arXiv subjects

Dong-Mei Xia

Publications and source records attributed to Dong-Mei Xia.

5 recordsLinked to original sources

arXiv2025

Constraints on the lepton asymmetry from DESI DR2 BAO data

It is important to explore the potential existence of lepton asymmetry in the neutrino sector. Conducting a joint analysis of DESI DR2 BAO data and \emph{Planck} 2018 CMB data, we obtain the upper limits on the neutrino degeneracy parameter, i.e., $ξ<0.56$ for the normal mass hierarchy while $ξ<0.62$ for the inverted mass hierarchy, at 95\% confidence level. Considering the influence of the dynamical dark energy, we find that these upper limits remain to be robust. This work may provide helpful implications for model buildings of the matter-antimatter asymmetry in the universe.

astro-ph.CO↗

arXiv2021

Constraining primordial black holes as dark matter at JUNO

As an attractive candidate for dark matter, the primordial black holes (PBHs) in the mass range ($10^{15} \sim 10^{16}$)$\mathrm{g}$ could be detected via their Hawking radiation, including neutrinos and antineutrinos of three flavors. In this paper, we investigate the possibility to constrain the PBH as dark matter by measuring (anti)neutrino signals at the large liquid-scintillator detector of Jiangmen Underground Neutrino Observatory (JUNO). Among six available detection channels, the inverse beta decay $\overlineν^{}_e + p \to e^+ + n$ is shown to be most sensitive to the fraction $f^{}_{\rm PBH}$ of PBHs contributing to the dark matter abundance. Given the PBH mass $M^{}_{\rm PBH} = 10^{15}~{\rm g}$, we find that JUNO will be able to place an upper bound $f^{}_{\rm PBH} \lesssim 3\times 10^{-5}$, which is 20 times better than the current best limit $f^{}_{\rm PBH} \lesssim 6\times 10^{-4}$ from Super-Kamiokande. For heavier PBHs with a lower Hawking temperature, the (anti)neutrinos become less energetic, leading to a relatively weaker bound.

hep-ph↗

arXiv2018

Constraints on the sum of neutrino masses using cosmological data including the latest extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample

We investigate the constraints on the sum of neutrino masses ($Σm_ν$) using the most recent cosmological data, which combines the distance measurement from baryonic acoustic oscillation in the extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample with the power spectra of temperature and polarization anisotropies in the cosmic microwave background from the Planck 2015 data release. We also use other low-redshift observations including the baryonic acoustic oscillation at relatively low redshifts, the supernovae of type Ia and the local measurement of Hubble constant. In the standard cosmological constant $Λ$ cold dark matter plus massive neutrino model, we obtain the $95\%$ \acl{CL} upper limit to be $Σm_ν<0.129~\mathrm{eV}$ for the degenerate mass hierarchy, $Σm_ν<0.159~\mathrm{eV}$ for the normal mass hierarchy, and $Σm_ν<0.189~\mathrm{eV}$ for the inverted mass hierarchy. Based on Bayesian evidence, we find that the degenerate hierarchy is positively supported, and the current data combination can not distinguish normal and inverted hierarchies. Assuming the degenerate mass hierarchy, we extend our study to non-standard cosmological models including the generic dark energy, the spatial curvature, and the extra relativistic degrees of freedom, respectively, but find these models not favored by the data.

astro-ph.CO↗

arXiv2016

Impacts of dark energy on weighing neutrinos: mass hierarchies considered

Taking into account the mass splittings between three active neutrinos, we investigate impacts of dark energy on constraining the total neutrino mass $\sum m_ν$ by using recent cosmological observations. We consider two typical dark energy models, namely, the $w$CDM model and the holographic dark energy (HDE) model, which both have an additional free parameter compared with the $Λ$CDM model. We employ the Planck 2015 data of CMB temperature and polarization anisotropies, combined with low-redshift measurements on BAO distance scales, type Ia supernovae, Hubble constant, and Planck lensing. Compared to the $Λ$CDM model, our study shows that the upper limit on $\sum m_ν$ becomes much looser in the $w$CDM model while much tighter in the HDE model. In the HDE model, we obtain the $95\%$ CL upper limit $\sum m_ν<0.105~\textrm{eV}$ for three degenerate neutrinos. This might be the most stringent constraint on $\sum m_ν$ by far and is almost on the verge of diagnosing the neutrino mass hierachies in the HDE model. However, the difference of $χ^2$ is still not significant enough to distinguish the neutrino mass hierarchies, even though the minimal $χ^2$ of the normal hierarchy is slightly smaller than that of the inverted hierarchy.

astro-ph.CO↗

arXiv2016

Constraining interacting dark energy models with latest cosmological observations

The local measurement of $H_0$ is in tension with the prediction of $Λ$CDM model based on the Planck data. This tension may imply that dark energy is strengthened in the late-time Universe. We employ the latest cosmological observations on CMB, BAO, LSS, SNe, $H(z)$ and $H_0$ to constrain several interacting dark energy models. Our results show no significant indications for the interaction between dark energy and dark matter. The $H_0$ tension can be moderately alleviated, but not totally released.

astro-ph.CO↗