arXiv subjects

H. Yan

Publications and source records attributed to H. Yan.

At least 19 recordsLinked to original sources

arXiv2026

Exploring Exotic Spin-Dependent Interactions Beyond the Standard Model: Theoretical Foundations and Experimental Investigations

New interactions mediated by novel particles propose solutions to several important questions in modern physics. Axions serve as examples of such particles; they are lightweight and interact weakly with ordinary matter. This category of particles, including those similar to axions-termed Axion-Like Particles (ALPs)-arises from diverse theoretical frameworks, such as the Peccei-Quinn mechanism addressing the strong CP problem, string theory, and spontaneous supersymmetry breaking. Given their light mass and weak coupling, ALPs are also possible candidates for cold dark matter. Introducing these new interactions mediated by novel particles not only tackles several challenges in modern physics but also raises a crucial question: Are there undiscovered interactions beyond the Standard Model? Many of the interactions predicted by these theories are spin-dependent, which is the primary focus of this review. In this review, we first outline the theoretical foundations for investigating exotic spin-dependent interactions, highlighting their importance in various models beyond the Standard Model. We examine the potential roles of new lightweight particles in mediating these interactions, which may enhance our understanding of dark matter. Relevant formulas derived from theoretical models are included to support experimental investigations. Following this theoretical framework, we conduct a detailed review of recent experimental efforts to detect these exotic interactions. A systematic review of current constraints on these interactions is presented, along with an assessment of various detection approaches.

hep-ph↗

arXiv2026

A Cosmic Archipelago of lensed metal-poor galaxies at $z\sim6$

The Cosmic Archipelago is an ensemble of galaxies, strongly lensed by the cluster MACSJ0416, showing extreme physical properties at $z\sim6.14$. We combine JWST/NIRCam with deep VLT/X-Shooter and JWST/NIRSpec IFU to perform a joint spectrophotometric analysis from the far ultraviolet to red optical rest-frame. We focus on CA4, a UV-faint ($M_{UV}=-17.7$), compact ($r_e=81\pm11$ pc) galaxy at $z=6.1446$, magnified by a factor $\mu=3.73$. CA4 is a young, low-mass ($M_\star =4.3\times10^6$ M$\odot$), star-forming (${\rm SFR}=0.46$ M$\odot$/yr), and metal-poor ($Z\sim0.02$ Z$\odot$) galaxy, and an efficient producer of ionizing photons ($\log(\xi_{ion}/{\rm erg^{-1} Hz})\sim25.5$). Its properties place CA4 at the poorly explored interface between massive stellar clusters and dwarf galaxies during the epoch of reionization. Moreover, CA4 shows large Ly$\alpha$ ($f_{esc}^{\rm Ly\alpha}\sim43\%$) and Lyman-continuum ($f_{esc}\sim47\%$) escape fractions, consistent with its small Ly$\alpha$ velocity offset ($\Delta v\sim100$ km/s) and extremely blue UV-continuum slope ($\beta=-3.10$). These characteristics suggest that such UV-faint, metal-poor galaxies may contribute significantly to cosmic reionization. We also confirm five additional systems at the redshift of the Cosmic Archipelago, magnified by factors up to 12.5. They are all young (mass-weighted ages $<11$ Myr) and metal-poor ($Z<0.05$ Z$_\odot$), spanning a wide range of stellar masses and SFRs. Given the large number of these bursty star-forming galaxies in a small cosmic volume, we estimate that the currently known members of the Cosmic Archipelago result in a significant overdensity at $z\sim6$ ($\Delta z\sim0.08$), with $\delta_{gal}=12.3^{+6.6}_{-4.6}$. These results highlight the Cosmic Archipelago as an unprecedented laboratory for studying the earliest groups of low-mass, low-metallicity galaxies during the epoch of reionization.

astro-ph.GA↗

arXiv2026

A high-performance quantum memory for quantum interconnects

Single photons are the flying qubits of choice for distributing entanglement in a quantum internet. Quantum memories embedded in quantum repeaters are crucial to overcome transmission loss and enhance the rate of quantum communication. A multimode memory can further boost the channel capacity. However, benchmarking and building a practical quantum memory that simultaneously optimizes multiple performance metrics poses two key challenges. Here, we introduce quantum interconnect rate to comprehensively quantify quantum memories, and further demonstrate a high-performance quantum memory that simultaneously integrates three essential criteria at once: large multimode capacity, high efficiency, and high fidelity. Operating on 11-dimensional spatial modes, our memory achieves a uniform efficiency exceeding 80% and qubit storage fidelities above 99%, enabling the efficient storage of high-dimensional qudits. Based on these capabilities, we estimate a distribution of 3.56 bits of quantum information over a 1000-km repeater link in one minute, highlighting a practical pathway toward scalable quantum interconnects and quantum networks.

quant-ph↗

arXiv2025

Light-induced Frequency Shift and Relaxation of Ground-State 3He via Metastability-Exchange Collisions

Metastability-exchange collisions (MECs) lie at the heart of metastability-exchange optical pumping (MEOP) in 3He, enabling the transfer of polarization from the metastable state to the ground state, as well as the optical detection of nuclear magnetic resonance. Leveraging MECs, optically pumped 3He nuclear magnetometers have been developed since the earliest demonstrations of MEOP. However, it also induces an additional frequency shift and relaxation of the nuclear spin precession, thereby limiting the sensitivity of the magnetometer. In this work, we identify a new source of frequency shift and relaxation in the 3He nuclear spin, arising from the light shift. This effect arises from an MEC-mediated interaction between light and the nucleon spin. We develop a theoretical model to describe this light-induced effect and highlight its significance in low magnetic fields. This effect is experimentally demonstrated, and its dependence on various parameters -- including magnetic field strength, light intensity, and wavelength -- is investigated. Our result provides a better understanding of the frequency shift and relaxation of 3He spin precession under MEOP conditions. Moreover, our experiment reveals an MEC-mediated coupling between the 3He nuclear spin and light, which may indicate the feasibility of MEC-assisted optical manipulation of 3He nuclear spins at the quantum level, as proposed in several theoretical schemes.

quant-ph↗

arXiv2025

New Limits on Exotic Muon Interactions Mediated by Axion-Like Particles

The precise measurement of the muon anomalous magnetic moment $a_\mu$ provides a sensitive probe of exotic interactions between muons mediated by light beyond the Standard Model (BSM) bosons. Recent advances in both experiment and theory have largely reconciled the long-standing discrepancy in $a_\mu$. Using the latest result, $\Delta a_\mu = a^{\rm exp}_\mu - a^{\rm SM}_\mu = (38 \pm 63) \times 10^{-11}$, we derive updated limits on light BSM boson-mediated exotic muon interactions.

hep-ph↗

arXiv2025

Breaking Kirchhoff's Law in Nonlinear Thermal Emission

Thermal radiation is strictly governed by Kirchhoff s law to reach thermal equilibrium. The violation of Kirchhoff s law decouples nonreciprocally the equity between absorptivity and emissivity, enabling exotic thermal engineering applications. However, achieving broadband nonreciprocal thermal emissivity and absorptivity remains a challenge. Here we experimentally demonstrate nonreciprocal and broadband thermal radiation by breaking Kirchhoff s law through nonlinear optical frequency conversion in a scattering medium. Thermal blackbody radiation is upconverted through sum-frequency generation with an intense infrared pump, while broadband conversion is enabled by the critical random quasi-phase-matching condition in the nonlinear nanocrystals. Moreover, a temporal transient measurement also indicates a possible active radiation cooling through such nonlinear thermal radiation. These results may pave a new way for nonlinear and active thermal management in critical applications like radiation cooling, energy harvesting, and infrared camouflage.

physics.optics↗

arXiv2025

New Limits on Ultralight Axionlike Dark Matter from Reanalyzed Data

New limits on the axion-nucleon coupling over the axion mass region $10^{-24} \leq m_a \leq 5 \times 10^{-21}$ eV are derived by reanalyzing data from laboratory measurements on Lorentz and $CPT$ violation. These results establish the first laboratory constraints on the axion-nucleon coupling for axion masses below $10^{-22}$ eV. For $10^{-22} \leq m_a \leq 5 \times 10^{-21}$ eV, the results improve upon previous laboratory limits by more than 3 orders of magnitude, exceeding for the first time the astrophysical limits from supernova SN1987A cooling. For the axion mass range of interest corresponding to ultralow frequencies, the crucial local phase of the axion field is considered. Furthermore, the obtained limits are nearly equivalent to those projected for a recently proposed experiment employing high-intensity neutron beams at the European Spallation Source. For an alternative type of axion-nucleon interaction, the quadratic wind coupling, the constraints exceed the current best results by approximately 2 orders of magnitude.

hep-ph↗

arXiv2024

Anatomy of a z=6 Lyman-{\alpha} emitter down to parsec scales: extreme UV slopes, metal-poor regions and possibly leaking star clusters

We present a detailed JWST/NIRSpec and NIRCam analysis of a gravitationally-lensed galaxy ($\rm \mu=17-21$) at redshift 6.14 magnified by the Hubble Frontier Field galaxy cluster MACS J0416. The target galaxy is overall a typical compact and UV-faint ($\rm M_{UV}=-17.8$) Lyman-$\alpha$ emitter, yet the large magnification allows the detailed characterization of structures on sub-galactic scales (down to a few parsecs). Prominent optical $\rm H\alpha$, $\rm H\beta$ and [OIII]$\lambda\lambda4959,5007$ lines are spatially resolved with the high spectral resolution grating (G395H, R~2700), with large equivalent widths, EW($\rm H\beta$+[OIII])$\gtrsim1000$ \AA, and elevated ionising photon production efficiencies $\rm log(\xi_{ion}/erg^{-1}Hz)=25.2-25.7$. NIRCam deep imaging reveals the presence of compact rest-UV bright regions along with individual star clusters of $\rm R_{eff}=3-8~pc$ in size and $\rm M\sim2\cdot10^5-5\cdot10^{6}~M_\odot$ in mass. These clusters are characterised by steep UV slopes, $\rm\beta_{UV}\lesssim-2.5$, which in some cases are associated with a dearth of line emission, indicating possible leaking of the ionizing radiation, as also supported by a Lyman-$\rm \alpha$ emission peaking at $\rm \sim100~km~s^{-1}$ from the systemic redshift. While the entire system is characterised by low-metallicity, $\sim0.1~Z_\odot$, the NIRSpec-IFU map also reveals the presence of a low-luminosity, metal-poor region with $\rm Z\lesssim2\%~Z_\odot$, barely detected in NIRCam imaging; this region is displaced by $\rm >200~pc$ from one of the brightest structures of the system in UV, and would have been too faint to detect if not for the large magnification of the system.

astro-ph.GA↗

arXiv2024

Extreme Ionizing Properties of Metal-Poor, Muv ~ -12 Star Complex in the first Gyr

We report the serendipitous discovery of a faint (M_UV > -12.2), low-metallicity (Z ~ 0.02 Zsun), ionizing source (dubbed T2c) with a spectroscopic redshift of z=6.146. T2c is part of a larger structure amplified by the Hubble Frontier Field galaxy cluster MACSJ0416, and was observed with JWST/NIRSpec IFU. Stacking the short-wavelength NIRCam data reveals no stellar continuum detection down to a magnitude limit of m_UV ~ 31.0 (3 sigma). However, prominent Hb, [OIII]4959,5007, and Ha emissions are detected, with equivalent widths exceeding 200A, 800A, and 1300A (3 sigma), respectively. The corresponding intrinsic (magnification-corrected x23 +/- 3) ultraviolet and optical rest-frame magnitudes exceed 34.4 and 33.9 (corresponding to M_uv and M_opt fainter than -12.2 and -12.8, at lambda_rest ~ 2000A and ~5000A, respectively), suggesting a stellar mass lower than a few 10^4 Msun under an instantaneous burst scenario. The inferred ionizing photon production efficiency (xi_ion) is high, xi_ion >~ 26.08(25.86) 3(5)sigma, assuming no dust attenuation and no Lyman continuum leakage, indicating the presence of massive stars despite the low mass of the object. The very poor sampling of the initial mass function at such low mass star-forming complex suggests that the formation of very massive stars might be favored in very low metallicity environments. T2c is surrounded by Balmer and weak oxygen emission on a spatial scale of a few hundred parsecs after correcting for lensing effects. This system resembles an HII region potentially powered by currently undetected, extremely efficient, low-metallicity star complexes or clusters. We propose that massive O-type stars populate this low-mass and metallicity high-redshift satellites, likely caught in an early and short formation phase, contributing to the ionization of the surrounding medium.

astro-ph.GA↗

arXiv2024

JWST's PEARLS: resolved study of the stellar and dust components in starburst galaxies at cosmic noon

Dusty star-forming galaxies (DSFGs) contribute significantly to the stellar buildup at cosmic noon. Major mergers and gas accretion are often invoked to explain DSFGs' prodigious star-formation rates (SFRs) and large stellar masses. We conducted a spatially-resolved morphological analysis of the rest-frame UV/NIR emission in three DSFGs at z~2.5. Initially discovered as CO emitters by NOEMA observations of a bright Herschel source, we observed them with the JWST/NIRCam as part of the PEARLS program. The NIRCam data reveal the galaxies' stellar populations and dust distributions on scales of 250 pc. Spatial variations in stellar mass, SFR, and dust extinction are determined in resolved maps obtained through pixel-based SED fitting. The CO emitters are massive, dusty starburst galaxies with SFRs=340-2500 Msun/yr, positioning them among the most active SFGs at 2<z<3. They belong to the ~1.5% of the entire JWST population with extremely red colors. Their morphologies are disk like, with radii of 2.0-4.4 kpc, and exhibit substructures such as clumps and spiral arms. The galaxies have dust extinctions up to Av=5-7 mag extending over several kpc with asymmetric distributions that include off-center regions resembling bent spiral arms and clumps. Their NIR dust-attenuation curve deviates from standard laws, possibly implying different dust-star geometries or dust grain properties than commonly assumed in starburst galaxies. The proximity of galaxies with consistent redshifts, strong color gradients, an overall disturbed appearance, asymmetric dust obscuration, and widespread star formation collectively favor interactions (minor mergers and flybys) as the mechanism driving the CO galaxies' exceptional SFRs. The galaxies' large masses and rich environment hint at membership in two proto-structures, as initially inferred from their association with a Planck-selected high-z source.

astro-ph.GA↗

arXiv2024

JWST Photometric Time-Delay and Magnification Measurements for the Triply-Imaged Type Ia "Supernova H0pe" at z = 1.78

Supernova (SN) H0pe is a gravitationally lensed, triply-imaged, Type Ia SN (SN Ia) discovered in James Webb Space Telescope imaging of the PLCK G165.7+67.0 cluster of galaxies. Well-observed multiply-imaged SNe provide a rare opportunity to constrain the Hubble constant ($H_0$), by measuring the relative time delay between the images and modeling the foreground mass distribution. SN H0pe is located at $z=1.783$, and is the first SN Ia with sufficient light curve sampling and long enough time delays for an $H_0$ inference. Here we present photometric time-delay measurements and SN properties of SN H0pe. Using JWST/NIRCam photometry we measure time delays of $\Delta t_{ab}=-116.6^{+10.8}_{-9.3}$ and $\Delta t_{cb}=-48.6^{+3.6}_{-4.0}$ observer-frame days relative to the last image to arrive (image 2b; all uncertainties are $1\sigma$), which corresponds to a $\sim5.6\%$ uncertainty contribution for $H_0$ assuming $70 \rm{km s^{-1} Mpc^{-1}}$. We also constrain the absolute magnification of each image to $\mu_{a}=4.3^{+1.6}_{-1.8}$, $\mu_{b}=7.6^{+3.6}_{-2.6}$, $\mu_{c}=6.4^{+1.6}_{-1.5}$ by comparing the observed peak near-IR magnitude of SN H0pe to the non-lensed population of SNe Ia.

astro-ph.CO↗

arXiv2024

TREASUREHUNT: Transients and Variability Discovered with HST in the JWST North Ecliptic Pole Time Domain Field

The JWST North Ecliptic Pole (NEP) Time Domain Field (TDF) is a $>$14 arcmin diameter field optimized for multi-wavelength time-domain science with JWST. It has been observed across the electromagnetic spectrum both from the ground and from space, including with the Hubble Space Telescope (HST). As part of HST observations over 3 cycles (the "TREASUREHUNT" program), deep images were obtained with ACS/WFC in F435W and F606W that cover almost the entire JWST NEP TDF. Many of the individual pointings of these programs partially overlap, allowing an initial assessment of the potential of this field for time-domain science with HST and JWST. The cumulative area of overlapping pointings is ~88 arcmin$^2$, with time intervals between individual epochs that range between 1 day and 4$+$ years. To a depth of $m_{AB}$ $\simeq$ 29.5 mag (F606W), we present the discovery of 12 transients and 190 variable candidates. For the variable candidates, we demonstrate that Gaussian statistics are applicable, and estimate that ~80 are false positives. The majority of the transients will be supernovae, although at least two are likely quasars. Most variable candidates are AGN, where we find 0.42% of the general $z$ $<$ 6 field galaxy population to vary at the $~3\sigma$ level. Based on a 5-year timeframe, this translates into a random supernova areal density of up to ~0.07 transients per arcmin$^2$ (~245 deg$^{-2}$) per epoch, and a variable AGN areal density of ~1.25 variables per arcmin$^2$ (~4500 deg$^{-2}$) to these depths.

astro-ph.GA↗

arXiv2023

PEARLS: JWST counterparts of micro-Jy radio sources in the Time Domain Field

The Time Domain Field (TDF) near the North Ecliptic Pole in JWST's continuous-viewing zone will become a premier "blank field" for extragalactic science. JWST/NIRCam data in a 16 arcmin$^2$ portion of the TDF identify 4.4 $\mu$m counterparts for 62 of 63 3 GHz sources with S(3 GHz) > 5 {\mu}Jy. The one unidentified radio source may be a lobe of a nearby Seyfert galaxy, or it may be an infrared-faint radio source. The bulk properties of the radio-host galaxies are consistent with those found by previous work: redshifts range from 0.14 to 4.4 with a median redshift of 1.33. The radio emission arises primarily from star formation in $\sim 2/3$ of the sample and from an active galactic nucleus in $\sim 1/3$, but just over half the sample shows evidence for an AGN either in the spectral energy distribution or by radio excess. All but three counterparts are brighter than magnitude 23 AB at 4.4 $\mu$m, and the exquisite resolution of JWST identifies correct counterparts for sources for which observations with lower angular resolution would mis-identify a nearby bright source as the counterpart when the correct one is faint and red. Up to 11% of counterparts might have been unidentified or misidentified absent NIRCam observations.

astro-ph.GA↗

arXiv2023

Missed prediction of the neutron halo in $^{37}$Mg

Halo phenomena have long been an important frontier in both experimental and theoretical nuclear physics. $^{37}$Mg was identified as a halo nucleus in 2014 and remains the heaviest nuclear halo system to date. While the halo phenomenon in $^{37}$Mg was not predicted before the discovery, its description has been still challenging afterwards. In this Letter, we report a microscopic and self-consistent description of the neutron halo in $^{37}$Mg using the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) that was developed in 2010. The experimental neutron separation energies and empirical matter radii of neutron-rich magnesium isotopes as well as the deformed $p$-wave halo characteristics of $^{37}$Mg are well reproduced without any free parameters. In particular, the orbital occupied by the halo neutron in $^{37}$Mg, exhibiting $p$-wave components comparable to those suggested in experiments, remains consistent across various employed density functionals including PC-F1, PC-PK1, NL3*, and PK1. The DRHBc theory investigated only even-even magnesium isotopes in previous works and for that reason missed predicting $^{37}$Mg as a halo nucleus before 2014. Although the core and the halo of $^{37}$Mg are both prolate, higher-order shape decoupling on the hexadecapole and hexacontatetrapole levels is predicted.

nucl-th↗

arXiv2023

Spectroscopy of the Supernova H0pe Host Galaxy at Redshift 1.78

Supernova (SN) H0pe was discovered as a new transient in James Webb Space Telescope (JWST) NIRCam images of the galaxy cluster PLCK G165.7+67.0 taken as part of the "Prime Extragalactic Areas for Reionization and Lensing Science" (PEARLS) JWST GTO program (# 1176) on 2023 March 30 (AstroNote 2023-96; Frye et al. 2023). The transient is a compact source associated with a background galaxy that is stretched and triply-imaged by the cluster's strong gravitational lensing. This paper reports spectra in the 950-1370 nm observer frame of two of the galaxy's images obtained with Large Binocular Telescope (LBT) Utility Camera in the Infrared (LUCI) in longslit mode two weeks after the \JWST\ observations. The individual average spectra show the [OII] doublet and the Balmer and 4000 Angstrom breaks at redshift z=1.783+/-0.002. The CIGALE best-fit model of the spectral energy distribution indicates that SN H0pe's host galaxy is massive (Mstar~6x10^10 Msun after correcting for a magnification factor ~7) with a predominant intermediate age (~2 Gyr) stellar population, moderate extinction, and a magnification-corrected star formation rate ~13 Msun/yr, consistent with being below the main sequence of star formation. These properties suggest that H0pe might be a type Ia SN. Additional observations of SN H0pe and its host recently carried out with JWST (JWST-DD-4446; PI: B. Frye) will be able to both determine the SN classification and confirm its association with the galaxy analyzed in this work.

astro-ph.GA↗

arXiv2023

Exotic spin-dependent interactions through unparticle exchange

The potential discovery of unparticles could have far-reaching implications for particle physics and cosmology. For over a decade, high-energy physicists have extensively studied the effects of unparticles. In this study, we derive six types of nonrelativistic potentials between fermions induced by unparticle exchange in coordinate space. We consider all possible combinations of scalar, pseudo-scalar, vector, and axial-vector couplings to explore the full range of possibilities. Previous studies have only examined scalar-scalar (SS), pseudoscalar-pseudoscalar (PP), vector-vector (VV), and axial-axial-vector (AA) type interactions, which are all parity even. We propose SP and VA interactions to extend our understanding of unparticle physics, noting that parity conservation is not always guaranteed in modern physics. We explore the possibilities of detecting unparticles through the long-range interactions they may mediate with ordinary matter. Dedicated experiments using precision measurement methods can be employed to search for such interactions. We discuss the properties of these potentials and estimate constraints on several coupling constants based on existing experimental data. Our findings indicate that the coupling between vector unparticles and fermions is constrained by up to 9 orders of magnitude more tightly than the previous limits.

hep-ph↗

arXiv2023

Collapse of the $N=28$ shell closure in the newly discovered $^{39}$Na and the development of deformed halos towards the neutron dripline

Halos and changes of nuclear magicities have been extensively investigated in exotic nuclei during past decades. The newly discovered $^{39}$Na with the neutron number $N=28$ provides a new platform to explore such novel phenomena near the neutron dripline of the sodium isotopic chain. We study the shell property and the possible halo structure in $^{39}$Na within the deformed relativistic Hartree-Bogoliubov theory in continuum. It is found that the lowering of $2p$ orbitals in the spherical limit results in the collapse of the $N=28$ shell closure in $^{39}$Na, and a well deformed ground state is established. The pairing correlations and the mixing of $pf$ components driven by deformation lead to the occupation of weakly bound or continuum $p$-wave neutron orbitals. An oblate halo is therefore formed around the prolate core in $^{39,41}$Na, making $^{39}$Na a single nucleus with the coexistence of several exotic structures, including the quenched $N=28$ shell closure, Borromean structure, deformed halo, and shape decoupling. The microscopic mechanisms behind the shape decoupling phenomenon and the development of halos towards dripline are revealed.

nucl-th↗

arXiv2023

Tunable Magnetic Properties in Sr$_2$FeReO$_6$ Double-Perovskite

Double-perovskite oxides have attracted recent attention due to their attractive functionalities and application potential. In this paper, we demonstrate the effect of dual controls, i.e., the deposition pressure of oxygen (P$_O2$) and lattice mismatch ($\epsilon$), on tuning magnetic properties in epitaxial double-perovskite Sr$_2$FeReO$_6$ films. In a nearly-lattice-matched Sr$_2$FeReO$_6$/SrTiO$_3$ film, the ferrimagnetic-to-paramagnetic phase transition occurs when P$_O2$ is reduced to 30 mTorr, probably due to the formation of Re$^{4+}$ ions that replace the stoichiometric Re$^{5+}$ to cause disorders of $B$-site ions. On the other hand, a large compressive strain or tensile strain shifts this critical P$_O2$ to below 1 mTorr or above 40 mTorr, respectively. The observations could be attributed to the modulation of $B$-site ordering by epitaxial strain through affecting elemental valence. Our results provide a feasible way to expand the functional tunability of magnetic double-perovskite oxides that hold great promise for spintronic devices.

cond-mat.str-el↗