Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

1

Recent Results from KTeV

• KL 0+-

• 0+-• |Vus| and related measurements

Phys Rev Lett 93, 181802 (2004) Phys Rev D70, 092005 (2004)

Phys Rev D80, 092007 (2004) Phys Rev D71, 012001 (2005)

Leo Bellantoni (FNAL)for the KTeV Collaboration

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

2

KL 0+-

Background from radiative muonicDalitz decay of the kaon, KL +-

Br(KL+-, m1 MeV) =

(10.4 STAT 0.7SYS) x10-9

Phys.Rev.D62:112001(2000)

-5.9+7.5

|KL> |KODD> + |KEVEN>Indirect CPV

0* 0l+l-

Direct CPV * * 0l+l-

0W+*W-*

** 0l+l- CPC

€

Br(KL → π 0l +l −) =

ε2 τ L

τ S

Br(KS → π 0l +l −)

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

3

Theoretical: Isidori, Smith & Unterdorfer, Eur.Phys.J.C36:57-66(2004)Combo of 0 + - & 0e+e- valuable in elucidating new physics

Experimental: Park, et.al. (HyperCP), Phys.Rev.Lett. 94,021801 (2005)

• Br( + p + -) = (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

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

4

KTeV’s existing limit on 0+- helps constrain P0

Br(+p+-) is too small for P0 to likely be a hadron - it is closerto 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- itwill contribute to KL 0+-

From HyperCP’s Br(+pP0), PDG lifetimes for +, KL and our limit Br(KL 0+-) < 3.8 x10-10 Phys.Rev.Lett. 84,5279(2000)

(+pP0) ~ 2.5 x10-19 MeV(KL 0+-) < 4.8 x10-24 MeV

Rules out P0 is J = 1- hypothesis New limit on Br(KL 0+-)

from full KTeV dataset in progress

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

5

Observation of 0+-

With 9 events from ‘99 dataset,no background events seen in wrong sign, or in 10x MC sample -

Normalized to 0 0, p

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

6

Long standing issue: 1st row unitarity

€

Vud

2+ Vus

2+ Vub

2≠1

@ ~2.2 levelBNL E865 (May 2003) found a higher valuefor Br(K+0e+) consistent with unitarity but giving |Vus| ~2.7 above existing Br(KLe) value.

|Vus| etc.

€

l 3 =Br KL → π ±l mν( )

τ L

=GF

2 mK5

384π 3

⎛

⎝ ⎜

⎞

⎠ ⎟SEW f+

2 t = 0( ) 1+ δ l( ) Vus

2 ˆ f 2∫

SEW Short range EW & QCD corrections - same for e,f+(0) Form factor at t = (Pl + P)

2 = 0; we use 0.961 0.008

[Leutwyler & Roos, 1984]

l Long range (mode-dependent) radiative corrections

Integral over phase space of form factor squared

€

ˆ f 2∫

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

7

€

l 3 =Br KL → π ±l mν( )

τ L

=GF

2 mK5

384π 3

⎛

⎝ ⎜

⎞

⎠ ⎟SEW f+

2 t = 0( ) 1+ δ l( ) Vus

2 ˆ f 2∫

Step 1: Radiative corrections

T.Andre, hep-ph/0406006

Take

€

− pπ( ) s Lγ α uL K 0 pK( ) =

f+ t( ) pK + pπ[ ] + f− t( ) pK − pπ[ ]

Evaluate with linear, quadratic and pole model form factors f

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

8

€

l 3 =Br KL → π ±l mν( )

τ L

=GF

2 mK5

384π 3

⎛

⎝ ⎜

⎞

⎠ ⎟SEW f+

2 t = 0( ) 1+ δ l( ) Vus

2 ˆ f 2∫

Step 2: Form factors

We parameterize with f+(t) and

fi expanded in powers of t / m2; coefficients are i

€

f0 t( ) = f+ t( ) +t

mK2 − mπ

2f− t( )

• Since pK is not known, there is a two-fold reconstruction ambiguity due to unseen • We use tl = (P’l + P’)

2 or t = (P’K - P’)2 -Basically, t

evaluated without longitudinal coordinates to momenta. Costs ~15% of statistical power• Some fits also use ml

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

9

Ke3 K3

Linear model x10-3

+28.320.57 27.451.08

0- 16.571.25

Quadratic model x10-3

+’ 21.671.99 17.033.65

+’’ 2.870.87 4.431.49

0- 12.811.83

Pole model fits also reported…

Linear model + values consistent withPDG values.

Quadratic term significant at 4 level Lowers phase space integral by ~1%.

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

10

Step 3: Check steps 1&2 with KLl

€

RKγ 3γ ≡Γ KL → π ±l mνγ; Eγ

* >10MeV( )

Γ KL → π ±l mν + nγ( )Acceptance corrections for 2nd via PHOTOS ~1.8% for Ke3

Andre’s prediction

KTeV’s measurement

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

11

€

l 3 =Br KL → π ±l mν( )

τ L

=GF

2 mK5

384π 3

⎛

⎝ ⎜

⎞

⎠ ⎟SEW f+

2 t = 0( ) 1+ δ l( ) Vus

2 ˆ f 2∫

Step 4: Get the branching ratio

€

KL → π ±l mν( ) Γ KL → nice( )Ordinarily, would measure something likewhere 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 = 1 constraintto get Br

€

Kμ 3

ΓKe3

Γ+−0ΓKe3

Γ000ΓKe3

Γ+−ΓKe3

Γ000Γ00

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

12

• Except for 000/Ke3, all ratios have final similar states

• Except for 00/000, all ratios in same trigger; this analysis similarto the ’/ neutral mode analysis

• K ratios without/with 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)%

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

13

More Cross-checks

Using lepton universality,

€

Kμ 3

ΓKe3

=1+ δμ

1+ δe

•ˆ f μ∫ˆ f e∫

Taking l from our radiative correction algorithm, phase-space integrals from our form

factor measurements K3 / Ke3 = 0.6660 0.0019 And from the direct measurement, K3 / Ke3 = 0.6640 0.0014 0.0022

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

14

Modes Partial Width Ratio

K3 / Ke30.66400.00140.0022

000 / Ke30.47820.00140.0053

0 / Ke30.30780.00050.0017

/ Ke3(4.8560.0170.023)10

3

00 / 000(4.4460.0160.019)10

3

From measured ratios to |Vus|

Br(Ke3) = 0.4067 0.0011Br(K3) = 0.2701 0.0009

Using K = 51.5 0.4 ns

(Ke3) = (7.897 0.065) x106 s-1

(K3) = (5.244 0.044) x106 s-1

Ke3: |Vus| = 0.2253 0.0023

K3: |Vus| = 0.2250 0.0023

Average: |Vus| = 0.2252 0.0008KTeV 0.0021ext

ratios,form factors

f+(0), K,rad corrs

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

15

(f+(0))

(Vud,Vub)

Compared to PDG-02, Br(Ke3) is ~5% (6 !) higher; Br(K3) not much

changed. Phase space integrals are lower by 1.7% and 4.2% in e and modes, including the ~1% shift from quadratic term

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

16

Conclusions• HyperCP’s anolomy in +p+- is not due to a (J)P

conserving vector boson• Final KTeV result on Br(KL 0+-) on its way -also, watch for KL ee KL ee form factors and branching ratio•Preliminary results on 0+- shown

• We have new and very precise results on major branching ratios, partial widths, |+-|, 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.

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

17

Spares

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

18

PDG 2002:

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

19

KL +-e+e-

From 5241 candidates (background of 185 14) in full dataset:

Interference betweenIB and DE amplitudesgives observable CPV

Preliminary Results

Moriond EW&UT 2005

Leo Bellantoni for the KTeV collaboration

20

KTeV detector (E832)

(p)/p ~ [ 1.7 (p/14GeV) ] x10-3

(E)/E ~ [ 4 20/E ] x10-3

0.043 X0 = 0.021 0 upstream of CsI

punchthrough = (1.0 0.1) x10-4 p(GeV)