Recent results on charm from Fermilab experiment E-687

Conference · Fri Nov 30 23:00:00 EST 1990

OSTI ID:6313931

Buchholz, D ^[1]; Gourlay, S ^[2]; Moroni, L ^[3]; Ratti, S P ^[4]; Shephard, W D ^[5]

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1. Northwestern Univ., Evanston, IL (USA)
2. Fermi National Accelerator Lab., Batavia, IL (USA)
3. Milan Univ. (Italy). Dipt. di Fisica Istituto Nazionale di Fisica Nucleare, Milan (Italy)
4. Pavia Univ. (Italy). Dipt. di Fisica Nucleare Istituto Nazionale di Fisica Nucleare, Pavia (Italy)
5. Notre Dame Univ., IN (USA)

About 10{sup 4} charm decays have been reconstructed from first-run data of Fermilab experiment E687 using the Fermilab Wide-Band Photon Spectrometer with the world's highest energy photon beam. The success of techniques for isolating and reconstructing charm event samples based on two complementary vertexing strategies is illustrated. Preliminary results are presented. These include lifetime value of (0.50 {plus minus} 0.06 {plus minus} 0.03)ps for the D{sub s}{sup +}, and (0.20 {plus minus} 0.03 {plus minus} 0.03)ps for the {Lambda}{sub c}{sup +}. Preliminary values for the D{sup +} and D{sup 0} lifetimes are consistent with currently accepted world averages. Signals for the Cabibbo-suppressed decays D{sup 0} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup +}{pi}{sup {minus}}, D{sup +} {yields} K{sup +}K{sup {minus}}{pi}{sup +}, and D{sup +} {yields} {phi}{pi}{sup +} are shown; for B(D{sup 0} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup +}{pi}{sup {minus}})/B(D{sup 0} {yields} K{sup {minus}}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}}) our preliminary value is 0.10 {plus minus} 0.02 {plus minus} 0.02. Preliminary values for ratios B(D{sup 0} {yields} {ovr K}{sup 0}K{sup +}K{sup {minus}})/B(D{sup 0} {yields} {ovr K}{sup 0}{pi}{sup +}{pi}{sup {minus}}) and B(D{sup 0} {yields} {ovr K}{sup 0}{phi})/B(D{sup 0} {yields} {ovr K}{sup 0}{pi}{sup +}{pi}{sup {minus}}) are 0.20 {plus minus} 0.06 and 0.16 {plus minus} 0.06. Preliminary results are given for cross sections of D*{sup {plus minus}} and D{sup {plus minus}} photoproduction on a Be target for the p{sup 2}{sub {tau}} dependence of D{sup {minus plus}} photoproduction and for the ratios D{double prime}/D*{sup +} and D*{sup {minus}}/D{sup {minus plus}}. The energy dependence of the total open charm photoproduction cross section is compared with model predictions for photon energies up to 350 GeV. 18 refs., 5 figs.

• Research Organization: Fermi National Accelerator Lab., Batavia, IL (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC02-76CH03000
• OSTI ID: 6313931
• Report Number(s): FNAL/C-90/261-E; CONF-900822--26; ON: DE91006811
• Country of Publication: United States
• Language: English

Related Subjects

645103* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Strong Interactions & Baryon & Meson Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
BASIC INTERACTIONS
BOSONS
BRANCHING RATIO
CHARM PARTICLES
CHARMED MESONS
CROSS SECTIONS
D MESONS
DECAY
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
INTERACTIONS
LAMBDA C PLUS
LIFETIME
LINEAR MOMENTUM
MASS SPECTRA
MESONS
PARTICLE DECAY
PARTICLE PRODUCTION
PHOTOPRODUCTION
PSEUDOSCALAR MESONS
SPECTRA
TRANSVERSE MOMENTUM