Publications by authors named "Badhrees I"

The vapor pressure isotopic effect (VPIE) of xenon has been measured using cryogenic distillation. The still is calibrated with argon and krypton and yields a measurement of ln( / ) ≃ (0.26 ± 0.

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We report on a comparison between the theoretically predicted and experimentally measured spectra of the first-forbidden nonunique β-decay transition ^{137}Xe(7/2^{-})→^{137}Cs(7/2^{+}). The experimental data were acquired by the EXO-200 experiment during a deployment of an AmBe neutron source. The ultralow background environment of EXO-200, together with dedicated source deployment and analysis procedures, allowed for collection of a pure sample of the decays, with an estimated signal to background ratio of more than 99 to 1 in the energy range from 1075 to 4175 keV.

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The experimental results on the ratios of branching fractions R(D)=B(B[over ¯]→Dτ^{-}ν[over ¯]_{τ})/B(B[over ¯]→Dℓ^{-}ν[over ¯]_{ℓ}) and R(D^{*})=B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}), where ℓ denotes an electron or a muon, show a long-standing discrepancy with the standard model predictions, and might hint at a violation of lepton flavor universality. We report a new simultaneous measurement of R(D) and R(D^{*}), based on a data sample containing 772×10^{6}  BB[over ¯] events recorded at the ϒ(4S) resonance with the Belle detector at the KEKB e^{+}e^{-} collider. In this analysis the tag-side B meson is reconstructed in a semileptonic decay mode and the signal-side τ is reconstructed in a purely leptonic decay.

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We report the first observation of the radiative decay of the ϒ(1S) into a charmonium state. The significance of the observed signal of ϒ(1S)→γχ_{c1} is 6.3 standard deviations including systematics.

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A search for neutrinoless double-β decay (0νββ) in ^{136}Xe is performed with the full EXO-200 dataset using a deep neural network to discriminate between 0νββ and background events. Relative to previous analyses, the signal detection efficiency has been raised from 80.8% to 96.

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We present the first measurements of absolute branching fractions of Ξ_{c}^{0} decays into Ξ^{-}π^{+}, ΛK^{-}π^{+}, and pK^{-}K^{-}π^{+} final states. The measurements are made using a dataset comprising (772±11)×10^{6} BB[over ¯] pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB e^{+}e^{-} collider. We first measure the absolute branching fraction for B^{-}→Λ[over ¯]_{c}^{-}Ξ_{c}^{0} using a missing-mass technique; the result is B(B^{-}→Λ[over ¯]_{c}^{-}Ξ_{c}^{0})=(9.

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We report the first observation of the double strange baryon Ξ(1620)^{0} in its decay to Ξ^{-}π^{+} via Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+} decays based on a 980  fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The mass and width are measured to be 1610.4±6.

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We report the first observation of the spontaneous polarization of Λ and Λ[over ¯] hyperons transverse to the production plane in e^{+}e^{-} annihilation, which is attributed to the effect arising from a polarizing fragmentation function. For inclusive Λ/Λ[over ¯] production, we also report results with subtracted feed-down contributions from Σ^{0} and charm. This measurement uses a dataset of 800.

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We present first evidence that the cosine of the CP-violating weak phase 2β is positive, and hence exclude trigonometric multifold solutions of the Cabibbo-Kobayashi-Maskawa (CKM) Unitarity Triangle using a time-dependent Dalitz plot analysis of B^{0}→D^{(*)}h^{0} with D→K_{S}^{0}π^{+}π^{-} decays, where h^{0}∈{π^{0},η,ω} denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BABAR and Belle experiments collected at the ϒ(4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6}BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6}BB[over ¯] pairs recorded by the Belle detector.

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We report the observation of ϒ(2S)→γη_{b}(1S) decay based on an analysis of the inclusive photon spectrum of 24.7  fb^{-1} of e^{+}e^{-} collisions at the ϒ(2S) center-of-mass energy collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We measure a branching fraction of B[ϒ(2S)→γη_{b}(1S)]=(6.

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We report the first observation of the hadronic transition ϒ(4S)→η^{'}ϒ(1S), using 496  fb^{-1} data collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We reconstruct the η^{'} meson through its decays to ρ^{0}γ and to π^{+}π^{-}η, with η→γγ. We measure B(ϒ(4S)→η^{'}ϒ(1S))=[3.

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Using data recorded with the Belle detector, we observe a new excited hyperon, an Ω^{*-} candidate decaying into Ξ^{0}K^{-} and Ξ^{-}K_{S}^{0} with a mass of 2012.4±0.7(stat)±0.

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We report the results of a search for the rare, purely leptonic decay B^{-}→μ^{-}ν[over ¯]_{μ} performed with a 711  fb^{-1} data sample that contains 772×10^{6}  BB[over ¯] pairs, collected near the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The signal events are selected based on the presence of a high momentum muon and the topology of the rest of the event showing properties of a generic B-meson decay, as well as the missing energy and momentum being consistent with the hypothesis of a neutrino from the signal decay. We find a 2.

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Results from a search for neutrinoless double-beta decay (0νββ) of ^{136}Xe are presented using the first year of data taken with the upgraded EXO-200 detector. Relative to previous searches by EXO-200, the energy resolution of the detector has been improved to σ/E=1.23%, the electric field in the drift region has been raised by 50%, and a system to suppress radon in the volume between the cryostat and lead shielding has been implemented.

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We report the first evidence for isospin violation in B→K^{*}γ and the first measurement of the difference of CP asymmetries between B^{+}→K^{*+}γ and B^{0}→K^{*0}γ. This analysis is based on the data sample containing 772×10^{6}BB[over ¯] pairs that was collected with the Belle detector at the KEKB energy-asymmetric e^{+}e^{-} collider. We find evidence for the isospin violation with a significance of 3.

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We report a study of the decay D^{0}→K_{S}^{0}K_{S}^{0} using 921  fb^{-1} of data collected at or near the ϒ(4S) and ϒ(5S) resonances with the Belle detector at the KEKB asymmetric energy e^{+}e^{-} collider. The measured time-integrated CP asymmetry is A_{CP}(D^{0}→K_{S}^{0}K_{S}^{0})=(-0.02±1.

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We report the first measurement of the τ lepton polarization P_{τ}(D^{*}) in the decay B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ} as well as a new measurement of the ratio of the branching fractions R(D^{*})=B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}), where ℓ^{-} denotes an electron or a muon, and the τ is reconstructed in the modes τ^{-}→π^{-}ν_{τ} and τ^{-}→ρ^{-}ν_{τ}. We use the full data sample of 772×10^{6}  BB[over ¯] pairs recorded with the Belle detector at the KEKB electron-positron collider. Our results, P_{τ}(D^{*})=-0.

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We report the first observation of the radiative charm decay D^{0}→ρ^{0}γ and the first search for CP violation in decays D^{0}→ρ^{0}γ, ϕγ, and K[over ¯]^{*0}(892)γ, using a data sample of 943  fb^{-1} collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The branching fraction is measured to be B(D^{0}→ρ^{0}γ)=(1.77±0.

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Using data collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider, we measure the energy dependence of the e^{+}e^{-}→h_{b}(nP)π^{+}π^{-} (n=1, 2) cross sections from thresholds up to 11.02 GeV. We find clear ϒ(10860) and ϒ(11020) peaks with little or no continuum contribution.

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We report the first observation of the decay Λ_{c}^{+}→pK^{+}π^{-} using a 980  fb^{-1} data sample collected by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. This is the first observation of a doubly Cabibbo-suppressed decay of a charmed baryon. We measure the branching ratio of this decay with respect to its Cabibbo-favored counterpart to be B(Λ_{c}^{+}→pK^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})=(2.

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We report the analysis of the three-body e^{+}e^{-}→BB[over ¯]π^{±}, BB[over ¯]^{*}π^{±}, and B^{*}B[over ¯]^{*}π^{±} processes, including the first observations of the Z_{b}^{±}(10610)→[BB[over ¯]^{*}+c.c.]^{±} and Z_{b}^{±}(10650)→[B^{*}B[over ¯]^{*}]^{±} transitions that are found to dominate the corresponding final states.

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We measure the decay B_{s}^{0}→K^{0}K[over ¯]^{0} using data collected at the ϒ(5S) resonance with the Belle detector at the KEKB e^{+}e^{-} collider. The data sample used corresponds to an integrated luminosity of 121.4  fb^{-1}.

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We report the first observation of the decays B^{0}→pΛ[over ¯]D^{(*)-}. The data sample of 711  fb^{-1} used in this analysis corresponds to 772×10^{6} BB[over ¯] pairs, collected at the ϒ(4S) resonance by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We observe 19.

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Using a sample of 771.6×10(6) ϒϒ(4S) decays collected by the Belle experiment at the KEKB e(+)e(-) collider, we observe, for the first time, the transition ϒ(4S)→ηh(b)(1P) with the branching fraction B[ϒ(4S)→ηh(b)(1P)]=(2.18±0.

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We report a measurement of the time-dependent CP asymmetry of B[over ¯]^{0}→D_{CP}^{(*)}h^{0} decays, where the light neutral hadron h^{0} is a π^{0}, η, or ω meson, and the neutral D meson is reconstructed in the CP eigenstates K^{+}K^{-}, K_{S}^{0}π^{0}, or K_{S}^{0}ω. The measurement is performed combining the final data samples collected at the ϒ(4S) resonance by the BABAR and Belle experiments at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6} BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6} BB[over ¯] pairs recorded by the Belle detector.

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