Constraints on new physics from K{yields}{pi}{nu}{nu}
- Institute of Theoretical Sciences, University of Oregon, Oregon 97403 (United States)
- Department of Physics, Peking University, Beijing (China)
We study constraints on new physics from the recent measurement of Br(K{sup +}{yields}{pi}{sup +}{nu}{nu}) by the E787 and E949 Collaborations. In our analysis, we consider two models of new physics: (a) extra down-type singlet quark model and (b) R-parity violating minimal supersymmetric standard model. We find that K{sup +}{yields}{pi}{sup +}{nu}{nu} along with other processes such as K{sub L}{yields}{mu}{sup +}{mu}{sup -},{epsilon}{sup '}/{epsilon} provide useful bounds on the parameter U{sub sd}, characterizing the off-diagonal Z-d-s coupling of model (a). The bounds on Re(U{sub sd}) from (K{sub L}{yields}{mu}{sup +}{mu}{sup -}){sub SD} and Im(U{sub sd}) from {epsilon}{sup '}/{epsilon} are so tight that the branching ratio of K{sup +}{yields}{pi}{sup +}{nu}{nu} can exceed the standard model value by at most a factor of 2. For model (b), we also obtain stringent bounds on certain combinations of the product of two {lambda}{sub ijk}{sup '} couplings originating from L number-violating operator L{sub i}Q{sub j}D{sub k}{sup c} using K{sup +}{yields}{pi}{sup +}{nu}{nu} and K{sub L}{yields}{mu}{sup +}{mu}{sup -} processes. Even with the stringent constraints on U{sub sd} [in model (a)] and on products of two Re couplings [model (b)], we find that the branching ratio B(K{sub L}{yields}{pi}{sup 0}{nu}{nu}) can be substantially different in both of the above models from those predicted in the standard model.
- OSTI ID:
- 20705582
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 70, Issue 9; Other Information: DOI: 10.1103/PhysRevD.70.093003; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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