BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Search for a low-mass scalar Higgs boson decaying to a tau pair in single-photon decays of Y(1S). Phys. Rev. D, 88(7), 071102–8pp.
Abstract: We search for a low-mass scalar CP-odd Higgs boson, A(0), produced in the radiative decay of the upsilon resonance and decaying into a tau(+)tau(-) pair: Y(1S) -> gamma A(0). The production of Y(1S) mesons is tagged by Y(2S) -> pi(+)pi(-) Y(1S) transitions, using a sample of (98.3 +/- 0.9) x 10(6) Y(2S) mesons collected by the BABAR detector. We find no evidence for a Higgs boson in the mass range 3: 5 <= m(A)0 <= 9: 2 GeV, and combine these results with our previous search for the tau decays of the light Higgs in radiative Y(3S) decays, setting limits on the coupling of A(0) to the b (b) over bar quarks in the range 0.09-1.9. Our measurements improve the constraints on the parameters of the next-to-minimal-supersymmetric Standard Model and similar theories with low-mass scalar degrees of freedom.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2014). Search for the decay (B)over-bar(0) -> Lambda(+)(c)(p)over-barp(p)over-bar. Phys. Rev. D, 89(7), 071102–7pp.
Abstract: We report a search for the decay (B) over bar (0) -> Lambda(+)(c)(p) over barp (p) over bar. Using a data sample of 471 x 10(6) B (B) over bar pairs collected with the BABAR detector at the PEP-II2 storage ring at SLAC, we find no events and set an upper limit on the branching fraction B((B) over bar (0) -> Lambda(+)(c)(p) over barp (p) over bar x B(Lambda(+)(c) -> pK(-)pi(+))/0.050 < 2.8 x 10(-6) at 90% C. L., where we have normalized B(Lambda(+)(c) -> pK(-)pi(+)) to the world average value.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2015). Search for a light Higgs resonance in radiative decays of the Upsilon(1S) with a charm tag. Phys. Rev. D, 91(7), 071102–9pp.
Abstract: A search is presented for the decay Upsilon(1S) -> gamma A(0), A(0) -> c (c) over barc, where A(0) is a candidate for the CP-odd Higgs boson of the next-to-minimal supersymmetric standard model. The search is based on data collected with the BABAR detector at the Upsilon(2S) resonance. A sample of Upsilon(1S) mesons is selected via the decay Upsilon(2S) -> pi(+)pi(-)Upsilon(1S) . The A(0) -> c (c) over bar decay is identified through the reconstruction of hadronic D-0, D+,and D-0 (2010)(+) meson decays. No significant signal is observed. The measured 90% confidence-level upper limits on the product branching fraction beta(Upsilon(1S) -> gamma A(0)) x beta(A(0) -> (c) over barc range from 7.4 x 10(-5) to 2.4 x 10(-3) for A(0) masses from 4.00 to 8.95 GeV/c(2) and 9.10 to 9.25 GeV/c(2), where the region between 8.95 and 9.10 GeV/c(2) is excluded because of background from Upsilon(2S) -> gamma chi(bJ)(1P), chi(bJ)(1P) -> gamma Upsilon(1S) decays.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2018). Search for the decay mode B-0 -> pp(p)over-bar (p)over-bar. Phys. Rev. D, 98(7), 071102–7pp.
Abstract: A search is presented for the four-body decay B-0 -> pp (p) over bar (p) over bar in a sample of 471 million B (B) over bar pairs collected with the BABAR detector, operated at the SLAC PEP-II asymmetric-energy e(+) e(-) collider. The center-of-mass energy is 10.58 GeV. From a fit to the distribution of the energy-substituted mass m(ES), the branching fraction B(B-0 -> pp (p) over bar (p) over bar) = (1.1 +/- 0.5 +/- 0.2) x 10(-7) is extracted, where the first uncertainty is statistical and the second is systematic. The significance of the signal, including the systematic uncertainty, is 2.9 standard deviations. The upper limit on the branching fraction is determined to be 2.0 x 10(-7) at 90% confidence level.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Amplitude analysis and measurement of the time-dependent CP asymmetry of B-0 -> (KSKSKS0)-K-0-K-0 decays. Phys. Rev. D, 85(5), 054023–21pp.
Abstract: We present the first results on the Dalitz-plot structure and improved measurements of the time-dependent CP-violation parameters of the process B-0 -> (KSKSKS0)-K-0-K-0 obtained using 468 x 10(6) B (B) over bar decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The Dalitz-plot structure is probed by a time-integrated amplitude analysis that does not distinguish between B-0 and (B) over bar (0) decays. We measure the total inclusive branching fraction B(B-0 -> (KSKSKS0)-K-0-K-0) = (6.19 +/- 0.48 +/- 0.15 +/- 0.12) x 10(-6), where the first uncertainty is statistical, the second is systematic, and the third represents the Dalitz-plot signal model dependence. We also observe evidence for the intermediate resonant states f(0)(980), f(0)(1710), and f(2)(2010). Their respective product branching fractions are measured to be (2.70(-1.19)(+1.25) +/- 0.36 +/- 1.17) x 10(-6), (0.50(-0.24)(+0.46) +/- 0.04 +/- 0.10) x 10(-6), and (0.54(-0.20)(+0.21) +/- 0.03 +/- 0.52) x 10(-6). Additionally, we determine the mixing-induced CP-violation parameters to be S = -0.94(-0.21)(+0.24) +/- 0.06 and C = -0.17 +/- 0.18 +/- 0.04, where the first uncertainty is statistical and the second is systematic. These values are in agreement with the standard model expectation. For the first time, we report evidence of CP violation in B-0 -> (KSKSKS0)-K-0-K-0 decays; CP conservation is excluded at 3.8 standard deviations including systematic uncertainties.
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