Search for rare decays of $$\mathrm {Z}$$ Z and Higgs bosons to $${\mathrm {J}/\psi } $$ J / ψ and a photon in proton-proton collisions at $$\sqrt{s}$$ s = 13 $$\,\text {TeV}$$ TeV

Abstract

A search is presented for decays of and Higgs bosons to a meson and a photon, with the subsequent decay of the to . The analysis uses data from proton-proton collisions with an integrated luminosity of 35.9 at collected with the CMS detector at the LHC. The observed limit on the decay branching fraction, assuming that the meson is produced unpolarized, is at 95% confidence level, which corresponds to a rate higher than expected in the standard model by a factor of 15. For extreme-polarization scenarios, the observed limit changes from to with respect to the unpolarized scenario. The observed upper limit on the branching fraction for where the meson is assumed to be transversely polarized is , a factor of 260 larger than the standard model prediction. The results for the Higgs boson are combined with previous data from proton-proton collisions at to produce an observed upper limit on the branching fraction for that is a factor of 220 larger than the standard model value.

Higgs Boson studies at future particle colliders

“…Within the LHC, the Higgs exclusive decays are the only direct probe of the u and d Yukawa couplings, while if s-tagging could be implemented at the LHC [70], then the strange Yukawa could be probed both inclusively and exclusively. On the experimental side, both ATLAS and CMS have reported upper bounds on H → J/ψγ [71,72], H → φ γ and h → ργ [73,74]. These processes receive contributions from two amplitudes, only one of which is proportional to the Yukawa coupling.…”

Precise evaluation of $h\to c\bar{c}$ and axion-like particle production

“…Finally we investigate the ALP associate production with the charm quark pair, and the constrain for the related parameters is estimated by assuming a condition of eq. (22). At the upgrade LHC, more and more events on Higgs boson decay will be accumulated, so that precise studies on h → cc and search for new particles in Higgs decay become possible.…”

“…Due to the absence of an observation of Higgs decays to charm quark, there are some bounds on the charm quark Yukawa coupling. An indirect search for the decay of the Higgs boson to charm quarks via the decay to J/ψγ is presented at LHC [20][21][22]. A direct search for the Higgs boson, produced in association with a vector boson (W or Z), and decaying to a charm quark pair is performed by CMS collaboration [23] and ATLAS collaboration [24] respectively.…”

Search for the rare decays and at LHCb

“…Thus, the study of hadronic-radiative W and Z bosons decays can provide stringent tests of the QCD factorization formalism [5]. After almost forty years from the discoveries of the W and Z bosons, no hadronic-radiative decay of these bosons has been observed, despite searches performed by the ATLAS [7][8][9][10][11], CMS [12], and CDF [13] collaborations. The current best limit is for the branching fraction of the decay [9].…”