HEP Colloquia 2026

by Daniele Marangotto

Thursday Jul 9, 2026, 2:30 PM → 3:30 PM Europe/Rome

Sala Consiliare (Department of Physics)

The charm of baryon polarisation

Charm baryon polarisation is a special probe in particle physics, giving a preferential access to heavy-quark spin-dependent physics. Polarisation measurements for baryons produced in different interactions can provide insights for both Beyond-the-Standard Model physics searches and on nonperturbative QCD dynamics.

Limited studies have been done until recently, though, due to the absence of large charm baryon datasets and effective polarisation extraction techniques.

In this talk, I will present the recent studies on charm baryon polarisation, including the development of polarisation measurement techniques, I performed working for the SELDOM ERC project.

The first part will cover the polarisation and amplitude analyses done on proton-proton and proton-gas collisions recorded by the LHCb experiment. They represent the first charm polarisation measurements from weak interaction production, potentially interesting for Beyond-the-Standard Model physics, and the first measurement of separate-charge Λc polarisation in fixed-target proton-gas collisions, useful for studying strong interaction polarising mechanisms.

The second part will focus on the polarisation measurement technique developed for charm baryons. This is based on amplitude models written in the helicity formalism determined from amplitude analyses, which permit to exploit both the high-statistics and the complex dynamics of three-body baryon decays to enhance polarisation sensitivity.

 

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