Lepton-Flavor-Violating Tau Decays

Lepton Flavor Violating Upper Limit:

♦ τ^- → l^- + γ

Decay Mode	Experiment	Reference	Upper Limit @ 90% C.L.	Luminosity
			(10^-8)	(fb^-1 @ ϒ(4S)) (unless otherwise mentioned)
τ^- → e^- γ	Belle	Phys.Lett.B666:16,2008	12	535
	BaBar	Phys.Rev.Lett.104:021802,2010	3.3	470 @ ϒ(4S), 31 @ ϒ(3S), 15 @ ϒ(2S)
τ^- → µ^- γ	Belle	Phys.Lett.B666:16,2008	4.5	535
	BaBar	Phys.Rev.Lett.104:021802,2010	4.4	470 @ ϒ(4S), 31 @ ϒ(3S), 15 @ ϒ(2S)

♦ τ^- → l^- + P⁰ (where P⁰ = π⁰, η, η’, K_s)

Decay Mode	Experiment	Reference	Upper Limit @ 90% C.L.	Luminosity
			(10^-8)	(fb^-1 @ ϒ(4S)) (unless otherwise mentioned)
τ^- → e^- π⁰	Belle	Blois 2010	2.2	802 @ ϒ(4S), 99 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.98:061803,2008	13	339
τ^- → µ^- π⁰	Belle	Blois 2010	2.7	802 @ ϒ(4S), 99 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.98:061803,2008	11	339
τ^- → e^- η	Belle	Blois 2010	4.4	802 @ ϒ(4S), 99 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.98:061803,2008	16	339
τ^- → µ^- η	Belle	Blois 2010	2.3	802 @ ϒ(4S), 99 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.98:061803,2008	15	339
τ^- → e^- η’	Belle	Blois 2010	3.6	802 @ ϒ(4S), 99 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.98:061803,2008	24	339
τ^- → µ^- η’	Belle	Blois 2010	3.8	802 @ ϒ(4S), 99 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.98:061803,2008	14	339
τ^- → e^- K_s	Belle	Phys.Lett.B692:4-9,2010	2.6	671
	BaBar	Phys.Rev.D79:012004,2009	3.3	469
τ^- → µ^- K_s	Belle	Phys.Lett.B692:4-9,2010	2.3	671
	BaBar	Phys.Rev.D79:012004,2009	4.0	469

♦ τ^- → l^- + S ( where S is a scalar meson)

♦ τ^- → l^- + V⁰ (where V⁰ is a vector boson)

Decay Mode	Experiment	Reference	Upper Limit @ 90% C.L.	Luminosity
			(10^-8)	(fb^-1 @ ϒ(4S)) (unless otherwise mentioned)
τ^- → e^- ρ⁰	Belle	Phys.Lett.B699:251-257,2011	1.8	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.103:021801,2009	4.6	451
τ^- → µ^- ρ⁰	Belle	Phys.Lett.B699:251-257,2011	1.2	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.103:021801,2009	2.6	451
τ^- → e^- K^*	Belle	Phys.Lett.B699:251-257,2011	3.2	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.103:021801,2009	5.9	451
τ^- → µ^- K^*	Belle	Phys.Lett.B699:251-257,2011	7.2	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.103:021801,2009	17	451
τ^- → e^- K^*	Belle	Phys.Lett.B699:251-257,2011	3.4	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.103:021801,2009	4.6	451
τ^- → µ^- K^*	Belle	Phys.Lett.B699:251-257,2011	7.0	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.103:021801,2009	7.3	451
τ^- → e^- φ	Belle	Phys.Lett.B699:251-257,2011	3.1	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.103:021801,2009	3.1	451
τ^- → µ^- φ	Belle	Phys.Lett.B699:251-257,2011	8.4	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.103:021801,2009	19	451
τ^- → e^- ω	Belle	Phys.Lett.B699:251-257,2011	4.8	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.100:071802,2008	11	384
τ^- → µ^- ω	Belle	Phys.Lett.B699:251-257,2011	4.7	782 @ ϒ(4S), 72 @ ϒ(5S)
	BaBar	Phys.Rev.Lett.100:071802,2008	10	384

♦ τ^- → l^- l⁺ l^-

♦ τ^- → l^- h⁺ h'^-, l^- h⁰ h⁰, h^- l⁺ h'^-

♦ τ^- → Λ + h^- (where h = π, K)

This page is maintained by Hisaki Hayashii and was last updated