Peter Christiansen
Professor
Enhanced Deuteron Coalescence Probability in Jets
Author
Summary, in English
The transverse-momentum (pT) spectra and coalescence parameters B2 of (anti)deuterons are measured in p-p collisions at s=13 TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest pT in the event (pTlead>5 GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons in the jet cone as compared with the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase-space distributions of nucleons are generated using pythia8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in pythia8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the B2Jet is not reproduced by the models, which instead give a decreasing trend. © 2023 CERN.
Department/s
- Particle and nuclear physics
Publishing year
2023
Language
English
Publication/Series
Physical Review Letters
Volume
131
Issue
4
Document type
Journal article
Publisher
American Physical Society
Topic
- Subatomic Physics
Keywords
- Coalescence
- Deuterium
- Nuclear reactions
- Tellurium compounds
- Coalescence modeling
- Jet axis
- Jet fragmentation
- Phase space distributions
- Phase spaces
- Production models
- Simple++
- Space distance
- Spectra's
- Transverse momenta
- Phase space methods
Status
Published
ISBN/ISSN/Other
- ISSN: 0031-9007