Showing papers by "Tariq Aziz published in 2004"
TL;DR: The evidence for direct charged particles (CP) violation in the decay B0→K+ π- was investigated with 253 fb-1 of data collected with the Belle detector at the KEKB e + e- collider.
Abstract: The evidence for direct charged particles (CP) violation in the decay B0→K+ π- was investigated with 253 fb-1 of data collected with the Belle detector at the KEKB e + e- collider. 275 x 106 BB pairs were used to observe a B→K±π∓ signal with 2140 ±53 events. Mixing induced CP violation in the B sector was established in b → ccs transitions. The result suggests large interference between tree and penguin diagrams and the existence of final state interactions.
99 citations
Journal Article•
85 citations
69 citations
TL;DR: The first observation of the charmless hyperonic B decay, B+-->LambdaLambdapiK+, is reported using a 140 fb(-1) data sample recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB (e+)(e-) collider.
Abstract: We report the first observation of the charmless hyperonic B decay, B+-->LambdaLambdaK+, using a 140 fb(-1) data sample recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB (e+)(e-) collider. The measured branching fraction is B(B+-->LambdaLambdaK+) = (2.91(+0.90)(-0.70) +/- 0.38) x 10(-6). We also perform a search for the related decay mode B+-->LambdaLambdapi+, but do not find a significant signal. We set a 90% confidence-level upper limit of B(B+-->LambdaLambdapi+) < 2.8 x 10(-6).
69 citations
TL;DR: In this article, the authors present a measurement of the unitarity triangle angle using a Dalitz plot analysis of the three-body decay of the neutral D meson from the B{sup {+-}}{yields}D{sup (*)}K{sup} process.
Abstract: We present a measurement of the unitarity triangle angle {phi}{sub 3} using a Dalitz plot analysis of the three-body decay of the neutral D meson from the B{sup {+-}}{yields}D{sup (*)}K{sup {+-}} process. The method employs the interference between D{sup 0} and D{sup 0} to extract both the weak and strong phases. We apply this method to a 140 fb{sup -1} data sample collected by the Belle experiment. The analysis uses the modes B{sup {+-}}{yields}DK{sup {+-}} and B{sup {+-}}{yields}D*K{sup {+-}}, D*{yields}D{pi}{sup 0}, where the neutral D meson decays into K{sub S}{pi}{sup +}{pi}{sup -}. We obtain 146 signal candidates for B{sup {+-}}{yields}DK{sup {+-}} and 39 candidates for B{sup {+-}}{yields}D*K{sup {+-}}. From a combined maximum likelihood fit to the B{sup {+-}}{yields}DK{sup {+-}} and B{sup {+-}}{yields}D*K{sup {+-}} modes, we obtain {phi}{sub 3}=77 deg. (+17 deg./-19 deg.)(stat){+-}13 deg. (syst){+-}11 deg. (model). The corresponding 2 standard deviation interval is 26 deg. <{phi}{sub 3}<126 deg.
63 citations
01 Jan 2004
41 citations
TL;DR: In this paper, limits on the energy scales at which the anomalous couplings could be manifest are set, ranging from 0.3 to 2.3 TeV depending on the new physics effect under consideration.
34 citations
TL;DR: In this article, the authors report the observation of B0 decays to the K+π-π0 final state using a data sample of 78 fb-1 collected by the Belle detector at the KEKB e+e-collider.
24 citations
TL;DR: In this paper, the mass of the Z boson was determined by using events from the e+e-→Zγ process with hard initial-state radiation collected with the L3 detector at center-of-mass energies between 183 and 209 GeV, in agreement with the value measured at the Z resonance.
14 citations
TL;DR: In this paper, the authors studied ρ 0ρ0 production in two-photon collisions between a quasi-real and a mid-virtuality photon with data collected at LEP at centre-of-mass energies 183
12 citations
01 Sep 2004
TL;DR: In this article, the authors presented new measurements of CP-violation parameters in B0 --> phi K0, K+ K- Ks, f0(980) Ks.
Abstract: We present new measurements of CP-violation parameters in B0 --> phi K0, K+ K- Ks, f0(980) Ks, eta' Ks, omega Ks, Ks pi0, and K*0 gamma (K*0 --> Ks pi0) decays based on a sample of 275 x 10^6 BBbar pairs collected at the Upsilon(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 decay modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. All results are preliminary.
TL;DR: In this article, a search for CP-violating asymmetry in B0-->D(*+/-)D-+ decays was performed. But the significance of nonzero CP asymmetry was only 2.7 standard deviations.
Abstract: We report a search for CP-violating asymmetry in B0-->D(*+/-)D-/+ decays. The analysis employs two methods of B0 reconstruction: full and partial. In the full reconstruction method all daughter particles of the B0 are required to be detected; the partial reconstruction technique requires a fully reconstructed D- and only a slow pion from the D(*+)-->D0pi(+)(slow) decay. From a fit to the distribution of the time interval corresponding to the distance between two B meson decay points we calculate the CP-violating parameters and find the significance of nonzero CP asymmetry to be 2.7 standard deviations.
Tata Institute of Fundamental Research1, University of Tokyo2, Nagoya University3, University of Tsukuba4, University of Cincinnati5, University of Sydney6, École Polytechnique Fédérale de Lausanne7, Budker Institute of Nuclear Physics8, Polish Academy of Sciences9, National Taiwan University10, National Central University11, Chonnam National University12, Gyeongsang National University13, Princeton University14, Virginia Tech15, Tohoku Gakuin University16, Nara Women's University17, Yonsei University18, Korea University19, Niigata University20, Tokyo Institute of Technology21, Kyungpook National University22, University of Ljubljana23, Panjab University, Chandigarh24, Goethe University Frankfurt25, Austrian Academy of Sciences26, Tokyo Metropolitan University27, Osaka University28, Hiroshima Institute of Technology29, Tokyo University of Agriculture and Technology30, Toho University31, Kanagawa University32, Sungkyunkwan University33, University of Nova Gorica34, Saga University35, Osaka City University36, National United University37, Tohoku University38, Peking University39, University of Science and Technology of China40
TL;DR: In this article, the first observation of decay modes of the B meson was reported, where B{sup 0,yields}D*{sup -}(5{pi}{sup +}]=(4.72{+-}0.59{+)-0.26{+ − 0.33)x10{sup − 3.
Abstract: We report the first observation of a number of decay modes of the B meson, namely B{sup 0}{yields}D*{sup -}(5{pi}){sup +}, B{sup +}{yields}D*{sup -}(4{pi}){sup ++}, and B{sup +}{yields}D*{sup 0}(5{pi}){sup +}, where (n{pi}) implies the combination of n charged pions. The analysis is based on a 140 fb{sup -1} data sample collected at the {upsilon}(4S) resonance with the Belle detector at KEKB. We measure B[B{sup 0}{yields}D*{sup -}(5{pi}){sup +}]=(4.72{+-}0.59{+-}0.71)x10{sup -3}, B[B{sup +}{yields}D*{sup -}(4{pi}){sup ++}]=(2.56{+-}0.26{+-}0.33)x10{sup -3}, and B[B{sup +}{yields}D*{sup 0}(5{pi}){sup +}]=(5.67{+-}0.91{+-}0.85)x10{sup -3}. We also provide improved measurements of the branching fractions for the decay modes B{sup 0}{yields}D*{sup -}(3{pi}){sup +}, B{sup +}{yields}D*{sup 0}(3{pi}){sup +}, and B{sup 0}{yields}D*{sup 0}(4{pi}){sup 0}.
TL;DR: In this article, the first evidence of the decay B0 --> rho0 pi0 was presented, using 140fb^-1 of data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+e-collider.
Abstract: We present the first evidence of the decay B0 --> rho0 pi0, using 140fb^-1 of data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider. We detect a signal with a significance of 3.5 standard deviations, and measure the branching fraction to be Br(B0 ->- rho0 pi0) = (5.1 +/- 1.6(stat) +/- 0.9(syst))*10^-6.
DOI•
01 Jan 2004
TL;DR: In this article, the CP-conserving triple-gauge-boson couplings, gZ 1, κγ, λγ, g Z 5, gZ and λZ are measured using hadronic and semi-leptonic W-pair events selected in 629 pb−1 of data collected at LEP with the L3 detector at centre-of-mass energies between 189 and 209 GeV.
Abstract: The CP-conserving triple-gauge-boson couplings, gZ 1 , κγ , λγ , g Z 5 , κZ and λZ are measured using hadronic and semi-leptonic W-pair events selected in 629 pb−1 of data collected at LEP with the L3 detector at centre-of-mass energies between 189 and 209 GeV. The results are combined with previous L3 measurements based on data collected at lower centre-of-mass energies and with the results from single-W production and from events with a single-photon and missing energy. Imposing the constraints 154 L3 Collaboration / Physics Letters B 586 (2004) 151–166 κZ = gZ 1 − tan2 θW(κγ − 1) and λZ = λγ , we obtain for the C and P conserving couplings the results: gZ 1 = 0.966 ± 0.033(stat) ± 0.015(syst), κγ = 1.013 ± 0.066(stat) ± 0.026(syst), λγ = −0.021 ± 0.035(stat) ± 0.017(syst). Results from the analysis of fully leptonic W-pair decays are also given. All results are in agreement with the Standard Model expectations and confirm the existence of self-couplings among electroweak gauge bosons. 2004 Published by Elsevier B.V.
01 Jan 2004
TL;DR: In this article, the authors measured decay amplitudes and triple-product correlations in B0-->phiK* decays based on 253 fb(-1) of data recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring.
Abstract: We present measurements of decay amplitudes and triple-product correlations in B-->phiK* decays based on 253 fb(-1) of data recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. The decay amplitudes for the three different helicity states are determined from the angular distributions of final-state particles. The longitudinal polarization amplitudes are found to be 0.45 +/- 0.05 +/- 0.02 for B0-->phiK(*0) and 0.52 +/- 0.08 +/- 0.03 for B+ -->phiK(*+) decays. CP- and T-odd CP-violating triple-product asymmetries are measured to be consistent with zero.
01 Jan 2004
TL;DR: In this article, an improved measurement of the branching fraction for the electroweak penguin process was presented, where l is an electron or a muon and X-s is a hadronic system containing an s-quark.
Abstract: We present an improved measurement of the branching fraction for the electroweak penguin process B -> X-sl(l)+(-), where l is an electron or a muon and X-s is a hadronic system containing an s-quark. The measurement is based on a sample of 152x10(6) Upsilon(4S)-> B (B) over bar events collected with the Belle detector at the KEKB energy asymmetric e(+)e(-) collider. The X-s hadronic system is reconstructed from one K+/- or K-S(0) and up to four pions, where at most one pion can be neutral. Averaging over both lepton flavors, the inclusive branching fraction is measured to be B(B -> X-sl(l)+(-))=(4.11 +/- 0.83(stat)(-0.81)(+0.85)(syst))x10(-6) for M-l(l)+(-)> 0.2 GeV/c(2).
Posted Content•
TL;DR: In this paper, the leptonic and radiative leptononic B decays were searched using the Belle detector at the KEKB asymmetric e^+ e^-collider and no evidence for signals in any mode was found.
Abstract: We have searched for the leptonic and radiative leptonic B decays, B^+ -> mu^+ nu, B^+ -> e^+ nu gamma and B^+ -> mu^+ nu gamma. Using a 140 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric e^+ e^- collider, we find no evidence for signals in any mode and set the following preliminary upper limits at 90% confidence level:
BR(B^+ -> mu^+ nu) < 2.0 * 10^-6,
BR(B^+ -> e^+ nu gamma) mu^+ nu gamma) < 2.3 * 10^-5.
01 Jan 2004
23 Aug 2004