New axion searches at flavor factories

Abstract

We assess the impact of searches at flavor factories for new neutral resonances that couple to both photons and gluons. These are well motivated by "heavy axion" solutions of the strong CP problem and by frameworks addressing both Dark Matter and the Higgs hierarchy problem. We use LHCb public diphoton data around the Bs mass to derive the current best limit on these resonances for masses between 4.9 and 6.3 GeV. We estimate that a future LHCb dedicated search would test an axion decay constant of O(TeV) for axion masses in the few-to-tens of GeV, being fully complementary to the low mass ATLAS and CMS searches. We also derive the impact of BABAR searches based on Υ decays and the future Belle-II reach.

Revisiting the production of ALPs at B-factories

“…The main goal of this paper is to re-examine existing BaBar and Belle flavor-conserving constraints on ALPs, and to identify the most promising experimental searches to be performed at the forthcoming Belle-II experiment. While there have been several studies discussing signatures of ALPs at B-factories [26][27][28][29], many clarifications are still needed. Firstly, the resonant contributions to the ALP production, via the e + e − → Υ(nS) → aγ process, have been overlooked before.…”

Coupling QCD-Scale Axionlike Particles to Gluons

“…Moreover, ALPs may explain the long-standing anomaly with the magnetic moment of the muon [10], and could provide a portal connecting SM particles to dark matter [11][12][13][14].ALPs are pseudo-Nambu-Goldstone bosons, and therefore, their masses, m a , are expected to be m a Λ. Recently, MeV-to-GeV scale, henceforth QCD-scale, ALPs have received considerable interest [15][16][17][18][19][20][21][22][23][24][25]; however, the phenomenological impact of ALP-gluon interactions is not well understood for QCD-scale ALPs. The effective Lagrangian describing such interactions iswhere c g is the dimensionless agg vertex coupling constant andG µν ≡ 1 2 µναβ G αβ .…”

Axion couplings to electroweak gauge bosons

“…This is the first such reinterpretation for g aγZ , g aZZ and g aW W . Even for g aγγ , the results of previous studies often did not apply and must be reanalysed: for instance the present bounds extracted from LEP and LHC data tend to focus on ALPs which would not have gluonic couplings, with very few exceptions [20,40,61,62]. Furthermore, we have included an estimation of the one-loop induced bounds for each EW axion coupling, which leads to supplementary constraints.…”

“…The region labelled "Flavour" is excluded by data from Babar [59] and LHCb [60], as computed in Ref. [40]. For high axion masses near the TeV scale, the limits from LHC are much stronger than those from LEP, because of the enhanced axion production via gluon-gluon fusion.…”