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Evidence for X(3872) --> Psi(2S) gamma in B+/- --> X(3872) K+/- Decays, and a Study of B --> ccbar gamma K
No full textIn a search for B {yields} c{bar c}{gamma} K decays with the BABAR detector, where c{bar c} includes J/{psi} and {psi}(2S), and K includes K{sup {+-}}, K{sub S}{sup 0} and K*(892), they find evidence for X(3872) {yields} J/{psi}{gamma} and X(3872) {yields} {psi}(2S){gamma} with 3.6{sigma} and 3.5{sigma} significance, respectively. They measure the product of branching fractions {Beta}(B{sup {+-}} {yields} X (3872)K{sup {+-}}) {center_dot} {Beta}(X(3872) {yields} J/{psi}{gamma}) = (2.8 {+-} 0.8(stat.) {+-} 0.2(syst.)) x 10{sup -6} and {Beta}(B{sup {+-}} {yields} X(3872)K{sup {+-}}) {center_dot} {Beta}(X(3872) {yields} {psi}(2S){gamma}) = (9.9 {+-} 2.9(stat.) {+-} 0.6(syst.)) x 10{sup -6}
A Study of B→cγK in the BaBar Experiment
No full textThe BABAR Collaboration is a high energy physics experiment located at the Stanford Linear Accelerator Center. The primary goal of the experiment is to study charge and parity violation in the B-meson sector, however the copious production of B mesons decaying to other final states allows for a wide-ranging physics program. In particular, one can access the charmonium system via colour-suppressed b → c decays of the type B → cK. This thesis presents a study of B →cγK decays where c includes J/Ψ and Ψ(2S), and K includes K±, KS0 and K*(892). The particular emphasis is on a search for the radiative decays X(3872) → J/Ψγ and X(3872) → Ψ(2S)γ. The X(3872) state is a recently-discovered resonance of undetermined quark composition, speculatively a conventional charmonium state or exotic four-quark di-meson molecule. This research is also sensitive to the well-known radiative charmonium decays B → χc1,2K, which are used as verification for the analysis technique. This dissertation sets the best B → χc1K branching fraction measurements to date, and sees the first evidence for factorization-suppressed B0 → χc2}K*0 decay at a level of 3.6σ. It also provides evidence for X(3872) → J/Ψγ and X(3872) → Ψ(2S)γ with 3.6σ and 3.3σ significance, respectively. The product of branching fractions β(B± → X(3872)K±) • β(X(3872) → J/Ψγ) = (2.8 ± 0.8(stat.) ± 0.2(syst.)) x 10{sup -6} and β(B{± → X(3872)K±) → β(X(3872) → Ψ(2S)γ) = (9.5 ± 2.7(stat.) ± 0.9(syst.)) x 10-6 are measured. These results improve upon previous X(3872) → J/Ψγ measurements, and represent the first evidence for X(3872) → Ψ(2S)γ
A study of B --> ccBAR γK in the BABAR experiment
No full textThe BABAR Collaboration is a high energy physics experiment located at the Stanford Linear Accelerator Center. The primary goal of the experiment is to study charge and parity violation in the B-meson sector, however the copious production of B mesons decaying to other final states allows for a
wide-ranging physics program. In particular, one can access the charmonium system via colour-suppressed b —> c decays of the type B —> ccBAR K. This thesis presents a study of B —> ccBAR γK decays where ccBAR includes
J/ψ and ψ(2S), and K includes K±, K°s and K*(892). The particular emphasis is on a search for the radiative decays X(3872) —> J/ψγ and X(3872) —> ψ(2S)γ. The X(3872) state is a recently-discovered resonance of
undetermined quark composition, speculatively a conventional charmonium
state or exotic four-quark di-meson molecule. This research is also sensitive
to the well-known radiative charmonium decays B —> Xcl,2K, which are used
as verification for the analysis technique.
This dissertation sets the best B —> Ｘc1K branching fraction measurements to date, and sees the first evidence for factorization-suppressed B⁰ —> Xc2K*⁰ decay at a level of 3,6σ. It also provides evidence for X(3872)
J/ψγ and X(3872) —> ψ(2S)γ with 3.6σ and 3.3σ significance, respectively. The product of branching fractions B(B± X(3872)K± . B(X(3872) —> J/ψγ
= (2.8 ± O.8(stat.) ± O.2(syst.)) x 10⁻⁶ and B(B± —> X(3872)K).
B(X(3872) —> ψ(2S)γ )=(9.5±2.7(stat.)±0.9(syst.)) x 10⁻⁶ are measured. These results improve upon previous X(3872) —> J/ψγ measurements, and represent the first evidence for X(3872) —> ψ(2S)γ.Science, Faculty ofPhysics and Astronomy, Department ofGraduat
Dalitz plot analyses of B-0 -> (D-DK+)-K-0 and B+-> (D)over-bar(-)D(0)K(+) decays
No full text© 2015, APS Journal
Measurement of the energy dependence of the ee → , and exclusive cross sections
No full textInternational audienceWe report the first measurement of the exclusive cross sections ee → , ee → , and ee → in the energy range from 10.63 GeV to 11.02 GeV. The B mesons are fully reconstructed in a large number of hadronic final states and the three channels are identified using a beam-constrained-mass variable. The shapes of the exclusive cross sections show oscillatory behavior with several maxima and minima. The results are obtained using data collected by the Belle experiment at the KEKB asymmetric-energy ee collider.[graphic not available: see fulltext
Measurements of the Branching Fractions , and
No full textInternational audienceUsing the data sample of 711 fb-1 of ϒ(4S) on-resonance data taken by the Belle detector at the KEKB asymmetric-energy electron-positron collider, we present the first measurements of branching fractions of the decays B-→Λ¯c-Ξc′0, B-→Λ¯c-Ξc(2645)0, and B-→Λ¯c-Ξc(2790)0. The signal yields for these decays are extracted from the recoil mass spectrum of the system recoiling against Λ¯c- baryons in selected B- candidates. The branching fraction of B-→Λ¯c-Ξc(2790)0 is measured to be (1.1±0.4±0.2)×10-3, where the first uncertainty is statistical and the second is systematic. The 90% credibility level upper limits on B(B-→Λ¯c-Ξc′0) and B(B-→Λ¯c-Ξc(2645)0) are determined to be 6.5×10-4 and 7.9×10-4, respectively
Measurements of the branching fractions B (B ̄0 → D∗+ π-) and B(B ̄0 →D∗+ K-) and tests of QCD factorization
No full textUsing (771.6±10.6)×106 BB ̄ meson pairs recorded by the Belle experiment at the KEKB e+e- collider, we report the branching fractions B(B ̄0→D∗+π-)=(2.62±0.02±0.09)×10-3 and B(B ̄0→D∗+K-)=(2.22±0.06±0.08)×10-4; the quoted uncertainties are statistical and systematic, respectively. A measurement of the ratio of these branching fractions is also presented, RK/π=B(B ̄→D∗+K-)/B(B ̄→D∗+π-)=(8.41±0.24±0.13)×10-2, where systematic uncertainties due to the D∗+ meson reconstruction cancel out. Furthermore, we report a new QCD factorization test based on the measured ratios for B ̄→D∗+h- and B ̄→D∗+l-ν decays at squared momentum transfer values equivalent to the mass of the h=π or K hadron. The parameters |a1(h)| are measured to be |a1(π)|=0.884±0.004±0.003±0.016 and |a1(K)|=0.913±0.019±0.008±0.013, where the last uncertainties account for all external inputs. These values are approximately 15% lower than those expected from theoretical predictions. Subsequently, flavor SU(3) symmetry is tested by measuring the ratios for pions and kaons, |a1(K)|2/|a1(π)|2=1.066±0.042±0.018±0.023, as well as for different particle species. The ratio is consistent with unity and therefore no evidence for SU(3) symmetry breaking effects is found at the 5% precision level
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