BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Search for B -> K-(*()) v(v)over-bar and invisible quarkonium decays. Phys. Rev. D, 87(11), 112005–13pp.
Abstract: We search for the flavor-changing neutral-current decays B -> K-(*()) v (v) over bar, and the invisible decays J/psi -> v (v) over bar and psi(2S) -> v (v) over bar via B -> K-(*())J/psi and B -> K-(*()) psi(2S), respectively, using a data sample of 471 x 10(6) B (B) over bar pairs collected by the BABAR experiment. We fully reconstruct the hadronBic decay of one of the B mesons in the Y(4S) -> B (B) over bar decay, and search for the B -> K-(*()) v (v) over bar decay in the rest of the event. We observe no significant excess of signal decays over background and report branching fraction upper limits of B(B+ -> K+ v (v) over bar) < 3.7 x 10(-5), B(B-0 -> K-0 v<(v)over bar>) < 8.1 x 10(-5), B(B+ -> K*(+) v<(v)over bar>) < 11.6 x 10(-5), B(B-0 -> K*(0) v<(v)over bar>), < 9.3 x 10(-5), and combined upper limits of B(B -> K v<(v)over bar>) < 3.2 x 10(-5) and B(B -> K* v<(v)over bar>) < 7.9 x 10(-5), all at the 90% confidence level. For the invisible quarkonium decays, we report branching fraction upper limits of B(J/psi -> v<(v)over bar>) < 3.9 x 10(-3) and B(psi(2S) -> v<(v)over bar> < 15.5 x 10(-3) at the 90% confidence level. Using the improved kinematic resolution achieved from hadronic reconstruction, we also provide partial branching fraction limits for the B -> K-(*()) v<(v)over bar> decays over the full kinematic spectrum.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Measurement of CP-violating asymmetries in B-0 -> (rho pi)(0) decays using a time-dependent Dalitz plot analysis. Phys. Rev. D, 88(1), 012003–26pp.
Abstract: We present results for a time-dependent Dalitz plot measurement of CP-violating asymmetries in the mode B-0 -> pi(+)pi(-)pi(0). The data set is derived from the complete sample of 471 x 10(6) B (B) over bar meson pairs collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at the SLAC National Accelerator Laboratory operating on the Upsilon(4S) resonance. We extract parameters describing the time-dependent B-0 -> rho pi decay probabilities and CP asymmetries, including C = 0.016 +/- 0.059 +/- 0.036, Delta C = 0.234 +/- 0.061 +/- 0.048, S = 0.053 +/- 0.081 +/- 0.034, and Delta S = 0.054 +/- 0.082 +/- 0.039, where the uncertainties are statistical and systematic, respectively. We perform a two-dimensional likelihood scan of the direct CP-violation asymmetry parameters for B-0 -> rho(+/-)pi(-/+) decays, finding the change in chi(2) between the minimum and the origin (corresponding to no direct CP violation) to be Delta chi(2) = 6.42. We present information on the CP-violating parameter alpha in a likelihood scan that incorporates B-+/- -> rho pi measurements. To aid in the interpretation of our results, statistical robustness studies are performed to assess the reliability with which the true values of the physics parameters can be extracted. Significantly, these studies indicate that alpha cannot be reliably extracted with our current sample size, though the other physics parameters are robustly extracted.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Measurement of the D*(2010)(+) natural linewidth and the D*(2010)(+)-D-0 mass difference. Phys. Rev. D, 88(5), 052003–20pp.
Abstract: We measure the mass difference, Delta m(0), between the D*(2010)(+) and the D-0 and the natural linewidth, Gamma, of the transition D*(2010)(+) -> D-0 pi(+). The data were recorded with the BABAR detector at center-of-mass energies at and near the Upsilon(4S) resonance, and correspond to an integrated luminosity of approximately 477 fb(-1). The D-0 is reconstructed in the decay modes D-0 -> K-pi(+) and D-0 -> K-pi(+)pi(-)pi(+). For the decay mode D-0 -> K-pi(+) we obtain Gamma = (83.4 +/- 1.7 +/- 1.5) keV and Delta m(0) = (145425.6 +/- 0.6 +/- 1.8) keV, where the quoted errors are statistical and systematic, respectively. For the D-0 -> K-pi(+)pi(-)pi(+) mode we obtain Gamma = (83.2 +/- 1.5 +/- 2.6) keV and Delta m(0) = (145426.6 +/- 0.5 +/- 2.0) keV. The combined measurements yield Gamma = (83.3 +/- 1.2 +/- 1.4) keV and Delta m(0) = (145425.9 +/- 0.4 +/- 1.7) keV; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Measurement of the D*(2010)(+) Meson Width and the D*(2010)(+) – D-0 Mass Difference. Phys. Rev. Lett., 111(11), 111801–8pp.
Abstract: We measure the mass difference Delta m(0) between the D*(2010)(+) and the D-0 and the natural linewidth Gamma of the transition D*(2010)(+) -> D-0 pi(+). The data were recorded with the BABAR detector at center-of-mass energies at and near the gamma(4S) resonance, and correspond to an integrated luminosity of approximately 477 fb(-1). The D-0 is reconstructed in the decay modes D-0 -> K-pi(+) and D-0 -> K-pi(+) and D-0 -> K-pi(+)pi(-)pi(+). For the decay mode D-0 -> K-pi(+) we obtain Gamma = (83.4 +/- 1.7 +/- 1.5) keV and Delta m(0) = (145425.6 +/- 0.6 +/- 18) keV, where the quoted errors are statistical and systematic, respectively. For the D-0 -> K-pi(+)pi(-)pi(+) mode we obtain Gamma = (83.2 +/- 1.5 +/- 2.6) keV and Delta m(0) = (145426.6 +/- 0.5 +/- 2.0) keV. The combined measurements yield Gamma = (83.3 +/- 1.2 +/- 1.4) keV and Delta m(0) (145425.9 +/- 0.4 +/- 1.7) keV; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Search for CP Violation in B-0-<(B-0)over bar> mixing using partial reconstruction of B-0 -> D*(-)Xl(+)nu(l) and a kaon tag. Phys. Rev. Lett., 111(10), 101802–7pp.
Abstract: We present results of a search for CP violation in B-0-(B) over bar (0) mixing with the BABAR detector. We select a sample of B0 -> D*-Xl(+)nu decays with a partial reconstruction method and use kaon tagging to assess the flavor of the other B meson in the event. We determine the CP violating asymmetryA(CP) [N((BB0)-B-0) – N((B-0) over bar (B-0) over bar)]/[N((B-0) over bar (B-0) over bar) + N((BB0)-B-0)] = (0.06 +/- 0.17 +/- 0.38-0.32)%, corresponding to Delta(CP) = 1- vertical bar q/p vertical bar = (0.29 +/- 0.84+1.88-1.61) X 10(-3).
|
BABAR Collaboration(Aubert, B. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2013). The BABAR detector: Upgrades, operation and performance. Nucl. Instrum. Methods Phys. Res. A, 729, 615–701.
Abstract: The BABAR detector operated successfully at the PEP-Il asymmetric e(+) e(-) collider at the SLAC National Accelerator Laboratory from 1999 to 2008. This report covers upgrades, operation, and performance of the collider and the detector systems, as well as the trigger, online and offline computing, and aspects of event reconstruction since the beginning of data taking.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Production of charged pions, kaons, and protons in e(+)e(-) annihilations into hadrons at root s=10.54 GeV. Phys. Rev. D, 88(3), 032011–26pp.
Abstract: Inclusive production cross sections of pi(+/-), K-+/- and p/(p) over bar per hadronic e(+)e(-) annihilation event are measured at a center-of-mass energy of 10.54 GeV, using a relatively small sample of very high quality data from the BABAR experiment at the PEP-II B-factory at the SLAC National Accelerator Laboratory. The drift chamber and Cherenkov detector provide clean samples of identified pi(+/-), K-+/-, and p/(p) over bar over a wide range of momenta. Since the center-of-mass energy is below the threshold to produce a B (B) over bar pair, with B a bottom-quark meson, these data represent a pure e(+)e(-) -> q (q) over bar sample with four quark flavors, and are used to test QCD predictions and hadronization models. Combined with measurements at other energies, in particular at the Z(0) resonance, they also provide precise constraints on the scaling properties of the hadronization process over a wide energy range.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Precision measurement of the e(+)e(-) -> K+K-(gamma) cross section with the initial-state radiation method at BABAR. Phys. Rev. D, 88(3), 032013–28pp.
Abstract: A precise measurement of the cross section for the process e(+)e(-) -> K+K-(gamma) from threshold to an energy of 5 GeV is obtained with the initial-state radiation (ISR) method using 232 fb(-1) of data collected with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV. The measurement uses the effective ISR luminosity determined from the e(+)e(-) -> mu(+)mu(-)(gamma)gamma(ISR) process with the same data set. The corresponding lowest-order contribution to the hadronic vacuum polarization term in the muon magnetic anomaly is found to be a(mu)(KK,LO) = (22.93 +/- 0.18(stat) +/- 0.22(syst)) x 10(-10). The charged kaon form factor is extracted and compared to previous results. Its magnitude at large energy significantly exceeds the asymptotic QCD prediction, while the measured slope is consistent with the prediction.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Search for a light Higgs boson decaying to two gluons or s(s)over-bar in the radiative decays of Upsilon(1S). Phys. Rev. D, 88(3), 031701–7pp.
Abstract: We search for the decay Upsilon(1S) -> A(0), A(0) -> gg or s (s) over bar, where A(0) is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric Standard Model. We use a sample of (17.6 +/- 0.3) x 10(6) Upsilon(1S) mesons produced in the BABAR experiment via e(+)e(-) -> Upsilon(2S) -> pi(+)pi(-)Upsilon(1S). We see no significant signal and set 90%-confidence-level upper limits on the product branching fraction B(Upsilon(1S) -> gamma A(0)) . B(A(0) -> gg or s (s) over bar ranging from 10(-6) to 10(-2) for A(0) masses in the range 0.5-9.0 GeV/c(2).
|
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.
|