Showing papers by "Université Paris-Saclay published in 2005"

Study of the B- → J/ΨK -π+π- decay and measurement of the B - → X(3872)K- branching fraction

Abstract: The authors study the decay B{sup -} {yields} J/{psi}K{sup -}{pi}{sup +}{pi}{sup -} using 117 million B{bar B} events collected at the {Upsilon}(4S) resonance with the BaBar detector at the PEP-II e{sup +}e{sup -} asymmetric-energy storage ring. They measure the branching fractions {Beta}(B{sup -} {yields} J/{psi}K{sup -} {pi}{sup +}{pi}{sup -}) = (116 {+-} 7(stat.) {+-} 9(syst.)) x 10{sup -5} and {Beta}(B{sup -} {yields} X(3872)K{sup -}) x {Beta}(X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -}) = (1.28 {+-} 0.41) x 10{sup -5} and find the mass of the X(3872) to be 3873.4 {+-} 1.4MeV/c{sup 2}. They search for the h{sub c} narrow state in the decay B{sup -} {yields} h{sub c} K{sup -}, h{sub c} {yields} J/{psi}{pi}{sup +}{pi}{sup -} and for the decay B{sup -} {yields} J/{psi}D{sup 0}{pi}{sup -}, with D{sup 0} {yields} K{sup -}{pi}{sup +}. They set the 90% C.L. limits {Beta}(B{sup -} {yields} h{sub c}K{sup -}) x {Beta}(h{sub c} {yields} J/{psi}{pi}{sup +}{pi}{sup -}) < 3.4 x 10{sup -6} and {Beta}(B{sup -} {yields} J/{psi}D{sup 0}{pi}{sup -}) < 5.2 x 10{sup -5}.

First results from the CERN axion solar telescope.

Abstract: Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field (``axion helioscope''), they would be transformed into x-rays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling ${g}_{a\ensuremath{\gamma}}l1.16\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$ at 95% C.L. for ${m}_{a}\ensuremath{\lesssim}0.02\text{ }\mathrm{eV}$. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses.

Passive radar using Global System for Mobile communication signal: theory, implementation and measurements

Abstract: Passive radars using illuminators of opportunity have attracted much attention in the international radar community. One existing radio transmission system that may be utilised for this purpose is the Global System for Mobile communication (GSM). The paper presents a study showing the feasibility of using a GSM signal for passive radar. The analysis of the GSM waveform, and any significance or influence it has with respect to the passive radar design considerations are investigated in detail. The paper describes fully the design and implementation of a low-cost GSM-based passive radar prototype in addition to the associated signal processing scheme. Numerous measurements for various ground-moving targets were investigated extensively. The preliminary processing results demonstrate the feasibility of using GSM signals as a radar waveform and have the potential capability to detect and track different types of ground-moving targets.

Systematic studies of the centrality and √sNN dependence of the dET/dη and dNch/dη in heavy ion collisions at midrapidity

Abstract: The PHENIX experiment at the relativistic heavy ion collider (RHIC) has measured transverse energy and charged particle multiplicity at midrapidity in $\mathrm{Au}+\mathrm{Au}$ collisions at center-of-mass energies $\sqrt{{s}_{\mathrm{NN}}}=19.6,130$, and $200\phantom{\rule{0.3em}{0ex}}\text{GeV}$ as a function of centrality. The presented results are compared to measurements from other RHIC experiments and experiments at lower energies. The $\sqrt{{s}_{\mathrm{NN}}}$ dependence of $dE{}_{T}/d\ensuremath{\eta}$ and $dN{}_{\mathrm{ch}}/d\ensuremath{\eta}$ per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of $dE{}_{T}/d\ensuremath{\eta}$ and $dN{}_{\mathrm{ch}}/d\ensuremath{\eta}$ is similar at all measured incident energies. At RHIC energies, the ratio of transverse energy per charged particle was found to be independent of centrality and growing slowly with $\sqrt{{s}_{\mathrm{NN}}}$. A survey of comparisons between the data and available theoretical models is also presented.

Photon events with missing energy in e(+)e(-) collisions at root s=130 to 209 GeV

Abstract: The production of single- and multi-photon events has been studied in the reaction e+e- -> gamma (gamma) + invisible particles. The data collected with the DELPHI detector during the years 1999 and 2000 at centre-of-mass energies between 191 GeV and 209 GeV was combined with earlier data to search for phenomena beyond the Standard Model. The measured number of light neutrino families was consistent with three and the absence of an excess of events beyond that predicted by the Standard Model processes was used to set limits on new physics. Both model-independent searches and searches for new processes predicted by supersymmetric and extra-dimensional models have been made. Limits on new non-standard model interactions between neutrinos and electrons were also determined.

Efficient Minimization Methods of Mixed l 2- l 1 and l 1- l 1 Norms for Image Restoration

Abstract: Image restoration problems are often solved by finding the minimizer of a suitable objective function. Usually this function consists of a data-fitting term and a regularization term. For the least squares solution, both the data-fitting and the regularization terms are in the $\ell$2 norm. In this paper, we consider the least absolute deviation (LAD) solution and the least mixed norm (LMN) solution. For the LAD solution, both the data-fitting and the regularization terms are in the $\ell$1 norm. For the LMN solution, the regularization term is in the $\ell$1 norm but the data-fitting term is in the $\ell$2 norm. Since images often have nonnegative intensity values, the proposed algorithms provide the option of taking into account the nonnegativity constraint. The LMN and LAD solutions are formulated as the solution to a linear or quadratic programming problem which is solved by interior point methods. At each iteration of the interior point method, a structured linear system must be solved. The preconditioned conjugate gradient method with factorized sparse inverse preconditioners is employed to solve such structured inner systems. Experimental results are used to demonstrate the effectiveness of our approach. We also show the quality of the restored images, using the minimization of mixed $\ell$2-$\ell$1 and $\ell1$-$\ell$1 norms, is better than that using only the $\ell$2 norm.

The sequence of rice chromosomes 11 and 12, rich in disease resistance genes and recent gene duplications.

Abstract: Background: Rice is an important staple food and, with the smallest cereal genome, serves as a reference species for studies on the evolution of cereals and other grasses Therefore, decoding its entire genome will be a prerequisite for applied and basic research on this species and all other cereals Results: We have determined and analyzed the complete sequences of two of its chromosomes, 11 and 12, which total 559 Mb (143% of the entire genome length), based on a set of overlapping clones A total of 5,993 non-transposable element related genes are present on these chromosomes Among them are 289 disease resistance-like and 28 defense-response genes, a higher proportion of these categories than on any other rice chromosome A three-Mb segment on both chromosomes resulted from a duplication 77 million years ago (mya), the most recent large-scale duplication in the rice genome Paralogous gene copies within this segmental duplication can be aligned with genomic assemblies from sorghum and maize Although these gene copies are preserved on both chromosomes, their expression patterns have diverged When the gene order of rice chromosomes 11 and 12 was compared to wheat gene loci, significant synteny between these orthologous regions was detected, illustrating the presence of conserved genes alternating with recently evolved genes Conclusion: Because the resistance and defense response genes, enriched on these chromosomes relative to the whole genome, also occur in clusters, they provide a preferred target for breeding durable disease resistance in rice and the isolation of their allelic variants The recent duplication of a large chromosomal segment coupled with the high density of disease resistance gene clusters makes this the most recently evolved part of the rice genome Based on syntenic alignments of these chromosomes, rice chromosome 11 and 12 do not appear to have resulted from a single whole-genome duplication event as previously suggested (Resume d'auteur)

Arabidopsis Sphingosine Kinase and the Effects of Phytosphingosine-1-Phosphate on Stomatal Aperture

Abstract: Sphingolipids are a major component of membrane lipids and their metabolite sphingosine-1-phosphate (S1P) is a potent lipid mediator in animal cells Recently, we have shown that the enzyme responsible for S1P production, sphingosine kinase (SphK), is stimulated by the phytohormone abscisic acid in guard cells of Arabidopsis (Arabidopsis thaliana) and that S1P is effective in regulating guard cell turgor We have now characterized SphK from Arabidopsis leaves SphK activity was mainly associated with the membrane fraction and phosphorylated predominantly the Δ4-unsaturated long-chain sphingoid bases sphingosine (Sph) and 4,8-sphingadienine, and to a lesser extent, the saturated long-chain sphingoid bases dihydrosphingosine and phytosphingosine (Phyto-Sph) 4-Hydroxy-8-sphingenine, which is a major sphingoid base in complex glycosphingolipids from Arabidopsis leaves, was a relatively poor substrate compared with the corresponding saturated Phyto-Sph In contrast, mammalian SphK1 efficiently phosphorylated Sph, dihydrosphingosine, and 4,8-sphingadienine, but not the 4-hydroxylated long-chain bases Phyto-Sph and 4-hydroxy-8-sphingenine Surface dilution kinetic analysis of Arabidopsis SphK with Sph presented in mixed Triton X-100 micelles indicated that SphK associates with the micellar surface and then with the substrate presented on the surface In addition, measurements of SphK activity under different assay conditions combined with phylogenetic analysis suggest that multiple isoforms of SphK may be expressed in Arabidopsis Importantly, we found that phytosphingosine-1-phosphate, similar to S1P, regulates stomatal apertures and that its action is impaired in guard cells of Arabidopsis plants harboring T-DNA null mutations in the sole prototypical G-protein α-subunit gene, GPA1

The Evolving Role of 131I for the Treatment of Differentiated Thyroid Carcinoma

Abstract: The use of radioactive iodine ((131)I) for the treatment of thyroid carcinoma has changed over the past 50 y. These changes are based on increasing awareness of the biophysical properties of (131)I and new discoveries concerning the biology of iodine handling by thyroid cells. The therapeutic administration of (131)I for thyroid remnant ablation and for metastases requires an appreciation of iodine clearance kinetics, of factors that can alter the occupancy time of (131)I within lesions, and of the role of thyroid-stimulating hormone in stimulating the sodium-iodide symporter. The potential complications and adverse events associated with (131)I are discussed. (131)I will continue to be a major weapon in the fight against metastatic thyroid carcinoma. Its future role will be modified by expanding knowledge of its relative risks and benefits.

e+e- → π+π -π+π-, K+K -π+π-, and K+K -K+K- cross sections at center-of-mass energies 0.5-4.5 GeV measured with initial-state radiation

Abstract: We study the process $e^+e^-\to\pi^+\pi^-\pi^+\pi^-\gamma$, with a hard photon radiated from the initial state. About 60,000 fully reconstructed events have been selected from 89 $fb^{-1}$ of BaBar data. The invariant mass of the hadronic final state defines the effective \epem center-of-mass energy, so that these data can be compared with the corresponding direct $e^+e^-$ measurements. From the $4\pi$-mass spectrum, the cross section for the process $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$ is measured for center-of-mass energies from 0.6 to 4.5 $GeV/c^2$. The uncertainty in the cross section measurement is typically 5%. We also measure the cross sections for the final states $K^+ K^- \pi^+\pi^-$ and $K^+ K^- K^+ K^-$. We observe the $J/\psi$ in all three final states and measure the corresponding branching fractions. We search for X(3872) in $J/\psi (\to\mu^+\mu^-) \pi^+\pi^-$ and obtain an upper limit on the product of the $e^+e^-$ width of the X(3872) and the branching fraction for $X(3872) \to J/\psi\pi^+\pi^-$.

Arabidopsis anaphase-promoting complexes: multiple activators and wide range of substrates might keep APC perpetually busy.

Abstract: The anaphase-promoting complex (APC), a multisubunit E3 ubiquitin ligase, is an essential regulator of the cell cycle from metaphase until S phase in yeast and metazoans. APC mediates degradation o ...

Dalitz-plot analysis of the decays B±→K±π∓π±

Abstract: We report a Dalitz-plot analysis of the charmless hadronic decays of charged B mesons to the final state K+/- pi-/+ pi+/-. Using a sample of 226.0 +/- 2.5 million BBbar pairs collected by the BaBar detector, we measure the magnitudes and phases of the intermediate resonant and nonresonant amplitudes for both charge conjugate decays. We present measurements of the corresponding branching fractions and their charge asymmetries that supersede those of previous BaBar analyses. We find the charge asymmetries to be consistent with zero.

Measurements of the B → Xsγ Branching Fraction and Photon Spectrum from a Sum of Exclusive Final States

Abstract: Using 88.9 million BB events collected by the BaBar detector at the Y(4S), we measure the branching fraction for the radiative penguin process B -> X_s gamma from the sum of 38 exclusive final states. The inclusive branching fraction above a minimum photon energy E_gamma > 1.9 GeV is BF (b -> s gamma) = (3.27 +/- 0.18 (stat.) +0.55/-0.40 (syst.) +0.04/-0.09 (theory)) 10^-4. We also measure the isospin asymmetry between B^- -> X_s ubar gamma and B^0bar -> X_s dbar gamma to be Delta_0- = -0.006 +/- 0.058 (stat.) +/- 0.009 (syst.) +/- 0.024 (B^0bar / B^-). The photon energy spectrum is measured in the B rest frame, from which moments are derived for different values of the minimum photon energy. We present fits to the photon spectrum and moments which give the heavy-quark parameters m_b and mu_pi^2. The fitted parameters are consistent with those obtained from semileptonic B -> X_c l nu decays, and are useful inputs for the extraction of Vub from measurements of semileptonic B -> X_u l nu decays.

Modeling of phased array transducers.

Abstract: Phased array transducers are multi-element transducers, where different elements are activated with different time delays. The advantage of these transducers is that no mechanical movement of the transducer is needed to scan an object. Focusing and beam steering is obtained simply by adjusting the time delay. In this paper the DPSM (distributed point source method) is used to model the ultrasonic field generated by a phased array transducer and to study the interaction effect when two phased array transducers are placed in a homogeneous fluid. Earlier investigations modeled the acoustic field for conventional transducers where all transducer points are excited simultaneously. In this research, combining the concepts of delayed firing and the DPSM, the phased array transducers are modeled semi-analytically. In addition to the single transducer modeling the ultrasonic fields from two phased array transducers placed face to face in a fluid medium is also modeled to study the interaction effect. The importance of considering the interaction effect in multiple transducer modeling is discussed, pointing out that neighboring transducers not only act as ultrasonic wave generators but also as scatterers.

Time-integrated and time-dependent angular analyses of B → J/ψKπ: A measurement of cos2β with no sign ambiguity from strong phases

Abstract: We present results on B -> J/yKp decays using e+e-annihilation data collected with the BABAR detector at the U(4S) resonance. The detector is located at the PEP-II asym.-energy storage ring facility at the Stanford Linear Accelerator Center. Using approx. 88*106 B-B pairs, we measure the decay amplitudes for the flavor eigenmodes and observe strong-phase differences indicative of final-state interactions with a significance of 7.6 std. deviations. We use the interference between the Kp S-wave and P-wave amplitudes in the region of the K*(892) to resolve the ambiguity in the detn. of these strong phases. We then perform an ambiguity-free measurement of cos2b using the angular and time-dependent asymmetry in B -> J/yK*0(KS0p0) decays. With sin2b fixed at its measured value and cos2b treated as an independent parameter, we find cos2b=2.72-0.79+0.50(stat)+-0.27(syst), detg. the sign of cos2b to be pos. at 86% C.L. [on SciFinder (R)]

Jet structure of baryon excess in Au+Au collisions at root SNN=200 GeV

Abstract: Two particle correlations between identified meson and baryon trigger particles with 2.5

Phenotypical characterisation of the isolated norfolk island population focusing on epidemiological indicators of cardiovascular disease.

Abstract: Objectives: Only 193 people from Pitcairn Island, all descended from 9 ‘Bounty’ mutineers and 12 Tahitian women, moved to the uninhabited Norfolk Island in 1856. Our objective was t

Midrapidity direct-photon production in p + p collisions at √s=200 GeV

Abstract: A measurement of direct photons in p+p collisions at root s=200 GeV is presented. A photon excess above background from pi(0)->gamma+gamma, eta ->gamma+gamma and other decays is observed in the transverse momentum range 5.5 < p(T)< 7 GeV/c. The result is compared to a next-to-leading-order perturbative QCD calculation. Within errors, good agreement is found between the QCD calculation and the measured result.

Inhomogeneous loop models with open boundaries

Abstract: We consider the crossing and non-crossing O(1) dense loop models on a semi-infinite strip, with inhomogeneities (spectral parameters) that preserve the integrability. We compute the components of the ground-state vector and obtain a closed expression for their sum, in the form of Pfaffian and determinantal formulae.

Amplitude analysis of the decay B±→π±π±π

Abstract: We present a Dalitz-plot analysis of charmless B+- decays to the final state pi+- pi+- pi-+ using 210 fb^-1 of data recorded by the BABAR experiment at sqrt(s) = 10.58 GeV. We measure the branching fractions B(B+- -> pi+- pi+- pi-+) = (16.2 +- 1.2 +- 0.9) x 10^-6 and B(B+- -> rho^0(770) pi+-) = (8.8 +- 1.0 +- 0.6 +0.1-0.7) x 10^-6. Measurements of branching fractions for the quasi-two-body decays B+- -> rho^0(1450) pi+-, B+- -> f_0(980) pi+- and B+- -> f_2(1270) pi+- are also presented. We observe no charge asymmetries for the above modes, and there is no evidence for the decays B+- -> chic0 pi+-, B+- -> f_0(1370) pi+- and B+- -> sigma pi+-.

Calculable toy model of the string-theory landscape

Abstract: Motivated by recent discussions of the string-theory landscape, we propose field-theoretic realizations of models with large numbers of vacua. These models contain multiple U(1) gauge groups, and can be interpreted as deconstructed versions of higher-dimensional gauge theory models with fluxes in the compact space. We find that the vacuum structure of these models is very rich, defined by parameter-space regions with different classes of stable vacua separated by boundaries. This allows us to explicitly calculate physical quantities such as the supersymmetry-breaking scale, the presence or absence of R-symmetries, and probabilities of stable versus unstable vacua. Furthermore, we find that this landscape picture evolves with energy, allowing vacua to undergo phase transitions as they cross the boundaries between different regions in the landscape. We also demonstrate that supergravity effects are crucial in order to stabilize most of these vacua, and in order to allow the possibility of cancelling the cosmological constant.

Study of B→π ν and B→ρ ν decays and determination of |Vub|

Abstract: We present an analysis of exclusive charmless semileptonic B-meson decays based on 83x10{sup 6} BB pairs recorded with the BABAR detector at the {upsilon}(4S) resonance Using isospin symmetry, we measure branching fractions B(B{sup 0}{yields}{pi}{sup -}l{sup +}{nu})=(138{+-}010{+-}016{+-}008)x10{sup -4} and B(B{sup 0}{yields}{rho}{sup -}l{sup +}{nu})=(214{+-}021{+-}048{+-}028)x10{sup -4}, where the errors are statistical, experimental systematic, and due to form-factor shape uncertainties We compare the measured distribution in q{sup 2}, the momentum-transfer squared, with theoretical predictions for the form factors from lattice QCD and light-cone sum rules, and extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |V{sub ub}|=(382{+-}014{+-}022{+-}011{sub -052}{sup +088})x10{sup -3} from B{yields}{pi}l{nu}, where the fourth error reflects the uncertainty of the form-factor normalization

Nomenclature of GES-Type Extended-Spectrum β-Lactamases

Abstract: In two recently published articles, Wachino et al. designated a novel ceftazidime-hydrolyzing class A extended-spectrum β-lactamase (ESBL) (GES-a) as GES-3 (4), and a new cephamycin-hydrolyzing and inhibitor-resistant class A ESBL (GES-b) as GES-4 (5). In actuality, their articles are fraught with misleading nomenclature of GES-type ESBLs and controvertible conclusions on the relationship between β-lactamase inhibitor resistance and an amino acid substitution in the center of the Ω-loop region. Before Wachino and colleagues submitted their sequences for GES-a and GES-b genes to the GenBank nucleotide databank (release dates, 25 May 2004 and 28 July 2004, respectively), sequences for GES-3 and GES-4 genes had already been released by Vourli et al. (3), the release date of which was 12 May 2004. As shown in Table ​Table1,1, GES-a and GES-b genes are completely different from GES-3 and GES-4 genes. GES-3 and GES-4 were capable of hydrolyzing imipenem (3), while GES-a could not hydrolyze imipenem and GES-b had a substrate profile extended to cephamycins as well as imipenem (4, 5). Presently, the different GES-type ESBLs have been designated by identical names. On the basis of priority of nomenclature, GES-a and GES-b genes should be renamed as GES-5 and GES-6 genes, respectively. TABLE 1. Amino acid substitutions of GES-type ESBLs In their efforts to persuade readers that GES-b has a strong inhibitor-resistant nature like IRT enzymes and that it maintains the capacity to hydrolyze cephamycins and imipenem as a result of a single substitution at position 170, the center of the Ω-loop region, Wachino et al. (5) stated: “In comparison with GES-1, GES-2 [containing a single substitution at position 170] showed an extended substrate specificity for imipenem and a lower affinity for β-lactamase inhibitors (1), as was seen with GES-4 [GES-b].” However, Poirel et al. (1) stated: “Inhibition studies as measured by IC50s with benzylpenicillin as a substrate showed that GES-2 activity was inhibited by clavulanic acid and tazobactam more than GES-1 is.” The IC50s (inhibitory concentrations) of clavulanic acid and tazobactam for GES-b (15.2 and 1.43 μM, respectively) were higher than those of GES-1 (5 and 2.5 μM, respectively), GES-2 (1 and 0.5 μM, respectively), and GES-a (1.5 and 0.19 μM, respectively). Two GES-type ESBLs (GES-2 and GES-b) containing a single substitution at position 170 showed a different inhibition profile. Although GES-b has a strong inhibitor-resistant nature like IRT enzymes, the conclusion that the G170S substitution found in the GES-b affected inhibitor resistance could not be supported by the data as presented. The renaming of GES-a and GES-b can help some authors to correctly designate new GES-type ESBLs, such as the novel enzymes identified from our nationwide survey supported by the Korea Research Foundation (KRF-2004-042-{"type":"entrez-nucleotide","attrs":{"text":"E00117","term_id":"2168418","term_text":"E00117"}}E00117).

Determination of A(FB)(b) at the Z pole using inclusive charge reconstruction and lifetime tagging

Abstract: A novel high precision method measures the b-quark forward-backward asymmetry at the Z pole on a sample of 3,560,890 hadronic events collected with the DELPHI detector in 1992 to 2000. An enhanced impact parameter tag provides a high purity b sample. For event hemispheres with a reconstructed secondary vertex the charge of the corresponding quark or anti-quark is determined using a neural network which combines in an optimal way the full available charge information from the vertex charge, the jet charge and from identified leptons and hadrons. The probability of correctly identifying b-quarks and anti-quarks is measured on the data themselves comparing the rates of double hemisphere tagged like-sign and unlike-sign events. The b-quark forward-backward asymmetry is determined from the differential asymmetry, taking small corrections due to hemisphere correlations and background contributions into account. The results for different centre-of-mass energies are: A_{FB}^b (89.449 GeV) = 0.0637 \pm 0.0143(stat.) \pm 0.0017(syst.) A_{FB}^b (91.231 GeV) = 0.0958 \pm 0.0032(stat.) \pm 0.0014(syst.) A_{FB}^b (92.990 GeV) = 0.1041 \pm 0.0115(stat.) \pm 0.0024(syst.) Combining these results yields the b-quark pole asymmetry A_{FB}^{b,0} = 0.0972 \pm 0.0030(stat.) \pm 0.0014(syst.)

The VHITAL Program to Demonstrate the Performance and Lifetime of a Bismuth-Fueled Very High Isp Hall Thruster

Abstract: In the Very High Isp Thruster with Anode Layer (VHITAL) Program the performance, plume and lifetime capability of the radiatively-cooled two stage, bismuth-fueled VHITAL-160 will be characterized in the US and Russia.

Measurement of the B0→D*-Ds*+ and Ds+→π+ branching fractions

Abstract: The authors present measurements of the branching fractions {Beta}(B{sup 0} {yields} D*{sup -}D*{sub s}{sup +}) and {Beta}(D{sub s}{sup +} {yields} {phi}{pi}{sup +}), based on 123 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} B factory. A partial reconstruction technique is used to measure {Beta}(B{sup 0} {yields} D*{sup -}D*{sub s}{sup +}) and the decay chain is fully reconstructed to measure the branching fraction product {Beta}(B{sup 0} {yields} D*{sup -} D*{sub s}{sup +}) x {Beta}(D{sub s}{sup +} {yields} {phi}{pi}{sup +}). Comparing these two measurements provides a model-independent determination of the D{sub s}{sup +} {yields} {phi}{pi}{sup +} branching fraction. They obtain {Beta}(B{sup 0} {yields} D*{sup -}D*{sub s}{sup +}) = (1.88 {+-} 0.09 {+-} 0.17)% and {Beta}(D{sub s}{sup +} {yields} {phi}{pi}{sup +}) = (4.81 {+-} 0.52 {+-} 0.38)%, where the first uncertainties are statistical and the second systematic.