Search for Lepton-Flavor-Violating and Lepton-Number-Violating $\tau \to \ell h h^\prime$ Decay Modes

We search for lepton-flavor and lepton-number-violating τ decays into a lepton ( ℓ = electron or muon) and two charged mesons ( h,h′=π± or K± ) using 854 fb−1 of data collected with the Belle detector at the KEKB asymmetric-energy e+e− collider. We obtain 90% confidence level upper limits on the τ→ℓhh′ branching fractions in the range (2.0–8.4)×10−8 . These results improve upon our previously published upper limits by factors of about 1.8 on average.

Note:

14 pages, 5 figures, submitted to Phys. Lett. B

11.30.Fs
13.35.Dx
14.60.Fg
BELLE
KEK-B
experimental results
electron positron: annihilation
tau: pair production
tau: semileptonic decay
lepton number: violation

References(25)

Figures(20)

[1]

Lepton flavor violation in the standard model extended by heavy singlet Dirac neutrinos

A. Ilakovac
(
- Zagreb U.
)

- Phys.Rev.D 62 (2000) 036010
•
e-Print:
- hep-ph/9910213
•
DOI:
- 10.1103/PhysRevD.62.036010

[2]

tau - mu flavor violation as a probe of the scale of new physics

- Phys.Rev.D 66 (2002) 053002
•
e-Print:
- hep-ph/0206056
•
DOI:
- 10.1103/PhysRevD.66.053002

[3]

Lepton flavor violation in tau decays

Chuan-Hung Chen
(
- Taiwan, Natl. Cheng Kung U. and
- NCTS, Taipei
)
,
Chao-Qiang Geng
(
- Taiwan, Natl. Tsing Hua U. and
- NCTS, Taipei
)

- Phys.Rev.D 74 (2006) 035010
•
e-Print:
- hep-ph/0605299
•
DOI:
- 10.1103/PhysRevD.74.035010

[4]

Lepton flavour violating semileptonic tau decays in constrained MSSM-seesaw scenarios

E. Arganda
(
- Madrid, Autonoma U. and
- Madrid, IFT
)
,
M.J. Herrero
(
- Madrid, Autonoma U. and
- Madrid, IFT
)
,
J. Portoles
(
- Valencia U., IFIC
)

- JHEP 06 (2008) 079
•
e-Print:
- 0803.2039
•
DOI:
- 10.1088/1126-6708/2008/06/079

[5]

Leptoquark on P ---> l+ nu, FCNC and LFV

- Phys.Lett.B 672 (2009) 172-176
•
e-Print:
- 0807.2373
•
DOI:
- 10.1016/j.physletb.2009.01.011

[6]

Unparticle-Induced Lepton Flavor Violating Decays tau- ---> l-(V0, P0)

- Phys.Lett.B 677 (2009) 150-156
•
e-Print:
- 0901.3266
•
DOI:
- 10.1016/j.physletb.2009.05.032

[7]

Lepton Flavor Violating $\tau$ Decays in Two Higgs Doublet Model III

Wen-Jun Li
(
- Henan Normal U. and
- Beijing, Inst. Theor. Phys.
)
,
Ying-Ying Fan
(
- Henan Normal U.
)
,
Gong-Wei Liu
(
- Henan Normal U.
)
,
Lin-Xia Lu
(
- Nanyang Normal U.
)

- Int.J.Mod.Phys.A 25 (2010) 4827-4837,
- Int.J.Mod.Phys.A 25 (2010) 1005038
•
e-Print:
- 1007.2894
•
DOI:
- 10.1142/S0217751X1005038X

[8]

Lepton flavor violation decays tau- ---> mu- P(1) P(2) in the topcolor-assisted technicolor model and the littlest Higgs model with T parity

Wei Liu
(
- Liaoning Normal U.
)
,
Chong-Xing Yue
(
- Liaoning Normal U.
)
,
Jiao Zhang
(
- Liaoning Normal U.
)

- Eur.Phys.J.C 68 (2010) 197-207
•
e-Print:
- 0910.2514
•
DOI:
- 10.1140/epjc/s10052-010-1311-9

[9]

The Belle Detector

Belle

Collaboration

•

A. Abashian

et al.

- Nucl.Instrum.Meth.A 479 (2002) 117-232
•
DOI:
- 10.1016/S0168-9002(01)02013-7

[10]

Overview of the KEKB accelerators

S. Kurokawa
(
- KEK, Tsukuba
)
,
Eiji Kikutani
(
- KEK, Tsukuba
)

- Nucl.Instrum.Meth.A 499 (2003) 1-7
•
DOI:
- 10.1016/S0168-9002(02)01771-0

[11]

Search for Lepton Flavor and Lepton Number Violating tau Decays into a Lepton and Two Charged Mesons

Belle

Collaboration

•

Y. Miyazaki
(
- Nagoya U.
)

et al.

- Phys.Lett.B 682 (2010) 355-362
•
e-Print:
- 0908.3156
•
DOI:
- 10.1016/j.physletb.2009.11.061

[12]

Search for lepton-flavor and lepton-number violation in the decay $\tau^- \to \ell^\mp h^\pm h^{\prime -}$

BaBar

Collaboration

•

Bernard Aubert
(
- Annecy, LAPP
)

et al.

- Phys.Rev.Lett. 95 (2005) 191801
•
e-Print:
- hep-ex/0506066
•
DOI:
- 10.1103/PhysRevLett.95.191801

[13]

Electron identification in Belle

- Nucl.Instrum.Meth.A 485 (2002) 490-503
•
e-Print:
- hep-ex/0108044
•
DOI:
- 10.1016/S0168-9002(01)02113-1

[14]

Muon identification in the Belle experiment at KEKB

et al.

- Nucl.Instrum.Meth.A 491 (2002) 1-2, 69-82
•
DOI:
- 10.1016/S0168-9002(02)01164-6

[15]

The Precision Monte Carlo event generator K K for two fermion final states in e+ e- collisions

S. Jadach
(
- DESY and
- Cracow, INP and
- CERN
)
,
B.F.L. Ward
(
- Tennessee U. and
- CERN and
- SLAC
)
,
Z. Was
(
- Cracow, INP and
- CERN
)

- Comput.Phys.Commun. 130 (2000) 260-325
•
e-Print:
- hep-ph/9912214
•
DOI:
- 10.1016/S0010-4655(00)00048-5

[16]

The EvtGen particle decay simulation package

D.J. Lange
(
- LLNL, Livermore
)

- Nucl.Instrum.Meth.A 462 (2001) 152-155
•
DOI:
- 10.1016/S0168-9002(01)00089-4

[17]

Monte Carlo program BHLUMI-2.01 for Bhabha scattering at low angles with Yennie-Frautschi-Suura exponentiation

S. Jadach
(
- CERN and
- Jagiellonian U.
)
,
E. Richter-Was
(
- Jagiellonian U.
)
,
B.F.L. Ward
(
- Tennessee U. and
- SLAC
)
,
Z. Was
(
- Cracow, INP
)

- Comput.Phys.Commun. 70 (1992) 305-344,
- Comput. Phys. Commun. 70 (1992) 305-344 and CERN Geneva - TH. 6230 (91/09,rec.Dec.) 42 p
•
DOI:
- 10.1016/0010-4655(92)90196-6