b s Hadronic Decays at Belle Sunghyon Kyeong Yonsei University, Seoul, Korea (on Behalf of the Belle Collaboration Europhysics Conference on High Energy Physics Kraków, Poland, 16- July, 9 sunghyon.kyeong@gmail.com
INTRODUCTION In the Standard Model (SM, Charmless hadronic B decays occur mainly via two processes. (i b s penguin diagram (ii b u tree diagram Charmless hadronic B-decays give us plenty of information. * Search for new physics effects by studying loop processes. * b s quark transitions are sensitive to physics beyond SM. * Direct CP Violation : Interefering SM amplitudes. * Measuring BF, angular correlations could help the phenomenological test/development of the theoretical models. Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 /
MOTIVATION * Measurements of f L in rare B decays to VV, such as B φk, have revealed an unexpectedly large fraction of transverse polarisation. * This implies that non-factorizable contributions to the decay amplitude play a significant role. * Further information about these effects can be obtained with B and f L in B ρ K (also b s penguin-dominated. BaBar s Results, PRL 97, 181, (6 with 3 1 6 B B Mode Y ε S B f L (events (% (σ (1 6 ρ K 18±3.9.3.6±.9±1.3.7±.9±.8 f (98K 83±19 1.7 3..6±.6±.9 Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 3 /
KEKB AND BELLE DETECTOR - Ring circumference of KEKB is approximately 3. km. - KEKB has two separate rings for e + and e. * located at energy asymmetric e + e collider KEKB. * Belle detactor has a large-solid-angle magnetic spectrometer, providing excellent tracking, vertexing and PID. Approximately.8 billion B B pairs recorded at Belle! Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 4 /
ANALYSIS METHOD * Recontruction Variables: - E = E B E beam : Energy difference - M bc = Ebeam P B : Beam-energy constrained mass - Invariant masses of ππ and K π (i.e. M ππ and M K π * Continuum (e + e q q Suppression: - Modified Fox-Wolfram moments, B flight direction (cos θ B, and the decay vertex differences between the signal B and that of the other B in z direction ( z. - Perform Figure of Merit study to get a continuum suppression cut value. * Veto B D ± X, D ± X, D X modes Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 /
YIELD EXTRACTION BY 4-D FIT 4-D Extended Unbinned ML Function: ( exp j Y N j cand ( L = Y j P i j N! where, P i j = P j (Mbc i P j( E i P j (MππP i j (MK i π, for component j, and i runs over all events in the sample. For Signal PDFs: where, f SCF is the SCF fraction. i=1 j (1 P i j = (1 f SCF P i true + f SCF P i SCF ( Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 6 /
Submitted to PRL arxiv:9.763v1 Measurements of B ρ K and B π + π K + π using a sample of 67 million B B pairs
SIGNAL MC DISTRIBUTIONS 1. M Kπ M Kπ M Kπ 1. 1. 1.1 1.1 1.1 1. 1. 1..9.9.9.8.8.8.6.8 1. 1. M ππ.6.8 1. 1. M ππ.6.8 1. 1. M ππ ρ K f (98K π + π K M Kπ 1. M Kπ 1. M Kπ 1. 1.1 1.1 1.1 1. 1. 1..9.9.9.8.8.8.6.8 1. 1. M ππ.6.8 1. 1. M ππ.6.8 1. 1. M ππ ρ K + π f (98K + π π + π K + π Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 8 /
BKG. MC DISTRIBUTIONS 6 4 3.4.4...6.6.7.7.8.8.9.4.4...6.6.7.7.8.8.9 4 3 3 -.1 -.8 -.6 -.4 -...4.6.8.1 -.1 -.8 -.6 -.4 -...4.6.8.1 6 4 3.6.7.8.9 1 1.1 1..6.7.8.9 1 1.1 1. 7 6 4 3.7.8.8.9.9 1 1. 1.1 1. 1. * Continuum (e + e q q. χ / ndf = 1.79 χ / ndf =.91 χ / ndf = 14.6 Events / MeV/c Events / 8MeV Events / 6MeV/c.7.8.8.9.9 1 1. 1.1 1. 1. χ / ndf = 1. Events / 18MeV/c M (GeV/c bc E (GeV M ππ (GeV/c M (GeV/c Kπ * Charmed B-decays (b c. Events / MeV/c Events / 8MeV Events / 6MeV/c Events / 18MeV/c M (GeV/c bc E (GeV M ππ (GeV/c M (GeV/c Kπ * Charmless B-decays (b s, u, d, B f (17K, and feeddowns B a 1 (16K +, B K + 1 (17π and B K + 1 (14π are also considered. Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 9 /
4D FITTING PROJECTION Events / MeV/c 8 6 4 (a Events / 8MeV 6 (b 4.4..6.7.8.9 -.1 -....1 M bc (GeV/c E (GeV Events / 6MeV/c 4 3 1 (c.6.8 1. 1. M ππ (GeV/c Events / 18MeV/c (d.8.9 1. 1.1 1. M Kπ (GeV/c Projection of the 4D fit results on to (a M bc, (b E, (c M ππ and (d M K π with the other variables required to be the signal criteria (except for the variable plotted. The curves are for the ρ K + π (solid-shaded, the sum of ρ K and f (98K (dashed, the sum of backgrounds (dotted, and the total (solid. Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 1 /
FITTING RESULTS Mode Y ε S B B UL (events (% (σ (1 6 (1 6 ρ K 77.6 +8.6 7.9.73.7.1 +.8 +.9.7. < 3.4 f (98K 1. +.4 19.3.6. 1.4 +.6 +.6..4 <. ρ K + π 7.8 +39.8 39. 11...8 ±. ±. - f (98K + π 16.9 +31.6 9.9 11.43 3. 1.4 ±.4 +.3.4 <.1 π + π K.7 +46.7 44.9 6.74 4. 4. +1.1 +.9 1. 1.6 - π + π K + π.4 +4.9 44.9 6.84..1 +1. +1.4 1.1.8 <.1 B and B UL of the non-resonant decay are partial one for the ranges: M ππ (., 1. GeV/c and M K π (.7, 1. GeV/c Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 11 /
ADDITIVE SYST. ERRROR Source ρk f K ρk π f K π ππk ππk π +4.4 Fitting PDFs.4 +11. f f (17K 11.3 +.6 f feed down 1.4 +1.9 f b s,u,d.1 +.1 f SCF.1 K +9. (143 Fitting bias Interference Sum (events. +.7. +6.6.6 +31. 1. +1.7 11.8 +.9 6.4 +.1.1 +.1. +1. 1. +14.7. +4.9. +.3.9 +. 1.3 +.8 9.1 +.3.3 +4.7 1. +7. 9.8 +19.9.6 +16.9 1.4 +11.. +14.7 17.3 +34.8 31.3 +4.1 3.6 +.3.1 +.3.4 +.3.4 +7.4 7.3 +. 19.3 +. 1. +4.3. +.6 3.9 +18.1 17.4 +9.4 7.9 +13.9 +3. 13.7.4 +8.7 +3. 3.8 1.9 +. +3.7 1..8 +8. +11.8 8.3 11.4 +. +69.1 4.8. +. +. 6.6 9.9 +3.8 3.6 - +. 69.8 +76. 4.6 Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 1 /
MULTIPLICATIVE SYST. ERROR Source ρk f K ρk π f K π ππk ππk π MC statistics ±. ±.7 ±1.3 ±1.7 ±1.3 ±.1 Tracking ±4. ±4. ±4. ±4. ±4. ±4. PID ±3.7 ±3.7 ±3.7 ±3.8 ±3.8 ±3.7 R q q cut ±3.4 ±3.4 ±3.4 ±3.4 ±3.4 ±3.4 N B B ±1.4 ±1.4 ±1.4 ±1.4 ±1.4 ±1.4 f L +16.7 18.9 - - - - - Sum (% +18..1 ±6.7 ±6.8 ±7. ±6.9 ±7. Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 13 /
SUMMARY * The first observation of the three-body decay B ρ K + π decay with.σ significance. * The first evidences for non-resonant B f (98K + π and B π + π K decays. * 9% C.L. upper limit for the fully non-resonant four-body decay B π + π K + π is calculated. * B and B UL of non-resonant decay are partial one for the ranges :. < M ππ < 1. and.7 < M K π < 1.. * Signal excesses for the two-body decays B f (98K and B ρ K. * More data set could help our understanding of the polarization puzzle in the ρk and new physics effect on B VV decays.
BACKUP SLIDES
CONTROL SAMPLE STUDY We study the B D (K + π π π + as our control sample. We perform D (M bc and E unbinned ML fit. We assume our control sample can be categorized into three components: B D (K πππ + signal, peaking background, and other non-resonant background. 8 7 Events / 3.6MeV/c 8 6 4 Events / 16MeV 6 4 3..1..3.4..6.7.8.9 M bc (GeV/c -. -. -.1 -. -..1.. E (GeV B of our control sample is consistent with the PDG value. Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 16 /
FITTING BIAS B ρ K 18 16 χ / ndf 6.494 / 9 y-axis 8.41 ± 1.936 slope.988 ±.7 18 16 14 χ / ndf 6.749 / 3 constant 7.6 ±.8 fitted Yields 14 1 8 6 4 fitted Yields - No. of input 1 1 8 6 4 4 6 8 1 14 * No. of input (ρ K - -4 4 6 8 1 14 * No. of input (ρ K B f (98K 1 χ / ndf 7.3 / 9 y-axis.731 ± 1.4 slope.986 ±.19 8 6 χ / ndf 8 / 3 constant 1.813 ±.74 fitted Yields 8 6 4 fitted Yields - No. of input 4 - -4-6 4 6 8 * No. of input (f K 1 3 4 6 7 8 9 * No. of input (f K Fitting biases are considered as the systematics uncertainty. Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 17 /
TOY MC STUDY (I Events / (.1 4 µ = -.191 ±.38 σ =.997 ±.7 4 3 1 Events / (.97 4 4 3 1 µ = 79.6 ± 1.1 σ = 9.7 ±.8 Events / (.1637 4 4 3 1 µ = -9.746 ±.4 σ = 1.66 ±.9 Events / (.14 4 4 3 1 µ = 3.68 ±.4 σ = 1.48 ±.8-4 -3 - -1 1 3 4-4 6 8 1 14 16 18-33 -3-31 -3-9 -8-7 -6 7 8 9 3 31 3 33 34 * Pull (ρ K * No. of fitting events (ρ K * Negative Error (ρ K * Positive Error (ρ K µ = -.1149 ±.38 σ = 1.1 ±.7 4 µ =. ±.76 σ =. ±.4 4 4 µ = -19.497 ±.41 σ = 1.69 ±.9 µ =.48 ±.39 σ = 1.4 ±.8 Events / (.1 3 1 Events / (. 3 1 Events / (.166 3 1 Events / (.1387 3 1-4 -3 - -1 1 3 4 * Pull (f K - 4 6 8 1 * No. of fitting events (f K -3 - -1 - -19-18 -17-16 * Negative Error (f K 17 18 19 1 3 4 * Positive Error (f K The definition of pull for contribution j is defined as pull(y j = Y j fit Y true j σ fit j Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 18 /
TOY MC STUDY (II Events / (.1 4 µ =.3 ±.39 σ = 1.14 ±.7 3 1 Events / ( 48.17 4 µ = 33 ± 18 σ = 479 ± 13 4 3 1 Events / (.963 4 4 3 1 µ = -449.4 ±. σ = 8.6 ± 1.6 Events / (.63 4 3 1 µ = 49.3 ±. σ =.8 ± 1.4-4 -3 - -1 1 3 4 3 4 4-6 -6 - - -4-4 - -3-3 4 4 6 6 7 Pull (qq No. of fitting events (qq Negative Error (qq Positive Error (qq 4 µ = -.14 ±.39 σ = 1.4 ±.8 4 µ = 48 ± 18 σ = 483 ± 13 4 µ = -49.3 ±. σ =.1 ± 1.4 4 4 µ = 449. ±. σ = 7.7 ± 1.6 Events / (.1 3 1 Events / ( 48.139 3 1 Events / (. 3 1 Events / (.87 3 1-4 -3 - -1 1 3 4 3 4-6 -6 - - -4-4 - -3 3 4 4 6 6 Pull (b c No. of fitting events (b c Negative Error (b c Positive Error (b c Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 19 /
BKG.-SUBTRACTED FIT Events / MeV/c 8 6 4.6.8 1. 1. 1.4 (GeV/c M ππ Events / MeV/c 3.8 1. 1. 1.4 (GeV/c M Kπ Figures show the yields obtained from the D M bc E fitting results as function of M ππ (left and M K π (right. Solid curves show the results of the fit and dashed lines indicates the non-resonant ππ (left and the non-resonant K π plus K (143 (right. The regions between the reddish straight lines show the nominal four-dimensional fit regions. Sunghyon Kyeong (Yonsei Univ. b s Hadronic Decay at Belle July 16-, 9 /