|
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Study of the reaction e(+)e(-) -> J/psi pi(+)pi(-) via initial-state radiation at BABAR. Phys. Rev. D, 86(5), 051102–9pp.
Abstract: We study the process e(+)e(-) -> J/psi pi(+)pi(-) with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BABAR detector at center-of-mass energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454 fb(-1). We investigate the J/psi pi(+)pi(-) mass distribution in the region from 3.5 to 5.5 GeV/c(2). Below 3.7 GeV/c(2) the psi (2S) signal dominates, and above 4 GeV/c(2) there is a significant peak due to the Y(4260). A fit to the data in the range 3.74-5.50 GeV/c(2) yields a mass value 4245 +/- 5(stat) +/- 4(syst) MeV/c(2) and a width value 114(-15)(+16)(stat) +/- 7(syst) MeV for this state. We do not confirm the report from the Belle Collaboration of a broad structure at 4.01 GeV/c(2). In addition, we investigate the pi(+)pi(-) system which results from Y(4260) decay.
|
|
|
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2015). Measurement of the branching fractions of the radiative leptonic tau decays tau -> e gamma v(v)over-bar and tau -> μgamma v(v)over-bar at BABAR. Phys. Rev. D, 91(5), 051103–8pp.
Abstract: We perform a measurement of the tau -> l gamma v (v) over bar (l = e, mu) branching fractions for a minimum photon energy of 10 MeV in the tau rest frame, using 431 fb(-1) of e(+) e(-) collisions collected at the center-of-mass energy of the Upsilon(4S) resonance with the BABAR detector at the PEP-II storage rings. We find B(tau -> μgamma v (v) over bar = (3.69 +/- 0.03 +/- 0.10) x 10(-3) and B(tau -> e gamma v (v) over bar = (1.847 +/- 0.015 +/- 0.052) x 10(-2), where the first quoted error is statistical and the second is systematic. These results are substantially more precise than previous measurements.
|
|
|
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Improved limits on B-0 decays to invisible final states and to nu nubar gamma. Phys. Rev. D, 86(5), 051105–8pp.
Abstract: We establish improved upper limits on branching fractions for B-0 decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for final states where the only visible product is a photon. Within the Standard Model, these decays have branching fractions that are below the current experimental sensitivity, but various models of physics beyond the Standard Model predict significant contributions for these channels. Using 471 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance by the BABAR experiment at the PEP-II e(+)e(-) storage ring at the SLAC National Accelerator Laboratory, we establish upper limits at the 90% confidence level of 2.4 x 10(-5) for the branching fraction of B-0 -> invisible and 1.7 x 10(-5) for the branching fraction of B-0 -> invisible + gamma.
|
|
|
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2017). Cross sections for the reactions e(+)e(-) -> (KSKL0)-K-0 pi(0), (KSKL0)-K-0 eta, and (KSKL0)-K-0 pi(0)pi(0) from events with initial-state radiation. Phys. Rev. D, 95(5), 052001–16pp.
Abstract: We study the processes e(+)e(-) -> (KSKL0)-K-0 pi(0)gamma, (KSKL0)-K-0 eta gamma, and (KSKL0)-K-0 pi(0)pi(0)gamma, where the photon is radiated from the initial state, providing cross section measurements for the hadronic final states over a continuum of center-of-mass energies. The results are based on 469 fb(-1) of data collected at or near the psi(4S) resonance with the BABAR detector at SLAC. We present the first measurements of the e(+)e(-) -> (KSKL0)-K-0 pi(0), (KSKL0)-K-0 eta, and (KSKL0)-K-0 pi(0)pi(0) cross sections up to a center-of-mass energy of 4 GeV and study their intermediate resonance structures. We observe J/psi decays to all of these final states for the first time, present measurements of their J/psi branching fractions, and search for psi(2S)decays.
|
|
|
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2015). Dalitz plot analyses of B-0 -> (D-DK+)-K-0 and B+-> (D)over-bar(-)D(0)K(+) decays. Phys. Rev. D, 91(5), 052002–14pp.
Abstract: We present Dalitz plot analyses for the decays of B mesons to (D-DK+)-K-0 and (D) over bar (DK+)-D-0-K-0. We report the observation of the D*(s1)(2700)(+) resonance in these two channels and obtain measurements of the mass M(D*(s1)(2700)(+)) = 2699(-7)(+14) MeV/c(2) and of the width Gamma(D*(s1)(2700)(+)) = 127(-19)(+24) MeV, including statistical and systematic uncertainties. In addition, we observe an enhancement in the (DK+)-K-0 invariant mass around 2350-2500 MeV/c(2) in both decays B-0 -> (D-DK+)-K-0 and B+ -> (D) over bar (DK+)-D-0-K-0, which we are not able to interpret. The results are based on 429 fb(-1) of data containing 471 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory.
|
|
