t Results from Belle For the Belle collaboration Hisaki Hayashii Nara, Japan BES-Belle-CLEO-Babar 2007 Joint Workshop IHEP, Beijing, 26-27 Nov. 2007 I’d like to present the recent results on tau physics from B factory experiments.

t- t hadronic decays nt Lepton Flavor Violating rare decays W- u-bar d/s t hadronic decays Ideal place to study low mass hadronic system as, am, ms, Vus, vacuum condensate QCD, Lattice and String Theory No final state interaction Non-strange and strange final states. Possible Jp Vector (1-, 1+) and Scalar (0-, 0+) Only pn, Kn decays are scalar states observed so far. Lepton Flavor Violating rare decays （One of the most） promising processes to look for beyond SM Nov. 27, 2007 BBCB Workshop

Outline　 A few selected topics on t-physics from Belle experiment are presented. 　　　　　　　　　study　 Branching fraction Mass spectrum (vector & scalar, M and width)　 t → Khn, Kp0hn (K*hn), and pp0hn Lepton Flavor Violation in t decays Prospect for Super-B t- → Ks p- nt In my talk, I’d like to cover three topics such as 1) check on the Lepton Universality 2) study of the 2pi mode, 3) the search for the Lepton Flavor Violation in tau decays And the decays with Kaons if the time is allowed. Nov. 27, 2007 BBCB Workshop

4 1. t- → Ksp-nt study Largest Br among decays with one K, it makes dominant contribution to the total strange hadronic spectrum function. Sensitive to ms, Vus Scalar resonance ? Necessary condition for CPV in t decay. 1-1 Events selections Ks + p-, tag-side; lepton sK---+++ttpppe/mnnn-e+e ( ) 351/fb data Nov. 27, 2007 BBCB Workshop 4

Two lepton (e,m) events are used for normalization. 5 1-2 Branching fraction B(t → Ksp-nt ) Two lepton (e,m) events are used for normalization. B(t → K0p-n) = 2.0xB(t → KS0p-n) = 0.808±0.004(stat.) ±0.026(syst.) % Nov. 27, 2007 BBCB Workshop

M(K*(892)-) = 895.47±0.20(stat.) ±0.44(syst.) ±0.59(mod.) MeV/c2 6 1-3 Ksp- mass spectrum K*(892) alone Best fit is achieved in K*0(800)+K*(892)+K*(1410)/ K*0 (1430) but not K*(892) alone. M(K*(892)-) = 895.47±0.20(stat.) ±0.44(syst.) ±0.59(mod.) MeV/c2 G(K*(892)-) = 42.2±0.6(stat.) ±1.0(syst.) ±0.7(mod.) MeV Nov. 27, 2007 BBCB Workshop

M(K*(892)-) = 895.47±0.20(stat.) ±0.44(syst.) ±0.59(mod.) MeV/c2 1-4 K*(892)- mass & width M(K*(892)-) = 895.47±0.20(stat.) ±0.44(syst.) ±0.59(mod.) MeV/c2 G(K*(892)-) = 42.2±0.6(stat.) ±1.0(syst.) ±0.7(mod.) MeV PDG 891.66±0.26 (896.00±0.25) 50.8±0.9 (50.3±0.6) K*± (K*0) Nov. 27, 2007 BBCB Workshop

t → Ksp-nt Summary Lusiani talk 8 Lusiani talk Highly precise measurement of B(t→K0p-n) is performed. Affects to the Vus value. Discussed by S. Banerjee (hep-ex/0707.3058) K*(890)- mass is significantly different from the current world average value. (Note: Other all measurements are from pure hadronic reactions.) K*(892) alone is not sufficient to describe Ksp- mass spectrum, needs K0*(800) and K*(1410) or K*0(1430). => Good news for CPV study in the Ksp system. Our results PDG-2007 B(t→K0p-n) (0.808±0.004±0.026) % (0.90±0.04) % M(K(892)*-) (895.47±0.20±0.44±0.59) MeV (891.66±0.26) MeV G(K(892)*-) (46.2±0.6±1.0±0.7) MeV (50.8±0.9) MeV Nov. 27, 2007 BBCB Workshop

2-1 Event selection with h→gg 2. t → Khn, Kp0hn (K*hn), and pp0hn study Analyze t-decay modes, involving an h, Because of poor statistics, previous measurements have large uncertainty. Data used are 485/fb ( 433M t pairs ),　x ～100 larger than previously. Physics motivations - CVC hypothesis, 　 - Chiral Lagrangian approach with WZW anomaly, -- 2nd class current for t-→p- h n study. - High mass resonance. h g K– e– e+ t+ t- 2-1 Event selection with h→gg Khn Kp0hn pp0hn 1-trk K p Ng 2 4 2g h h & p0 sig-side tag-side 1-trk, Ng<2, trk = m/e 　|Vthrust|>0.8; 　 Msig<Mt ; 　Mtag<Mt (m/e)+ Nov. 27, 2007 BBCB Workshop

2-2 h→gg yield measurement May 10, 2007 Belle Analysis Meeting 10 2-2 h→gg yield measurement Fit data with (signal=Crystal Ball function + BG=second-order polynomial function) t→Khn c2/dof=0.824 t→Kp0hn c2/dof=0.988 c2/dof=0.936 t→pp0hn Khn Kp0hn pp0hn yields 1387 ± 44 270 ± 33 5959 ± 105 mass (MeV/c2) 544.9 ± 0.6 544.4 ± 1.0 544.3 ± 0.4 resolution (MeV/c2) 11.0 ± 0.6 10.7 ± 1.5 11.6 ± 0.3 Nov. 27, 2007 BBCB Workshop 10

2-3 Extract Branching fractions 11 2-3 Extract Branching fractions Consider cross-feed among the decays, (h-yield)-(qq+others) Cross-feed rates Detection efficiencies detection eff. & cross-feed rates Selection Khn Kp0hn pp0hn 9.41×10-3 3.71×10-4 1.50×10-5 1.14×10-4 3.46×10-3 7.09×10-5 1.74×10-5 2.32×10-4 4.71×10-3 Efficiencies (e’s) include B(h →gg). h-yield qq others Khn Kp0hn pp0hn 1387±43 (ev) 30.6±15.6 1.1±0.2 15.1±3.8 18.0±1.0 270±33 27.0±8.5 1.2±0.4 16.0±0.9 85.3±4.6 5959±105 212±29 71.6±20 2.4±0.1 9.4±2.4 Nov. 27, 2007 p-p0p0hn BBCB Workshop

consistent 2-5 Systematic uncertainties (%) (1.61±0.05±0.09)×10-4 12 2-5 Systematic uncertainties (%) Khn Kp0hn pp0hn (h→gg) (h→ppp) contaminations of Khn ― 0.6 0.0018 contaminations of Kp0hn 0.3 0.4 0.042 contaminations of pp0hn 0.075 0.1 3.3 contaminations of pp0p0hn contaminations of qq 1.5 6.0 0.5 K/p ID 2.8 2.2 1.0 lepton ID 2.3 2.6 tracking 1.3 luminosity 1.6 p0 detection 2.0 p0 veto signal MC 1.7 0.7 B(h→p-p+p0) 1.8 Total 5.6 6.1 8.9 5.0 2-6 Branching fractions Our results Khn (h→gg) (h→p-p+p0) (1.61±0.05±0.09)×10-4 (1.65±0.16±0.10)×10-4 Khn combined (1.62 ± 0.10) ×10-4 Kp0hn (4.7 ±1.1 ±0.4 )×10-5 pp0hn (1.39±0.03±0.07)×10-3 consistent Nov. 27, 2007 BBCB Workshop

B(K*-hn)=(1.10±0.19±0.07) ×10-4 t→Kp0hn decay is dominated by 13 2-7 t→K(892)*-hn analysis Continuum BG t→Kp0hn decay is　dominated by t →K(892)*hn Efficiency (%) K*- yields K*-n BG qq BG 0.115 119±19 2.3±0.9 6.5±2.3 Efficiency (e) include B(K*-→K-p0)=0.333, B(h→gg)=0.394, and B(t→lnn)=0.352. Systematic error (%) peaking BG (tt) 0.94 peaking BG (qq) 2.4 K/p ID 2.2 lepton ID 2.5 tracking 1.3 luminosity 1.6 p0 detection 2.0 p0 veto 2.8 Signal MC 1.7 Total 6.1 B(K*-hn)=(1.10±0.19±0.07) ×10-4 Nov. 27, 2007 BBCB Workshop

Summary for decays involving h 14 Summary for decays involving h Precise B(t→K-hn; K-p0hn; K*hn; p-p0hn) measurements largely improve PDG07 data. B(t→p-p0hn) agrees with a CVC calculation, 1.5x10-3 by Gilman. Systematic theoretical study is awaited, along with new data. Preliminary Our results PDG-2007 B(t→Khn) (1.62±0.10) ×10-4 (2.7±0.6) ×10-4 B(t→Kp0hn) (4.7±1.1±0.4)×10-5 (1.8±0.9)×10-5 B(t→K(892)*-hn) (1.10±0.19±0.07)×10-4 (2.9±0.9)×10-4 B(t→pp0hn) (1.39±0.03±0.07)×10-3 (1.77±0.24)×10-3 Nov. 27, 2007 BBCB Workshop

3.Search for Lepton Flavor Violation Sizeable LFV is expected in many extension of the SM SUSY + vR, see-saw mechanism Higgs dominated mechanism Here We present updated searches based on ～530/fb data (preliminary) t→m g, e g t→３ｌ　　（ｌ＝e, m) t→ l Vector (Vector =r, f, K*, w) Nov. 27, 2007 BBCB Workshop

m g t General event selection  (signal)  LFV generic t decay e- e+ t m g signal side tag side  (signal)  LFV　 of exclusive decay mode &  (tag)  single track with (n g) + missing Single prong mode occupies >80% of decay. Simple but strong constraints does not exist due to neutrino missing . BG’s: tt, continuum, mm, ee, gg, BB signal evaluation: minv – DE minv ~mtau & DE=E-Ebeam~0 Blind analysis Evaluation of upper limit The event selection is common. We require each LFV exclusive decay for signal side and the existence of the single track in the tag-side. After requiring some cuts to reduce the background, the final signal evaluation is carried out in the two-dimensional plane of the invariant-mass versus DE. The analysis is carried out by blinding the signal region when optimizing the signal selection criteria. If there are no significant candidates, the upper limit is evaluated either by Feldman-Cousins method or by a maximum likelifood fit. For small numbers of events in signal-region: event-counting is done with Feldman-Cousins method. For events >= a few 10’s in signal-region: maximum likelihood fit is applied and upper-limit is evaluated with toy-MC. Nov. 27, 2007 BBCB Workshop

search for tmg 535/fb remaining events: 71ev./(535/fb) analysis: same with previous one, but with tighter requirements remaining events: 71ev./(535/fb) signal detection eff: 6.7% signal region: 2s ellipse signal extraction: UEML fit: s=-3.9, b=13.9 (allow negative s and its prob. 25%) s(90% CL) = 2.0 ev signal data DE (GeV) blinded region Mmg (GeV/c2) projection First we show the results with full data sample for mu gamma process.After appling the same selection criteria, 94 event is remained in this wide errea. The signal region is defined by the green ellipse which correspond the 2sigma. The projection of the blue band region is given in this figure, where the grey area is the expected signal distribution. By making a fit with signal and background, the upper limit Br of mu gamma decay is determined to be 4.5 times 10to minus 8 at 90%C.L. no signal events are found. Br<4.5x10-8 at 90%C.L.(mg) Nov. 27, 2007 BBCB Workshop

Search for teg 535/fb Remaining events: 55ev in 5s box Signal detection eff: 3.0% Signal region: 2s ellipse Signal extraction: UEML fit: s=-0.1, b=5.1 s(90% CL) = 3.3 ev Br < 1.2x10-7 at 90% CL (e g) Nov. 27, 2007 BBCB Workshop

Search for t3l 535/fb e-m+m- e-e+e- m-e+m- Selection criteria is optimized for each modes. m-m+m- m-e+e- m-e+e- m-m+m- Negligible BG Keeping high efficiency Preliminary For other modes such as 3lepton or one-lepton plus resonaces, the background is still negligible level. This is an exmaple for 3-leptons. mode e(%) NBG Nobs S90 Br, 10-8 m- e+ m- 10.8 0.02 2.44 <2.3 m-e-e+ 9.3 0.04 2.43 <2.7 m-m-m+ 7.6 0.07 2.41 <3.2 e-m-m+ 6.1 0.05 <4.1 m+e-e- 12.5 0.01 e-e-e+ 6.0 0.40 2.10 <3.6 Nov. 27, 2007 BBCB Workshop

l + Vector meson (r, f, K* or w) 543/fb Preliminary m K*0 m f m w m r0 e f e r0 e w e K*0 BG is negligible except for mw and m r0 modes. The main BG for those modes is t→pw n for mw mode, and t →3pn+ qq continuum for mr0 mode, where one p is miss-identified as m. Nov. 27, 2007 BBCB Workshop

l + (r, f, K* or w) results 543/fb Preliminary l + (r, f, K* or w) results 543/fb mode e(%) NBG Nobs S90 Br, 10-8 m- f 3.1 0.11 1 4.2 <13 e- f 2.34 <7.6 m- w 2.5 0.19 2.27 <9.1 e- w <0.09 4.34 <18 m- K*0 3.7 0.22 2.24 <6.1 e- K*0 3.0 0.05 2.42 <8.0 4.0 0.10 4.23 <11 3.2 <0.17 2.45 <7.7 m- r0 4.9 1.04 3.34 <6.9 e- r0 3.9 <0.12 2.46 <6.3 Nov. 27, 2007 BBCB Workshop

4. Future prospect for LFV decays Super-B factory Background: Still negligible for t→３ｌ　　（ｌ＝e, m) t→ l Vector sensitivity improves as 1/L Non negligible for t→m g, e g but tradable. Sensitivity achieves 10-9 area Based on MC simulation assuming the current level of efficiency and background. Nov. 27, 2007 BBCB Workshop

Monte Carlo simulation of t→m g signal at a Super-B . t→m g Br(t→mg)=10-8 is assumed. Same level of current BG and efficiency is assumed. With 75/ab of data the significance of such a decay is expected exceed 5 s. Nov. 27, 2007 BBCB Workshop

Correlation: t-→ mg vs m- →eg The correlation between Br(t →mg) and for Br(m→e g) provide a unique tool to identify the nature of the New Physics models. MEG sensitivity hep-ph/0710.3799 Super-B sensitivity LFV decay depends on the Physics at GUT scale Once it is found, a model independent analysis for 3l case (A.I. Sanda, hep-ph/0711.0792) MnR = 4 x 10-14 GeV Nov. 27, 2007 BBCB Workshop

謝謝 Nov. 27, 2007 BBCB Workshop

Backup: Vus from t data by Pich [previous value] Br and spectrum measurements can determine both Vus and ms. where hep-ex/0707.3058 Nov. 27, 2007 BBCB Workshop

2-4 B(t →Khn) with h→p+p-p0 27 2-4 B(t →Khn) with h→p+p-p0 3-trk & Ng=2 1-trk = K 2g forms p0 sig-side p- p+ g g h K– t- e+ t+ e– result of fitting yield 241±21 mass (MeV/c2) 547.4±0.7 resolution(MeV/c2) 　7.5±0.4 (m/e)+ Efficiencies (e’s) include B(h →ppp). h-yield qq others Khn Kp0hn pp0hn e ’s 1.56×10-3 241±21 (ev) 9.1±2.2 <1.18 3.3±0.8 5.8±1.3 Nov. 27, 2007 BBCB Workshop

　　　　LFV related paper L. Calibbi et al., Phys. Rev. D 74, 116002 (2006)[hep-ph/0206021] SO(10) M. Blanke et al., JHEP 0705 (2007) 035012[hep-ph/0702136] Little Higgs V. Cirigliano et al., Nucl. Phys. B763 (2007) 2287, MSSM B. Grinstein et al., Nucl. Phys. B763 (2007) 35; B728 (2005) 121. S. Antusch et al., JHEP 0611 (2006) 090. E. Arganda and M.J. Herrero, Phys. Rev. D73 (2006) 055003. M. Ciuchini et al., JHEP 0705 (2007) 112. P. Paradisi, JHEP 0602 (2006) 050; 0510 (2005) 006. Nov. 27, 2007 BBCB Workshop