arXiv subjects

Jongkuk Kim

Publications and source records attributed to Jongkuk Kim.

32 records · Page 2Linked to original sources

arXiv2022

Compatibility of muon $g-2$, $W$ mass anomaly in type-X 2HDM

Recently CDF II Collaboration reported that they measured W boson mass precisely. The measurement is deviated from the Standard Model (SM) Prediction at 7$σ$. Also, the recent FNAL measurement of the muon magnetic moment shows a $4.2σ$ deviation. To resolve the W boson as well as the muon $(g-2)$ anomalies, we explore the type-X two Higgs doublet model (2HDM). We analyze the $(m_A, \tanβ)$ parameter space of the type-X 2HDM consistent with the muon $(g-2)$, lepton universality test and recent $W$ boson mass measurments from the CDF II collaboration. We find that the measurement of the $h\to AA$ branching ratio gives a strong lower mass bound on $m_H$.

hep-ph↗

arXiv2021

Muon $g-2$ in $U(1)_{μ-τ}$ Symmetric Gauged Radiative Neutrino Mass Model

We explore muon anomalous magnetic moment (muon $g-2$) in a scotogenic neutrino model with a gauged lepton number symmetry $U(1)_{μ-τ}$. In this model, a dominant muon $g-2$ contribution comes not from an additional gauge sector but from a Yukawa sector. In our numerical $Δχ^2$ analysis, we show that our model is in favor of normal hierarchy with some features. We demonstrate one benchmark point, satisfying muon $g-2$ at the best fit value $25.1\times10^{-10}$.

hep-ph↗

arXiv2020

Dispersion of neutrinos in a medium

We analyze the dispersion relations of Weyl or Majorana, and Dirac neutrinos in a complex scalar medium which interacts with the neutrinos through Yukawa couplings. They are solved by perturbative calculation in various limits representing different physical situations, some of which allow the medium-induced neutrino oscillation to occur. Remarkably, peculiar dispersion relations arise differently for Majorana or Dirac neutrinos in the non-relativistic limit. This provides an unpleasant restriction on the cosmological scenario of a scalar dark matter coupling to neutrinos. At present, the model parameter space is constrained by the neutrino scattering with dark matter through astrophysical neutrino observations.

hep-ph↗

arXiv2020

Search for sterile neutrino with light gauge interactions: recasting collider, beam-dump, and neutrino telescope searches

We investigate features of the sterile neutrinos in the presence of a light gauge boson $X^μ$ that couples to the neutrino sector. The novel bounds on the active-sterile neutrino mixings $| U_{\ell 4} |^2$, especially for tau flavor ($l = τ$), from various collider and fixed target experiments are explored. Also, taking into account the additional decay channel of the sterile neutrino into a light gauge boson ($ν_4 \to ν_\ell e^+ e^-$), we explore and constrain a parameter space for low energy excess in neutrino oscillation experiments.

hep-ph↗

arXiv2020

A radiative seesaw model linking to XENON1T anomaly

We propose an attractive model that excess of electron recoil events around 1-5 keV reported by the XENON1T collaboration nicely links to the tiny neutrino masses based on a radiative seesaw scenario. Our dark matter(DM) is an isospin singlet inert boson that plays an role in generating non-vanishing neutrino mass at one-loop level, and this DM inelastically interacts with a pair of electrons at one-loop level that is required to explain the XENON1T anomaly. It is also demanded that the mass difference between an excited DM and DM has to be of the order keV. Interestingly, the small mass difference $\sim$keV is proportional to the neutrino masses. It suggests that we have double suppressions through the tiny mass difference and the one-loop effect. Then, we show some benchmark points to explain the XENON1T anomaly, satisfying all the constraints such as the event ratio of electrons of XENON1T, a long lived particle be longer than the age of Universe, and relic density in addition to the neutrino oscillation data and lepton flavor violations(LFVs).

hep-ph↗

arXiv2020

XENON1T excess in local $Z_2$ DM models with light dark sector

Recently XENON1T Collaboration announced that they observed some excess in the electron recoil energy around a 2-3 keV. We show that this excess can be interpreted as exothermic scattering of excited dark matter (XDM), $XDM + e_{atomic} \rightarrow DM + e_{free}$ on atomic electron through dark photon exchange. We consider DM models with local dark $U(1)$ gauge symmetry that is spontaneously broken into its $Z_2$ subgroup by Krauss-Wilczek mechanism. In order to explain the XENON1T excess with the correct DM thermal relic density within freeze-out scenario, all the particles in the dark sector should be light enough, namely $\sim O(100)$ MeV for scalar DM and $\sim O(1-10)$ MeV for fermion DM cases. And even lighter dark Higgs $ϕ$ plays an important role in the DM relic density calculation: $X X^\dagger \rightarrow Z' ϕ$ for scalar DM ($X$) and $χ\barχ \rightarrow ϕϕ$for fermion DM ($χ$) assuming $m_{Z'} > m_χ$. Both of them are in the $p$-wave annihilation, and one can easily evade stringent bounds from Planck data on CMB on the $s$-wave annihilations, assuming other dangerous $s$-wave annihilations are kinematically forbidden.

hep-ph↗

arXiv2019

Neutrino Oscillations in Dark Matter

We study neutrino oscillations in a medium of dark matter which generalizes the standard matter effect. A general formula is derived to describe the effect of various mediums and their mediators to neutrinos. Neutrinos and anti-neutrinos receive opposite contributions from asymmetric distribution of (dark) matter and anti-matter, and thus it could appear in precision measurement of neutrino or anti-neutrino oscillations. Furthermore, the standard neutrino oscillation can occur from the symmetric dark matter effect even for massless neutrinos.

hep-ph↗

arXiv2019

Searching for Flavored Gauge Bosons

Standard Model may allow an extended gauge sector with anomaly-free flavored gauge symmetries, such as $L_{i} - L_{j}$, $B_{i} - L_{j}$, and $B - 3L_{i}$, where $i,j=1,2,3$ are flavor indices. We investigate phenomenological implications of the new flavored gauge boson $Z^{\prime}$ in the above three classes of gauge symmetries. Focusing on the gauge boson mass above 5 GeV, we use the lepton universality test in the $Z$ and $τ/μ$ decays, LEP searches, LHC searches, neutrino trident production bound, and LHC $Z\rightarrow 4μ$ searches to put constraints on the $g^{\prime}-M_{Z^{\prime}}$ plane. When $L_1$ is involved, the LEP bounds on the $e^{-}e^{+} \rightarrow \ell^{-}\ell^{+}$ processes give the most stringent bounds, while the LHC bound becomes the strongest constraints in the large $M_{Z^{\prime}}$ region when $B_{i}$ is involved. The bound from $Z\rightarrow 4μ$ productions, which is applicable for $L_2$-involved scenarios, provides stringent bounds in the small $M_{Z^{\prime}}$ region. One exception is the $B-3L_2$ scenario, in which case only a small region is favored due to the lepton universality.

hep-ph↗

arXiv2019

Electron EDM and Muon anomalous magnetic moment in Two-Higgs-Doublet Models

The CP violating two-Higgs doublet model of type-X may enhance significantly the electric and magnetic moment of leptons through two-loop Barr-Zee diagrams. We analyze the general parameter space of the type-X 2HDM consistent with the muon $g-2$ and the electron EDM measurements to show how strongly the CP violating parameter is constrained in the region explaining the muon $ g-2$ anomaly.

hep-ph↗

arXiv2019

Constraining dark matter-neutrino interactions with IceCube-170922A

Astrophysical neutrinos travel long distances from their sources to the Earth traversing dark matter halos of clusters of galaxies and that of our own Milky Way. The interaction of neutrinos with dark matter may affect the flux of neutrinos. The recent multi-messenger observation of a high energy neutrino, IceCube-170922A, can give a robust upper bound $σ/M_{dm} \lesssim 5.1\times 10^{-23} {\rm cm}^2 /$GeV on the interaction between neutrino and dark matter at a neutrino energy of 290 TeV allowing 90\% suppression. Combining the constraints from CMB and LSS at different neutrino energies, we can constrain models of dark matter-neutrino interactions.

astro-ph.CO↗

arXiv2018

Thermal production of light Dirac right-handed sneutrino dark matter

We consider the production of right-handed (RH) sneutrino dark matter in a model of Dirac neutrino where neutrino Yukawa coupling constants are very small. Dark matter RH sneutrinos are produced by scatterings and decays of thermal particles in the early Universe without reaching thermal equilibrium due to the small Yukawa couplings. We show that not only decays of thermal particles but also the thermal scatterings can be a dominant source as well as non-thermal production in a scenario with light sneutrinos and charged sleptons while other supersymmetric particles are heavy. We also discuss the cosmological implications of this scenario.

hep-ph↗

arXiv2018

Non-thermal WIMP baryogenesis

We propose a WIMP baryogensis achieved by the annihilation of non-thermally produced WIMPs from decay of heavy particles, which can result in low reheating temerature. Dark matter (DM) can be produced non-thermally during a reheating period created by the decay of long-lived heavy particle, and subsequently re-annihilate to lighter particles even after the thermal freeze-out. The re-annihilation of DM provides the observed baryon asymmetry as well as the correct relic density of DM. We investigate how wahout effects can affect the generation of the baryon asymmetry and study a model suppressing them. In this scenario, we find that DM can be heavy enough and its annihilation cross section can also be larger than that adopted in the usual thermal WIMP baryogenesis.

hep-ph↗

arXiv2017

Magnetoresistance in copper at high frequency and high magnetic fields

In halo dark matter axion search experiments, cylindrical microwave cavities are typically employed to detect signals from the axion-photon conversion. To enhance the conversion power and reduce the noise level, cavities are placed in strong solenoid magnetic fields at sufficiently low temperatures. Exploring high mass regions in cavity-based axion search experiments requires high frequency microwave cavities and thus understanding cavity properties at high frequencies in extreme conditions is deemed necessary. We present a study of the magnetoresistance of copper using a cavity with a resonant frequency of 12.9 GHz at the liquid helium temperature in magnetic fields up to 15 T utilizing a second generation high temperature superconducting magnet. The observations are interpreted to be consistent with the anomalous skin effect and size effect. This is the first measurement of magnetoresistance at a high frequency (> 10 GHz) in high magnetic fields (> 10 T).

physics.ins-det↗

arXiv2016

Galactic center GeV gamma-ray excess from dark matter with gauged lepton numbers

The recently observed excess in gamma-ray signal near the Galactic center suggests that dark matter particles may annihilate into charged fermions that produce gamma-ray to be observed. In this paper, we consider a leptonic dark matter, which annihilates into the standard model leptons, $μ^+ μ^-$ and $τ^+ τ^-$, by the interaction of the gauged lepton number ${\rm U(1)}_{L_μ-L_τ}$ and fits the observed excess. Interestingly, the necessary annihilation cross section for the observed gamma-ray flux provides a good fit to the value for the relic abundance of dark matter. We identify the preferred parameter space of the model after taking the existing experimental constraints from the precision measurements including the muon $(g-2)$, tau decay, neutrino trident production, dark matter direct detection, LHC, and LEP experiments.

hep-ph↗