# Presentation: 616097

## Future K experiments at the AGS

- Organizers:  S. Kettell, L. Littenberg, M. Marx
- RHIC/AGS Users’ Meeting   12 May 2004

## A2: Future K Experiments at the AGS

**When:** 13 May 2004, starting 9am
**Where:** Hamilton Seminar Room (Chemistry)
**What:** Scheduled and possible K experiments to be run at the AGS in the next decade
**What else: **Context for this – current status and future plans for K experiments elsewhere, theoretical perspectives
**Who:** those working in, or interested in working in this area, those with new ideas...

## What’s it all about?

- Great opportunity to economically carry out AGS experiments between RHIC fills
- One example of DOE doing so
- NSF getting involved
- Known excellent “targets” in K decay
- We’ll hear about the two already being exploited
- New ones may emerge
- [your idea here]
- Need to examine opportunities in light of what is being done (& likely to be done) elsewhere

## Agenda

- E949 – S. Kettell
- KTeV – J. Whitmore
- NA48 present – S. Giudici
- Lepton flavor violation (theory) – R. Shrock
- Lepton flavor violation (experiment) – A. Bellavance
- K  Theory – Y. Grossman
- KLOE – M. Moulsen
- OKA – D. Vavilov
- NA48 future – G. Ruggiero
- K experiments in Japan – T. Komatsubara
- Future Kaon program at FNAL – P. Cooper
- Plans for Ke3 at BNL – J. Comfort
- KOPIO –  D. Bryman

## Recent History at AGS

| Experiment | Beam | Flux (TP) | s.e.s | result |
| --- | --- | --- | --- | --- |
| E787
K++ | 0.7GeV/c
separated | 10-30 | 810-11 | 1.6+1.8-0.8 10-10 |
| E865
K+++e- | ~6GeV/c
unsepar. | ~10 | 510-12 | <1.210-11
 |
| E871
KLe | <pk> ~ 4GeV/c | ~15 | 210-12 | 4.710-12 |

## Current/upcoming AGS Exps

| Experiment | Beam | Flux (TP) | s.e.s | result |
| --- | --- | --- | --- | --- |
| E949
K++ | 0.7GeV/c
separated | 70 | ~1.510-11 | ~1.510-10 |
| KOPIO
KL0 | <pK> ~ 0.6GeV/c
bunched | 100 | ~710-13 | ~310-11 |

## Already on the menu: K

- _

- BR(K+)  |Vtd|2                               BR(KL)  (**Im**Vtd)2

## Buchalla and Buras, Nucl. Phys. B548, 309 (1999); Buras et al.,hep-ph/0402112; Isidori,hep-ph/307014. 

*Buchalla and Buras, Nucl. Phys. ****B548****, 309 (1999); Buras et al.,hep-ph/0402112; Isidori,hep-ph/307014*.

## SM

***Differences sensitive to new physics – virtually free of uncertainties.***

*****

*****

**E949 – Measurement of B(****K****+********+******** )**

**Contributing Countries and Institutions**:
**US**         --- BNL, FNAL, University of New Mexico, Stony Brook
**Japan **   --- Fukui, KEK, Kyoto, National Defense Academy, Osaka, RCNP
**Canada** --- Alberta, University of British Columbia, TRIUMF
**Russia **  --- IHEP, INR

**$75M Expenditure including**
**   ****$10M Upgrade of E787  **

## E949 Beamline

- Very pure separated low energy beam,
- 600-800 MeV/c      80% K+
- Up to ~25M K+/pulse
- (can stop ~ 25%)

## E949 Results

**E949 Results**

- E949 has observed a **3****rd**** K****+********+******** **event:
**B(K****+********+********)=1.47        ********10****-10**
**          ****(SM: 0.8 ********10****-10****)**
- 0.006<|Vtd|<0.027
- -0.7710-3<*Re*t<1.0610-3
- 0.2310-3<|t|<1.0610-3
-  |*Im*t|<0.8910-3
- Submitted to PRL

## Aim:

**Aim:**
- >40 events
- With S:B>2:1

## Microbunched Beam

- KOPIO needs bunches of 200-300ps every 40 ns, extinction <10-3 between
- Bunch width achieved, working on extinction
- Bunching  technique could be used in other beams, for other purposes

## Slide 15

## Shashlyk calorimeter

- 2 X0 Preradiator

- Beam  veto

- Vacuum
-    tank

- DS Veto

- Barrel, US
-    Veto

- CP veto

## Other Experiments Discussed for AGS

- Ke3  check of CKM unitarity
- There’s a talk about this tomorrow
- K+0+ polarization (multi-Higgs)
-  Recently done at KEK
- K+++ - polarization (|Vtd|)
- KL0+ - polarization (CP-violation)

## Last Thoughts

- Upcoming program supported by NSF
- Additional experiments cheap to run
- Although proton economics non-trivial
- Smaller scale (sociological advantages)
- Interesting AGS capabilities facilitate new ideas
- Unprecedented intensities
- bunching of various sorts
- Low energies (can time K’s, stop them, stop ’s)
- Workshop will help refine any new ideas
- Near term opportunities
- Open KOPIO collaboration meeting Friday