Rare exclusive decays of the Z-boson revisited

Abstract

The realization that first- and second-generation Yukawa couplings can be probed by decays of the Higgs boson to a meson in association with a photon has renewed interest in such rare exclusive decays. We present here a detailed study of the rare $Z$-boson processes $Z\to J/\psi +\gamma$, $Z\to {\rm Y}+\gamma$, and $Z\to \varphi +\gamma$ that can serve as benchmarks for the analogous Higgs-boson decays. We include both direct-production and fragmentation contributions to these decays, and consider the leading QCD corrections and the relativistic corrections to the $J/\psi$ and ${\rm Y}$ processes. We present numerical predictions for the branching ratios that include a careful accounting of the theoretical uncertainties.

19 pages, 1 figure; numerical bug in Upsilon branching ratio fixed; matches published version

References in corpus (3)

• Improved determination of color-singlet nonrelativistic QCD matrix elements for S-wave charmonium
• An Exclusive Window onto Higgs Yukawa Couplings
• Relativistic corrections to Higgs boson decays to quarkonia

Cited by in corpus (18)

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• Search for Higgs and $Z$ Boson Decays to $\varphi \gamma$ with the ATLAS Detector
• Long-lived light neutralinos at future $Z-$factories
• Rare and exclusive few-body decays of the Higgs, Z, W bosons, and the top quark
• Searches for exclusive Higgs and $Z$ boson decays into a vector quarkonium state and a photon using $139$ fb${}^{-1}$ of ATLAS $\sqrt{s}=13$ TeV proton$-$proton collision data
• $Z$ boson radiative decays to a $S$-wave quarkonium at NNLO and NLL accuracy
• $Z$ boson radiative decays to a $P$-wave quarkonium at NNLO and LL accuracy
• Analysis of double-$J/\psi$ production in $Z$ decay at next-to-leading-order QCD accuracy
• Search for the rare decays $W^{+}\to D_s^{+}\gamma$ and $Z\to D^0\gamma$ at LHCb
• Comprehensive studies of ${\rm Y}$ inclusive production in $Z$ boson decay
• Search for exclusive Higgs and $Z$ boson decays to $\omega \gamma$ and Higgs boson decays to $K^{\ast }\gamma$ with the ATLAS detector
• Search for rare decays of the Z and Higgs bosons to a J/$\psi$ or $\psi$(2S) meson and a photon in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Next-to-leading order QCD corrections to $Z\to {\eta }_Q+Q+\bar{Q}$
• Impact of $Z\to {\eta }_{c,b}+g+g$ on the inclusive ${\eta }_{c,b}$ meson yield in $Z$-boson decay
• Searches for exclusive Higgs boson decays into $D^{\ast }\gamma$ and $Z$ boson decays into $D^0\gamma$ and $K_s^0\gamma$ in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Mass biases in reconstructing exclusive radiative hadronic decays of W bosons at the LHC
• Next-to-leading order analysis of $J/\psi +\gamma$ production in photon-photon collisions at CEPC