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D. A. Milanes

Publications and source records attributed to D. A. Milanes.

7 recordsLinked to original sources

Initial-State Radiation Measurement of the e+e- -> pi+pi-pi+pi- Cross Section

We study the process e+e- -> pi+pi-pi+pi-gamma, with a photon emitted from the initial-state electron or positron, using 454.3 fb^-1 of data collected with the BABAR detector at SLAC, corresponding to approximately 260,000 signal events. We use these data to extract the non-radiative sigma(e+e- ->pi+pi-pi+pi-) cross section in the energy range from 0.6 to 4.5 Gev. The total uncertainty of the cross section measurement in the peak region is less than 3%, higher in precision than the corresponding results obtained from energy scan data.

hep-ex

A Measurement of the Semileptonic Branching Fraction of the B_s Meson

We report a measurement of the inclusive semileptonic branching fraction of the B_s meson using data collected with the BaBar detector in the center-of-mass (CM) energy region above the Upsilon(4S) resonance. We use the inclusive yield of phi mesons and the phi yield in association with a high-momentum lepton to perform a simultaneous measurement of the semileptonic branching fraction and the production rate of B_s mesons relative to all B mesons as a function of CM energy. The inclusive semileptonic branching fraction of the B_s meson is determined to be B(B_s to l nu X)=9.5 (+2.5/-2.0)(stat)(+1.1/-1.9)(syst)%, where l indicates the average of e and mu.

hep-ex

Study of radiative bottomonium transitions using converted photons

We use 111+/-1 million Upsilon(3S) and 89+/-1 million Upsilon(2S) events recorded by the BaBar detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions between bottomonium states using photons that have been converted to e+e- pairs by the detector material. We observe Upsilon(3S) -> gamma chi_b0,2(1P) decay, make precise measurements of the branching fractions for chi_b1,2(1P,2P) -> gamma Upsilon(1S) and chi_b1,2(2P) -> gamma Upsilon(2S) decays, and search for radiative decay to the eta_b(1S) and eta_b(2S) states.

hep-ex

Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)

Using a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the $h_b(1P)$ spin-singlet partner of the P-wave chi_{bJ}(1P) states in the sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We observe an excess of events above background in the distribution of the recoil mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.1sigma, including systematic uncertainties. We obtain the value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).

hep-ex

Search for hadronic decays of a light Higgs boson in the radiative decay Upsilon --> gamma A0

We search for hadronic decays of a light Higgs boson (A0) produced in radiative decays of an Upsilon(2S) or Upsilon(3S) meson, Upsilon --> gamma A0. The data have been recorded by the BABAR experiment at the Upsilon(3S) and Upsilon(2S) center of mass energies, and include (121.3 \pm 1.2) x 10^6 Upsilon(3S) and (98.3 \pm 0.9) x 10^6 Upsilon(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions B(Upsilon(nS)-->gamma A0) x B(A0-->hadrons) (n=2 or 3) that range from 1 x 10^{-6} for an A0 mass of 0.3 GeV/c^2 to 8 x 10^{-5} at 7 GeV/c^2.

hep-ex

Observation of the baryonic B decay B0bar --> Lambda_c^+ anti-Lambda K-

We report the observation of the baryonic B decay B0bar --> Lambda_c^+ anti-Lambda K- with a significance larger than 7 standard deviations based on 471x10^6$ BBbar pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. We measure the branching fraction for the decay B0bar --> Lambda_c^+ anti-Lambda K- to be (3.8 \pm 0.8_{stat} \pm 0.2_{sys} \pm 1.0_{Lambda_c^+})x10^{-5}. The uncertainties are statistical, systematic, and due to the uncertainty in the Lambda_c^+ branching fraction. We find that the Lambda_c^+ K^- invariant mass distribution shows an enhancement above 3.5 GeV/c^2.

hep-ex

The lightest Higgs boson production at photon colliders in the 2HDM-III

The branching ratios of the lightest CP-even Higgs boson $h^0$, in the framework of the General Two Higgs Doublet Model are calculated. Different scenarios are presented taking into account constraints obtained in previous works on the flavor changing neutral currents factors. Plausible scenarios with flavour changing processes at tree level like $b \bar s$ and $t \bar c$ are analyzed for relevant region of parameters. The loop-induced Higgs couplings to photon pairs can be tested with a photon collider. The number of events of $h^0$ as a resonance in photon colliders are calculated taking into account its corresponding background signal in TESLA, CLIC and NLC.

hep-ph