High Energy Physics Seminar next Thursday - Germani

[HECAP - Margherita Di Giovannantonio]

*_HIGH ENERGY PHYSICS SEMINARS_*
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*Thursday, 01 October *2026, at *16:00* - *_Euler Lecture Hall 
_*-*https://indico.ictp.it/event/11512/*


Davide Germani (Sapienza University of Rome)


*“Old Tools for New Puzzles: From Toponium Physics to the Exotic Nature 
of $X(3872)$**"*
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_Abstract_

High-precision measurements by the ATLAS and CMS collaborations at the 
Large Hadron Collider have opened new avenues in heavy quark 
phenomenology. Interestingly, answering modern questions at the frontier 
of particle physics often relies on adapting and repurposing 
well-established theoretical tools developed decades ago. In this 
seminar, we present two case studies illustrating how contemporary data 
analysis benefits from classic field-theoretic methods.
In the first part, we review the physics of toponium $t\bar{t}$ near the 
production threshold, drawing on recent theoretical works by Paolo Nason 
and collaborators tailored for ATLAS and CMS analyses. We discuss 
threshold resummation effects, non-perturbative QCD corrections, and how 
the short lifetime of the top quark dictates the formation and decay 
dynamics of quasi-bound $t\bar{t}$ states at collider energies.
In the second part, we turn our attention to exotic hadron spectroscopy, 
focusing on the benchmark state $X(3872)$ and the debate surrounding its 
interpretation as a compact state versus a loosely bound $D^0 
\bar{D}^{*0}$ hadronic molecule. We compare the conventional Flatté 
parametrization with an Effective Field Theory approach that 
incorporates an inverted sign in the kinetic term, showing the physical 
implications of this negative kinetic term and its direct connection to 
a negative effective range.
Through these examples, this talk emphasizes how emerging anomalies and 
non-trivial structures in hadron spectroscopy can be systematically 
resolved by revisiting and building upon established theoretical techniques.
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To join via *Zoom*, please register here:

_https://zoom.us/meeting/register/LcUvVSYYR3aUbycaqC75OA_