Based on $e^{+}{e}^{-}$ annihilation data collected with the BESIII detector at center-of-mass energies from 4.600 to 4.699 GeV, corresponding to an integrated luminosity of $4.5{\mathrm{fb}}^{-1}$, we present the first measurement of the longitudinal polarization of $\mathrm{\Lambda }$ hyperon produced in the inclusive decay ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }X$, where $X$ denotes any allowed final states. The polarizations are determined to be ${\mathcal{P}}_{\mathrm{\Lambda }}=-0.393\pm 0.055_{\mathrm{stat}}\pm 0.020_{\mathrm{syst}}$ and ${\mathcal{P}}_{\overline{\mathrm{\Lambda }}}=0.288\pm 0.056_{\mathrm{stat}}\pm 0.017_{\mathrm{syst}}$. A search for $CP$ violation is performed using an asymmetry constructed from the $\mathrm{\Lambda }$ polarization and the $\mathrm{\Lambda }\to p{\pi }^{-}$ decay asymmetry parameter, and ${\mathcal{A}}_{CP}^{\mathrm{pol}}=0.15\pm 0.12_{\mathrm{stat}}\pm 0.03_{\mathrm{syst}}$ was obtained. Furthermore, an updated measurement of the absolute branching fraction is reported as $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }X)=(38.07\pm 0.38_{\mathrm{stat}}\pm 0.49_{\mathrm{syst}})\%$, representing a fourfold precision improvement over the previous BESIII measurement. A search for $CP$ violation in the decay rate yields ${\mathcal{A}}_{CP}^{\mathrm{dir}}=(1.5\pm {1.0}_{\mathrm{stat}}\pm {1.0}_{\mathrm{syst}})\%$. No evidence for $CP$ violation is observed in this inclusive charm baryon decay. The subscripts ‘stat’ and ‘syst’ denote statistical and systematic uncertainties, respectively.

The cytoplasm of eukaryotic cells is a complex fluid that harbors a variety of membrane-enveloped organelles with distinct spatial distributions and duties. Peroxisomes, for example, are vesicular entities with radii in the sub-micron range, dispersed all over the cytoplasm to provide oxidative reaction vessels across the cell. Here, we have tracked peroxisomes as biologically relevant tracer particles to explore the local structure of the cytoplasm. Focusing on the vast majority of (sub)diffusively moving peroxisomes, we show that these display a significant motion anisotropy even in the absence of intact actin filaments and microtubules or when the endoplasmic reticulum (ER) is disrupted. In untreated cells, the local preference direction aligns with a global axis that correlates with the cell’s long axis; disrupting the cytoskeleton or the ER progressively randomizes this alignment. Altogether, our data indicate that the cytoplasm features a weak nematic substructure rather than being an isotropic fluid.

We investigate the sensitivity of the Electron-Ion Collider (EIC) to invisible final states in coherent exclusive electroproduction. The characteristic signal is a forward proton with reduced energy and little additional detector activity. Using the excellent particle detection capabilities and kinematics reconstruction at the EIC, we argue that backgrounds can be strongly suppressed. While our analysis applies to various states, we specifically focus on vector and pseudoscalar particles: (i) neutral mesons [$P={\pi }^0,{\eta }^{(\prime )},V={\rho }^0,\omega ,\varphi$], whose invisible standard model decays are extremely suppressed, and (ii) gluon-coupled axionlike particles (ALPs) decaying invisibly to a dark sector. With the baseline detector and a conservative residual-background estimate, the EIC can improve the sensitivity to invisible $\eta$, ${\eta }^{\prime }$, $\omega$, and $\varphi$ decays by factors of about 4–40 and probe invisible ${\rho }^0$ decays for the first time. With further background reduction and optimized detector performance, the projected sensitivity may reach branching fractions as small as $4\times {10}^{-11}$. In addition, under the same conditions, the EIC would directly probe invisibly decaying ALPs with the couplings up to $f_a\sim {10}^5\mathrm{GeV}$ and masses in the range 0.1–2 GeV.

We present numerical calculations, and simulations performed on a Rydberg atom quantum simulator, of the adiabatic evolution of closed many-body quantum systems around a quantum phase transition. We demonstrate that the end-to-end transfer error, for a given process duration, can be suppressed by adopting smooth initial and final scheduling functions for the Hamiltonian. We consider a one-dimensional mixed-field Ising model, as well as a chain of Rydberg atoms, and compare numerical calculations and results on a commercially available quantum computer for the end-to-end transfer error with different schedule functions. We provide a new rigorous proof under minimal regularity assumptions of the known result that if the time dependent Hamiltonian is $n$ times differentiable with vanishing first to $n$ th order derivatives in the beginning and in the end, the infidelity with respect to the final adiabatic eigenstate scales as $1/T^{n+1}$ when evolving for time $T$.

Spin squeezing is both a fundamental witness of quantum entanglement and a key resource for quantum-enhanced metrology. While all-to-all interactions provide a paradigmatic route to generate spin squeezing, many programmable quantum simulators naturally realize finite-range interactions that induce coupling between collective spin dynamics and finite-momentum spin-wave modes, thereby degrading the achievable squeezing. Here we develop an optimization-based global-control strategy for enhancing spin squeezing in a two-dimensional XX model with dipolar interactions. By combining rotor-spin-wave theory with an extension to open boundary conditions, we enable efficient optimization of control protocols for large finite-range interacting systems. We show that a single collective transverse field generates squeezing beyond the conventional two-axis-twisting benchmark across system sizes accessible to numerical benchmarking. The optimized dynamics exploits squeezing-axis reorientation while suppressing spin-wave excitations, thereby stabilizing strong squeezing over extended times. We further implement the optimized protocol in a two-dimensional Rydberg-atom array and experimentally observe enhanced, long-lived spin squeezing in good agreement with theory.

We present a search of data from the first part of the fourth observing run of LIGO-Virgo-KAGRA for three kinds of dark matter—dilatons (spin-0), dark photons (spin-1), and tensor bosons (spin-2)—using three independent methods, each extended to search for all three candidates. Each dark matter candidate could interact with different standard-model particles in the instruments, causing unique differential strains on the interferometers. While we do not find any evidence for a signal, we place the most stringent upper limits to date on the couplings of each dark matter model to the interferometers. For scalars with masses between $[4\times {10}^{-14},1.5\times {10}^{-13}]\mathrm{eV}$ that couple to photons or electrons, our constraints on the scalar-to-electron or photon coupling improve upon those from the third observing run by 1 order of magnitude, with the tightest limit of $\sim {10}^{-20}{\mathrm{GeV}}^{-1}$ at a mass of $\sim 2\times {10}^{-13}\mathrm{eV}$. For vectors with masses between $[7\times {10}^{-13},8.47\times {10}^{-12}]\mathrm{eV}$ that couple to baryons, our constraints on the dark-photon or baryon coupling supersede those from MICROSCOPE and Eöt-Wash by 1 to 2 orders of magnitude, reaching a minimum of $\sim 5\times {10}^{-24}$ at a mass of $\sim {10}^{-12}\mathrm{eV}$. For tensors with masses of $[4\times {10}^{-14},8.47\times {10}^{-12}]\mathrm{eV}$ (the full mass range analyzed) that couple via a Yukawa interaction, our constraints, which are the first obtained from gravitational-wave interferometers, surpass those from fifth-force experiments by 4 to 5 orders of magnitude, achieving a limit as low as $\sim 8\times {10}^{-9}$ at $\sim 2\times {10}^{-13}\mathrm{eV}$. Our results show that each method has substantially different sensitivity to each dark matter candidate, highlighting the importance of a multimethod approach to search for new physics. Moreover, they demonstrate that gravitational-wave interferometers can simultaneously probe multiple ultralight dark matter models and place unprecedented constraints on tensor fields arising in a broad range of modified-gravity theories.

A search is presented for the production of two additional Higgs bosons from an off-shell Z boson, where both additional particles decay to $\tau$ lepton pairs. The search is performed with a data sample collected with the CMS detector from proton-proton collisions at the LHC at $\sqrt{s}=13\text{TeV}$, corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$. No deviation from the standard model background is observed. Exclusion limits are set on the type-X two-Higgs-doublet model alignment scenario. These results exclude previously unexplored regions of parameter space and provide constraints complementary to those from earlier searches.

A search for supersymmetric electroweakinos is performed using events with a low-momentum (soft) isolated track and large missing transverse momentum, targeting nearly mass-degenerate higgsinolike charginos and neutralinos. For mass splittings of 0.3–1 GeV, the chargino decays to the lightest neutralino and a low-momentum pion, which can produce a soft, potentially displaced track. A parametrized neural network separates signal from background using kinematic and impact parameter information. The analysis uses $138{\mathrm{fb}}^{-1}$ of proton-proton collision data at a center-of-mass energy of 13 TeV recorded with the CMS detector. No significant excess above the standard model expectation is observed. At 95% confidence level, the considered higgsino model is excluded for mass splittings in the range 0.28–1.15 GeV and for chargino masses up to 185 GeV, setting stringent constraints on natural supersymmetry scenarios.

Event-by-event transverse momentum correlations are sensitive to the equation of state of strongly interacting matter and are expected to exhibit anomalous fluctuations in the vicinity of the QCD critical point. We report the first measurements of two-particle transverse momentum ($p_{\mathrm{T}}$) correlations for mid-rapidity charged particles in fixed-target $\mathrm{Au}+\mathrm{Au}$ collisions at nucleon-nucleon center-of-mass energies $\sqrt{s_{\mathrm{NN}}}=3.0–7.7\mathrm{GeV}$, measured by the STAR experiment during the Beam Energy Scan (BES) Phase II program. The dependence of the scaled correlator on the number of participating nucleons ($N_{\mathrm{part}}$) is studied to test expectations from an independent-source scenario, where the correlations are expected to scale as $1/\sqrt{N_{\mathrm{part}}}$. We observe a clear breakdown of the expected scaling behavior in central collisions and identify a statistically significant nonmonotonic dependence of the $p_{\mathrm{T}}$ correlations on collision energy, with a significance of approximately $5\sigma$. In contrast, transport-model calculations and data from mid-central collisions yield significances of only $2\sigma$ and $1.4\sigma$, respectively—insufficient to support a claim of nonmonotonicity. These observations provide new constraints on the equation of state at high baryon density and may be sensitive to the presence of a QCD critical point.

In July 2025 the Large Hadron Collider collided ${}^{16}\mathrm{O}{}^{16}\mathrm{O}$ and ${}^{20}\mathrm{Ne}{}^{20}\mathrm{Ne}$ isotopes in a quest to understand the physics of ultrarelativistic light ion collisions. One of the key motivations for this run was to discover partonic energy loss in systems with a small quark-gluon plasma. In this Letter we combine a Baier-Dokshitzer-Mueller-Peigné-Schiff and Zakharov based model, a weighted path based energy loss prescription, and jewel together with two realistic geometries of the ${}^{16}\mathrm{O}$ and ${}^{20}\mathrm{Ne}$ isotopes. The different sizes of the ions affect the energy loss in characteristically different ways depending on the model.

We investigated the $\overline{K}$-nucleus interaction through the simultaneous measurement of the inclusive ${}^{12}\mathrm{C}(K^{-},p)$ and exclusive $K^{-}$ escape ${}^{12}\mathrm{C}(K^{-},p{K}_{\mathrm{esc}}^{-})$ reactions at $1.8\mathrm{GeV}/c$ at J-PARC. The present measurement explicitly focuses on the $K^{-}$ escape process for the first time, successfully accomplishing a direct experimental determination of the imaginary part of the $K^{-}$ optical potential. The differential cross section for the $K^{-}$ escape reaction was determined to be $436\pm 6(\mathrm{stat}.)\pm 44(\mathrm{syst}.)\mathrm{\mu }\mathrm{b}/\mathrm{sr}$. A simultaneous likelihood fit yielded real and imaginary potential strengths of $V_0=-{72}_{-5}^{+3}(\mathrm{stat}.{)}_{-8}^{+0}(\mathrm{syst}.)\mathrm{MeV}$ and $W_0=-{100}_{-1}^{+7}(\mathrm{stat}.{)}_{-16}^{+0}(\mathrm{syst}.)\mathrm{MeV}$ at the nuclear center, respectively. The derived $W_0$ is significantly stronger than that predicted by theoretical models based on one-nucleon processes, ssuggesting possible contributions from processes involving multiple nucleons.

We introduce the instantaneous eigenstate method to study the evolution of quantum states in nondispersive, homogeneous media with arbitrary time-varying permittivity and permeability. This method leverages the Heisenberg equation to bypass the Schrödinger equation, which leads to a complicated infinite set of coupled differential equations. Instead, the method allows the computation of the state evolution by solving only two coupled differential equations. Using this approach, we draw general conclusions about photon statistics in time-varying media. Our findings reveal that the maximum probability of generating a single photon pair from vacuum in such media is 25%, while Bell states can be created with a maximum probability of 84%. Additionally, we demonstrate that the spectral response of emitted photons depends on the temporal profiles of permittivity and permeability and provide a method to determine the required profiles for specified spectral profiles. These results provide deep insights into photon state manipulation in time-varying media. Furthermore, the instantaneous eigenstate method opens new opportunities to study state evolution in other systems where the Heisenberg equation offers a more tractable solution than the Schrdinger equation.

Bound states in the continuum (BICs) can confine photonic excitations in open systems without conventional cavities or band gaps, making them promising candidates for long-lived quantum storage and single-photon control. Their use as quantum resources is limited, however, by two basic difficulties: they are dark to incident photons, and they are not protected by a spectral gap from the surrounding continuum. We address these difficulties in a giant atom coupled to a one-dimensional waveguide by separating radiative access from BIC-preserving manipulation. Atomic-frequency modulation dynamically breaks and restores the destructive-interference condition, allowing a mode-matched single photon to be captured into, and released from, the BIC. Symmetric coupling modulation, in contrast, preserves the BIC condition throughout the evolution and continuously changes the atomic and photonic weights of the stored state. This BIC-preserving deformation realizes a gapless adiabatic control problem: for a regular embedded continuum, the intrinsic leakage probability is proportional to the ramp rate rather than quadratically suppressed as in gapped systems. The linear scaling originates from near-resonant scattering states at the BIC energy and is independent of microscopic dispersion except through the prefactor. These results establish a coherent capture-control-release protocol for a populated BIC and identify the fundamental error law for manipulating quantum states that remain embedded in a gapless environment.

Dispersion engineering via geometric confinement is essential to integrated nonlinear photonics. However, prevailing methodologies rely on semiempirical Sellmeier models that assume idealized material purity, neglecting the pronounced dispersion shifts induced by residual impurities like hydrogen-related bonds. Here, we demonstrate that these residual bonds fundamentally alter the dispersion landscape spanning from the ultraviolet (UV) to the midinfrared (MIR) spectra. Specifically, they introduce MIR vibrational absorption while simultaneously modifying UV electronic transitions, shifting the band gap and UV pole. We show that the spectral tension between these UV and MIR modifications dictates the group velocity dispersion from the visible to the near-infrared via the Kramers–Kronig causality. We experimentally validate this phenomenon through systematic characterization of broadband loss and dispersion in ultralow-loss silicon nitride photonic integrated circuits. By rigorously incorporating these effects, we bridge the gap between empirical fitting and predictive physical modeling. Our Letter resolves long-standing discrepancies in dispersion engineering, providing precision control essential for next-generation integrated photonics.