Measurement of matter-antimatter differences in beauty baryon decays

The LHCb collaboration

doi:10.1038/nphys4021

Measurement of matter-antimatter differences in beauty baryon decays

The LHCb collaboration

European Organization for Nuclear Research
University Santiago de Compostela
University of Bristol
Clermont-Auvergne University
Aix-Marseille Université
Fakultät Physik
University of Dortmund
SUPA
University of Glasgow
Science Park 105
Petersburg Nuclear Physics Institute (PNPI)
Imperial College London
University of Cincinnati
Instituto de Biofisica da UFRJ
INFN
Laboratoire de l'Accélérateur Linéaire
ENAC-IIC-GEL
Istituto Nazionale di Fisica Nucleare, Sezione di Firenze
Sezione INFN di Ferrara
University of Ferrara
University of Maryland, College Park
School of Physics and Astronomy
University of Manchester
University of Heidelberg
Kurchatov Institute
Syracuse University
Sezione di Roma
Department of Physics
University of Warwick
ICCUB
University of Barcelona
Pontifícia Universidade Católica do Rio de Janeiro
Institute for Nuclear Physics
National Centre for Nuclear Research (NCBJ)
Université Savoie Mont Blanc
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
Centro Brasileiro de Pesquisas Fisicas

Research output: Contribution to journal › Article › peer-review

102 Citations (Scopus)

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 Λ_b ⁰ baryons 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 Λ_b ⁰ to 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.

Original language	English
Pages (from-to)	391-396
Number of pages	6
Journal	Nature Physics
Volume	13
Issue number	4
DOIs	https://doi.org/10.1038/nphys4021
Publication status	Published - 1 Apr 2017

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10.1038/nphys4021

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@article{900fc9fe0a9e4336a0e0af058c252dd0,

title = "Measurement of matter-antimatter differences in beauty baryon decays",

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 Λb 0 baryons 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 Λb 0 to 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.",

author = "\{The LHCb collaboration\} and R. Aaij and B. Adeva and M. Adinolfi and Z. Ajaltouni and S. Akar and J. Albrecht and F. Alessio and M. Alexander and S. Ali and G. Alkhazov and \{Alvarez Cartelle\}, P. and Alves, \{A. A.\} and S. Amato and S. Amerio and Y. Amhis and L. An and L. Anderlini and G. Andreassi and M. Andreotti and Andrews, \{J. E.\} and Appleby, \{R. B.\} and F. Archilli and P. D'Argent and \{Arnau Romeu\}, J. and A. Artamonov and M. Artuso and E. Aslanides and G. Auriemma and M. Baalouch and I. Babuschkin and S. Bachmann and Back, \{J. J.\} and A. Badalov and C. Baesso and S. Baker and W. Baldini and Barlow, \{R. J.\} and C. Barschel and S. Barsuk and W. Barter and M. Baszczyk and V. Batozskaya and B. Batsukh and V. Battista and A. Bay and L. Beaucourt and J. Beddow and F. Bedeschi and I. Bediaga and F. Fleuret",

year = "2017",

month = apr,

day = "1",

doi = "10.1038/nphys4021",

language = "English",

volume = "13",

pages = "391--396",

journal = "Nature Physics",

issn = "1745-2473",

publisher = "Nature Research",

number = "4",

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TY - JOUR

T1 - Measurement of matter-antimatter differences in beauty baryon decays

AU - The LHCb collaboration

AU - Aaij, R.

AU - Adeva, B.

AU - Adinolfi, M.

AU - Ajaltouni, Z.

AU - Akar, S.

AU - Albrecht, J.

AU - Alessio, F.

AU - Alexander, M.

AU - Ali, S.

AU - Alkhazov, G.

AU - Alvarez Cartelle, P.

AU - Alves, A. A.

AU - Amato, S.

AU - Amerio, S.

AU - Amhis, Y.

AU - An, L.

AU - Anderlini, L.

AU - Andreassi, G.

AU - Andreotti, M.

AU - Andrews, J. E.

AU - Appleby, R. B.

AU - Archilli, F.

AU - D'Argent, P.

AU - Arnau Romeu, J.

AU - Artamonov, A.

AU - Artuso, M.

AU - Aslanides, E.

AU - Auriemma, G.

AU - Baalouch, M.

AU - Babuschkin, I.

AU - Bachmann, S.

AU - Back, J. J.

AU - Badalov, A.

AU - Baesso, C.

AU - Baker, S.

AU - Baldini, W.

AU - Barlow, R. J.

AU - Barschel, C.

AU - Barsuk, S.

AU - Barter, W.

AU - Baszczyk, M.

AU - Batozskaya, V.

AU - Batsukh, B.

AU - Battista, V.

AU - Bay, A.

AU - Beaucourt, L.

AU - Beddow, J.

AU - Bedeschi, F.

AU - Bediaga, I.

AU - Fleuret, F.

PY - 2017/4/1

Y1 - 2017/4/1

N2 - 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 Λb 0 baryons 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 Λb 0 to 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.

AB - 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 Λb 0 baryons 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 Λb 0 to 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.

U2 - 10.1038/nphys4021

DO - 10.1038/nphys4021

M3 - Article

AN - SCOPUS:85011692302

SN - 1745-2473

VL - 13

SP - 391

EP - 396

JO - Nature Physics

JF - Nature Physics

IS - 4

ER -

Measurement of matter-antimatter differences in beauty baryon decays

Abstract

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