# Strong interactions

### Heavy ions and hidden sectors

The meeting was inspired by several recent proposals to take advantage of the unique environment of heavy-ion collisions at the LHC to search for new phenomena.

### New constraints on charm–quark hadronisation

Heavier quarks, such as charm, can provide unique insights as they are produced early in the collisions, and their interactions with the QGP differ from their lighter cousins.

### Studying neutron stars in the laboratory

The ALICE collaboration is now using the scattering between particles produced in collisions at the LHC to constrain interaction potentials in a new way.

### The proton laid bare

What a proton is depends on how you look at it, or rather on how hard you hit it.

### ALICE sheds new light on high-pT suppression

These results demonstrate that with the correct treatment of biases from the parton–parton interactions the observed suppression in Pb–Pb collisions is consistent with results from p–Pb collisio...

The quarkonium yield is suppressed in heavy-ion collisions when compared with proton–proton collisions because the binding force is screened by the hot and dense medium.

### CASTOR calorimetry delves into gluon saturation

This largely unexplored phenomenon is expected to occur when the gluons in a hadron overlap transversally, and is enhanced for hadrons with high atomic numbers.

### New measurements shine a light on the proton

The ALICE collaboration has measured the photoproduction of J/ψ mesons.

This is essential to understand how charm-quark hadronisation is affected by the presence of the quark–gluon plasma.

### Suppression of the Λ(1520) resonance in Pb–Pb collisions

Due to their short lifetimes, they decay when the system is still dense and the decay products scatter in the hadron gas, reducing the observed number of decays.