A measurement of the $CP$ asymmetry difference in $\varLambda_{c}^{+} \to pK^{-}K^{+}$ and $p\pi^{-}\pi^{+}$ decays

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

Note:

All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2017-044.html

Charm physics
CP violation
Flavor physics
Hadron-Hadron scattering (experiments)
p p: scattering
p p: colliding beams
Lambda/b0: hadronic decay
Lambda/c+: hadronic decay
asymmetry: difference
dimension: 5

References(27)

Figures(0)

[1]

Standard model CP violation and baryon asymmetry

- Mod.Phys.Lett.A 9 (1994) 795-810
•
e-Print:
- hep-ph/9312215
•
DOI:
- 10.1142/S0217732394000629

[2]

Review of Particle Physics

C. Patrignani
(
- Bologna U. and
- INFN, Bologna
)
,
K. Agashe
(
- Maryland U.
)
,
G. Aielli
(
- U. Rome 2, Tor Vergata (main)
)
,
C. Amsler
(
- U. Bern, AEC and
- Stefan Meyer Inst. Subatomare Phys.
)
,
M. Antonelli
(
- Frascati
)

et al.

- Chin.Phys.C 40 (2016) 10, 100001
•
DOI:
- 10.1088/1674-1137/40/10/100001

[3]

Averages of $b$ -hadron, $c$ -hadron, and $\tau$ -lepton properties as of summer 2016

HFLAV

Collaboration

•

Y. Amhis
(
- Orsay, LAL
)

et al.

- Eur.Phys.J.C 77 (2017) 12, 895
•
e-Print:
- 1612.07233
•
DOI:
- 10.1140/epjc/s10052-017-5058-4

[4]

Measurement of matter-antimatter differences in beauty baryon decays

LHCb

Collaboration

•

Roel Aaij
(
- CERN
)

et al.

- Nature Phys. 13 (2017) 391-396
•
e-Print:
- 1609.05216
•
DOI:
- 10.1038/nphys4021

[5]

Measurement of $CP$ asymmetry in $D^0 \rightarrow K^- K^+$ and $D^0 \rightarrow \pi^- \pi^+$ decays

LHCb

Collaboration

•

Roel Aaij
(
- NIKHEF, Amsterdam
)

et al.

- JHEP 07 (2014) 041
•
e-Print:
- 1405.2797
•
DOI:
- 10.1007/JHEP07(2014)041

[6]

Measurement of the difference of time-integrated CP asymmetries in $D^0 \rightarrow K^{-} K^{+}$ and $D^0 \rightarrow \pi^{-} \pi^{+}$ decays

LHCb

Collaboration

•

Roel Aaij
(
- CERN
)

et al.

- Phys.Rev.Lett. 116 (2016) 19, 191601
•
e-Print:
- 1602.03160
•
DOI:
- 10.1103/PhysRevLett.116.191601

[7]

Probing CP Asymmetries in Charm Baryons Decays

I.I. Bigi
(
- Notre Dame U.
)

e-Print:
- 1206.4554

[8]

Study of the production of $\Lambda_b^0$ and $\overline{B}^0$ hadrons in $pp$ collisions and first measurement of the $\Lambda_b^0\rightarrow J/\psi pK^-$ branching fraction

LHCb

Collaboration

•

R. Aaij
(
- CERN
)

et al.

- Chin.Phys.C 40 (2016) 1, 011001
•
e-Print:
- 1509.00292
•
DOI:
- 10.1088/1674-1137/40/1/011001

[9]

Measurement of the $CP$ asymmetry in $B_s^0-\overline{B}{}_s^0$ mixing

LHCb

Collaboration

•

Roel Aaij
(
- CERN
)

et al.

- Phys.Rev.Lett. 117 (2016) 6, 061803,
- Phys.Rev.Lett. 118 (2017) 12, 129903 (addendum)
•
e-Print:
- 1605.09768
•
DOI:
- 10.1103/PhysRevLett.117.061803