Speaker
Description
High-multiplicity measurements in pp and p--Pb collisions have revealed the presence of phenomena typically attributed to the creation of a quark-gluon plasma. Events with multiple parton-parton interactions (MPIs) have been proposed as one possible explanation of this observation. MPIs play a significant role in describing the soft component of the hadronic interactions, and at LHC energies also affect the production of heavy quarks. Quarkonium measurements in small systems, such as production and flow as a function of the event activity as well as double quarkonium production, offer a special insight into MPIs. In addition, other results integrated over multiplicity represent an important baseline. A wide variety of quarkonium measurements in pp collisions, including also less standard observables like polarization and production in association with jets, are crucial to clarify production mechanisms at play, as they are not yet fully understood. Furthermore, measurements in p--Pb collisions allow one to investigate cold nuclear matter effects, such as the modification of nuclear parton distribution functions.
In this contribution, new published multiplicity dependent $\psi$(2S) and $\Upsilon$($n$S) ($n$ = 1,2,3) measurements, carried out at forward rapidity in pp collisions at $\sqrt{s}$ = 13 TeV and p--Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV, along with quarkonium excited-to-ground state ratios, will be discussed. A wide collection of new measurements in pp collisions at 13 TeV, including $\Upsilon$(1S) polarization, J/$\psi$ $v_{2}$, as well as J/$\psi$ produced in pairs or associated with jets, with the latter based on the usage of TRD triggered data, will be shown. Moreover, new published results of the prompt and non-prompt J/$\psi$ nuclear modification at midrapidity in p-Pb collisions at $\sqrt{s}$ = 8.16 TeV will be presented. Results will be compared with available theoretical calculations.
| What kind of work does this abstract pertain to? | Experimental |
|---|---|
| Which experiment is this abstract related to? | ALICE |
