First measurement of the strong proton-φ interaction at the LHC


The φ meson is an interesting probe to test the partial restoration of chiral symmetry, as modifications of its in-medium properties are predicted. Studying the meson-nucleon interaction in vacuum provides valuable input and constrains theoretical models needed to correctly interpret experimental measurements of nuclear collisions.   

The 2-body interaction, illustrated on the right figure plot, has been measured for the first time by the ALICE collaboration at the LHC in pp collisions at √sNN= 13 TeV using correlations in momentum space, which are sensitive to the relative distance of the particles. Especially, the small inter-particle distance that characterise the hadron production in ultra-relativistic pp collisions at the Large Hadron Collider, gives rise to a pronounced correlation signal (shown in the left figure) that allows to pin down a moderately attractive proton-φ  interaction with a small absorption cross-section. 

Further reading:

ALICE collaboration, arXiv:2105.05578

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