Search for D{sup 0}-{bar D}{sup 0} mixing and doubly-Cabibbo-suppressed decays of the D{sup 0} in hadronic final states

Journal Article · Thu Jan 01 00:00:00 EST 1998 · Physical Review, D

OSTI ID:628724

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 ^[1]; Gagnon, P; Leslie, J; OShaughnessy, K ^[2]; Meadows, B; dOliveira, A B; Perera, L P; Santha, A K; Sokoloff, M D ^[3]; Herrera, G ^[4]; Appel, J A; Banerjee, S ; Carter, T; Halling, A M; James, C; Kwan, S; Lundberg, B; Thorne, K ^[5]; Burnstein, R A; Kasper, P A; Peng, K C; Rubin, H A ^[6]; Nguyen, A; Reay, N W; Sidwell, R A; Stanton, N R; Witchey, N; Yoshida, S; Zhang, C ^[7]; Blaylock, G ^[8]; Aitala, E M; Cremaldi, L M; Gounder, K; Quinn, B; Rafatian, A; Reidy, J J; Summers, D J; Yi, D ^[9]; Tripathi, A K ^[10]; Langs, D C; Schwartz, A J; Wiener, J ^[11]; Fernandez, A; dOliveira, A B ^[12]; Copty, N K; Purohit, M V ^[13]; Burchat, P R; Zaliznyak, R ^[14]; Ashery, D; Hurvits, G; MayTal-Beck, S; Weiss-Babai, R ^[15]; Bracker, S B ^[16]; Milburn, R H; Napier, A ^[17]; Radeztsky, S; Sheaff, M; 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. The Ohio State University, Columbus, Ohio 43210 (United States)
11. Princeton University, Princeton, New Jersey 08544 (United States)
12. Universidad Autonoma de Puebla, Puebla (Mexico)
13. University of South Carolina, Columbia, South Carolina 29208 (United States)
14. Stanford University, Stanford, California 94305 (United States)
15. Tel Aviv University, Tel Aviv (Israel)
16. 317 Belsize Drive, Toronto, Ontario, M4S 1M7 (CANADA)
17. Tufts University, Medford, Massachusetts 02155 (United States)

We present results of a search for D{sup 0}-{bar D}{sup 0} mixing and doubly-Cabibbo-suppressed decays of the D{sup 0} in Fermilab experiment E791, a fixed-target charm hadroproduction experiment. We look for evidence of mixing in the decay chain D{sup {asterisk}}{r_arrow}{pi}D{r_arrow}{pi}(K{pi} or K{pi}{pi}{pi}). If the charge of the pion from the D{sup {asterisk}} decay is the same as the charge of the kaon from the D decay (a {open_quotes}wrong-sign{close_quotes} event), mixing may have occurred. Mixing can be distinguished from other sources of wrong-sign events (such as doubly-Cabibbo-suppressed decays) by analyzing the distribution of decay times. We see no evidence of mixing. Allowing for CP violation in the interference between DCS and mixing amplitudes our fitted ratio for mixed to unmixed decay rates is r{sub mix}=(0.39{sub {minus}0.32}{sup +0.36}{plus_minus}0.16){percent}. This corresponds to a 90{percent} C.L. upper limit of r{sub mix}{lt}0.85{percent}. The sensitivity of this result is comparable to that of previous measurements, but the assumptions made in fitting the data are notably more general. We present results from many fits to our data under various assumptions. If we assume r{sub mix}=0, we find a two-sigma wrong-sign enhancement in the K{pi} mode which we ascribe to doubly Cabibbo-suppressed decays. The ratios of doubly Cabibbo-suppressed decays to Cabibbo-favored decays are r{sub dcs}(K{pi})=(0.68{sub {minus}0.33}{sup +0.34}{plus_minus}0.07){percent} and r{sub dcs}(K{pi}{pi}{pi})=(0.25{sub {minus}0.34}{sup +0.36}{plus_minus}0.03){percent}. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 628724
• Journal Information: Physical Review, D, Vol. 57, Issue 1; Other Information: PBD: Jan 1998
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
D MESONS
STANDARD MODEL
D NEUTRAL MESONS
ANTI-D NEUTRAL MESONS
MIXING
D*-2010 MESONS
WEAK HADRONIC DECAY
PIONS
KAONS
CP INVARIANCE