发表机构
Università degli Studi di Salerno; Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Salerno, Sezione di Napoli（萨莱诺大学; 意大利国家核物理研究所，萨莱诺协作组，那不勒斯分部）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出非弹性电弱暗物质的佩切伊-奎因起源模型，结合LUX-ZEPLIN实验数据，解释其单核反冲事例，说明暗物质丰度由电弱二重态和QCD轴子共同提供。
AI 中文摘要
LUX-ZEPLIN（LZ）实验在延伸至核反冲能$E_R\roughly270$keV的搜寻中，报告了一个重建在$E_R=248\textrm{}^{+23}_{\textrm{stat}}\textrm{}^{+23}_{\textrm{sys}}$keV的核反冲事例。我们研究一种非弹性电弱（EW）二重态解释，其中自发佩切伊-奎因（PQ）对称性破缺留下剩余宇称，稳定更轻的中性态并产生马约拉纳劈裂。一个带PQ荷的单重态费米子从PQ破缺真空期望值获得马约拉纳质量，积分掉后诱导出劈裂矢量型EW二重态的五维算符。最小KSVZ色区提供QCD反常。对于代表性PQ破缺能标$v_S=4.4\times10^{11}$GeV和马约拉纳质量$M_N\roughly50$TeV，由关系$M_N=y_Sv_S/\roots{2}$得$y_S\roughly1.6\times10^{-7}$，而与LZ相关的劈裂要求希格斯-二重态汤川耦合$y\roughly0.023$。在标准热历史中，EW二重态仅构成暗物质的一个子成分。探测高速度尾的速率估计给出代表性基准点：$M_D\roughly380$--$420$GeV，$\udb12\roughly323$--$330$keV，$\udb13\roughly0.12$--$0.15$，产生量级为1的LZ事例数。剩余丰度由QCD轴子通过真空 misalignment 提供，对应合适的$v_S$和初始角。激发态的辐射寿命约$3\times10^{-2}$s，衰变长度约20km，使LZ呈现单个核反冲的拓扑，同时在地球升频散射后可产生互补的发光信号。
英文摘要
The LUX-ZEPLIN (LZ) experiment has reported a nuclear recoil event reconstructed at $E_R=248\pm23_{\rm stat}\pm23_{\rm sys}{\rm\,keV}$ in a dedicated high-recoil search. We investigate an inelastic electroweak (EW) doublet interpretation in which spontaneous Peccei-Quinn (PQ) breaking leaves a residual parity that stabilizes the lighter neutral state and generates its Majorana splitting. A PQ-charged singlet fermion acquires a Majorana mass from the PQ-breaking vacuum expectation value and, once integrated out, induces the dimension-five operator that splits a vectorlike EW doublet, while a minimal KSVZ sector supplies the QCD anomaly. For $v_S=4.4\times10^{11}{\rm\,GeV}$ and $M_N\simeq50{\rm\,TeV}$, the LZ-motivated splitting requires $y\simeq0.023$. In a standard thermal history, the EW doublet is subdominant. Three kinematic benchmarks with $M_D=297.0$, $396.4$, and $549.7{\rm\,GeV}$, $δ_χ\simeq304$-$343{\rm\,keV}$, and $ξ_χ\simeq0.073$-$0.250$ each yield about one recoil event, while their accepted spectra peak below the observed recoil energy, so they are interpreted as kinematic rather than spectral best-fit points. The remaining abundance can be supplied by the QCD axion through vacuum misalignment. We recompute solar capture for the subdominant thermal WIMP component and compare the resulting annihilation signal with the IceCube $W^+W^-$ limit, finding the LZ-motivated standard-thermal branch excluded under the assumptions adopted here. The excited state has a millisecond-scale radiative lifetime and kilometer-scale decay length, leaving the LZ topology dominated by a single nuclear recoil while allowing complementary luminous signals after terrestrial upscattering.
Comments15 pages, 2 figures. v3: Substantially revised phenomenological analysis with a dedicated solar capture and IceCube analysis for the subdominant thermal EW component; updated discussion of recent work
