Top pair threshold revisited

IF 4.9 2区物理与天体物理 Q2 PHYSICS, PARTICLES & FIELDS

The European Physical Journal C Pub Date : 2026-10-07 DOI:10.1140/epjc/s10052-026-16444-y

Torbjörn Sjöstrand, Valery A. Khoze, Christian T. Preuss

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Abstract

Recently the CMS and ATLAS Collaborations have found evidence for an unexpectedly large \({\textrm{t}}{\bar{\textrm{t}}}\) cross section in the threshold region, with an excess of the order of 5–10 pb relative to continuum perturbative calculations. A convenient approach to the theoretical study of this region, unifying the above- and below-threshold behaviour, is the non-relativistic Green’s function formalism. It was first applied to top production more than 35 years ago, well before the discovery of the top. We therefore revive and dissect the old formalism, and put it back together in a more consistent form, suited for Monte Carlo event generation. Combined with some practical prescriptions, it can be applied to current conditions. As an example, the below-threshold cross section comes out to be of the order of 6.5 pb, i.e. comparable with the CMS and ATLAS numbers. The new code is publicly available in the Pythia event generator so can be used for more detailed comparisons.

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重审了顶对阈值

最近，CMS和ATLAS合作发现了在阈值区域有一个出乎意料的大\({\textrm{t}}{\bar{\textrm{t}}}\)横截面的证据，相对于连续介质摄动计算，其横截面超过了5-10 pb的数量级。统一阈值以上和阈值以下行为的一种方便的理论研究方法是非相对论格林函数形式论。早在35年前，它就被首次应用于顶部生产，远远早于顶部的发现。因此，我们恢复和剖析旧的形式主义，并把它放在一起，在一个更一致的形式，适合蒙特卡洛事件生成。结合一些实际处方，可适用于实际情况。例如，阈值以下的截面约为6.5 pb，即与CMS和ATLAS的数值相当。新的代码可以在Pythia事件生成器中公开获得，因此可以用于更详细的比较。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

The European Physical Journal C 物理-物理：粒子与场物理

CiteScore

8.10

自引率

15.90%

发文量

1008

审稿时长

2-4 weeks

期刊介绍： Experimental Physics I: Accelerator Based High-Energy Physics Hadron and lepton collider physics Lepton-nucleon scattering High-energy nuclear reactions Standard model precision tests Search for new physics beyond the standard model Heavy flavour physics Neutrino properties Particle detector developments Computational methods and analysis tools Experimental Physics II: Astroparticle Physics Dark matter searches High-energy cosmic rays Double beta decay Long baseline neutrino experiments Neutrino astronomy Axions and other weakly interacting light particles Gravitational waves and observational cosmology Particle detector developments Computational methods and analysis tools Theoretical Physics I: Phenomenology of the Standard Model and Beyond Electroweak interactions Quantum chromo dynamics Heavy quark physics and quark flavour mixing Neutrino physics Phenomenology of astro- and cosmoparticle physics Meson spectroscopy and non-perturbative QCD Low-energy effective field theories Lattice field theory High temperature QCD and heavy ion physics Phenomenology of supersymmetric extensions of the SM Phenomenology of non-supersymmetric extensions of the SM Model building and alternative models of electroweak symmetry breaking Flavour physics beyond the SM Computational algorithms and tools...etc.