A measurement of the CP asymmetry difference between Λc+ → pK−K+ and pπ−π+ decays

• Published in: The journal of high energy physics Vol. 2018; no. 3; pp. 1 - 21
• Main Authors: Alfonso Albero, A., Alkhazov, G., Alves, A. A., Appleby, R. B., Aslanides, E., Babuschkin, I., Badalov, A., Baker, S., Barlow, R. J., Barter, W., Baryshnikov, F., Bediaga, I., Beliy, N., Bencivenni, G., Bezshyiko, Ia, Birnkraut, A., Blanc, F., Bowcock, T. J. V., Cattaneo, M., Cenci, R., Cheung, S. F., Ciambrone, P., Cliff, H. V., Contu, A., Costa Sobral, C. M., D’Ambrosio, C., De Bruyn, K., Dosil Suárez, A., Ebert, M., Eisenhardt, S., Evans, H. M., Farry, S., Fazzini, D., Fernandez Prieto, A., Fontanelli, F., Färber, C., Gallorini, S., Gao, Y., Garrido, L., Gligorov, V. V., Golutvin, A., Gomes, A., Gys, T., Henry, L., Ilten, P., Jacobsson, R., Jans, E., Jones, C. R., Karodia, S., Keizer, F., Kirn, T., Krokovny, P., Lacarrere, D., Lafferty, G., Latham, T., Leflat, A., Lionetto, F., Lisovskyi, V., Martinelli, M., Meinert, N., Michielin, E., Minzoni, L., Mitzel, D. S., Mogini, A., Müller, D., Naik, P., Nikitin, N., Passaleva, G., Pescatore, L., Petrolini, A., Pinci, D., Playfer, S., Ponce, S., Qian, W., Quagliani, R., Redi, F., Robbe, P., Romero Vidal, A., Ruiz Vidal, J., Santovetti, E., Sarpis, G., Schopper, A., Skwarnicki, T., Stenyakin, O., Straumann, U., Teubert, F., Tourinho Jadallah Aoude, R., Tran, M. T., Vacca, C., Velthuis, J. J., Vieites Diaz, M., Waldi, R., Watson, N. K., Wicht, J., Wimberley, J., Witek, M., Yang, Z., Yushchenko, O., Zarebski, K. A., Zhang, Y.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2018; Springer Nature B.V; Springer Berlin; SpringerOpen
• Subjects: Charm physics; Classical and Quantum Gravitation; CP violation; Decay; Elementary Particles; Flavor physics; Hadron-Hadron scattering (experiments); High energy physics; Luminosity; Particle collisions; Physics; Physics and Astronomy; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Experimental Physics; Relativity Theory; Skewed distributions; Statistical analysis; Statistical methods; String Theory; Flavor physics; Charm physics; CP violation; Hadron-Hadron scattering (experiments)
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP03(2018)182

A bstract The difference between the CP asymmetries in the decays Λ c +  →  pK − K + and Λ c +  →  pπ − π + is presented. Proton-proton collision data taken at centre-of-mass energies of 7 and 8 TeV collected by the LHCb detector in 2011 and 2012 are used, corresponding to an integrated luminosity of 3 fb −1 . The Λ c + candidates are reconstructed as part of the Λ b 0  →  Λ c + μ − X decay chain. In order to maximize the cancellation of production and detection asymmetries in the difference, the final-state kinematic distributions of the two samples are aligned by applying phase-space-dependent weights to the Λ c +  →  pπ − π + sample. This alters the definition of the integrated CP asymmetry to A CP wgt ( pπ − π + ). Both samples are corrected for reconstruction and selection efficiencies across the five-dimensional Λ c + decay phase space. The difference in CP asymmetries is found to be Δ A C P w g t = A C P p K − K + − A C P w g t p π − π + = 0.30 ± 0.91 ± 0.61 % , where the first uncertainty is statistical and the second is systematic.