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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2018). Measurement of the spectral function for the tau(-) -> K- K(S)v(tau) decay. Phys. Rev. D, 98(3), 032010–11pp.
Abstract: The decay tau(-) -> K- K(S)v(tau) has been studied using 430 x 10(6) e(+) e(-) -> tau(+) tau(-) events produced at a center-of-mass energy around 10.6 GeV at the PEP-II collider and studied with the BABAR detector. The mass spectrum of the K- K-S system has been measured and the spectral function has been obtained. The measured branching fraction B(tau(-) -> K- K(S)v(tau)) = (0.739 +/- 0.011 (stat) +/- 0.020 (syst)) x 10(-3) is found to be in agreement with earlier measurements.
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BABAR Collaboration(Lees, J. P. et al), Lopez-March, N., Martinez-Vidal, F., & Oyanguren, A. (2011). Measurement of the mass and width of the D_s1 (2536)+ meson. Phys. Rev. D, 83(7), 072003–14pp.
Abstract: The decay width and mass of the D-s1(2536)(+) meson are measured via the decay channel D-s1(+) -> (D*+KS0) using 385 fb(-1) of data recorded with the BABAR detector in the vicinity of the Gamma(4S) resonance at the PEP-II asymmetric-energy electron-positron collider. The result for the decay width is Gamma(D-s1(+)) = 92 +/- 0.03(stat.) +/- 0.04(syst.) MeV. For the mass, a value of m(D-s1(+)) = 2535.08 +/- 0.01(stat.) +/- 0.15(syst.) MeV/c(2) is obtained. The mass difference between the D-s1(+) and the D*+ is measured to be m(D-s1(+)) – m(D*+) = 524.83 +/- 0.01(stat.) +/- 0.04(syst.) MeV/c(2), representing a significant improvement compared to the current world average. The unnatural spin-parity assignment for the D-s1(+) meson is confirmed.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2015). Study of the e(+)e(-) -> K+K- reaction in the energy range from 2.6 to 8.0 GeV. Phys. Rev. D, 92(7), 072008–16pp.
Abstract: The e(+)e(-) -> K+K- cross section and charged-kaon electromagnetic form factor are measured in the e(+)e(-) center-of-mass energy range (E) from 2.6 to 8.0 GeV using the initial-state radiation technique with an undetected photon. The study is performed using 469 fb(-1) of data collected with the BABAR detector at the PEP-II2 e(+)e(-) collider at center-of-mass energies near 10.6 GeV. The form factor is found to decrease with energy faster than 1/E-2 and approaches the asymptotic QCD prediction. Production of the K+K- final state through the J/psi and psi(2S) intermediate states is observed. The results for the kaon form factor are used together with data from other experiments to perform a model-independent determination of the relative phases between electromagnetic (single-photon) and strong amplitudes in J/psi and psi(2S). K+K- decays. The values of the branching fractions measured in the reaction e(+)e(-) -> K+K- are shifted relative to their true values due to interference between resonant and nonresonant amplitudes. The values of these shifts are determined to be about +/- 5% for the J/psi meson and +/- 15% for the psi(2S) meson.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Measurement of the e(+)e(-) -> p(p)over-bar cross section in the energy range from 3.0 to 6.5 GeV. Phys. Rev. D, 88(7), 072009–12pp.
Abstract: The e(+)e(-) -> p (p) over bar cross section and the proton magnetic form factor have been measured in the center-of-mass energy range from 3.0 to 6.5 GeV using the initial-state radiation technique with an undetected photon. This is the first measurement of the form factor at energies higher than 4.5 GeV. The analysis is based on 469 fb-1 of integrated luminosity collected with the BABAR detector at the PEP-II collider at e(+)e(-) center-of-mass energies near 10.6 GeV. The branching fractions for the decays J/psi -> p (p) over bar and psi(2S) -> p (p) over bar have also been measured.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Measurement of B (B -> Xs gamma), the B -> Xs gamma photon energy spectrum, and the direct CP asymmetry in B -> Xs+d gamma decays. Phys. Rev. D, 86(11), 112008–33pp.
Abstract: The photon spectrum in B -> X-s gamma decay, where X-s is any strange hadronic state, is studied using a data sample of (382.8 +/- 4.2) x 10(6) e(+)e(-) -> Upsilon(4S) -> B (B) over bar events collected by the BABAR experiment at the PEP-II collider. The spectrum is used to measure the branching fraction B(B -> X-s gamma) (3.21 +/- 0.15 +/- 0.29 +/- 0.08) x 10(-4) and the first, second, and third moments < E-gamma > = 2.267 +/- 0.019 +/- 0.032 +/- 0.003 GeV, <(E-gamma – < E-gamma >)(2)> = 0.0484 +/- 0.0053 +/- 0.0077 +/- 0.0005 GeV2, and <(E-gamma – < E-gamma)(3)> = -0.0048 +/- 0.0011 +/- 0.0011 +/- 0.0004 GeV3, for the range E-gamma > 1.8 GeV, where E-gamma is the photon energy in the B-meson rest frame. Results are also presented for narrower E-gamma ranges. In addition, the direct CP asymmetry A(CP)(B -> Xs+d gamma) is measured to be 0.057 +/- 0.063. The spectrum itself is also unfolded to the B-meson rest frame; that is the frame in which theoretical predictions for its shape are made.
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