Search for CP Violation in the Decay $\tau^- -> \pi^- K^0_S (>= 0 \pi^0) \nu_tau$

We report a search for CP violation in the decay \tau- -> \pi - \K^0_S (>= 0 \pi 0) \nu_\tau\ using a dataset of 437 million \tau\ lepton pairs, corresponding to an integrated luminosity of 476 fb^{-1}, collected with the BABAR detector at the PEP-II asymmetric energy e+e- storage rings. The CP-violating decay-rate asymmetry is determined to be (-0.45 +/- 0.24 +/- 0.11)%, approximately three standard deviations from the Standard Model prediction of (0.33 +/- 0.01)%.

Note:

7 pages, 2 encapsulated postscript figures, submitted to Phys. Rev. D (Rapid Communications)

13.35.Dx
11.30.Er
CP: violation
tau-: semileptonic decay
decay rate: asymmetry: measured
electron positron: annihilation
tau: pair production
tau+: semileptonic decay
BaBar
experimental results

References(17)

Figures(8)

A 'Known' CP asymmetry in tau decays

I.I. Bigi
(
- Notre Dame U.
)
,
A.I. Sanda
(
- Nagoya U.
)

- Phys.Lett.B 625 (2005) 47-52
•
e-Print:
- hep-ph/0506037
•
DOI:
- 10.1016/j.physletb.2005.08.033

Search for CP violation in the decay $D^\pm \to K_S^0\pi^\pm$

BaBar

Collaboration

•

P. del Amo Sanchez
(
- Annecy, LAPP
)

et al.

- Phys.Rev.D 83 (2011) 071103
•
e-Print:
- 1011.5477
•
DOI:
- 10.1103/PhysRevD.83.071103

Search for CP violation in the decays $D^+_{(s)} \to K_S^0\pi^+$ and $D^+_{(s)} \to K_S^0K^+$

Belle

Collaboration

•

B.R. Ko
(
- Korea U.
)

et al.

- Phys.Rev.Lett. 104 (2010) 181602
•
e-Print:
- 1001.3202
•
DOI:
- 10.1103/PhysRevLett.104.181602

Search for CP violation in $\tau \to K^0_S \pi \nu_\tau$ decays at Belle

Belle

Collaboration

•

M. Bischofberger
(
- Nara Women's U.
)

et al.

- Phys.Rev.Lett. 107 (2011) 131801
•
e-Print:
- 1101.0349
•
DOI:
- 10.1103/PhysRevLett.107.131801

Search for CP violation in tau ---> K pi tau-neutrino decays

CLEO

Collaboration

•

G. Bonvicini
(
- Wayne State U.
)

et al.

- Phys.Rev.Lett. 88 (2002) 111803
•
e-Print:
- hep-ex/0111095
•
DOI:
- 10.1103/PhysRevLett.88.111803

The BaBar detector

BaBar

Collaboration

•

Bernard Aubert
(
- Annecy, LAPP
)

et al.

- Nucl.Instrum.Meth.A 479 (2002) 1-116
•
e-Print:
- hep-ex/0105044
•
DOI:
- 10.1016/S0168-9002(01)02012-5

Observation of CP violation in $B^0 \to K^{+} \pi^{-}$ and $B^0 \to \pi^{+} \pi^{-}$

BaBar

Collaboration

•

Bernard Aubert
(
- Annecy, LAPP
)

et al.

- Phys.Rev.Lett. 99 (2007) 021603
•
e-Print:
- hep-ex/0703016
•
DOI:
- 10.1103/PhysRevLett.99.021603

Limits on tau Lepton-Flavor Violating Decays in three charged leptons

BaBar

Collaboration

•

J.P. Lees
(
- Annecy, LAPP
)

et al.

- Phys.Rev.D 81 (2010) 111101
•
e-Print:
- 1002.4550
•
DOI:
- 10.1103/PhysRevD.81.111101

Precision calculation for e+ e- ---> 2f: The KK MC project

- Nucl.Phys.B Proc.Suppl. 116 (2003) 73-77,
•
e-Print:
- hep-ph/0211132
•
DOI:
- 10.1016/S0920-5632(03)80147-0

The tau decay library TAUOLA: Version 2.4

S. Jadach
(
- CERN and
- Cracow, INP
)
,
Z. Was
(
- CERN and
- Cracow, INP
)
,
R. Decker
(
- Karlsruhe U.
)
,
Johann H. Kuhn
(
- Karlsruhe U.
)

- Comput.Phys.Commun. 76 (1993) 361-380
•
DOI:
- 10.1016/0010-4655(93)90061-G

High-energy physics event generation with PYTHIA 5.7 and JETSET 7.4

Torbjorn Sjostrand
(
- CERN
)

- Comput.Phys.Commun. 82 (1994) 74-90,
- CERN Geneva - TH. 7111 (93/12,rec.Jan.94) 17 p. and e: CERN th-7111-93
•
DOI:
- 10.1016/0010-4655(94)90132-5