Ablikim, M (reprint author), Inst High Energy Phys, Beijing 100049, Peoples R China.
Using a data sample of integrated luminosity of about 33 pb(-1) collected around 3.773 GeV with the BESII detector at the BEPC collider, the semileptonic decays D+ -> phi e(+)nu(e), D+ -> phi mu(+)nu(mu) and the hadronic decay D+ -> phi pi(+) are studied. The upper limits of the branching fractions are set to be BF(D+ -> phi e(+)nu(e)) < 2.01% and BF(D+ -> phi pi(+)nu(mu)) < 2.04% at the 90% confidence level. The ratio of the branching fractions for D+ -> phi pi(+) relative to D+ -> K-pi(+)pi(+) is measured to be 0.057 +/- 0.011 +/- 0.003. In addition, the branching fraction for D+ -> phi pi(+) is obtained to be (5.2 +/- 1.0 +/- 0.4) x 10(-3).