1. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 1 K L →   Beyond Grossman-Nir Bound July 24 @ EPS-HEP2015, Wien

2. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 2 K L → π 0 νν Beyond Grossman-Nir Bound Outline I. Kaon: the Oldest Frontier Fixation on Grossman-Nir Bound ― Shake It Off ! II. Blind Senses Stupid is as stupid does / KOTO Could Win Big III. Explicit Model (existence proof) Gauged L  – L  related to muon g – 2  +... IV. Where Else? ― an Illustration “ Exotic ” Rare K & B Decays V. Conclusion Fuyoto, WSH, Kohda, 1412.4397 (PRL’15) and to appear [see also talk by M. Kohda]

3. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 3 I. Kaon: the Oldest Frontier mostly Fixation: Grossman-Nir Bound 1997 ― S h a k e I t O f f ! 68+

4. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 4 “ Blind man blessed by senses. ” Grossman-Nir Limit @ J-PARC but... KOTO @ 100 hrs (2013) ~ E391a, but... mostly S h a k e I t O f f !

5. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 5 II. Blind Senses Stupid is as stupid does. [ Forrest Can Run; ’nd became Rich! ]

6. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 6 stable blinding spot Bound on K →  X  1/200 weaker than K  →   bound

7. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 7 See Not Window basically Same as E787/949 @ BNL @ CERN See Neither The KOTO Expt at J-PARC can discover above the Grossman-Nir Bound ! KL → XKL → X A Surprise ! “Trivial” Kinematic exclusion: “ Blind man Blessed by Senses. ” Fuyoto, WSH, Kohda

8. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 8 “ Blind man blessed by senses. ” @ J-PARC mostly Shake It Off ! discovery The KOTO Expt at J-PARC can discover above the Grossman-Nir Bound ! KL → XKL → X Grossman-Nir Limit 3/8 but … KOTO @ 100 hrs (2013) ~ E391a, but … Starting Now Discovery Starting “ Now ” ! KL → XKL → X

9. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 9 III. Explicit Model (existence proof) gauged L  – L  related to muon g – 2  +...

10. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 10 “unconstrained” Q, D, U: vector-like quarks with Z′ charge “ gauged L  – L  ” See M. Kohda’s talk today, Top session. Our Original Interest B → K *    

11. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 11 gauged L  – L  Altmannshofer, Gori, Pospelov, Yavin [PRD  PRL] Neutrino Trident Production “ Neutrino Trident Production ” Quite Weakly Coupled New Physics Light Particle New Physics from Light Particle !? “LBNE” but not DM 1406.2332

12. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 12 New Physics Light Particle New Physics from Light Particle !? gauged L  – L  SM-assisted loop s  dZ ′ ; b  sZ ′ Fuyoto, WSH, Kohda, 1412.4397 Tune away by Z 2 flow of U(1)′ charge Q, D, U : vector-like quarks with Z′ charge 〈ϕ〉 : generates Z′ mass

13. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 13 See Not Window basically Same as E787/949 @ BNL @ CERN See Neither The KOTO Expt at J-PARC above can discover above Grossman-Nir Bound the Grossman-Nir Bound ! Fuyoto, WSH, Kohda, 1412.4397 A Surprise ! “ Trivial” Kinematic exclusion: “ Blind man Blessed by Senses. ”

14. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 14 IV. Where Else? ― an Illustration Circumstantial Hints/Possibilities in Rare B & K Decays

15. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 15 BaBar’13 (471M BB(bar)) BaBar: mild hint in B + → K + N.B. B(B → K   ) << B(K →   ) Fuyoto, WSH, Kohda, 1412.4397 10 bins driven by lowest bin Belle needs to follow up with the Binned m mis analysis. (  Belle II)

16. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 16 285 MeV 300260 “ excess ” Range of “ excess ” Can be repeated by NA62 Can be repeated by NA62 The 2 nd Window N.B. KTeV 2000 search for is more stringent. See M. Kohda’s talk. “ excess ” in 1 st bin

17. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 17 LHCb 3 fb , JHEP 1406 Low q 2 Spike Search in B         * LHCb should do the “ extra work ”* for lowest q 2 Fuyoto, WSH, Kohda, 1412.4397 * * Private Communication with LHCb N.B. Talk by A. Mauri 7/23 on LHCb Dark Boson search in K *      probably more constraining

18. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 18 Y Uc & Y Ut should be reasonable in strength 135 MeV285 MeV Perhaps 100 TeV SPPC/FCChh Needed Fuyoto, WSH, Kohda, 1412.4397 and to appear See M. Kohda’s talk in Top session. Opportunity

19. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 19 V. Conclusion K L → π 0 + nothing: can occur above Grossman-Nir Bound  KOTO ! If See Early Event(s), Try Hard to Kill... But not Overly So. If above GN Bound, then likely “π 0 ” mass object. When KOTO reaches below GN Bound, concept still effective.  KOTO/NA62/LHCb/Belle(II) all in game. Run, KOTO, Run ! (that slips thru NA62)

20. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 20

21. K L → π 0 νν > GN ? George W.S. Hou (NTU) EPSHEP, Wien, 7/24/2015 21 Light “ g-2 ” Z’ decay is prompt, even when highly boosted. Z’ →  Z’ → 