Study of the effects of fluid-structure Interaction on submerged bodies

A preliminary bibliographic survey was conducted, explaining concepts as mass effect and void ratio as well as looking into other papers with relevant previous results. The numerical model used was that of a fluid-solid interaction. A harmonic analysis type was chosen for the plate modes and a modal type for the acoustic modes. The geometry studied consists of a circular plate surrounded by a two-phase fluid, a mixture of air and water. This mixture was defined by its void-ratio parameter, which is dependent on the density and the sound speed. Ansys simulations were conducted in order to find the wanted modes of vibration for the plate and the acoustic modes for the surrounding fluid. The acoustic modes of vibration (considering all solid eliminated) were analysed, studying its frequency’s dependence on void ratio, density and sound speed and comparing its mode shapes. Fluid-structure coupled modes of vibration for the plate were also studied, to be more specific those with an axisymmetric circular shape. Finally, the coupling effect between the acoustic and the structural modes was studied. The results confirm that a dependence between the plate modes of vibration and the surrounding mixture exists, and it’s ruled by the mixture density. A big coupling effect between some acoustic modes and plate modes was also found, which made the further analysis of the plate modes of vibration difficult

Measurement of the e+e− → p¯p cross section in the energy range from 3.0 to 6.5 GeV

The e + e − → p ¯ p 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 / ψ → p ¯ p and ψ ( 2 S ) → p ¯ p have also been measured

Search for lepton-flavor-violating decays D-0 -> X(0)e(+/-)mu(-/+)

We present a search for seven lepton-flavor-violating neutral charm meson decays of the type D0→X0e±μ∓, where X0 represents a π0, K0S, ¯K*0, ρ0, ϕ, ω, or η meson. The analysis is based on 468  fb−1 of e+e− annihilation data collected at or close to the Υ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signals are observed, and we establish 90% confidence level upper limits on the branching fractions in the range (5.0−22.5)×10−7. The limits are between 1 and 2 orders of magnitude more stringent than previous measurements

Search for Rare or Forbidden Decays of the D-0 Meson

We present a search for nine lepton-number-violating and three lepton-flavor-violating neutral charm decays of the type D0→h'−h−ℓ'+ℓ+ and D0→h'−h+ℓ'±ℓ∓, where h and h′ represent a K or π meson and ℓ and ℓ′ an electron or muon. The analysis is based on 468  fb−1 of e+e− annihilation data collected at or close to the Υ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the twelve modes, and we establish 90% confidence level upper limits on the branching fractions in the range (1.0-30.6)×10−7. The limits are between 1 and 3 orders of magnitude more stringent than previous measurements

Precision measurement of the e+e- → K+K-(γ) cross section with the initial-state radiation method at BABAR

A precise measurement of the cross section for the process e + e − → K + K − ( γ ) 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 − → μ + μ − ( γ ) γ 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 K K , LO μ = ( 22.93 ± 0.18 stat ± 0.22 syst ) × 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

Search for new π0-like particles produced in association with a τ-lepton pair

We report on a search in e + e − annihilations for new π 0 -like particles produced in association with a τ -lepton pair. These objects, with a similar mass and similar decay modes to π 0 mesons, could provide an explanation for the non-asymptotic behavior of the pion-photon transition form factor observed by the BABAR Collaboration. No significant signal is observed, and limits on the production cross section at the level of 73 fb or 370 fb, depending on the model parameters, are determined at 90% confidence level. These upper limits lie below the cross section values needed to explain the BABAR form factor data

Search for the decay B¯0 → Λ+cp¯pp¯

We report a search for the decay ¯ B 0 → Λ + c ¯ p p ¯ p . Using a data sample of 471 × 1 0 6 B ¯ B pairs collected with the BABAR detector at the PEP-II2 storage ring at SLAC, we find no events and set an upper limit on the branching fraction B ( ¯ B 0 → Λ + c ¯ p p ¯ p ) × B ( Λ + c → p K − π + ) 0.050 < 2.8 × 1 0 − 6 at 90% C.L., where we have normalized B ( Λ + c → p K − π + ) to the world average value

Improved measurements of the branching fractions for B0 → π+π− and B0 → K+π−, and a search for B0 → K+K−

We present measurements of the branching fractions for the charmless two-body decays B 0 → π + π − and B 0 → K + π − , and a search for the decay B 0 → K + K − . We include the effects of final-state radiation from the daughter mesons for the first time, and quote branching fractions for the inclusive processes B 0 → h + h ' − n γ , where h and h ′ are pions or kaons. The maximum value of the sum of the energies of the n undetected photons, E max  γ , is mode-dependent. Using a data sample of approximately 227 × 10 6 Υ ( 4 S ) → B ¯¯¯ B decays collected with the BABAR detector at the PEP-II asymmetric-energy e + e − collider at SLAC, we measure: B ( B 0 → π + π − n γ ; E max  γ = 150     MeV ) = ( 5.1 ± 0.4 ± 0.2 ) × 10 − 6 , B ( B 0 → K + π − n γ ; E max  γ = 105     MeV ) = ( 18.1 ± 0.6 ± 0.6 ) × 10 − 6 , B ( B 0 → K + K − n γ ; E max  γ = 59     MeV ) < 0.5 × 10 − 6 ( 90 %     confidence level ) , where the first uncertainty is statistical and the second is systematic. Theoretical calculations can be used to extrapolate from the above measurements the nonradiative branching fractions, B 0 . Using one such calculation, we find: B 0 ( B 0 → π + π − ) = ( 5.5 ± 0.4 ± 0.3 ) × 10 − 6 , B 0 ( B 0 → K + π − ) = ( 19.1 ± 0.6 ± 0.6 ) × 10 − 6 , B 0 ( B 0 → K + K − ) < 0.5 × 10 − 6 ( 90 %     confidence level ) . Meaningful comparison between theory and experiment, as well as combination of measurements from different experiments, can be performed only in terms of these nonradiative quantities

Measurement of time-dependent CP asymmetries in B0 → D(*)±π∓ and B0 → D±ρ∓ decays

We present updated results on time-dependent C P asymmetries in fully reconstructed B 0 → D ( * ) ± π ∓ and B 0 → D ± ρ ∓ decays in approximately 232 × 10 6 Υ ( 4 S ) → B ¯¯¯ B events collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. From a time-dependent maximum-likelihood fit we obtain for the parameters related to the C P violation angle 2 β + γ : a D π = − 0.010 ± 0.023 ± 0.007 , c D π lep = − 0.033 ± 0.042 ± 0.012 , a D ∗ π = − 0.040 ± 0.023 ± 0.010 , c D ∗ π lep = 0.049 ± 0.042 ± 0.015 , a D ρ = − 0.024 ± 0.031 ± 0.009 , c D ρ lep = − 0.098 ± 0.055 ± 0.018 , where the first error is statistical and the second is systematic. Using other measurements and theoretical assumptions, we interpret the results in terms of the angles of the Cabibbo-Kobayashi-Maskawa unitarity triangle and find | sin  ( 2 β + γ ) | > 0.64     ( 0.40 ) at 68% (90%) confidence level

Search for the decay B0 → K0SK0SK0L

We present the first search for the decay B 0 → K 0 S K 0 S K 0 L using a data sample of 232 × 10 6 B ¯¯¯ B pairs. We find no statistically significant evidence for the nonresonant component of this decay. Our central value for the branching fraction, assuming the true Dalitz distribution is uniform and excluding the ϕ resonance, is B ( B 0 → K 0 S K 0 S K 0 L ) = ( 2.4 + 2.7 − 2.5 ± 0.6 ) × 10 − 6 where the errors are statistical and systematic, respectively. We set a single-sided Bayesian upper limit of B ( B 0 → K 0 S K 0 S K 0 L ) < 7.4 × 10 − 6 at 90% confidence level using a uniform prior probability for physical values. Assuming the worst-case true Dalitz distribution, where the signal is entirely in the region of lowest efficiency, the 90% confidence level upper limit is B ( B 0 → K 0 S K 0 S K 0 L ) < 16 × 10 − 6