Search for charged lepton flavor violating; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline">; <mml:mi>Z</mml:mi>; </mml:math>; and; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline">; <mml:msup>; <mml:mi>Z</mml:mi>; <mml:mo>′</mml:mo>; </mml:msup>; </mml:math>; boson decays in proton-proton collisions at; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline">; <mml:msqrt>; <mml:mi>s</mml:mi>; </mml:msqrt>; <mml:mo>=</mml:mo>; <mml:mn>13</mml:mn>; <mml:mtext> </mml:mtext>; <mml:mtext> </mml:mtext>; <mml:mi>TeV</mml:mi>; </mml:math> | CU Experts

; A search for flavor violating decays of the; ; Z; ; boson to charged leptons is performed using data from proton-proton collisions at; ; ; s; ; =; 13; ; ; TeV; ; collected with the CMS detector at the LHC, corresponding to an integrated luminosity of; ; 138; ; ; ; fb; ; −; 1; ; ; ; . Each of the decays; ; Z; →; e; μ; ; ,; ; Z; →; e; τ; ; , and; ; Z; →; μ; τ; ; is considered. The data are consistent with the backgrounds expected from standard model processes. For the; ; Z; →; e; μ; ; channel the observed (expected) 95% confidence level upper limit on the branching fraction is; ; 1.9; (; 2.0; ); ×; ; 10; ; −; 7; ; ; ; , which is the most stringent direct limit to date on this process; the corresponding limits for the; ; Z; →; e; τ; ; and; ; Z; →; μ; τ; ; channels are; ; 13.8; (; 11.4; ); ×; ; 10; ; −; 6; ; ; ; and; ; 12.0; (; 5.3; ); ×; ; 10; ; −; 6; ; ; ; , respectively. Additionally, the; ; e; μ; ; final state is used to search for lepton flavor violating decays of; ; ; Z; ′; ; ; resonances in the mass range from 110 to; ; ; 500; ; ; GeV; ; ; . No significant excess is observed above the predicted background levels.;

Hayrapetyan A; Makarenko V; Tumasyan A; Adam W; Andrejkovic JW; Benato L; Bergauer T; Dragicevic M; Giordano C; Hussain PS

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