We present a search for f{sub J}(2220) production in radiative J/{psi}{yields}{gamma}f{sub J}(2220) decays using 460 fb{sup -1} of data collected with the BABAR detector at the SLAC PEP-II e{sup ...+}e{sup -} collider. The f{sub J}(2220) is searched for in the decays to K{sup +}K{sup -} and K{sub S}{sup 0}K{sub S}{sup 0}. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/{psi}{yields}{gamma}f{sub J}(2220) and f{sub J}(2220){yields}K{sup +}K{sup -}(K{sub S}{sup 0}K{sub S}{sup 0}) as a function of spin and helicity are set at the level of 10{sup -5}, below the central values reported by the Mark III experiment.
We report the measurement of the Cabibbo-Kobayashi-Maskawa CP-violating angle {gamma} through a Dalitz plot analysis of neutral D-meson decays to K{sub S}{sup 0}{pi}{sup +}{pi}{sup -} and K{sub ...S}{sup 0}K{sup +}K{sup -} produced in the processes B{sup {+-}}{yields}DK{sup {+-}}, B{sup {+-}}{yields}D*K{sup {+-}} with D*{yields}D{pi}{sup 0}, D{gamma}, and B{sup {+-}}{yields}DK*{sup {+-}} with K*{sup {+-}}{yields}K{sub S}{sup 0}{pi}{+-}, using 468 million BB pairs collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. We measure {gamma}=(68{+-}14{+-}4{+-}3) deg. (modulo 180 deg.), where the first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the uncertainty in the description of the neutral D decay amplitudes. This result is inconsistent with {gamma}=0 (no direct CP violation) with a significance of 3.5 standard deviations.
We report a direct measurement of D{sup 0}-D{sup 0} mixing parameters through a time-dependent amplitude analysis of the Dalitz plots of D{sup 0}{yields}K{sub S}{sup 0}{pi}{sup +}{pi}{sup -} and, for ...the first time, D{sup 0}{yields}K{sub S}{sup 0}K{sup +}K{sup -} decays. The low-momentum pion {pi}{sub s}{sup +} in the decay D{sup *+{yields}}D{sup 0{pi}}{sub s}{sup +} identifies the flavor of the neutral D meson at its production. Using 468.5 fb{sup -1} of e{sup +}e{sup -} colliding-beam data recorded near {radical}(s)=10.6 GeV by the BABAR detector at the PEP-II asymmetric-energy collider at SLAC, we measure the mixing parameters x=1.6{+-}2.3(stat){+-}1.2(syst){+-}0.8(model)x10{sup -3}, and y=5.7{+-}2.0(stat){+-}1.3(syst){+-}0.7(model)x10{sup -3}. These results provide the best measurement to date of x and y. The knowledge of the value of x, in particular, is crucial for understanding the origin of mixing.
The ratio R{sub {tau}{mu}({Upsilon}(1S))}={Gamma}{sub {Upsilon}(1S){yields}{tau}}{sup +}{sub {tau}}{sup -}/{Gamma}{sub {Upsilon}(1S){yields}{mu}}{sup +}{sub {mu}}{sup -} is measured using a sample of ...(121.8{+-}1.2)x10{sup 6{Upsilon}}(3S) events recorded by the BABAR detector. This measurement is intended as a test of lepton universality and as a search for a possible light pseudoscalar Higgs boson. In the standard model (SM) this ratio is expected to be close to 1. Any significant deviations would violate lepton universality and could be introduced by the coupling to a light pseudoscalar Higgs boson. The analysis studies the decays {Upsilon}(3S){yields}{Upsilon}(1S){pi}{sup +{pi}-}, {Upsilon}(1S){yields}l{sup +}l{sup -}, where l={mu}, {tau}. The result, R{sub {tau}{mu}({Upsilon}(1S))}=1.005{+-}0.013(stat){+-}0.022(syst), shows no deviation from the expected SM value, while improving the precision with respect to previous measurements.
Charged-lepton flavor-violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models ...with leptoquarks or compositeness. We present a search for such processes in a sample of 99x10{sup 6{Upsilon}}(2S) decays and 117x10{sup 6{Upsilon}}(3S) decays collected with the BABAR detector. We place upper limits on the branching fractions B({Upsilon}(nS){yields}e{sup {+-}{tau}{+-}}) and B({Upsilon}(nS){yields}{mu}{sup {+-}{tau}{+-}}) (n=2,3) at the 10{sup -6} level and use these results to place lower limits of order 1 TeV on the mass scale of charged-lepton flavor-violating effective operators.
The specifications and schemes of the main components of the power supplies of the unbalance currents of focusing and defocusing magnets with a series feeding scheme of a nuclotron are presented and ...the devices are described. The devices were made on the basis of thyristor rectifiers. High operating speed, small ripples, and low noise of the output current are achieved through the use of transistor blocks for the current regulation in a linear mode. The special feature of the described power supplies is the operation of the thyristor rectifiers in the so-called tracking mode that allows to minimise the power losses on the pass transistor bank and to regenerate the energy stored in the inductive elements to the AC network. An additional feedback loop is applied for precision current regulation.
Three-dimensional (3D) silicon detectors are emerging as one of the most promising technologies for the innermost layers of tracking devices for the foreseen upgrades of the LHC. 3D sensors ...compatible with the CMS readout, fabricated at FBK (Trento, Italy), were tested in the laboratory and with a 120GeV/c proton beam at the FNAL test beam facility, before and after irradiation up to a fluence of 3.5×1015neq/cm2. Preliminary results of the data analysis are presented.
•3D characterized in laboratory, tested with beam and irradiated with 800MeV protons.•Leakage current: few hundred nA before irradiation, ∼10μA after irradiation.•Depletion voltage: 20V. Breakdown voltage: 25–35V, not increasing after irradiation.•Efficiency: 97.5%, increasing when tilting sensors with respect to the beam.•Radiation effect: lower efficiency and lower collected charge.
A new 15-kA energy-evacuation switch based on the operational experience of the protection system of Nuclotron superconducting magnets has been developed. It is used at the test bench of ...superconducting magnets being produced for NICA (Nuclotron-based Ion Collider fAcility, which is implemented at the Joint Institute for Nuclear Research (JINR)) 1 and FAIR (Facility for Antiproton and Ion Research, Darmstadt, Germany) accelerator facilities.
We report a measurement of the branching fractions for Bbar -> D(*)(pi)l-nubar decays based on 341.1 fb-1 of data collected at the Upsilon(4S) resonance with the babar detector at the PEP-II e+e- ...storage rings. Events are tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We obtain B(B- -> D0l-nubar) = (2.33 +/- 0.09(stat.) +/- 0.09(syst.))%, B(B- -> D*0l-nubar) = (5.83 +/- 0.15(stat.) +/- 0.30(syst.))%, B(B0bar -> D+l-nubar) = (2.21 +/- 0.11(stat.) +/- 0.12(syst.))%, B(B0bar -> D*+l-nubar) = (5.49 +/- 0.16(stat.) +/- 0.25(syst.))%, B(B- -> D+pi-l-nubar) = (0.42 +/- 0.06(stat.) +/- 0.03(syst.))%, B(B- -> D*+pi-l-nubar) = (0.59 +/- 0.05(stat.) +/- 0.04(syst.))%, B(B0bar -> D0pi+l-nubar) = (0.43 +/- 0.08(stat.) +/- 0.03(syst.))%, and B(B0bar -> D*0pi+l-nubar) = (0.48 +/- 0.08(stat.) +/- 0.04(syst.))%.
PDF
