# Strong interactions

### Quark-matter mysteries on the run in Bari

Among the highlights at Strangeness in Quark Matter 2019 were reports on where strangeness enhancement is localised in phase space.

### Bottomonium elliptic-flow no-show

Bottomonia are the first hadrons that do not seem to "flow" in heavy-ion collisions at the LHC.

### 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.