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Recent Results from KTeV

Recent Results from KTeV. Leo Bellantoni (FNAL) for the KTeV Collaboration. K L  p 0 m + m - X 0  S + m - n | V us | and related measurements Phys Rev Lett 93 , 181802 (2004) Phys Rev D70 , 092005 (2004) Phys Rev D80 , 092007 (2004) Phys Rev D71 , 012001 (2005).

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Recent Results from KTeV

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  1. Recent Results from KTeV Leo Bellantoni (FNAL) for the KTeV Collaboration KLp0m+m- X0S+m-n |Vus| and related measurementsPhys Rev Lett 93, 181802 (2004) Phys Rev D70, 092005 (2004) Phys Rev D80, 092007 (2004) Phys Rev D71, 012001 (2005) Leo Bellantoni for the KTeV collaboration

  2. |KL>  |KODD> + e|KEVEN> Indirect CPV  p0g*  p0l+l- Direct CPV p0g*  p0Z*  p0l+l- p0W+*W-*  p0g*g*  p0l+l-CPC Br(KLm+m-gg, mgg > 1 MeV) = (10.4STAT 0.7SYS) x10-9 Phys.Rev.D62:112001(2000) +7.5 -5.9 KLp0m+m- Background from radiative muonic Dalitz decay of the kaon, KLm+m-   Leo Bellantoni for the KTeV collaboration

  3. Theoretical: • Isidori, Smith & Unterdorfer, • Eur.Phys.J.C36:57-66(2004) • Combo of p0m+m- & p0e+e- • valuable in elucidating new physics • Experimental: • Park, et.al. (HyperCP), Phys.Rev.Lett. 94,021801 (2005) • Br(S+pm+m-) = (8.6 STAT 5.5SYST) x10-8 (3 events) • Expectation is ~ 0.1 x10-8 • All 3 events at the same mass: 214.3 0.5 MeV; C.L. for this in S.M. is 0.8% +6.6 -5.4 May indicate a new neutral intermediate state, P0 Leo Bellantoni for the KTeV collaboration

  4. KTeV’s existing limit on p0m+m- helps constrain P0 Br(S+pm+m-) is too small for P0 to likely be a hadron - it is closer to the sort of rate typical of EM interactions (J)P conservation limits a pointlike P0 to (J)P = 0- or 1- ; but if P0 is 1- it will contribute to KLp0m+m- From HyperCP’s Br(S+pP0), PDG lifetimes for S+, KL and our limit Br(KLp0m+m-) < 3.8 x10-10Phys.Rev.Lett. 84,5279(2000) G(S+pP0) ~ 2.5 x10-19MeV G(KLp0m+m-) < 4.8 x10-24MeV Rules out P0 is J = 1- hypothesis New limit onBr(KLp0m+m-) from full KTeV dataset in progress Leo Bellantoni for the KTeV collaboration

  5. Observation of X0S+m-n With 9 events from ‘99 dataset, no background events seen in wrong sign, or in 10x MC sample - Normalized to X0Lp0, Lpp- Leo Bellantoni for the KTeV collaboration

  6. Long standing issue: 1st row unitarity SEWShort range EW & QCD corrections - same for e,m f+(0) Form factor at t = (Pl + Pn)2 = 0; we use 0.961 0.008 [Leutwyler & Roos, 1984] dl Long range (mode-dependent) radiative corrections Integral over phase space of form factor squared |Vus| etc. BNL E865 (May 2003) found a higher value for Br(K+p0e+n) consistent with unitarity but giving |Vus| ~2.7s above existing Br(KLpen) value. @ ~2.2 s level Leo Bellantoni for the KTeV collaboration

  7. Step 1: Radiative corrections T.Andre, hep-ph/0406006 Take Evaluate with linear, quadratic and pole model form factors f Leo Bellantoni for the KTeV collaboration

  8. Step 2: Form factors We parameterize with f+(t) and fi expanded in powers of t / mp2; coefficients are li • Since pK is not known, there is a two-fold reconstruction ambiguity due to unseen n • We use tl = (P’l + P’n)2 or tp = (P’K - P’p)2 -Basically, t evaluated without longitudinal coordinates to momenta. Costs ~15% of statistical power • Some fits also use mlp Leo Bellantoni for the KTeV collaboration

  9. Pole model fits also reported… Linear model l+ values consistent with PDG values. Quadratic term significant at 4s level Lowers phase space integral by ~1%. Leo Bellantoni for the KTeV collaboration

  10. Andre’s prediction KTeV’s measurement Step 3: Check steps 1&2 with KLplng Acceptance corrections for 2ndg via PHOTOS ~1.8% for Ke3 Leo Bellantoni for the KTeV collaboration

  11. Step 4: Get the branching ratio Ordinarily, would measure something like where the “nice” mode has high statistics, a well-known rate, and is similar to Kl3 in the detector. Sadly, there is no “nice” mode. Measure these 5 ratios, use S = 1 constraint to get Br Leo Bellantoni for the KTeV collaboration

  12. Except for G000/GKe3, all ratios have final similar states • Except for G00/G000, all ratios in same trigger; this analysis similarto the e’/e neutral mode analysis • K ratios without/with m ID agree to (0.08 0.02stat)% • K+ ratios without/with 0 reconstruction in CsI-factor ~4 change in acceptance- agree to (0.03  0.28stat)% Leo Bellantoni for the KTeV collaboration

  13. Using lepton universality, More Cross-checks Taking dl from our radiative correction algorithm, phase-space integrals from our form factor measurements GKm3 / GKe3 = 0.6660 0.0019 And from the direct measurement,GKm3 / GKe3 = 0.6640 0.00140.0022 Leo Bellantoni for the KTeV collaboration

  14. From measured ratios to |Vus| Br(Ke3) = 0.4067 0.0011 Br(Km3) = 0.2701 0.0009 Using tK = 51.5 0.4 ns G(Ke3) = (7.897 0.065) x106s-1 G(Km3) = (5.244 0.044) x106s-1 Ke3: |Vus| = 0.2253  0.0023 K3: |Vus| = 0.2250  0.0023 Average: |Vus| =0.2252  0.0008KTeV  0.0021ext f+(0), tK, rad corrs G ratios, form factors Leo Bellantoni for the KTeV collaboration

  15. s(Vud,Vub) s(f+(0)) Compared to PDG-02, Br(Ke3) is ~5% (6s!) higher; Br(Km3) not much changed. Phase space integrals are lower by 1.7% and 4.2% in e and m modes, including the ~1% shift from quadratic term Leo Bellantoni for the KTeV collaboration

  16. Conclusions • HyperCP’s anolomy inS+pm+m- is not due to a (J)P • conserving vector boson • Final KTeV result on Br(KLp0m+m-) on its way -also, watch for KLe+e-g, KLp+p-e+e- form factors and branching ratio • Preliminary results onX0S+m-n shown • We have new and very precise results on major branching ratios, partial widths, |h+-|, form factors, radiative semileptonic decays, and |Vus| in the KL system. They show a great deal of internal consistency and solve the CKM 1st-row unitarity problem. Leo Bellantoni for the KTeV collaboration

  17. Spares Leo Bellantoni for the KTeV collaboration

  18. PDG 2002: Leo Bellantoni for the KTeV collaboration

  19. KLp+p-e+e- Interference between IB and DE amplitudes gives observable CPV From 5241 candidates (background of 185 14) in full dataset: Preliminary Results Leo Bellantoni for the KTeV collaboration

  20. KTeV detector (E832) s(p)/p ~ [ 1.7  (p/14GeV) ] x10-3 0.043 X0 = 0.021 L0 upstream of CsI s(E)/E ~ [ 4  20/E ] x10-3 p punchthrough = (1.0  0.1) x10-4p(GeV) Leo Bellantoni for the KTeV collaboration

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