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Title: Search for a feebly interacting particle X in the decay K+ → π+X
A bstract A search for the K + → π + X decay, where X is a long-lived feebly interacting particle, is performed through an interpretation of the K + → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ analysis of data collected in 2017 by the NA62 experiment at CERN. Two ranges of X masses, 0–110 MeV /c 2 and 154–260 MeV /c 2 , and lifetimes above 100 ps are considered. The limits set on the branching ratio, BR( K + → π + X ), are competitive with previously reported searches in the first mass range, and improve on current limits in the second mass range by more than an order of magnitude.
Authors:
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Award ID(s):
1806430
Publication Date:
NSF-PAR ID:
10272507
Journal Name:
Journal of High Energy Physics
Volume:
2021
Issue:
3
ISSN:
1029-8479
Sponsoring Org:
National Science Foundation
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