1 / 14

Search for Direct CP Violation in 3-body Cabibbo Suppressed D 0 Decays

Search for Direct CP Violation in 3-body Cabibbo Suppressed D 0 Decays. Kalanand Mishra, G. Mancinelli, B. T. Meadows, M. D. Sokoloff University of Cincinnati. Motivation Strategy Summary and outlook. Charm AWG 08/17/2006. CP Violation in D 0 Decay.

klilley
Télécharger la présentation

Search for Direct CP Violation in 3-body Cabibbo Suppressed D 0 Decays

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Search for Direct CP Violation in 3-body Cabibbo Suppressed D0 Decays Kalanand Mishra, G. Mancinelli, B. T. Meadows, M. D. Sokoloff University of Cincinnati • Motivation • Strategy • Summary and outlook Charm AWG 08/17/2006

  2. CP Violation in D0 Decay CPV expected to be small in the charm sector SM predictions O(0.1%) Look for particle Û anti-particle rate differences CPV > 1% will be a strong evidence for non-SM processes - - Where f is: p+p-p0 [π, …] and K+K-p0[K*K, π0 , …].Decays to these final states are Cabibbo-suppressed, enhancing the possibility that interference with non-SM amplitudes could produce direct CP violation. University of Cincinnati

  3. Why 3-body CS modes ? • The best hope for SM predicted CP violation in Charm decays is in CS modes. The prediction for CF decays are too small. • 3-body decays permit the measurement of phase differences which are required to create direct CP violation in the interference between SM and non-SM processes. • These are relatively high statistics modes (45000 D0/D0barπππ0 & 6800 D0/D0barKKπ0 events). • Since we can normalize measurements relative to the whole phase space (Dalitz plot), the dependence on πs tagging efficiency is negligible. University of Cincinnati

  4. direct CPV Strategy • need interference between diagrams with different strong (i) and weak phases (i) : • Perform separate Dalitz plot analyses of D0π-π+π0 (K-K+π0) and D0barπ+π-π0 (K+K-π0). • Models have already been established in both cases that provide good description of data. University of Cincinnati

  5. What is Known ? • CLEO measure ACP in D0π-π+π0 mode ACP = 0.01 + 0.05 • No ACP measurements available for D0K-K+π0 • Other analysis are under way to measure CP asymmetry in D0K-K+, π-π+ modes Measure the difference between the integral of the coherent sum of all amplitudes across the DP for D0 and D0bar, divided by the area of the DP. +0.07 -0.05 • ACP(K+K-) = 0.014 ± 0.010 • ACP(π+π-) = 0.013 ± 0.012 • ACP(π0π0) = 0.00 ± 0.05 • ACP(K+K-π+π-) = -0.08 ± 0.07 PDG 2006  University of Cincinnati

  6. Dalitz Plot Fit Results: π-π+π0 BAD 1174 University of Cincinnati

  7. Dalitz Plot Fit Results: K-K+π0 BAD 1502 University of Cincinnati

  8. What we have looked at ? • Our sensitivity to observe CP asymmetry is higher in the D0π-π+π0 decay because of the higher statistics in this mode. • However, I have started with D0K-K+π0 mode since recently I have been working on this Dalitz plot analysis. • Start by looking at the distribution of moments of the cosine of the helicity angle in data for both D0 and D0bar events. • Then perform separate Dalitz plot fit for CP conjugate events. University of Cincinnati

  9. Moments of cosH [K+π0] D0 __ D0 University of Cincinnati

  10. Moments of cosH [K-π0] D0 __ D0 University of Cincinnati

  11. Moments of cosH [K-K+] D0 __ D0 University of Cincinnati

  12. Separate DP Fits Amplitude Phase f0(980)0.65 ± 0.140.48 ± 0.13 0.9103.2 ± 13.483.0 ± 18.1 0.9 f2’(1525)1.12 ± 0.210.85 ± 0.20 0.9-38.8 ± 8.5-45.0 ± 10.6 0.5 (1020)0.74 ± 0.020.73 ± 0.020.3-17.7 ± 10.3-21.0 ± 12.6 0.2 K*-(892)0.64 ± 0.020.65 ± 0.020.3-30.5 ± 3.5-40.6 ± 3.3 2.1 K*+(1410)0.64 ± 0.601.09 ± 0.570.5120.6 ± 36.7115.5 ± 20.5 0.1 K*-(1410)2.91 ± 0.452.94 ± 0.530.0184.1 ± 9.8159.6 ± 8.4 1.9 K+π0 SW4.50 ± 1.393.08 ± 1.110.863.1 ± 8.9100.4 ± 11.4 2.6 K-π0 SW4.92 ± 0.684.12 ± 0.860.7154.0 ± 14.8114.7 ± 16.2 1.8 D0 D0bar D0 D0bar # SD # SD University of Cincinnati

  13. Separate DP Fits Amplitude Phase K*-(892)0.63 ± 0.020.66 ± 0.021.1-30.8 ± 3.3-41.1 ± 3.2 2.2 K*+(1410)0.30 ± 0.311.04 ± 0.301.7 87.6 ± 70.5100.7 ± 16.0 0.3 K*-(1410)2.80 ± 0.272.72 ± 0.280.2182.8 ± 6.9168.8 ± 6.1 1.5 K+π0 SW4.85 ± 0.743.65 ± 0.581.366.9 ± 7.286.3 ± 10.3 1.6 K-π0 SW4.78 ± 0.633.59 ± 0.571.4160.0 ± 8.6 123.6 ± 10.5 2.7 D0 D0bar D0 D0bar # SD # SD Parameters for CP eigen states are fixed to the ones obtained from the combined fit. University of Cincinnati

  14. Summary • After performing D0π-π+π0, K-K+π0 Dalitz plot analysis, we have started looking into CP asymmetries in the conjugate decays. • We will keep documenting (BAD 1531) as we move along. • We aim for a preliminary result for DPF 2006. University of Cincinnati

More Related