Showing papers by "J. Haba published in 2003"
TL;DR: In this article, the decay amplitudes for the different helicity states are measured from the angular distributions of final state particles in the transversity basis. And they are shown to be consistent with zero.
Abstract: We present the first measurement of decay amplitudes in $B\ensuremath{\rightarrow}\ensuremath{\varphi}{K}^{*}$ and measurements of branching fractions in $B\ensuremath{\rightarrow}\ensuremath{\varphi}{K}^{(*)}$ decays based on $78.1\text{ }{\mathrm{f}\mathrm{b}}^{\ensuremath{-}1}$ of data recorded at the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB ${e}^{+}{e}^{\ensuremath{-}}$ storage ring. The decay amplitudes for the different $\ensuremath{\varphi}{K}^{*0}$ helicity states are measured from the angular distributions of final state particles in the transversity basis. The longitudinal and transverse complex amplitudes are $|{A}_{0}{|}^{2}=0.43\ifmmode\pm\else\textpm\fi{}0.09\ifmmode\pm\else\textpm\fi{}0.04$, $|{A}_{\ensuremath{\perp}}{|}^{2}=0.41\ifmmode\pm\else\textpm\fi{}0.10\ifmmode\pm\else\textpm\fi{}0.04$, $\mathrm{arg} ({A}_{\ensuremath{\parallel}})=\ensuremath{-}2.57\ifmmode\pm\else\textpm\fi{}0.39\ifmmode\pm\else\textpm\fi{}0.09$, and $\mathrm{arg} ({A}_{\ensuremath{\perp}})=0.48\ifmmode\pm\else\textpm\fi{}0.32\ifmmode\pm\else\textpm\fi{}0.06$. The direct $CP$-violating asymmetries are found to be consistent with zero.
94 citations
01 Jan 2003
TL;DR: These results are consistent with the spin-parity assignments of 0(+) for the D(sJ)(2317) and 1(+ for theD(sSJ)(2457) and 2(+)(s) for the dipion decay mode.
Abstract: We report measurements of the properties of the D(+)(sJ)(2317) and D(+)(sJ)(2457) resonances produced in continuum e(+)e(-) annihilation near sqrt[s]=10.6 GeV. The analysis is based on an 86.9 fb(-1) data sample collected with the Belle detector at KEKB. We determine the masses to be M(D(+)(sJ)(2317))=2317.2+/-0.5(stat)+/-0.9(syst) MeV/c(2) and M(D(+)(sJ)(2457))=2456.5+/-1.3(stat)+/-1.3(syst) MeV/c(2). We observe the radiative decay mode D(+)(sJ)(2457)-->D(+)(s)gamma and the dipion decay mode D(+)(sJ)(2457)-->D(+)(s)pi(+)pi(-) and determine their branching fractions. No corresponding decays are observed for the D(sJ)(2317) state. These results are consistent with the spin-parity assignments of 0(+) for the D(sJ)(2317) and 1(+) for the D(sJ)(2457).
84 citations
TL;DR: In this article, the authors report the observation of the flavor-changing neutral current decay B-->K*l(+l-) and an improved measurement of the decay B+l- where l represents an electron or a muon, with a data sample of 140 fb(-1) accumulated at the Y(4S) resonance with the Belle detector at KEKB.
Abstract: We report the observation of the flavor-changing neutral current decay B-->K*l(+l-) and an improved measurement of the decay B-->Kl(+l-), where l represents an electron or a muon, with a data sample of 140 fb(-1) accumulated at the Y(4S) resonance with the Belle detector at KEKB. The results for the branching fractions are B(B-->K*l(+l-))=(11.5(-2.4)(+2.6)+/-0.8+/-0.2)x10(-7) and B(B-->Kl(+l-))=(4.8(-0.9)(+1.0)+/-0.3+/-0.1)x10(-7), where the first error is statistical, the second is systematic and the third is from model dependence.
69 citations
21 Feb 2003-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: KEKB has been operated since December 1998 to deliver BB pairs for a physics detector as discussed by the authors, and the authors describe the commissioning procedure of KEKB and its operation in detail.
Abstract: KEKB has been operated since December, 1998, to deliver BB pairs for a physics detector. In this paper,we describe the commissioning procedure of KEKB.
44 citations
TL;DR: In this article, branching fractions and charge asymmetries for exclusive decays of charged and neutral B mesons to two-body final states containing a charmonium meson, J/Ψ or Ψ/(2S), were reported.
Abstract: We report branching fractions and charge asymmetries for exclusive decays of charged and neutral B mesons to two-body final states containing a charmonium meson, J/Ψ or Ψ/(2S). This result is based on a 29.4 fb-1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider. © 2003 The American Physical Society.
40 citations
TL;DR: In this paper, a precise determination of the Z0-B0 mixing parameter Δmd based on the time evolution of same-sign and opposite-sign dilepton yields in Y(45) decays was reported.
Abstract: We report a precise determination of the Z0-B0 mixing parameter Δmd based on the time evolution of same-sign and opposite-sign dilepton yields in Y(45) decays. Data were collected with the Belle detector at KEKB. Using data samples of 29.4 fb-1 recorded at the γ(4S) resonance and 3.0 fb-1 recorded at an energy 60 MeV below the resonance, we measure Δmd=[0.503±0.008(stat) ±0.010(syst)] ps-1. From the same analysis, we also measure the ratio of charged and neutral B meson production at the γ(4S), f +/f0= 1-01 ±0.03(stat)±0.09(syst), and CPT violation parameters in B0-B0 mixing, (cos θ)=0.00±0.12(stat) ±0.01(syst) and ℑ(cos θ)=0.03±0.01(stat)±0.03(syst). © 2003 The American Physical Society.
29 citations
TL;DR: In this paper, a measurement of CP-violation parameters in the b→sqq penguin transitions (q = s,u,d) based on a 78 fb-1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB energyasymmetric e+e- collider is presented.
Abstract: We present a measurement of CP-violation parameters in the b→sqq penguin transitions (q = s,u,d) based on a 78 fb-1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB energyasymmetric e+e- collider. One neutral B meson is reconstructed in the φKS 0, K+K -KS 0, or η′ KS 0 decay channel, and the flavor of the accompanying B meson is identified from its decay products. CP violation parameters for each of the three modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. © 2003 The American Physical Society.
24 citations
TL;DR: The results suggest that different biological dysfunctions could each underlie particular neuroendocrine and sleep EEG disturbances in major depression.
23 citations
Tohoku University1, University of Tokyo2, Nagoya University3, University of Tsukuba4, University of Cincinnati5, University of Sydney6, Peking University7, Polish Academy of Sciences8, University of Lausanne9, Utkal University10, Budker Institute of Nuclear Physics11, University of Maribor12, National Taiwan University13, Sungkyunkwan University14, Gyeongsang National University15, University of Melbourne16, University of Ljubljana17, National Kaohsiung Normal University18, Osaka University19, Nara Women's University20, Tohoku Gakuin University21, Seoul National University22, Yonsei University23, Korea University24, Chiba University25, Aomori University26, Niigata University27, Tokyo Metropolitan University28, Saga University29, Panjab University, Chandigarh30, Goethe University Frankfurt31, Austrian Academy of Sciences32, University of Science and Technology of China33, Hiroshima Institute of Technology34
TL;DR: In this paper, the decay B- → DCPK and its charge conjugate were investigated using a data sample of 85.4 × 106 BB pairs recorded at the γ(4S) resonance with the Belle detector at the KEKB asymmetric e+e- storage ring.
Abstract: We report results on the decay B- → DCPK - and its charge conjugate using a data sample of 85.4 × 106 BB pairs recorded at the γ(4S) resonance with the Belle detector at the KEKB asymmetric e+e- storage ring. Ratios of branching fractions of Cabibbo-suppressed to Cabibbo-favored processes are determined to be Β(B- → D0K -)/Β(B- → D0 π-) = 0.077±0.005(stat)±0.006(syst), Β(B- → D 1K-)/Β(B- → D1π - = 0.093 ±0.018(stat)±0.008(syst) and Β(B - → D2K-)/Β(B- → D2 π-) = 0-108±0.019(stat)±0.007(syst) where the indices 1 and 2 represent the CP= + 1 and CP= - 1 eigenstates of the D0-D0 system, respectively. We find the partial-rate charge asymmetries for B- → DCPK- to be A1 =0.06±0.19(stat)±0.04(syst) and A2 = -0.19±0.17(stat)±0.05(syst). © 2003 The American Physical Society.
22 citations
University of Cincinnati1, Niigata University2, Tohoku University3, University of Tokyo4, Nara Women's University5, University of Tsukuba6, University of Sydney7, Peking University8, University of Lausanne9, Budker Institute of Nuclear Physics10, Utkal University11, Polish Academy of Sciences12, University of Maribor13, National Taiwan University14, Sungkyunkwan University15, Gyeongsang National University16, Tokyo Metropolitan University17, University of Ljubljana18, Saga University19, University of Melbourne20, Nagoya University21, Seoul National University22, Yokkaichi University23, Chiba University24, Aomori University25, Korea University26, Panjab University, Chandigarh27, University of Science and Technology of China28, Austrian Academy of Sciences29, Tata Institute of Fundamental Research30, Chuo University31, Osaka University32, Hiroshima Institute of Technology33, Osaka City University34, Kyoto University35
TL;DR: In this paper, a study of B 0 → D(*)0 π+π-decays using 29.1 fb-1 of e+e- annihilation data recorded at the γ(4S) resonance with the Belle detector at the KEKB storage ring is presented.
18 citations
01 Jan 2003
TL;DR: In this paper, a hybrid photo-detector (HPD) consisting of a photocathode and a multi-pixel avalanche diode (MP-AD) has been developed for these years.
Abstract: A hybrid photo-detector (HPD) consisting of a photocathode and a multi-pixel avalanche diode (MP-AD) has been developed for these years. One of the features of the HPD is a good energy resolution, and it was shown in our previous study that the further improvement would be possible by reducing the fluctuation of charge loss in the dead layer at the entrance of the MP-AD. In this paper, we report on the result of the improvement with the newly developed HPD whose MP-AD encapsulated has a thinner dead layer than before. It is demonstrated that the new HPD has a much better energy resolution which enables the clear counting up to nine photoelectrons. Other features like a uniformity among the pixels or a photocathode sensitivity of the HPD are also presented.
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TL;DR: In this article, the authors reported the first example of a b → s sbar s s bar s sBar s transition, and measured the branching fraction for this decay was measured to be B(B^{+-} -> phi phi K = (2.6 ^{+1.1}_{-0.9} +- 0.85 GeV/c^2.3) x 10^{-6} for a phi invariant mass below 2.
Abstract: We report the observation of the decay mode B -> phi phi K based on an analysis of 78 fb^{-1} of data collected with the Belle detector at KEKB. This is the first example of a b -> s sbar s sbar s transition. The branching fraction for this decay is measured to be B(B^{+-} -> phi phi K^{+-}) = (2.6 ^{+1.1}_{-0.9} +- 0.3) x 10^{-6} for a phi phi invariant mass below 2.85 GeV/c^2. Results for other related charmonium decay modes are also reported.
TL;DR: In this article, an improved measurement of the partial-rate CP asymmetry in B±→K0π± decays was reported, based on a data sample of 85×106 BB pairs collected at the Y(4S) resonance with the Belle detector at the KEKB e +e- storage ring.
Abstract: We report an improved measurement of the partial-rate CP asymmetry in B±→K0π± decays. The analysis is based on a data sample of 85×106 BB pairs collected at the Y(4S) resonance with the Belle detector at the KEKB e +e- storage ring. We measure ACP(K 0π±) = 0.07-0.08 +0.09 +0.03 +0.01, where the first and second errors are statistical and systematic, respectively; the corresponding 90% confidence-level interval is -0.10
TL;DR: In this paper, the authors report on a search for the decay modes of the Belle detector at KEKB with the first time with the branching fractions, and upper limits at 90% C.L. are presented.
Abstract: We report on a search for ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{(*)0}{\overline{K}}^{(*)0}$ decays based on $85\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ events collected with the Belle detector at KEKB. The ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{0}{\overline{K}}^{0}$ and ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{0}{\overline{K}}^{*0}$ decays have been observed for the first time with the branching fractions $\mathcal{B}({\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{0}{\overline{K}}^{0})=({5.0}_{\ensuremath{-}1.2}^{+1.3}\ifmmode\pm\else\textpm\fi{}0.6)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ and $\mathcal{B}({\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{0}{\overline{K}}^{*0})=({4.8}_{\ensuremath{-}1.0}^{+1.1}\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. No significant signal has been found for the ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{*0}{\overline{K}}^{(*)0}$ and ${\overline{B}}^{0}\ensuremath{\rightarrow}{\overline{D}}^{(*)0}{\overline{K}}^{*0}$ decay modes, and upper limits at 90% C.L. are presented.
TL;DR: In this paper, a 29.1 fb(-1) sample was collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) storage ring.
Abstract: We report studies of the Cabibbo-suppressed decay B+/- --> DCPK+/-, where D-CP denotes CP eigenstates of the D-0 - (D) over bar (0) system. The analysis is based on a 29.1 fb(-1) sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) storage ring. We measure ratios of branching fractions, relative to Cabibbo-favored B+/--->D(CP)pi+/-, of B>(B- --> D1K-)/B(B- --> D(1)pi(-)) = 0.125 +/-0.036 +/- 0.010 and B(B- --> D2K-)/B(B- --> D(2)pi(-)) = 0.119 +/- 0.028 +/- 0.006; the index 1 (2) denotes the CP = +1 (-1) eigenstate. We also extract the partial rate asymmetries for B+/- --> DCPK+/-, finding A(1) = 0.29 +/- 0.26 +/- 0.05 and A(2) = -0.22 +/- 0.24 +/- 0.04.
16 Aug 2003
Tokyo Institute of Technology1, Niigata University2, Tohoku University3, University of Tokyo4, University of Tsukuba5, Toyama National College of Maritime Technology6, University of Sydney7, University of Hawaii8, National Taiwan University9, Princeton University10, University of Melbourne11, KEK12, Chinese Academy of Sciences13, Osaka University14, Brookhaven College15, Polish Academy of Sciences16, Jožef Stefan Institute17, Kanagawa University18, University of Toronto19, Lawrence Berkeley National Laboratory20
TL;DR: In this article, a new data acquisition system (DAQ) utilizing PC farms for the upgraded silicon vertex detector (SVD2) in the Belle experiment at the KEKB factory was developed.
Abstract: We have developed a new data acquisition system (DAQ) utilizing PC farms for the upgraded silicon vertex detector (SVD2) in the Belle experiment at the KEKB factory. The SVD upgrade will increase the number of readout channels by about 50% to 110592. The maximum trigger rate is also expected to rise to 1.0kHz due to the increasing beam intensity from KEKB. To manage the increased dataflow, we have constructed the DAQ system with twelve Linux PCs, each of which is directly connected to three flash AD converter boards through PCI data I/O boards. The advantages of using the PCs include the ease of software maintenance, market availability of hardware when replacements are needed, scalability and much improved processing speed. In order to decrease the data transfer load to the data storage system, we have developed data sparsification algorithms that calculate pedestal and noise, find particle hit channels and thus reduce the data down to 5% of the original volume. We have measured the data processing speed of the system at various read-out channel occupancy levels. The system is able to process data at a 1.3kHz trigger rate with 5% occupancy and will thus be able to handle the anticipated 1.0kHz trigger rate.
Journal Article•
TL;DR: In this article, an improved measurement of CP-violation parameters in B 0 → ΦK 0 S, K + K - K 0 S, and η'K 0S decays based on a 140 fb - 1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB energy-asymmetric e + e - collider.
Abstract: We present an improved measurement of CP-violation parameters in B 0 → ΦK 0 S, K + K - K 0 S , and η'K 0 S decays based on a 140 fb - 1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB energy-asymmetric e + e - collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the three modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. We find that the observed CP asymmetry in the B → ΦK 0 S decay differs from the standard model (SM) expectation by 3.5 standard deviations, while the other cases are consistent with the SM.
Princeton University1, Niigata University2, Tohoku University3, University of Tokyo4, University of Tsukuba5, University of Sydney6, National Taiwan University7, University of Melbourne8, Austrian Academy of Sciences9, Osaka University10, Tokyo Institute of Technology11, Polish Academy of Sciences12, Kanagawa University13, University of Toronto14
TL;DR: In this article, a new hardware trigger Level 1.5 was designed and installed that takes advantage of the digitized SVD hit data to deal with the increasing luminosity and higher beam currents of the KEKB factory.
Abstract: During the summer shutdown of 2003, the new silicon vertex detector SVD2 was installed in Belle at the KEKB factory and started to take data in October 2003. It provides important improvements in the tracking capabilities and adds new trigger functionality. In addition, a new hardware trigger Level 1.5 was designed and installed that takes advantage of the digitized SVD hit data. The improvement in the Belle trigger system will be important to deal with the increasing luminosity and higher beam currents of the KEKB factory.
01 Jan 2003
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TL;DR: In this article, the authors report evidence for the decay of the Belle detector with a significance of 3.4 standard deviations, and measure the branching fraction to be the same as in this paper.
Abstract: We report evidence for the decay ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$. The analysis is based on a data sample of ${\mathrm{152}\mathrm{\ifmmode\times\else\texttimes\fi{}}\mathrm{10}}^{6}$ $B\overline{B}$ pairs collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB ${e}^{+}{e}^{\ensuremath{-}}$ storage ring. We detect a signal for ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ with a significance of 3.4 standard deviations, and measure the branching fraction to be $\mathrm{[}\mathrm{1.7}\ifmmode\pm\else\textpm\fi{}\mathrm{0.6}\mathrm{(}\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}\mathrm{)}\ifmmode\pm\else\textpm\fi{}\mathrm{0.2}\mathrm{(}\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}\mathrm{)}\mathrm{]}\ifmmode\times\else\texttimes\fi{}{\mathrm{10}}^{\ensuremath{-}\mathrm{6}}$.