幺正双共振 S 矩阵
Unitary Dual-Resonance S-matrices
AI总结：
研究双共振模型 S 矩阵幺正性问题，通过明确构建不同传统的完全幺正双共振振幅，将零宽度共振塔提升为物理吸收谱并使振幅幺正化，所得 S 矩阵局部解析，为绘制强耦合 S 矩阵空间开辟新途径。
AI中文摘要：
双共振模型以紧凑解析形式实现交叉对称性、雷吉行为和无限多个共振，但它们的规范树级实现缺乏真正的 S 矩阵幺正性。本文明确构建了与传统世界面构造不同的完全幺正双共振振幅。零宽度共振塔被提升为具有交叉和雷吉组织特征的物理吸收谱，通过不同于标准趋肤效应的机制使振幅幺正化。所得 S 矩阵是局部且解析的，可包含可控的第二页雷吉轨迹以及可观的非弹性。更广泛地说，我们的构造为绘制一致的强耦合 S 矩阵空间开辟了一条新途径。
英文摘要：
Dual-resonance models realize crossing symmetry, Regge behavior and infinitely many resonances in a compact analytic form but their canonical tree-level realizations fall short of genuine S-matrix unitarity. Here we explicitly construct fully unitary dual-resonance amplitudes distinct from the conventional worldsheet construction. The zero-width resonance towers are promoted into a physical absorptive spectrum that retains their characteristic crossing and Regge organization, while unitarizing the amplitude through a mechanism distinct from standard eikonalization. The resulting S-matrices are also local and analytic, and can contain controllable second-sheet Regge trajectories as well as substantial inelasticity. More broadly, our construction opens up a new route to charting the space of consistent strongly coupled S-matrices.
