KOPIO Capabilities:Other Physics Goals24 June 2005Michael SivertzBNLMeasuring Rare Kaon Decays with KOPIO

KOPIO CapabilitiesHermetic Veto Coverage for both charged particles and photonsHigh precision Shashlyk Calorimetry forEM Showers in CalorimeterPrecision Charged Particle Tracking in PreradiatorTime-of-Flight measurement for Kaon MomentumHigh Intensity Kaon Beam giving sensitivity corresponding to 1014 KL decays

Decay modes with a poAnalysis of the decay mode KL po S with S unobserved can simultaneously be used in a search for decays to a sGoldstino (superpartners of Goldstone fermions) that could be a Scalar weakly interacting boson. Current limits from E-949:B(K+ p+ S) < 5.9 x 10-11 Look for the Pseudoscalar sGoldstino in KL po po PLimit from ISTRA for Mp

KL po g g and KL po po gKL po g g gives information on the CP allowed contribution to KL po e+e-.KTEV gives a result of ~10-7 for the Br.If KOPIO can deal with the po po background, then we should be able to add to this result.

B(KL po po g) < 5.6 x 10-6 from NA31.Conflicting predictions:Heiliger and Sehgal predict 10-8Ecker, Neufeld and Pich predict 7 x 10-11KOPIO should be able to improve on the existing limit.

Radiative Decays:KL gg, KL gg* KL g*g* KL gggAt what rate we can accept radiative decays without compromising rare decay modes?

DecayExptKaon decaysEventsBkgdPDG ValueggNA314.7 x 108110000700B=(5.900.07) x 10-4ge+e-NA48KTEV4.1 x 1096.4 x 101168649340010476B=(1.000.05) x 10-5aK*= -0.1860.0110.009 gm+m-KTEV6.4 x 10119327222B=(3.620.040.08) x 10-7aK*= -0.160+0.026-0.028e+e-e+e-KTEV6.4 x 101110567.9B=(4.160.130.13) x 10-8aK*= -0.030.130.04e+e-m+m-KTEV6.4 x 10111320.8B=(2.690.240.12) x 10-9m+m- m+m-----Not possible at KOPIOgggNA314.7 x 108--B < 2.4 x 10-7

po po scattering length from KL popopo decays NA48 measured (N. Cabibbo, 2005) rescattering of popo in 2 x 108 K+p+popo decays. Observed a cusp in the m2 plot. From this they were able to obtain S-wave scattering lengths.KOPIO hopes to be able to add to this.(a0-a2)mp=0.2810.007(stat)0.014(syst)0.014(theo)mpopo in K+p+popo

KL beta decayCurrent predictions for KL K e n are ~10-8. Look for K+p+po with a po vertex that is displaced, with back-to-back pions, and a very low energy electron. Background from KL p+po e n has energetic electrons and narrow pion opening angle.Beta decay rate is proportional to Dm5 where Dm is the KL-K+ mass difference.Measurement of the beta decay rate could yield a KL-K+ mass difference to ~10keV

Tagged po decays and KL LifetimeKOPIO anticipates accumulating data on ~1014 kaon decays. This will include a large sample of 2po and 3po decays.Tagging these po decays will allow improved measurements of e.g. po e+ e- (6.2 0.5) x 10-8 po n n

SummaryLots of possibilities for new physics and improved precision measurement with the anticipated KOPIO data set.Looking for new collaborators to help us with the physics program and build the detector to accomplish these goals.New ideas welcome!