Search for heavy neutral leptons in $$W^+\rightarrow \mu ^{+}\mu ^{\pm }\, \text {jet}$$ decays



Aaij, R, Abellán Beteta, C, Ackernley, T, Adeva, B, Adinolfi, M, Afsharnia, H, Aidala, CA, Aiola, S, Ajaltouni, Z, Akar, S
et al (show 980 more authors) (2021) Search for heavy neutral leptons in $$W^+\rightarrow \mu ^{+}\mu ^{\pm }\, \text {jet}$$ decays. The European Physical Journal C, 81 (3).

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Abstract

<jats:title>Abstract</jats:title><jats:p>A search is performed for heavy neutrinos in the decay of a <jats:italic>W</jats:italic> boson into two muons and a jet. The data set corresponds to an integrated luminosity of approximately <jats:inline-formula><jats:alternatives><jats:tex-math>$$3.0\, \text {fb} ^{-1} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>3.0</mml:mn> <mml:mspace /> <mml:msup> <mml:mtext>fb</mml:mtext> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> of proton–proton collision data at centre-of-mass energies of 7 and <jats:inline-formula><jats:alternatives><jats:tex-math>$$8\, \text {TeV} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>8</mml:mn> <mml:mspace /> <mml:mtext>TeV</mml:mtext> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> collected with the LHCb experiment. Both same-sign and opposite-sign muons in the final state are considered. Data are found to be consistent with the expected background. Upper limits on the coupling of a heavy neutrino with the Standard Model neutrino are set at <jats:inline-formula><jats:alternatives><jats:tex-math>$$95\%$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>95</mml:mn> <mml:mo>%</mml:mo> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> confidence level in the heavy-neutrino mass range from 5 to <jats:inline-formula><jats:alternatives><jats:tex-math>$$50\, \text {GeV/}c^2 $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>50</mml:mn> <mml:mspace /> <mml:mtext>GeV/</mml:mtext> <mml:msup> <mml:mi>c</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula>. These are of the order of <jats:inline-formula><jats:alternatives><jats:tex-math>$$10^{-3}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> </mml:math></jats:alternatives></jats:inline-formula> for lepton-number-conserving decays and of the order of <jats:inline-formula><jats:alternatives><jats:tex-math>$$10^{-4}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>4</mml:mn> </mml:mrow> </mml:msup> </mml:math></jats:alternatives></jats:inline-formula> for lepton-number-violating heavy-neutrino decays.</jats:p>

Item Type: Article
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 21 Apr 2021 10:20
Last Modified: 19 Oct 2021 07:36
DOI: 10.1140/epjc/s10052-021-08973-5
Open Access URL: https://link.springer.com/content/pdf/10.1140/epjc...
URI: https://livrepository.liverpool.ac.uk/id/eprint/3120042