Searches for lepton number violation and resonances in K ^± → πμμ decays

Journal Article · Sat Mar 18 00:00:00 EDT 2017 · Physics Letters B

DOI:https://doi.org/10.1016/j.physletb.2017.03.029· OSTI ID:1367908

Batley, J. R.; Kalmus, G.; Lazzeroni, C.; Munday, D. J.; Slater, M. W.; Wotton, S. A.; Arcidiacono, R.; Bocquet, G.; Cabibbo, N.; Ceccucci, A.; Cundy, D.; Falaleev, V.; Fidecaro, M.; Gatignon, L.; Gonidec, A.; Kubischta, W.; Maier, A.; Massri, K. ; Norton, A.; Patel, M. ; Peters, A.; Balev, S.; Frabetti, P. L.; Gersabeck, E.; Goudzovski, E.; Hristov, P.; Kekelidze, V.; Kozhuharov, V.; Litov, L.; Madigozhin, D.; Molokanova, N.; Polenkevich, I.; Potrebenikov, Yu.; Stoynev, S.; Zinchenko, A.; Monnier, E.; Swallow, E.; Winston, R.; Rubin, P.; Walker, A.; Baldini, W.; Cotta Ramusino, A.; Dalpiaz, P.; Damiani, C.; Fiorini, M.; Gianoli, A.; Martini, M.; Petrucci, F.; Savrié, M.; Scarpa, M.; Wahl, H.; Bizzeti, A.; Lenti, M.; Veltri, M.; Calvetti, M.; Celeghini, E.; Iacopini, E.; Ruggiero, G.; Behler, M.; Eppard, K.; Kleinknecht, K.; Marouelli, P.; Masetti, L.; Moosbrugger, U.; Morales Morales, C.; Renk, B.; Wache, M.; Wanke, R.; Winhart, A.; Coward, D.; Dabrowski, A.; Fonseca Martin, T.; Shieh, M.; Szleper, M.; Velasco, M.; Wood, M. D.; Cenci, P.; Pepe, M.; Petrucci, M. C.; Anzivino, G.; Imbergamo, E.; Nappi, A.; Piccini, M.; Raggi, M.; Valdata-Nappi, M.; Cerri, C.; Fantechi, R.; Collazuol, G.; DiLella, L.; Lamanna, G.; Mannelli, I.; Michetti, A.; Costantini, F.; Doble, N.; Fiorini, L.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Venditti, S.; Bloch-Devaux, B.; Cheshkov, C.; Chèze, J. B.; De Beer, M.; Derré, J.; Marel, G.; Mazzucato, E.; Peyaud, B.; Vallage, B.; Holder, M.; Ziolkowski, M.; Biino, C.; Cartiglia, N.; Marchetto, F.; Bifani, S.; Clemencic, M.; Goy Lopez, S.; Dibon, H.; Jeitler, M.; Markytan, M.; Mikulec, I.; Neuhofer, G.; Widhalm, L.

The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003$$-$$2004. A new upper limit on the rate of the lepton number violating decay $$K^{\pm}\to\pi^{\mp}\mu^{\pm}\mu^{\pm}$$ is reported: $$\mathcal{B}(K^{\pm}\to\pi^{\mp}\mu^{\pm}\mu^{\pm})<8.6 \times 10^{-11}$$ at 90% CL. Searches for two-body resonances $$X$$ in $$K^{\pm}\to\pi\mu\mu$$ decays (such as heavy neutral leptons $$N_4$$ and inflatons $$\chi$$) are also presented. Finally, in the absence of signals, upper limits are set on the products of branching fractions $$\mathcal{B}(K^{\pm}\to\mu^{\pm}N_4)\mathcal{B}(N_4\to\pi\mu)$$ and $$\mathcal{B}(K^{\pm}\to\pi^{\pm}X)\mathcal{B}(X\to\mu^+\mu^-)$$ for ranges of assumed resonance masses and lifetimes. The limits are in the $$(10^{-11},10^{-9})$$ range for resonance lifetimes below 100 ps.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: The NA48/2 collaboration
• Grant/Contract Number: AC02-07CH11359; AC02-76SF00515
• OSTI ID: 1367908
• Alternate ID(s): OSTI ID: 1369395
• Report Number(s): FERMILAB-PUB-16-700-TD; CERN-EP-2016-310; 1503402
• Journal Information: Physics Letters B, Vol. 769, Issue C; ISSN 0370-2693
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

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