The kinetic dark-mixing in the light of CoGENT and XENON100

TL;DR

The paper investigates a dark $U(1)_D$ sector that communicates with the Standard Model through kinetic mixing $\delta$ and hosts a dark matter candidate, assessing viability under relic-density, electroweak precision, and direct-detection constraints from XENON100 and CDMS, in light of CoGeNT, DAMA, and CRESST signals. It computes the DM relic abundance via $Z_D$-mediated annihilation, maps the allowed $(M_{Z_D}, \delta)$ region for fixed $m_{\psi_0}$, and demonstrates a viable window with $M_{Z_D} \lesssim 40$ GeV and $10^{-4} \lesssim \delta \lesssim 10^{-3}$. The work also shows how the combination of the relic-density requirement and near-pole annihilation pins the parameter space and explains how some regions remain compatible with XENON100 depending on the pole proximity and detection efficiencies. It further analyzes the possible interpretations of DAMA/CoGeNT/CRESST excesses within this portal, suggesting a cohesive scenario where light $Z_D$ and modest kinetic mixing yield observable signals without contradicting current bounds. Overall, the results provide a concrete, testable blueprint for probing hidden $U(1)_D$ gauge sectors with ongoing and upcoming direct-detection and collider experiments.

Abstract

Several string or GUT constructions motivate the existence of a dark U(1)_D gauge boson which interacts with the Standard Model only through its kinetic mixing. We compute the dark matter abundance in such scenario and the constraints in the light of the recent data from CoGENT, CDMSII and XENON100. We show in particular that a region with relatively light WIMPS, M_{Z_D}< 40 GeV and a kinetic mixing 10^-4 < delta < 10^-3 is not yet excluded by the last experimental data and seems to give promising signals in a near future. We also compute the value of the kinetic mixing needed to explain the DAMA/CoGENT/CRESST excesses and find that for M_{Z_D}< 30 GeV, delta ~ 10^-3 is sufficient to fit with the data.

Figures (4)

• Figure 1: Two examples of allowed parameter space for $m_{\psi_0}=10$ GeV (left) and $m_{\psi_0}=5$ GeV (right). The points between the full-red region respect the 5$\sigma$ WMAP constraint, the points below the dashed-black line do not exceed accelerator data on precision tests, and the points above the dotted-green line are excluded by XENON100 data.
• Figure 2: Constraints coming from WMAP (red boxes), electroweak data (black line), and recent direct detection analysis of XENON100 after correction of their efficiency factor XENON100
• Figure 3: Parameter space allowed within 90 % of C.L. for the CoGeNT signal (blue), DAMA without channeling (red), with channeling (green), CRESST (black), and the exclusion region depending on the hypothesis concerning $L_{eff}$ (se the text for details).
• Figure 4: Points still allowed by electroweak, cosmological and direct detection constraints in the plane ($M_{\psi_0}$; $\sigma^p_{SI}$). The green region corresponds to CoGeNT (minimum $\chi^2$, with contours at 90 and 99.9% C.L.), assuming a constant background contamination COGENT. The DAMA regions (goodness-of-fit, also at 90 and 99.9 % C.L.) are given both with (upper black region) and without (lower black region) channelling DAMA2. The black dashed line is the 90 % C.L. exclusion limit for the CDMS-Si CDMS2 and the brown full line the 90% C.L. exclusion limit for the CRESST I experiment CRESSTI. The blue dotted lines corresponds to the 90% C.L. exclusion limit from the XENON100 experiment corresponding respectively to the LeffMed (left), Leffmin (middle) and LeffZep (right) scintillation efficiency -see text for details.