Speaker
Description
High multiplicity events of small colliding systems at high c.m.s. energies show similar collective features as those observed in events
of heavy ion collisions with comparable multiplicities, such as long-range near-side correlations and v_n coefficients [1,2]. Whether this behaviour may be attributed to the presence of a deconfined state in small systems is an open question.
Recent analyses of pp and p-Pb collisions also show an universal enhancement of heavy-flavour particles [3], that is usually attributed to multiple parton interactions (MPI) and higher gluon radiation associated with short distance production processes [4,5]. While we cannot expect to be able to apply hard probes on the medium created in the collisions of small systems, phenomena like MPI or Color reconnection (CR) may cause a modification of the jet shapes that can in principle be experimentally accessible.
We have carried out extensive studies using Monte Carlo event generators. We give predictions for multiplicity-dependent jet structures, and propose a way to validate the presence and extent of effects such as MPI or Color Reconnection, based on the detection of non-trivial jet shape modification in high multiplicity events. We also propose a definition of a characteristic jet size measure that is independent of multiplicity [6].
References:
[1] CMS Coll., JHEP 09 (2010) 091
[2] CMS Coll., Phys.Rev.Lett. 112 (2014) 082301
[3] ALICE Coll., JHEP 1608 (2016) 078
[4] S. Porteboeuf, R. Granier de Cassagnac, Nucl.Phys.Proc.Suppl. 214 (2011) 181
[5] T. Sjostrand, M. van Zijl, Phys.Rev.D 36 (1987) 2019.
[6] Z.V., https://indico.cern.ch/event/684046/contributions/2809561/attachments/1571304/2478958/Zoltan_Varga_ZimanyiSchool.pdf
| Content type | Theory |
|---|---|
| Centralised submission by Collaboration | Presenter name already specified |
