Jul 26 – 30, 2021
Europe/Berlin timezone

Extending the ALICE strong-interaction studies to nuclei: measurement of proton-deuteron correlations in pp collisions at $\sqrt{s} = 13$ TeV

Jul 28, 2021, 9:45 AM


Parallel session talk T06: QCD and Hadronic Physics


Bhawani Singh


The large data sample of high-multiplicity pp collisions collected by ALICE allows for the precise measurement of the size of the source producing primary hadrons, opening the door to the study of the interaction of different hadron species using femtoscopy techniques. The momentum correlation between (anti)protons and (anti)deuterons measured in pp collisions at $\sqrt{s}=$ 13 TeV with ALICE is studied here for the first time. The measured correlation function for ($\bar{\rm p}$)${\rm p}$–($\bar{\rm d}$)${\rm d}$ pairs is compared with theoretical predictions based on both Coulomb interaction only and Coulomb plus strong interactions, employing the Lednický-Lyuboshitz model and the scattering parameters extracted from p-d scattering experiments. In both cases, the measured correlation function cannot be reproduced by the predictions. This deviation is interpreted as a demonstration of the late formation time of (anti)deuterons in hadron-hadron collisions. This observation is key for the understanding of the production mechanism of light (anti)nuclei, which is an open issue in high-energy physics and has also important consequences for the study of antinuclei formation in the interstellar medium either from collisions triggered by high-energy cosmic rays or by dark matter decays.

Collaboration / Activity ALICE

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