Search for CP violation in Ξ−b→pK−K−decays

Physical Review D - Particles, Fields, Gravitation and Cosmology. 2021. Vol. 104. No. 5. Article 052010.

Aaij R., Boldyrev A., Derkach D., Hushchyn M., Karpov M., Maevskiy A., Ratnikov F., Ryzhikov A., Ustyuzhanin A., Arzymatov K., Belavin V., Philippov A., Popov S.

A search for CP violation in charmless three-body Ξ−b→pK−K− decays is performed using pp collision data recorded with the LHCb detector, corresponding to integrated luminosities of 1  fb−1 at a center-of-mass energy √s=7  TeV, 2  fb−1 at √s=8  TeV and 2  fb−1 at √s=13  TeV. A good description of the phase-space distribution is obtained with an amplitude model containing contributions from Σ(1385), Λ(1405), Λ(1520), Λ(1670), Σ(1775) and Σ(1915) resonances. The model allows for CP -violation effects, which are found to be consistent with zero. The branching fractions of Ξ−b→Σ(1385)K−, Ξ−b→Λ(1405)K−, Ξ−b→Λ(1520)K−, Ξ−b→Λ(1670)K−, Ξ−b→Σ(1775)K− and Ξ−b→Σ(1915)K− decays are also reported. In addition, an upper limit is placed on the product of ratios of Ω−b and Ξ−b fragmentation fractions and the Ω−b→pK−K− and Ξ−b→pK−K− branching fractions.

Keywords: анализ данных, data analysis, high energy physics, физика высоких энергий

Publication based on the results of: Machine learning to check and improve the quality of data collected at the Large Hadron Collider and other particle physics experiments (2021)