BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., & Oyanguren, A. (2011). Searches for the baryon- and lepton-number violating decays B0 -> Lambda_c+ l-, B- --> Lambda l-, and B- --> (Lambda)bar l-. Phys. Rev. D, 83(9), 091101–8pp.
Abstract: Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either Lambda(c) or Lambda and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range (3.2-520) x 10(-8) are set on the branching fractions at the 90% confidence level.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2011). Study of Y(3S, 2S) -> eta Y(1S) and Y(3S, 2S) -> pi(+) pi(-) Y(1S) hadronic transitions. Phys. Rev. D, 84(9), 092003–8pp.
Abstract: We study the Y(3S, 2S) -> eta Y(1S) and Y (3S,2S) -> pi(+)pi(-) transitions with 122 x 10(6) x Y(3S) and 100 x 10(6) Y (2S) mesons collected by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider. We measure B[Y(2S) -> eta Y(1S)] = (2.39 +/- 0.31 (stat) +/- 0.14(syst)) x 10(-4) and Gamma[Y(2S) -> eta Y(1S)]/Gamma[Y(2S) ->pi(+)pi(-)(1S)] – (2.39 +/- 0.31(stat) +/- 0.14(syst)) x 10(-3). We find no evidence for Y(3S) -> eta Y (1S) and obtain B[Y(3S) -> eta Y(1S)] < 1.0 x 10(-4) and Gamma[Y (3S) -> eta Y(1S)/Gamma[Y(3S) -> pi(+)pi(-) Y(1S)] < 2.3 x 10(-3) as upper limits at the 90% confidence level. We also provide improved measurements of the Y(S) – Y(1S) and Y(3S) – Y (1S) mass differences, 562.170 +/- 0.007(stat) +/- 0.088(syst). MeV/c(2) and 893.813 +/- 0: 015(stat) +/- 0.107(syst.) MeV/c(2), respectively.
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BABAR Collaboration(Lees, J. P. et al), Lopez-March, N., Martinez-Vidal, F., & Oyanguren, A. (2011). Evidence for the h(b)(1P) meson in the decay Y(3S) -> pi(0)h(b)(1P). Phys. Rev. D, 84(9), 091101–8pp.
Abstract: Using a sample of 122 x 10(6) Y(3S) events recorded with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at SLAC, we search for the h(b)(1P) spin-singlet partner of the P-wave X(bJ)(1P) states in the sequential decay Y(3S) -> pi(0)h(b) (1P), hb(1P) -> gamma eta(b)(1S). We observe an excess of events above background in the distribution of the recoil mass against the pi(0) at mass 9902 +/- 4(stat) +/- 2(syst) MeV/c(2). The width of the observed signal is consistent with experimental resolution, and its significance is 3.1 sigma, including systematic uncertainties. We obtain the value (4.3 +/- 1.1(stat) +/- 0.9(syst) x 10(-4) for the product branching fraction B(Y(3S) -> pi(0)h(b)) XB (h(b) -> gamma eta(b))
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2011). Observation of the rare decay B(+) -> K(+) pi(0)pi(0) and measurement of the quasi-two-body contributions B(+) -> K* (892)(+) pi(0), B(+) -> f(0)(980)K(+), and B(+) -> chi(c0)K(+). Phys. Rev. D, 84(9), 092007–11pp.
Abstract: We report an analysis of charmless hadronic decays of charged B mesons to the final state K(+) pi(0)pi(0), using a data sample of (470.9 +/- 2.8) x 10(6) B (B) over bar events collected with the BABAR detector at the Y(4S) resonance. We observe an excess of signal events, with a significance above 10 standard deviations including systematic uncertainties, and measure the branching fraction and CP asymmetry to be B(B(+) -> K(+) pi(0)pi(0)) = (16.2 +/- 1.2 +/- 1.5) x 10(-6) and A(CP)(B(+) -> K(+) pi(0)pi(0)) = -0.06 +/- 0.06 +/- 0.04, where the uncertainties are statistical and systematic, respectively. Additionally, we study the contributions of the B(+) -> K*(892)(+) pi(0), B(+) -> f(0)(980)K(+), and B(+) -> chi(c0)K(+) quasi-two-body decays. We report the world's best measurements of the branching fraction and CP asymmetry of the B(+) -> K(+) pi(0)pi(0) and B(+) -> K(+)(892)(+) pi(0) channels.
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2012). Observation and study of the baryonic B-meson decays B -> D(*) p(p)over-bar (pi)(pi). Phys. Rev. D, 85(9), 092017–21pp.
Abstract: We present results for B-meson decay modes involving a charm meson, protons, and pions using 455 x 10(6) B (B) over bar pairs recorded by the BaBar detector at the SLAC PEP-II asymmetric-energy e(+)e(-) collider. The branching fractions are measured for the following ten decays: (B) over bar (0) -> D-0 p (p) over bar, (B) over bar (0) -> D*(0) p (p) over bar, (B) over bar (0) -> D+ p (p) over bar pi(-) , (B) over bar (0) -> D-0 p (p) over bar pi(-) , B- -> D-0 p (p) over bar pi(-) , B- -> D*(0) p (p) over bar pi(-) , (B) over bar (0) -> D-0 p (p) over bar pi(-) pi(+) , (B) over bar (0) -> D*(0) p (p) over bar pi(-) pi(+) B- -> D+ p (p) over bar pi(-) pi(-) , and B- -> D*(0) p (p) over bar pi(-) pi(-). The four B- and the two five-body (B) over bar (0) modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(p (p) over bar) and M(D-(*)0 p) invariant- mass distributions show enhancements near threshold values. In the four-body mode (B) over bar (0) -> D+ p (p) over bar pi(-) , the M(p pi(-)) distribution shows a narrow structure of unknown origin near 1: 5 GeV/c(2). The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.
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