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-depe...
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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 B0→D(*)h0 with D→KS0π+π− decays, where h0∈{π0,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)×106BB¯ pairs recorded by the BABAR detector and (772±11)×106BB¯ pairs recorded by the Belle detector. The results of the measurement are sin2β=0.80±0.14(stat)±0.06(syst)±0.03(model) and cos2β=0.91±0.22(stat)±0.09(syst)±0.07(model). The result for the direct measurement of the angle β of the CKM Unitarity Triangle is β=[22.5±4.4(stat)±1.2(syst)±0.6(model)]°. The measurement assumes no direct CP violation in B0→D(*)h0 decays. The quoted model uncertainties are due to the composition of the D0→KS0π+π− decay amplitude model, which is newly established by performing a Dalitz plot amplitude analysis using a high-statistics e+e−→cc¯ data sample. CP violation is observed in B0→D(*)h0 decays at the level of 5.1 standard deviations. The significance for cos2β>0 is 3.7 standard deviations. The trigonometric multifold solution π/2−β=(68.1±0.7)° is excluded at the level of 7.3 standard deviations. The measurement resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle.
We report measurements of sin2β and cos2β using a time-dependent Dalitz plot analysis of B0→D(*)h0 with D→KS0π+π− decays, where the light unflavored and neutral hadron h0 is a π0, η, or ω meson. The analysis ...
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We report measurements of sin2β and cos2β using a time-dependent Dalitz plot analysis of B0→D(*)h0 with D→KS0π+π− decays, where the light unflavored and neutral hadron h0 is a π0, η, or ω meson. The analysis uses a combination of the final data sets of the BaBar and Belle experiments containing 471×106 and 772×106 BB¯ pairs collected at the ϒ(4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. We measure sin2β=0.80±0.14(stat)±0.06(syst)±0.03(model) and cos2β=0.91±0.22(stat)±0.09(syst)±0.07(model). The result for the direct measurement of the angle is β=(22.5±4.4(stat)±1.2(syst)±0.6(model))°. The last quoted uncertainties are due to the composition of the D0→KS0π+π− decay amplitude model, which is newly established by a Dalitz plot amplitude analysis of a high-statistics e+e−→cc¯ data sample as part of this analysis. We find the first evidence for cos2β>0 at the level of 3.7 standard deviations. The measurement excludes the trigonometric multifold solution π/2−β=(68.1±0.7)° at the level of 7.3 standard deviations and therefore resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle. The hypothesis of β=0° is ruled out at the level of 5.1 standard deviations, and thus CP violation is observed in B0→D(*)h0 decays. The measurement assumes no direct CP violation in B0→D(*)h0 decays.
The first search for double charged charmoniumlike state production in ϒ(1S) and ϒ(2S) decays and in e+e− annihilation at s=10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the...
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The first search for double charged charmoniumlike state production in ϒ(1S) and ϒ(2S) decays and in e+e− annihilation at s=10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant signals are observed in any of the studied modes, and the 90% credibility level upper limits on their product branching fractions in ϒ(1S) and ϒ(2S) decays [B(ϒ(1S,2S)→Zc+Zc(′)−)×B(Zc+→π++cc¯) (cc¯=J/ψ, χc1(1P), ψ(2S))] and the product of Born cross section and branching fraction for e+e−→Zc+Zc(′)− (σ(e+e−→Zc+Zc(′)−)×B(Zc+→π++cc¯)) at s=10.52, 10.58, and 10.867 GeV are determined. Here, Zc refers to the Zc(3900) and Zc(4200) observed in the πJ/ψ final state, the Zc1(4050) and Zc2(4250) in the πχc1(1P) final state, and the Zc(4050) and Zc(4430) in the πψ(2S) final state.
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