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$K^+\to \pi^+\nu\bar\nu$
Motivated by the new experimental information reported by the BNL--E787 Collaboration, we analyse the present impact and the future prospects opened by the measurement of $\br(K^+\to\pi^+\nu\bar\nu)$. Although still affected by a large error, the BNL--E787 result favours values of $\br(K^+\to \pi^+\...
Autores principales: | , |
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Lenguaje: | eng |
Publicado: |
2001
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1016/S0370-2693(02)01328-X http://cds.cern.ch/record/530724 |
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author | D'Ambrosio, Giancarlo Isidori, Gino |
author_facet | D'Ambrosio, Giancarlo Isidori, Gino |
author_sort | D'Ambrosio, Giancarlo |
collection | CERN |
description | Motivated by the new experimental information reported by the BNL--E787 Collaboration, we analyse the present impact and the future prospects opened by the measurement of $\br(K^+\to\pi^+\nu\bar\nu)$. Although still affected by a large error, the BNL--E787 result favours values of $\br(K^+\to \pi^+\nu\bar\nu)$ substantially larger than what expected within the Standard Model. As a result, this data already provide non-trivial constraints on the unitarity triangle, when interpreted within the Standard Model framework. We stress the importance of the clean relation between $\br(K^+\to \pi^+\nu\bar\nu)$, $\sin2\beta$ and $\Delta M_{B_d}/\Delta M_{B_s}$ that in the next few years could provide one of the deepest probes of the Standard Model in the sector of quark-flavour dynamics. A speculative discussion about possible non-standard interpretations of a large $\br(K^+\to \pi^+\nu\bar\nu)$ is also presented. Two main scenarios naturally emerge: those with direct new-physics contributions to the $s \to d \nu\bar\nu$ amplitude and those with direct new-physics effects only in $B_d$--$\bar B_d$ mixing. Realistic models originating these two scenarios and possible future strategies to clearly identify them are briefly discussed. |
id | cern-530724 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 2001 |
record_format | invenio |
spelling | cern-5307242023-06-03T02:18:34Zdoi:10.1016/S0370-2693(02)01328-Xhttp://cds.cern.ch/record/530724engD'Ambrosio, GiancarloIsidori, Gino$K^+\to \pi^+\nu\bar\nu$Particle Physics - PhenomenologyMotivated by the new experimental information reported by the BNL--E787 Collaboration, we analyse the present impact and the future prospects opened by the measurement of $\br(K^+\to\pi^+\nu\bar\nu)$. Although still affected by a large error, the BNL--E787 result favours values of $\br(K^+\to \pi^+\nu\bar\nu)$ substantially larger than what expected within the Standard Model. As a result, this data already provide non-trivial constraints on the unitarity triangle, when interpreted within the Standard Model framework. We stress the importance of the clean relation between $\br(K^+\to \pi^+\nu\bar\nu)$, $\sin2\beta$ and $\Delta M_{B_d}/\Delta M_{B_s}$ that in the next few years could provide one of the deepest probes of the Standard Model in the sector of quark-flavour dynamics. A speculative discussion about possible non-standard interpretations of a large $\br(K^+\to \pi^+\nu\bar\nu)$ is also presented. Two main scenarios naturally emerge: those with direct new-physics contributions to the $s \to d \nu\bar\nu$ amplitude and those with direct new-physics effects only in $B_d$--$\bar B_d$ mixing. Realistic models originating these two scenarios and possible future strategies to clearly identify them are briefly discussed.Motivated by the new experimental information reported by the BNL--E787 Collaboration, we analyse the present impact and the future prospects opened by the measurement of $\br(K^+\to\pi^+\nu\bar\nu)$. Although still affected by a large error, the BNL--E787 result favours values of $\br(K^+\to \pi^+\nu\bar\nu)$ substantially larger than what expected within the Standard Model. As a result, this data already provide non-trivial constraints on the unitarity triangle, when interpreted within the Standard Model framework. We stress the importance of the clean relation between $\br(K^+\to \pi^+\nu\bar\nu)$, $\sin2\beta$ and $\Delta M_{B_d}/\Delta M_{B_s}$ that in the next few years could provide one of the deepest probes of the Standard Model in the sector of quark-flavour dynamics. A speculative discussion about possible non-standard interpretations of a large $\br(K^+\to \pi^+\nu\bar\nu)$ is also presented. Two main scenarios naturally emerge: those with direct new-physics contributions to the $s \to d \nu\bar\nu$ amplitude and those with direct new-physics effects only in $B_d$--$\bar B_d$ mixing. Realistic models originating these two scenarios and possible future strategies to clearly identify them are briefly discussed.Motivated by the new experimental information reported by the BNL--E787 Collaboration, we analyse the present impact and the future prospects opened by the measurement of $\br(K^+\to\pi^+\nu\bar\nu)$. Although still affected by a large error, the BNL--E787 result favours values of $\br(K^+\to \pi^+\nu\bar\nu)$ substantially larger than what expected within the Standard Model. As a result, this data already provide non-trivial constraints on the unitarity triangle, when interpreted within the Standard Model framework. We stress the importance of the clean relation between $\br(K^+\to \pi^+\nu\bar\nu)$, $\sin2\beta$ and $\Delta M_{B_d}/\Delta M_{B_s}$ that in the next few years could provide one of the deepest probes of the Standard Model in the sector of quark-flavour dynamics. A speculative discussion about possible non-standard interpretations of a large $\br(K^+\to \pi^+\nu\bar\nu)$ is also presented. Two main scenarios naturally emerge: those with direct new-physics contributions to the $s \to d \nu\bar\nu$ amplitude and those with direct new-physics effects only in $B_d$--$\bar B_d$ mixing. Realistic models originating these two scenarios and possible future strategies to clearly identify them are briefly discussed.Motivated by the new experimental information reported by the BNL-E787 Collaboration, we analyse the present impact and the future prospects opened by the measurement of B (K + →π + ν ν ̄ ) . Although still affected by a large error, the BNL-E787 result favours values of B (K + →π + ν ν ̄ ) substantially larger than what expected within the Standard Model. As a result, this data already provide non-trivial constraints on the unitarity triangle, when interpreted within the Standard Model framework. We stress the importance of the clean relation between B (K + →π + ν ν ̄ ) , sin2 β and ΔM B d / ΔM B s that in the next few years could provide one of the deepest probes of the Standard Model in the sector of quark-flavour dynamics. A speculative discussion about possible non-standard interpretations of a large B (K + →π + ν ν ̄ ) is also presented. Two main scenarios naturally emerge: those with direct new-physics contributions to the s→dν ν ̄ amplitude and those with direct new-physics effects only in B d – B ̄ d mixing. Realistic models originating these two scenarios and possible future strategies to clearly identify them are briefly discussed.hep-ph/0112135CERN-TH-2001-355CERN-TH-2001-355oai:cds.cern.ch:5307242001-12-10 |
spellingShingle | Particle Physics - Phenomenology D'Ambrosio, Giancarlo Isidori, Gino $K^+\to \pi^+\nu\bar\nu$ |
title | $K^+\to \pi^+\nu\bar\nu$ |
title_full | $K^+\to \pi^+\nu\bar\nu$ |
title_fullStr | $K^+\to \pi^+\nu\bar\nu$ |
title_full_unstemmed | $K^+\to \pi^+\nu\bar\nu$ |
title_short | $K^+\to \pi^+\nu\bar\nu$ |
title_sort | $k^+\to \pi^+\nu\bar\nu$ |
topic | Particle Physics - Phenomenology |
url | https://dx.doi.org/10.1016/S0370-2693(02)01328-X http://cds.cern.ch/record/530724 |
work_keys_str_mv | AT dambrosiogiancarlo ktopinubarnu AT isidorigino ktopinubarnu |