1. L. Littenberg - BNL K-Rare Decays Frascati - 27 May 05
Concluding Remarks
L. Littenberg - BNL
K-Rare Decays Frascati - 27 May 05

2. Isidori Arguments

3. Motivation, c’d

4. K & MSSM

5. Contribution of K after LHC

6. E949

7. E787/949 Events
E949 Event

8. Products of E787/949
SPI measurements
Analysis methods

9. J-PARC K++ LOI Stopped K+ experiment Builds on E787/949 experience
Lower energy separated beam
Higher B spectrometer
More compact apparatus
Better resolution
Finer segmentation
Improved  veto (crystal barrel)
Aims for 50 events
Not an early experiment for J-PARC
Needs beamline
place on the floor
$ for detector

10. K decay at rest Decades of experience
Bckgnd <1.5 x 10-11
Almost everything well-understood
Can confidently scale in most parameters
Biggest questions are money and will
Need appropriate beamline
Need better duty cycle
Need funding for detector
Need collaboration
Could be sure of ~50 SM events, maybe 100 if pnn2 region can be used

11. NA48/3

12. NA48/3 Ambitious in-flight attempt to get ~65 SM events with good S:B
Benefits from several years of thought (CKM, etc.)
Brute force approach to beam
Needs some development of techniques
Has reasonable toolset
Equiv p* resolution 1.3 MeV/c (c.f. 2.3 for E949)
Redundant background rejection methods
Benefit of decay in vacuum, high energy
Concerns
There’s always a beam pion
Unanticipated background

13. E391a KL0

14. Confronting the Enemy Run 1 expected s.e.s ~ 10-8, expected BG ~310-9
KL  gg
KL  popopo
KL  p+p-po
KL  popo
po produced at CC02
po produced at CV (?)
Run 1 expected s.e.s ~ 10-8, expected BG ~310-9

15. Responding to experience
Run I  Run  Run 3
Neutron background much reduced, now confronting KL decay contribution
Confident they can reduce the background to < 10-9

16. Products of E381a Beam design & MC proofing
Photonuclear SPI measurements
Charged particle inefficency
measurements

17. Deeper, more granular crystals
E391a to J-PARC
50 more KL
Thicker photon vetoes
Deeper, more granular crystals
Faster electronics
Goal: 40 evts in 3 years, starting in 2009?, S:B ~ 1

18. J-PARC KL - Part II
Evts
3 options:
180 60
290

19. KLOD IHEP 60 GeV proton beam - take off at 35 mr KL’s peak at ~6 GeV/c
Aim to get 28 events/9 background in 3 years
Could be ready to run in 2008?

20. KOPIO

21. Kinematic Separation of Signal and Backgrounds

22. KOPIO Products Charged particle ineff. measurements
3rd generation shashliyk
Accelerator R&D
Bomb detection

23. Future History K+ SM KL

24. K & Ke+e-
Could enhanced endpoint of K show up in Ke+e-?
With UC, predicted BR at endpoint predicted as ~10-8
That part of Ke+e- maybe 3 larger.
 gives K  Ke+e- maybe 400 times smaller.
In amplitude 20 times smaller
Could be 10% effect in interference?