Polarimetry in Λc⁺ → p K⁻ π⁺#
The polarimeter vector field for multibody decays of a spin-half baryon is introduced as a generalisation of the baryon asymmetry parameters. Using a recent amplitude analysis of the \(\Lambda^+_\mathrm{c} \to p K^- \pi^+\) decay performed at the LHCb experiment, we compute the distribution of the kinematic-dependent polarimeter vector for this process in the space of Mandelstam variables to express the polarised decay rate in a model-agnostic form. The obtained representation can facilitate polarisation measurements of the \(\Lambda^+_\mathrm{c}\) baryon and eases inclusion of the \(\Lambda^+_\mathrm{c} \to p K^- \pi^+\) decay mode in hadronic amplitude analyses.
This website shows all analysis results that led to the publication of LHCb-PAPER-2022-044. More information on this publication can be found on the following pages:
Publication on JHEP: J. High Energ. Phys. 2023, 228 (2023)
Publication on arXiv: arXiv:2301.07010
Record on CDS: cds.cern.ch/record/2838694
Record for the source code on Zenodo: 10.5281/zenodo.7544989
Archived documentation on GitLab Pages: lc2pkpi-polarimetry.docs.cern.ch
Archived repository on CERN GitLab: gitlab.cern.ch/polarimetry/Lc2pKpi
Active repository on GitHub containing discussions: github.com/ComPWA/polarimetry
Behind SSO login (LHCb members only)
LHCb TWiki page: twiki.cern.ch/twiki/bin/viewauth/LHCbPhysics/PolarimetryLc2pKpi
Charm WG meeting: indico.cern.ch/event/1187317
RC approval presentation: indico.cern.ch/event/1213570
Silent approval to submit: indico.cern.ch/event/1242323
Python package#
Each of the pages contain code examples for how to reproduce the results with the Python package hosted at github.com/ComPWA/polarimetry. However, to quickly get import the model in another package, it is possible to install the package from PyPI:
pip install polarimetry-lc2pkpi
Each of the models can then simply be imported as
import polarimetry
model = polarimetry.published_model("Default amplitude model")
model.intensity.cleanup()
For more examples of how to use the codebase, see the following pages.
Table of contents
- 1. Nominal amplitude model
- 2. Cross-check with LHCb data
- 3. Intensity distribution
- 4. Polarimeter vector field
- 5. Uncertainties
- 6. Average polarimeter per resonance
- 7. Appendix
- 7.1. Dynamics lineshapes
- 7.2. DPD angles
- 7.3. Phase space sample
- 7.4. Alignment consistency
- 7.5. Benchmarking
- 7.6. Polarimeter field serialization
- 7.7. Model serialization
- 7.8. Amplitude model with LS-couplings
- 7.9. SU(2) → SO(3) homomorphism
- 7.10. Determination of polarization
- 7.11. Interactive visualization
- 8. Bibliography
- 9. API
Tip
Several cross-checks with Julia can be found here.
Tip
Figures for the paper can be downloaded here:
- Figure 2:
- Figure 3a:
- Figure 3b:
- Figure 4:
All other exported figures can be found here.
Notebook execution times
Document |
Modified |
Method |
Run Time (s) |
Status |
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2024-05-04 17:42 |
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32.54 |
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2024-05-04 17:43 |
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83.92 |
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2024-05-04 17:43 |
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2.49 |
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2024-05-04 17:46 |
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172.88 |
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2024-05-04 17:46 |
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2.14 |
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2024-05-04 17:46 |
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2.72 |
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2024-05-04 17:51 |
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306.09 |
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2024-05-04 17:52 |
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48.74 |
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2024-05-04 17:53 |
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18.16 |
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2024-05-04 17:54 |
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66.33 |
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2024-05-04 18:04 |
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598.73 |
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2024-05-04 18:05 |
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113.35 |
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2024-05-04 18:06 |
cache |
2.21 |
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2024-05-04 18:09 |
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227.11 |
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2024-05-04 18:13 |
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225.94 |
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2024-05-04 19:02 |
cache |
2962.4 |
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2024-05-04 19:28 |
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1514.85 |
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2024-05-04 19:31 |
cache |
219.55 |
✅ |