaboration), F. Delcarro (for JPAC Collaboration), I. Denisenko (for JPAC Collaboration), O. Yu. Denisov (for JPAC Collaboration), S. V. Donskov (for JPAC Collaboration), N. Doshita (for JPAC Collaboration), Ch. Dreisbach (for JPAC Collaboration), W. Dunnweber (for JPAC Collaboration), R. R. Dusaev (for JPAC Collaboration), D. Ecker (for JPAC Collaboration), P. Faccioli (for JPAC Collaboration), M. Faessler (for JPAC Collaboration), M. Finger (for JPAC Collaboration), M. jr Finger (for JPAC Collaboration), H. Fischer (for JPAC Collaboration), K. J. Flothner (for JPAC Collaboration), W. Florian (for JPAC Collaboration), J. M. Friedrich (for JPAC Collaboration), V. Frolov (for JPAC Collaboration), L. G. Garcia Ordonez (for JPAC Collaboration), O. P. Gavrichtchouk (for JPAC Collaboration), S. Gerassimov (for JPAC Collaboration), J. Giarra (for JPAC Collaboration), D. Giordano (for JPAC Collaboration), A. Grasso (for JPAC Collaboration), A. Gridin (for JPAC Collaboration), M. Grosse Perdekamp (for JPAC Collaboration), B. Grube (for JPAC Collaboration), M. Gruner (for JPAC Collaboration), A. Guskov (for JPAC Collaboration), P. Haas (for JPAC Collaboration), D. von Harrach (for JPAC Collaboration), M. Hoffmann (for JPAC Collaboration), N. d'Hose (for JPAC Collaboration), C. -Y. Hsieh (for JPAC Collaboration), S. Ishimoto (for JPAC Collaboration), A. Ivanov (for JPAC Collaboration), T. Iwata (for JPAC Collaboration), V. Jary (for JPAC Collaboration), R. Joosten (for JPAC Collaboration), E. Kabuss (for JPAC Collaboration), F. Kaspar (for JPAC Collaboration), A. Kerbizi (for JPAC Collaboration), B. Ketzer (for JPAC Collaboration), G. V. Khaustov (for JPAC Collaboration), J. H. Koivuniemi (for JPAC Collaboration), V. N. Kolosov (for JPAC Collaboration), K. Kondo Horikawa (for JPAC Collaboration), I. Konorov (for JPAC Collaboration), A. Yu. Korzenev (for JPAC Collaboration), A. M. Kotzinian (for JPAC Collaboration), O. M. Kouznetsov (for JPAC Collaboration), A. Koval (for JPAC Collaboration), F. Kunne (for JPAC Collaboration), K. Kurek (for JPAC Collaboration), R. P. Kurjata (for JPAC Collaboration), G. Kurten (for JPAC Collaboration), A. Kveton (for JPAC Collaboration), K. Lavickova (for JPAC Collaboration), S. Levorato (for JPAC Collaboration), Y. -S. Lian (for JPAC Collaboration), J. Lichtenstadt (for JPAC Collaboration), P. -J. Lin (for JPAC Collaboration), R. Longo (for JPAC Collaboration), V. E. Lyubovitskij (for JPAC Collaboration), A. Maggiora (for JPAC Collaboration), N. Makke (for JPAC Collaboration), G. K. Mallot (for JPAC Collaboration), A. Maltsev (for JPAC Collaboration), A. Martin (for JPAC Collaboration), J. Marzec (for JPAC Collaboration), J. Matousek (for JPAC Collaboration), T. Matsuda (for JPAC Collaboration), C. Menezes Pires (for JPAC Collaboration), F. Metzger (for JPAC Collaboration), W. Meyer (for JPAC Collaboration), M. Mikhasenko (for JPAC Collaboration), E. Mitrofanov (for JPAC Collaboration), D. Miura (for JPAC Collaboration), Y. Miyachi (for JPAC Collaboration), R. Molina (for JPAC Collaboration), A. Moretti (for JPAC Collaboration), A. Nagaytsev (for JPAC Collaboration), D. Neyret (for JPAC Collaboration), M. Niemiec (for JPAC Collaboration), J. Novy (for JPAC Collaboration), W. -D. Nowak (for JPAC Collaboration), G. Nukazuka (for JPAC Collaboration), A. G. Olshevsky (for JPAC Collaboration), M. Ostrick (for JPAC Collaboration), D. Panzieri (for JPAC Collaboration), B. Parsamyan (for JPAC Collaboration), S. Paul (for JPAC Collaboration), H. Pekeler (for JPAC Collaboration), J. -C. Peng (for JPAC Collaboration), M. Pesek (for JPAC Collaboration), D. V. Peshekhonov (for JPAC Collaboration), M. Peskova (for JPAC Collaboration), S. Platchkov (for JPAC Collaboration), J. Pochodzalla (for JPAC Collaboration), V. A. Polyakov (for JPAC Collaboration), C. Quintans (for JPAC Collaboration), G. Reicherz (for JPAC Collaboration), C. Riedl (for JPAC Collaboration), D. I. Ryabchikov (for JPAC Collaboration), A. Rychter (for JPAC Collaboration), A. Rymbekova (for JPAC Collaboration), V. D. Samoylenko (for JPAC Collaboration), A. Sandacz (for JPAC Collaboration), S. Sarkar (for JPAC Collaboration), I. A. Savin (for JPAC Collaboration), G. Sbrizzai (for JPAC Collaboration), H. Schmieden (for JPAC Collaboration), A. Selyunin (for JPAC Collaboration), S. Seriubin (for JPAC Collaboration), L. Sinha (for JPAC Collaboration), D. Spulbeck (for JPAC Collaboration), A. Srnka (for JPAC Collaboration), M. Stolarski (for JPAC Collaboration), M. Sulc (for JPAC Collaboration), H. Suzuki (for JPAC Collaboration), S. Tessaro (for JPAC Collaboration), F. Tessarotto (for JPAC Collaboration), A. Thiel (for JPAC Collaboration), F. Tosello (for JPAC Collaboration), A. Townsend (for JPAC Collaboration), V. Tskhay (for JPAC Collaboration), B. Valinoti (for JPAC Collaboration), B. M. Veit (for JPAC Collaboration), J. F. C. A. Veloso (for JPAC Collaboration), A. Vijayakumar (for JPAC Collaboration), M. Virius (for JPAC Collaboration), M. Wagner (for JPAC Collaboration), S. Wallner (for JPAC Collaboration), K. Zaremba (for JPAC Collaboration), M. Zavertyaev (for JPAC Collaboration), M. Zemko (for JPAC Collaboration), E. Zemlyanichkina (for JPAC Collaboration), M. Ziembicki (for JPAC Collaboration), for the COMPASS Collaboration (for JPAC Collaboration), C. Fernandez-Ramirez (for JPAC Collaboration), M. Mikhasenko (for JPAC Collaboration), L. Bibrzycki (for JPAC Collaboration), G. Foti (for JPAC Collaboration), N. Hammoud (for JPAC Collaboration), V. Mathieu (for JPAC Collaboration), G. Montana (for JPAC Collaboration), R. J. Perry (for JPAC Collaboration), A. Pilloni (for JPAC Collaboration), A. Rodas (for JPAC Collaboration), V. Shastry (for JPAC Collaboration), W. A. Smith (for JPAC Collaboration), A. P. Szczepaniak (for JPAC Collaboration), D. Winney (for JPAC Collaboration)

原始论文采用 CC BY 4.0 许可（http://creativecommons.org/licenses/by/4.0/）。 ✨ 这是对下方论文的AI生成解释。它不是由作者撰写或认可的。如需技术准确性，请参阅原始论文。阅读完整免责声明

想象一下，宇宙是一个巨大的、隐形的乐高积木组，但这些积木不是由塑料制成的，而是由纯粹的能量和规则构成的。几十年来，物理学家一直试图弄清楚这些碎片是如何拼凑在一起，从而构建出我们周围看到的物质（如质子和中子）的。他们有一本名为“标准模型”的规则书，书中指出大多数粒子是由被称为“夸克”的更小的碎片组成的，并通过一种被称为“强相互作用”的力量粘合在一起。但转折在于：规则书还暗示，可能存在一些“奇异”的乐高创造物——这些结构不仅使用了标准的积木，还将“胶水”本身也作为建筑模块之一。这些被称为“混合介子”。寻找它们就像是在寻找一个没人知道存在的视频游戏秘密关卡；它将证明，把宇宙维系在一起的“胶水”本身也可以作为拼图的一部分。

长期以来，科学家们一直在寻找这些奇异混合介子，主要通过碰撞粒子并观察产生的碎片中的特定模式。他们非常清楚自己要寻找什么：具有“奇异量子数”的粒子，这是一种时髦的说法，指的是一种普通的夸克-反夸克对所无法拥有的奇特属性组合。这就像是尝试只用蓝色和黄色的积木来搭建一个红色的立方体；如果你看到了红色立方体，你就知道你一定使用了一种特殊的、隐藏的成分。大问题一直是：这些奇异混合介子是作为短暂存在的粒子产生并消失，还是以不同的方式存在？

这就是这篇新论文发挥作用的地方。一个名为 COMPASS 实验的庞大国际科学家团队决定从一个完全不同的角度来研究这个问题。他们不再仅仅将混合介子视为被“创造”然后又破碎的东西，而是将其视为在碰撞过程中被“交换”的东西。把它想象成一场接力赛或传球游戏。通常，你从一个人向另一个人投掷一个球（一个粒子）。但在这次实验中，科学家们意识到，有时这种“投掷”本身涉及一个在玩家之间传递的秘密、奇异的对象，那不是一个球，而是一个幽灵般的力波。

该团队分析了将负 $\pi$ 介子束撞向质子靶的数据。他们专门寻找产生的碎片：一种 $\eta$ 介子和 $\pi$ 介子的混合物。他们专注于高能碰撞，即粒子以极高速度飞出的情况。通过使用一种超精确的、非分箱分析（这意味着他们逐一观察每一个事件，而不是将它们分入不同的桶中），他们能够分离出粒子相互作用的不同方式。

这里有一个重大发现：数据展示了一个清晰、无可争议的“奇异 Reggeon”信号。在高速物理的世界里，“Reggeon”就像是一个粒子阶梯，随着你向上攀爬，阶梯的层级会变得越来越重，旋转得也越来越快。这些阶梯中的大多数是由“正常”粒子组成的。但科学家们发现了一个由“奇异”粒子组成的阶梯。他们将这个奇异阶梯与一个特定的、此前曾被怀疑过的粒子—— $\pi_1(1600)$ 联系了起来。

证据极其有力。团队计算出，该信号是由随机偶然现象产生的概率小于十亿分之一。在科学术语中，该信号的一种碰撞显著性为 $9.9\sigma$ ，另一种为 $5.5\sigma$ 。为了让你理解，在科学界，“5 西格玛”是一个宣布发现的金标准；而这个团队已经远远超越了这一点。

这意味着什么？这意味着奇异的 $\pi_1(1600)$ 不仅仅是一个产生并破碎的粒子；它也是粒子碰撞时发生的一种基本的“交换”。这就像是科学家们发现，维系宇宙的“胶水”不仅能把东西固定在原位，还可以像接力赛中的接力棒一样在彼此之间传递。这证实了强相互作用的动力学比我们想象的更加丰富和复杂。论文明确排除了仅靠我们已知的“正常”交换来解释数据的可能性；奇异交换对于使数学公式成立是绝对必要的。

研究人员谨慎地指出，虽然他们发现了这种奇异交换，但并不一定“解决”了混合介子的整个谜团。相反，他们打开了一扇新的窗口。他们发现这种奇异轨迹与著名的“Pomeron”（这是这些碰撞中一种标准的、类似于真空的交换）并列存在。这一发现表明，未来的实验（如 GlueX 实验）可能会看到更多这些奇异效应，特别是在那些“正常”交换被禁止的不同类型的碰撞中。

简而言之，这篇论文报告了在高能散射中首次观测到奇异 Reggeon 交换。它证明了奇异的 $\pi_1(1600)$ 不仅仅是一个转瞬即逝的共振态，而且在粒子高速相互作用中扮演着核心角色，它是驱动碰撞的基本组成部分之一。这是理解宇宙“胶水”如何运作的一大步，证实了我们一直在搜寻的那些奇异物质是真实存在的，而且它们就在行动的核心之中。

技术摘要：首次观测到奇异 Reggeon

问题与动机
通过量子色动力学（QCD）的自由度来理解强子谱是研究非摄动强相互作用的核心目标。虽然已经发现了许多超越朴素夸克模型的奇异态（特别是涉及重夸克的态），但涉及轻夸克的候选态仍是研究的重点。其中一类主要的候选者是混合介子——即具有显式胶子激发态的强子。这些态通常在具有奇特量子数（ $J^{PC}$ ）的末态中被寻找，例如 $\eta\pi$ 和 $\eta'\pi$ ，这些量子数是简单的夸克-反夸克对所无法实现的。

COMPASS 实验的高统计量测量已经确立了在 $\eta\pi^-$ 中 1.4 GeV/ $c^2$ 附近以及在 $\eta'\pi^-$ 中 1.6 GeV/ $c^2$ 附近的结构的存在。来自联合物理分析中心（JPAC）的耦合通道分析解决了这些峰值的性质，将其鉴定为单一自旋奇异共振态 $\pi_1(1600)$ 的体现。然而，这些态在高能下的动力学过程，特别是在 Regge 理论背景下的动力学，尚未得到充分解耦。高能反应通常由 Reggeon（增加自旋态的轨迹）的交换来参数化。虽然 Pomeron（真空量子数）和普通的介子轨迹（例如 $a_2, f_2$ ）已得到公认，但在外围产生过程中，是否存在并发挥作用的奇异 Reggeon 轨迹仍有待实验证实。

方法论
本文展示了对反应 $\pi^- p \to \eta^{(\prime)}\pi^- p$ 的高统计量 COMPASS 数据的非分箱、逐事件分析。该数据集包含约 270,000 个 $\eta\pi^-$ 事件和 85,000 个 $\eta'\pi^-$ 事件，覆盖高达 6 GeV/ $c^2$ 的不变质量范围。分析侧重于外围产生区域（对靶质子的四动量转移较小， $t_p \in [-1, -0.1]$ GeV $^2/c^2$ ）和高质量区域（ $m_{\eta\pi} > 2.4$ GeV/ $c^2$ ），在这些区域，双 Regge（DR）交换机制预计将占据主导地位。

产生振幅使用双 Regge 形式进行建模，涉及在产生的介子之间交换的顶端 Reggeon ( $R_t$ ) 以及在质子与介子系统之间交换的底端 Reggeon ( $R_b$ )。该模型包括：

领先的普通交换： $a_2 f_2$ , $a_2 P$ , $f_2 f_2$ , $f_2 P$ , $P f_2$ , 以及 $P P$ 。
次领先的普通交换： $a'_2$ 轨迹。
奇异交换： $\pi_1$ 轨迹（负符号，奇自旋）。

分析利用扩展负对数似然（ENLL）拟合 Gottfried-Jackson 系标架下的事件分布。接受度效应通过 TGEANT 框架传播的蒙特卡洛模拟进行修正。拟合参数包括每个振幅的强度系数 ( $c_i$ ) 和顶点处的斜率参数 ( $b_i$ )。包含奇异 $\pi_1$ 轨迹的显著性是通过使用 Wilks 定理比较嵌套模型来确定的。

主要贡献与结果
这项工作的核心贡献是首次观测到了高能散射中的奇异 Reggeon 交换。分析表明，仅包含领先普通 Regge 交换的模型无法描述数据，特别是在 $\eta\pi^-$ 通道中的前向峰事件。

奇异交换的必要性： 当基础模型（领先普通交换）扩展到包含次领先的 $a'_2$ 轨迹时，对数据的描述有所改善，但仍然不足。必须引入奇异的 $\pi_1$ 轨迹才能重现观察到的前向-后向不对称性和强度分布。
统计显著性： $\pi_1$ 交换的显著性通过比较包含与不包含 $\pi_1$ 轨迹的模型似然值来量化。结果显示， $\eta\pi^-$ 通道的显著性为 9.9 $\sigma$ ， $\eta'\pi^-$ 通道的显著性为 5.5 $\sigma$ 。这些显著性超过了 5 $\sigma$ 的发现阈值。
轨迹鉴定： 观测到的奇异交换最合理的鉴定是 $\pi_1(1600)$ 轨迹。分析确认，该轨迹在高质量区域与 Pomeron 一起在领先阶贡献。
底端交换动力学： 研究还量化了底端交换的贡献，发现虽然 Pomeron ( $P$ ) 占主导地位，但 $f_2$ 交换在较宽的角度范围内都有显著贡献，特别是在较小的 $t_p$ 处。
不对称性： 前向-后向不对称性 ( $A(m_{\eta\pi})$ ) 被发现显著不为零，这为共振区之外的奇奇异波提供了直接证据。DR 振幅成功重现了这种不对称性，证实了在选定运动学区域内双 Regge 机制的主导地位。

意义
论文声称，这些发现确立了对奇异 Reggeon 交换的首次观测。这一结果意味着产生奇异波的动力学比此前认识的更为丰富：混合介子不仅作为产生的共振态出现，还作为交换的轨迹出现。这为研究 QCD 中的胶子激发提供了互补的窗口。

作者指出，这些发现为 GlueX 实验中的类似测量提供了动力，在 GlueX 中，极化光束和对 $\eta^{(\prime)}\pi^0$ 末态的访问可以由于禁止 Pomeron 交换而隔离出奇异贡献。此外，该分析为在低能部分波提取中引入解析性约束开辟了道路，有望提高混合介子参数的确定精度。对于次主导交换（如 $f_2$ 底端交换）的量化也被强调为对衍射部分子分布函数及未来寻找 Odderon 至关重要。

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