Abstract
Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 GeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions. The measurements are compared to various predictions from event generators and analytical calculations.
| Original language | English |
|---|---|
| Number of pages | 17 |
| Journal | Physical Review Letters |
| Volume | 120 |
| Issue number | 14 |
| DOIs | |
| Publication status | Published - 30 Aug 2017 |
| Externally published | Yes |
Bibliographical note
Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIN-16-006 (CMS Public Pages)'Keywords
- nucl-ex
- hep-ex