A Precision Measurement of the Lambda_c Baryon Mass

The $\Lambda_c^+$ baryon mass is measured using $\Lambda_c^+\to\Lambda K^0_S K^+$ and $\Lambda_c^+\to\Sigma^0 K^0_S K^+$ decays reconstructed in 232 fb$^{-1}$ of data collected with the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ storage ring. The $\Lambda_c^+$ mass is measured to be $2286.46\pm0.14\mathrm{MeV}/c^2$. The dominant systematic uncertainties arise from the amount of material in the tracking volume and from the magnetic field strength.Comment: 14 pages, 8 postscript figures, submitted to Phys. Rev.

Fisica. Elettromagnetismo e onde

Il presente volume offre una trattazione completa dell'elettromagnetismo classico e dell'ottica, geometrica e fisica, con una struttura che ne permette l'adattamento a diversi corsi di studio. Gli argomenti dei vari capitoli sono introdotti partendo dalla descrizione di esperimenti e poi formalizzati in termini matematici via via più generali e rigorosi. La Terza edizione del testo è rivista e aggiornata in chiave moderna e leggera: molti contenuti aggiuntivi, sotto forma di Paragrafi, Esempi e Note, sono ora consultabili in formato digitale negli Ulteriori approfondimenti in ebook

High precision bidimensional readout for LST

We describe a high precision bidimensional readout for a large plastics Limited Streamer Tube (LST) system, using induced charge analog readout for the coordinate along the wires and digital readout with drift time for the other. In a test we easily obtained a resolution in the drift coordinate of about 150 \u3bcm with the possibility of solving left/right ambiguity using digital strip information

Drift time measurements in limited streamer tubes

We have investigated the performances of drift time techniques applied to limited streamer tubes. A resolution of 3c 150 \u3bcm in the coordinate across the wire is found and a way to solve the left-right ambiguity is presented

Measurement of J/psi -> N(N)over-bar branching ratios and estimate of the phase of the strong decay amplitude

The results of new measurements of Jrcªnn and Jrcªpp performed by the FENICE experiment are reported. The relative phase f, between the strong and the electromagnetic decay amplitudes, is achieved from the branching ratios JrcªNN and from the nucleon form factors measurements near the Jrc . It turns out fs89o"15o, in agreement with other Jrc decay amplitudes

Search for a narrow resonance about the \u3be(2230) in the formation channel bar-p p\u2192K+K 12

The reaction p-bar p -> K+ K- has been studied for incident antiproton momenta between 1.3 and 1.5 GeV/c. A continuous scan has been made for invariant masses of the p-bar p system between 2220 and 2240 MeV/c2 with a resolution of 0.6 MeV/c2 in the \u3be (2230) region. No structure has been observed. Upper limits are given

DETERMINATION OF THE ELECTRIC AND MAGNETIC FORM-FACTORS OF THE PROTON IN THE TIME-LIKE REGION

The s dependence of the electromagnetic proton form factors in the time-like region has been determined from the threshold (s = 4M(p)2) up to s = 4.2 GeV2. Data were collected in a dedicated experiment performed at the LEAR antiproton ring at CERN, increasing by one order of magnitude the available statistics. Total and differential cross section of the ppBAR --> e-e+ reaction have been measured. The electric and magnetic form factors are found to have comparable value. The observed form factor shows a clear steep s dependence close to the threshold