Light Cone 2021: Physics of Hadrons on the Light Front

Accessing the coupled-channels dynamics using femtoscopic correlations with ALICE at LHC

2 Dec 2021, 16:50

20m

Emerald Hall B (Jeju Booyoung Hotel)

Contributed talk Parallel Session

Speaker

Valentina Mantovani Sarti (Technische Universitaet Muenchen)

Description

Systems as ${\mathrm{K}}^{-}\mathrm{p}$ and baryon--antibaryon ($\mathrm{B}\bar{\mathrm{B}}$) are both characterised by the presence, already at the production threshold, of strong inelastic channels which can affect the properties and the formation of bound states and resonances. In the $\bar{\mathrm{K}}\mathrm{N}$ system, the $\mathrm{\Lambda }(1405)$ arises from the interplay between the $\bar{\mathrm{K}}\mathrm{N}$ and the coupled $\mathrm{\Sigma }\pi$ channel. Experimental constraints on the different $\bar{\mathrm{K}}\mathrm{N}$ coupled-channels are needed to provide a full description of the nature and properties of the $\mathrm{\Lambda }(1405)$. Similarly, baryon–antibaryon systems are characterised by the dominant contribution of several mesonic channels related to the presence of annihilation processes acting below 1 fm. The possible existence of baryon--antibaryon bound states is still under debate due to a limited amount of data for the $\mathrm{p}-\bar{\mathrm{p}}$ system available, and either scarce or absent experimental data for $\mathrm{B}\bar{\mathrm{B}}$ systems containing strangeness. The femtoscopy technique measures the correlation of particle pairs at low relative momentum. This method applied in small colliding systems, as pp and p--Pb collisions at ALICE provided high-precision data on several baryon--baryon and meson--baryon pairs showing a great sensitivity to the underlying strong potential and to the introduction of the different coupled-channels. In this talk, we will present femtoscopic correlations measured by ALICE in pp collisions at $\sqrt{s}=13$ TeV, separately for data samples obtained with minimum-bias and high-multiplicity triggers, and in peripheral and ultra--peripheral p--Pb and Pb--Pb collisions at $\sqrt{s}=5.02$ TeV. In particular, we will show results on the ${\mathrm{K}}^{-}\mathrm{p}$ correlation function which for the first time provide experimental evidence of the opening of the coupled isospin breaking channel $\overline{{\mathrm{K}}^0}-\mathrm{n}$ and on the $\mathrm{\Sigma }\pi$ channel contributions. Finally, results from baryon--antibaryon pairs ($\mathrm{p}\bar{\mathrm{p}}$, $\mathrm{p}\bar{\mathrm{\Lambda }}$ and $\mathrm{\Lambda }\bar{\mathrm{\Lambda }}$) will be shown for the first time. The effect of annihilation channels on the correlation function and a quantitative determination of the inelastic contributions in the three different pairs will be discussed.

Presentation materials

Abstract_LightCone2021.pdf