Differences in the behaviour of matter and antimatter have been observed in K and B meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as CP violation. Here, using data from the LHCb experiment at the Large Hadron Collider, we search for CP-violating asymmetries in the decay angle distributions of Λb0baryons decaying to pπ-π+π-and pπ-K+K-final states. These four-body hadronic decays are a promising place to search for sources of CP violation both within and beyond the standard model of particle physics. We find evidence for CP violation in Λb0to pπ-π+π-decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for CP violation in the baryon sector

Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., et al. (2017). Measurement of matter-antimatter differences in beauty baryon decays. NATURE PHYSICS, 13(4), 391-396 [10.1038/nphys4021].

Measurement of matter-antimatter differences in beauty baryon decays

Belloli, N.;Borgheresi, A.;Borsato, M.;Calvi, M.;Carniti, P.;Cassina, L.;Fazzini, D.;Gotti, C.;Grillo, L.;Khanji, B.;Martinelli, M.;Matteuzzi, C.;Petruzzo, M.;
2017

Abstract

Differences in the behaviour of matter and antimatter have been observed in K and B meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as CP violation. Here, using data from the LHCb experiment at the Large Hadron Collider, we search for CP-violating asymmetries in the decay angle distributions of Λb0baryons decaying to pπ-π+π-and pπ-K+K-final states. These four-body hadronic decays are a promising place to search for sources of CP violation both within and beyond the standard model of particle physics. We find evidence for CP violation in Λb0to pπ-π+π-decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for CP violation in the baryon sector
Articolo in rivista - Articolo scientifico
Physics and Astronomy (all)
English
2017
13
4
391
396
open
Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., et al. (2017). Measurement of matter-antimatter differences in beauty baryon decays. NATURE PHYSICS, 13(4), 391-396 [10.1038/nphys4021].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/187808
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