The distribution of angular correlations between prompt charm hadrons and primary charged particles in pp collisions is sensitive to the charm-quark hadronisation process. In this letter, charm-baryon correlations are measured for the first time by studying the azimuthal-angle difference between charged particles and prompt Λc+ baryons produced in pp collisions at a centre-of-mass energy of s=13 TeV, with the ALICE detector. Λc+ baryons are reconstructed at midrapidity (|y|<0.5) in the transverse-momentum interval 3<16 GeV/c, and correlated with charged particles with pT>0.3 GeV/c and pseudorapidity |η|<0.8. For 3<5 GeV/c, the comparison with published measurements of D-meson and charged-particle correlations in the same collision system hints at a larger number of low-momentum particles associated with Λc+-baryon triggers than with D-meson triggers, both in the collinear and opposite directions with respect to the trigger particle. These differences can be quantified by the comparison of the properties of the near- and away-side correlation peaks, and are not reproduced by predictions of various Monte Carlo event generators, generally underpredicting the associated particle yields at pTassoc<1 GeV/c. This tension between Λc+-baryon and D-meson associated peak yields could suggest a modified fragmentation of the charm quark, or a different hadronisation process, when a charm baryon is produced in the final state.

Studying charm hadronisation into baryons with azimuthal correlations of Λ+c with charged particles in pp collisions at √s = 13 TeV / Alice, C., Acharya, S., Agarwal, A., Aglieri Rinella, G., Aglietta, L., Agnello, M., Agrawal, N., Ahammed, Z., Ahmad, S., Ahn, S.U., Ahuja, I., Akindinov, A., Akishina, V., Al-Turany, M., Aleksandrov, D., Alessandro, B., Alfanda, H.M., Alfaro Molina, R., Ali, B., Alici, A., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - ELETTRONICO. - 868/2025:(2025), pp. 139681.1-139681.18. [10.1016/j.physletb.2025.139681]

Studying charm hadronisation into baryons with azimuthal correlations of Λ+c with charged particles in pp collisions at √s = 13 TeV

Camerini, P.;Cattaruzzi, S.;Contin, G.;De Martin, C.;Fragiacomo, E.;Luparello, G.;Margagliotti, G. V.;Piano, S.;Rui, R.;Villani, A.;Zaccolo, V.;
2025-01-01

Abstract

The distribution of angular correlations between prompt charm hadrons and primary charged particles in pp collisions is sensitive to the charm-quark hadronisation process. In this letter, charm-baryon correlations are measured for the first time by studying the azimuthal-angle difference between charged particles and prompt Λc+ baryons produced in pp collisions at a centre-of-mass energy of s=13 TeV, with the ALICE detector. Λc+ baryons are reconstructed at midrapidity (|y|<0.5) in the transverse-momentum interval 3<16 GeV/c, and correlated with charged particles with pT>0.3 GeV/c and pseudorapidity |η|<0.8. For 3<5 GeV/c, the comparison with published measurements of D-meson and charged-particle correlations in the same collision system hints at a larger number of low-momentum particles associated with Λc+-baryon triggers than with D-meson triggers, both in the collinear and opposite directions with respect to the trigger particle. These differences can be quantified by the comparison of the properties of the near- and away-side correlation peaks, and are not reproduced by predictions of various Monte Carlo event generators, generally underpredicting the associated particle yields at pTassoc<1 GeV/c. This tension between Λc+-baryon and D-meson associated peak yields could suggest a modified fragmentation of the charm quark, or a different hadronisation process, when a charm baryon is produced in the final state.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11368/3135110
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