Measurements of Lifetimes and a Limit on the Lifetime Difference in the Neutral D -Meson System

Journal Article · Thu Jul 01 04:00:00 EDT 1999 · Physical Review Letters

OSTI ID:365855

Amato, S; Anjos, J C; Bediaga, I; Carvalho, H S; Gobel, C; de Mello Neto, J R; de Miranda, J M; dos Reis, A C; Santoro, A F; Solano, J ^[1]; Gagnon, P; Leslie, J; OShaughnessy, K ^[2]; Meadows, B; dOliveira, A B; Perera, L P; Santha, A K; Schwartz, A J; Sokoloff, M D ^[3]; Herrera, G ^[4] ; Appel, J A; Banerjee, S; Carter, T; Denisenko, K; Halling, A M; James, C; Kwan, S; Lundberg, B; Stefanski, R J; Thorne, K ^[5]; Burnstein, R A; Kasper, P A; Peng, K C; Rubin, H A ^[6]; Mihalcea, D; Nguyen, A; Reay, N W; Sidwell, R A; Stanton, N R; Tripathi, A K; Witchey, N; Yang, S M; Yoshida, S; Zhang, C ^[7]; Blaylock, G ^[8]; Aitala, E M; Cremaldi, L M; Gounder, K; Quinn, B; Rafatian, A; Reidy, J J; Sanders, D A; Summers, D J; Yi, D ^[9]; Wiener, J ^[10]; Fernandez, A; dOliveira, A B ^[11]; Copty, N K; Fox, G F; Langs, D C; Purohit, M V ^[12]; Burchat, P R; Zaliznyak, R ^[13]; Ashery, D; Hurvits, G; MayTal-Beck, S; Weiss-Babai, R ^[14]; Bracker, S B ^[15]; Milburn, R H; Napier, A ^[16]; others, and

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1. Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil)
2. University of California, Santa Cruz, California 95064 (United States)
3. University of Cincinnati, Cincinnati, Ohio 45221 (United States)
4. CINVESTAV, Mexico City (Mexico)
5. Fermilab, Batavia, Illinois 60510 (United States)
6. Illinois Institute of Technology, Chicago, Illinois 60616 (United States)
7. Kansas State University, Manhattan, Kansas 66506 (United States)
8. University of Massachusetts, Amherst, Massachusetts 01003 (United States)
9. University of Mississippi, University, Mississippi 38677 (United States)
10. Princeton University, Princeton, New Jersey 08544 (United States)
11. Universidad Autonoma de Puebla, Puebla (Mexico)
12. University of South Carolina, Columbia, South Carolina 29208 (United States)
13. Stanford University, Stanford, California 94305 (United States)
14. Tel Aviv University, Tel Aviv (Israel)
15. Box 1290, Enderby, British Columbia, V0E 1V0 (CANADA)
16. Tufts University, Medford, Massachusetts 02155 (United States)

Using the large hadroproduced charm sample collected in experiment E791 at Fermilab, we report the first directly measured constraint on the decay-width difference {Delta}{Gamma} for the mass eigenstates of the D{sup 0} -{ovr D}{sup 0} system. We obtain our result from lifetime measurements of the decays D{sup 0}{r_arrow}K{sup {minus}}{pi}{sup +} and D{sup 0}{r_arrow}K{sup {minus}}K{sup +} , under the assumption of {ital CP} invariance, which implies that the {ital CP} eigenstates and the mass eigenstates are the same. The lifetime of D{sup 0}{r_arrow}K{sup {minus}}K{sup +} (the {ital CP}-even final state) is {tau}{sub KK}=0.410{plus_minus}0.011{plus_minus}0.006 ps , and the lifetime of D{sup 0}{r_arrow}K{sup {minus}}{pi}{sup +} (an equal mixture of {ital CP}-odd and {ital CP}-even final states) is {tau}{sub K{pi}}=0.413{plus_minus}0.003{plus_minus}0.004 ps . The decay-width difference is {Delta}{Gamma}=2({Gamma}{sub KK}{minus}{Gamma}{sub K {pi}})=0.04{plus_minus}0.14{plus_minus}0.05 ps{sup {minus}1} . We relate these measurements to measurements of mixing in the neutral D -meson system. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 365855
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 1 Vol. 83; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CP INVARIANCE
D MESONS
D NEUTRAL MESONS
EIGENSTATES
KAONS MINUS
KAONS PLUS
LIFETIME
PARTICLE DECAY
PIONS PLUS