Top pair threshold revisited — Draconitic Research

Abstract

Recently the CMS and ATLAS Collaborations have found evidence for an unexpectedly large tt̅ t 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.

Effective Hardcore Exclusion Without Exclusion: Two-Species Pair Annihilation Revisited
Su-Chan Park, Foster Thompson
arXiv31 Aug 2026PreprintCC BY 4.0Full textStatistical & nonlinear physicsarXiv
Observation of an excess at the top quark pair production threshold in the single-lepton channel
Arzunik Gevorgyan, Aram Hayrapetyan, Vladimir Makarenko +2,541
HAL3 Sep 2026PreprintLicence not statedHigh-energy & particle physicsHAL
Muon pair production in electron-positron collisions close to threshold in the presence of a strong laser field
N. Mahlin, S. Villalba-Chávez, C. Müller
Physics Letters B30 Oct 2026Peer-reviewedCC BY 4.0Full textAtomic, molecular & optical physicsCrossrefDOAJ
Determining the Threshold Excess in Top-Quark Pair Production through a Global PDF Analysis
Richard D. Ball, Jaco ter Hoeve
arXiv15 Oct 2026PreprintCC BY 4.0Full textHigh-energy & particle physicsarXiv
The Longest Increasing Subsequence Problem revisited
Silvio Franz, Roberto Mulet
Communications in Theoretical Physics3 Oct 2026Peer-reviewedLicence not statedGeneral physicsHAL

Cite

BibTeX RIS

BibTeX

@article{sjostrand2026pair,
  title = {{Top pair threshold revisited}},
  author = {Torbjörn Sjöstrand and Valery A. Khoze and Christian T. Preuss},
  journal = {The European Physical Journal C},
  year = {2026},
  month = oct,
  doi = {10.1140/epjc/s10052-026-16444-y},
  url = {https://link.springer.com/10.1140/epjc/s10052-026-16444-y},
  note = {CC BY 4.0},
}

RIS

TY  - JOUR
TI  - Top pair threshold revisited
AU  - Torbjörn Sjöstrand
AU  - Valery A. Khoze
AU  - Christian T. Preuss
PY  - 2026
DA  - 2026/10/07
JO  - The European Physical Journal C
DO  - 10.1140/epjc/s10052-026-16444-y
UR  - https://link.springer.com/10.1140/epjc/s10052-026-16444-y
AB  - Recently the CMS and ATLAS Collaborations have found evidence for an unexpectedly large tt̅ t 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.
SN  - 1434-6044
SN  - 1434-6052
ER  -

Abstract

Related

Cite