The 248 keV LZ Recoil: A Possible Hint of Non-SM-Like Quark Yukawa Couplings with a Scalar-Portal Dark Matter
Abstract
The recent observation of an isolated nuclear recoil event at an energy of 248± 23 (stat)± 23 (sys) keV, as reported by the LUX-ZEPLIN (LZ) collaboration, can be an intriguing signature for Beyond the Standard Model (BSM) possibilities, particularly for dark matter (DM). This paper explores a scenario in which the observed recoil could simultaneously signal inelastic DM and a flavor-specific New Physics (NP) interaction in the quark sector. Considering a minimal extension of the Standard Model (SM) with two closely degenerate Z2-odd vector-like fermions (VLFs), interacting with the SM via a scalar portal, the analysis shows that a perfect agreement with the observed 248 keV nuclear recoil can be achieved if the quark Yukawa couplings are allowed to deviate from their SM values. The underlying quarkophilic NP can originate from a dimension-6 effective operator at a NP scale Λ≤ 𝒪(10) TeV. Future collider searches can be crucial to test/falsify the proposal.
Related
- Multi-Higgs production from a theory of varying Higgs quartic and top Yukawa couplings
- Off-shell Higgs boson measurements: Yukawa couplings, self-coupling, compositeness, and width
- Axion Portal Dark Matter and the LUX-ZEPLIN High-Recoil Event
- Exothermic Higgs portal: from LUX-ZEPLIN recoil to Gamma Rays
- A possible interpretation of the LUX-ZEPLIN recoil event in the 2HD+a scenario
BibTeX
@misc{de2026recoil,
title = {{The 248 keV LZ Recoil: A Possible Hint of Non-SM-Like Quark Yukawa Couplings with a Scalar-Portal Dark Matter}},
author = {Bibhabasu De},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.23096},
eprint = {2609.23096},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.23096},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The 248 keV LZ Recoil: A Possible Hint of Non-SM-Like Quark Yukawa Couplings with a Scalar-Portal Dark Matter
AU - Bibhabasu De
PY - 2026
DA - 2026/09/22
PB - arXiv
DO - 10.48550/arxiv.2609.23096
UR - https://arxiv.org/abs/2609.23096
AB - The recent observation of an isolated nuclear recoil event at an energy of 248± 23 (stat)± 23 (sys) keV, as reported by the LUX-ZEPLIN (LZ) collaboration, can be an intriguing signature for Beyond the Standard Model (BSM) possibilities, particularly for dark matter (DM). This paper explores a scenario in which the observed recoil could simultaneously signal inelastic DM and a flavor-specific New Physics (NP) interaction in the quark sector. Considering a minimal extension of the Standard Model (SM) with two closely degenerate Z_2-odd vector-like fermions (VLFs), interacting with the SM via a scalar portal, the analysis shows that a perfect agreement with the observed 248 keV nuclear recoil can be achieved if the quark Yukawa couplings are allowed to deviate from their SM values. The underlying quarkophilic NP can originate from a dimension-6 effective operator at a NP scale Λ≤ 𝒪(10) TeV. Future collider searches can be crucial to test/falsify the proposal.
ER -