Stringent Limits Research Articles

Detection of X-Ray Polarized Emission and Accretion-disk Winds with IXPE and NICER in the Black Hole X-Ray Binary 4U 1630−47

We detect a high level of polarization in the X-ray emission of the black hole binary 4U 1630–47 in an observation with the Imaging X-ray Polarimetry Explorer. The 2–8 keV polarization degree is 8% at a position angle of 18°, with the polarization degree increasing significantly with energy, from ∼6% at ∼2 keV to ∼11% at ∼8 keV. The continuum emission in the spectrum of simultaneous observations with the Neutron Star Interior Composition Explorer (NICER) is well described with only a thermal disk spectrum, with stringent upper limits to any Comptonized emission from the corona. Together with the lack of significant variability in the Fourier power spectrum, this suggests that the source was in the high soft state at the time of these observations. The NICER spectrum reveals the presence of several absorption lines in the 6–9 keV band that we fit with two ionized absorbers, providing evidence of the presence of a strong disk wind, which supports the idea that the source was in the soft state. Previous measurements of X-ray polarization in other sources in harder states were associated with the corona or the jet in those systems. Given that the corona is significantly absent in this observation of 4U 1630–47, and that the jet in black hole binaries is quenched in the high soft state, we speculate that in this observation of 4U 1630–47, the polarization likely arises from the direct and reflected radiation of the accretion disk in this source.

Searching for Intragroup Light in Deep U-band Imaging of the COSMOS Field

We present the results of deep, ground based U-band imaging with the Large Binocular Telescope of the Cosmic Evolution Survey field as part of the near-UV imaging program, UVCANDELS. We utilize a seeing sorted stacking method along with night-to-night relative transparency corrections to create optimal depth and optimal resolution mosaics in the U-band, which are capable of reaching point source magnitudes of AB∼26.5 mag at 3σ. These ground-based mosaics bridge the wavelength gap between the Hubble Space Telescope WFC3 F275W and ACS F435W images and are necessary to understand galaxy assembly in the last 9–10 Gyr. We use the depth of these mosaics to search for the presence of U-band intragroup light (IGrL) beyond the local universe. Regardless of how groups are scaled and stacked, we do not detect any U-band IGrL to unprecedented U-band depths of ∼29.1–29.6 mag arcsec−2, which corresponds to an IGrL fraction of ≲1% of the total group light. This stringent upper limit suggests that IGrL does not contribute significantly to the Extragalactic Background Light at short wavelengths. Furthermore, the lack of UV IGrL observed in these stacks suggests that the atomic gas observed in the intragroup medium is likely not dense enough to trigger star formation on large scales. Future studies may detect IGrL by creating similar stacks at longer wavelengths or by pre-selecting groups which are older and/or more dynamically evolved similar to past IGrL observations of compact groups and loose groups with signs of gravitational interactions.

Implications for Primordial Black Holes from Cosmological Constraints on Scalar-induced Gravitational Waves

Sufficiently large scalar perturbations in the early universe can create overdense regions that collapse into primordial black holes (PBHs). This process is accompanied by the emission of scalar-induced gravitational waves that behave like an extra radiation component, thus contributing to the relativistic degrees of freedom (N eff). We show that the cosmological constraints on N eff can be used to pose stringent limits on PBHs created from this particular scenario as well as the relevant small-scale curvature perturbation (). We show that the combination of cosmic microwave background (CMB), baryon acoustic oscillation, and Big Bang nucleosynthesis data sets can exclude supermassive PBHs with peak mass M • ∈ [5 × 105, 5 × 1010] M ⊙ as the major component of dark matter, while the detailed constraints depend on the shape of the PBHs’ mass distribution. A future CMB mission such as CMB-S4 can greatly broaden this constraint window to M • ∈ [8 × 10−5, 5 × 1010] M ⊙, covering substellar masses. These limits on PBHs correspond to a tightened constraint on on scales of k ∈ [10, 1022] Mpc−1, much smaller than those probed by direct CMB and large-scale structure power spectra.

Search for heavy resonances and quantum black holes in eμ, eτ, and μτ final states in proton-proton collisions at sqrt{s} = 13 TeV

A search is reported for heavy resonances and quantum black holes decaying into eμ, eτ, and μτ final states in proton-proton collision data recorded by the CMS experiment at the CERN LHC during 2016–2018 at sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. The eμ, eτ, and μτ invariant mass spectra are reconstructed, and no evidence is found for physics beyond the standard model. Upper limits are set at 95% confidence level on the product of the cross section and branching fraction for lepton flavor violating signals. Three benchmark signals are studied: resonant τ sneutrino production in R parity violating supersymmetric models, heavy Z′ gauge bosons with lepton flavor violating decays, and nonresonant quantum black hole production in models with extra spatial dimensions. Resonant τ sneutrinos are excluded for masses up to 4.2TeV in the eμ channel, 3.7TeV in the eτ channel, and 3.6TeV in the μτ channel. A Z′ boson with lepton flavor violating couplings is excluded up to a mass of 5.0TeV in the eμ channel, up to 4.3Te V in the eτ channel, and up to 4.1TeV in the μτ channel. Quantum black holes in the benchmark model are excluded up to the threshold mass of 5.6TeV in the eμ channel, 5.2TeV in the eτ channel, and 5.0TeV in the μτ channel. In addition, model-independent limits are extracted to allow comparisons with other models for the same final states and similar event selection requirements. The results of these searches provide the most stringent limits available from collider experiments for heavy particles that undergo lepton flavor violating decays.

Performance Analysis of WHR Systems for Marine Applications Based on sCO2 Gas Turbine and ORC

Waste heat recovery (WHR) can represent a solution to improve the efficiency of ships’ propulsion, helping to exceed stringent greenhouse gas emission limits. This is particularly suitable in the case of propulsion based on gas turbines due to their medium-high temperature level of the exhaust gases. This study analyzes the performance of a hybrid energy grid, in which the heat is recovered by the exhaust gases of an aeroderivative gas turbine, a GE LM2500+, when the bottoming system is a supercritical CO2 gas turbine. Given the issues and peculiarities related to the onboard installation, where size and weight are fundamental concerns, six WHR schemes have been analyzed. They span from the simple cycle to partial preheated and regenerative, to a cascade layout in which an ORC system receives thermal power by the sCO2 GT. The influence of the seawater temperature on the performance of the hybrid energy system has been also considered. The energetic and exergetic performance comparison of the different schemes has been carried out by using the commercial software Thermoflex. The results showed that an increase in overall performance by up to 29% can be obtained and that the increase in seawater temperature can lead to a decrease in the overall performance.

The largest constructed treatment wetland project in the world: The story of the Everglades stormwater treatment areas

The Everglades Stormwater Treatment Areas (STAs) are the largest complex of constructed treatment wetlands in the world with a current treatment area of over 25,000 ha which will total approximately 25,900 ha by the end of 2025. They are designed to remove phosphorus from agricultural and urban stormwater runoff, and when there is available capacity, they can also receive and treat water from Lake Okeechobee. STA-treated water is then sent south to the Everglades to support restoration and maintenance of this unique ecosystem. The recommendation to build treatment wetlands began in 1988 with the Lake Okeechobee Technical Advisory Committee, and the mandate to operate and maintain the STAs continues today through operating permits and consent orders issued to the South Florida Water Management District (SFWMD) by the Florida Department of Environmental Protection. The permits and consent orders set forth a stringent phosphorus water quality-based effluent limit (WQBEL) that must be met starting in 2026. SFWMD has conducted extensive research on treatment wetland function and phosphorus removal efficiency to support construction, management, and operation of the STAs to achieve the WQBEL. The most recent work has been conducted under the Restoration Strategies Science Plan. This 11-year research program began in 2013 and will continue through 2024 to address six key scientific questions aimed at assisting the SFWMD in meeting the WQBEL for discharges from the Everglades STAs. What follows in this Special Edition are articles discussing the results and conclusions from several of these studies.

Ozonation Vs sequential solar driven processes as simultaneous tertiary and quaternary treatments of urban wastewater: A life cycle assessment comparison

Solar driven advanced oxidation processes (S-AOPs) have been successfully investigated in the last years as tertiary and quaternary treatment of urban wastewater for simultaneous inactivation of microorganisms and removal of contaminants of emerging concern (CECs), respectively. However, the lack of data about the comparison with consolidated technologies, including also the evaluation of their impact on the environment, has contributed to humper their application at full scale so far. In this study, the environmental impact of a new S-AOP, namely sequential treatment (ST) with sunlight/H2O2 and solar photo-Fenton (SPF) at neutral pH (using Ethylenediamine-N, N′-disuccinic acid (EDDS) as chelating agent) operated at pilot scale in a raceway pond reactor, was compared to a pilot scale ozonation (O3) treatment unit in terms of simultaneous bacteria inactivation and CECs removal, through a Life Cycle Assessment (LCA). Different urban wastewater treatment plant (UWWTP) sizes and scenarios (namely effluent disposal and reuse) were evaluated. While the reuse scenario resulted in a higher impact compared to the disposal scenario in the construction/deconstruction phase, due to the more stringent limits that resulted in longer treatment time and a higher consumption of raw materials, the positive impact on water resources saving compared to disposal makes the reuse scenario a more sustainable solution. Despite O3 disinfection by-products were taken into account, ST resulted in a higher toxicity to human health (0.27·10−9 DALYs Vs 2.11 10−9 DALYs, respectively) due to the higher residual concentration of the target CECs. However, it is noteworthy that both values are significantly lower than the acceptable DALYs value (≤10−6). Chemicals, energy, groundwater consumption and residual CECs can affect resources 1125 and 1874 times more for O3 treatment than for the ST, for disposal and reuse scenarios, respectively. The total impact of O3 on the human health was 13 and 19 times higher compared to ST, for disposal and reuse scenarios, respectively, due to the higher energy and chemical consumption. According to the LCA results, ST resulted in a better overall environmental performance compared to O3 and it is a more sustainable and attractive solution in particular for small UWWTPs.

Environmental life cycle assessment of treatment and management strategies for food waste and sewage sludge

A consequential life cycle assessment (LCA) was utilized to compare the environmental impacts of food waste and sewage sludge management strategies. The strategies included a novel two-phase anaerobic digestion (AD) system and alternatives including landfill, waste-to-energy, composting, anaerobic membrane bioreactor, and conventional AD (wet continuous stirred-tank reactor [CSTR]). The co-management of food waste with sewage sludge was also considered for the two-phase AD system and for a conventional AD reactor. A multidimensional LCA approach was taken, considering the five-midpoint impact categories of global warming, smog, human health particulate, acidification, and eutrophication estimated using the U.S. EPA Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts. Co-management of food waste and sewage sludge using the novel two-phase AD system was shown to maximize energy recovery and had a net global warming benefit while reducing other environmental impacts compared with the alternative management strategies. It had similar relative environmental advantages across all categories as conventional AD, with the advantage of a smaller physical footprint. However, both approaches featured net environmental burdens when the background electric grid intensity fell below 0.25 kg CO2-eq kWh−1, as could be expected in a decarbonized electric future. Upgrading the biogas produced from AD to renewable natural gas can displace the use of fossil natural gas for other non-electricity energy requirements that are difficult to decarbonize and may extend the time period of significant environmental benefits of utilizing AD for organic waste management. Treatment of the nutrient-rich supernatant generated by the novel two-phase AD system could be an obstacle for utilities with stringent nutrient discharge limits. Future research and full-scale implementation are needed to demonstrate the benefits of the two-phase AD system predicted through this analysis.

Test of Causal Nonlinear Quantum Mechanics by Ramsey Interferometry with a Trapped Ion.

Quantum mechanics requires the time evolution of the wave function to be linear. While this feature has been associated with the preservation of causality, a consistent causal nonlinear theory was recently developed. Interestingly, this theory is unavoidably sensitive to the full physical spread of the wave function, rendering existing experimental tests for nonlinearities inapplicable. Here, using well-controlled motional superpositions of a trapped ion, we set a stringent limit of 5.4×10^{-12} on the magnitude of the unitless scaling factor ε[over ˜]_{γ} for the predicted causal nonlinear perturbation.

A Search for OH 18 cm Emission from Intermediate-velocity Gas at High Galactic Latitudes

We present search results of 22 high-latitude (∣b∣ > 25°) sightlines for OH 18 cm emission using the 305 m radio telescope at the Arecibo Observatory. These sightlines appear in neutral hydrogen emission at intermediate velocities −90 ≤ V LSR ≤ −20 km s−1 and are predicted to have a sufficient molecular composition so as to be detectable in molecular emission. Such objects, known as intermediate-velocity molecular clouds (IVMCs), have historically been detected through 12CO emission. Recent studies indicate that IVMCs may be widespread in the galaxy and have important implications for models of the interstellar medium and star formation. However, we report nondetections of OH emission toward the 22 sightlines and provide stringent upper limits on the OH column density. Using available H i and A v data in combination with existing state-of-the-art PDR models, we estimate H2 column densities and find that they are more than an order of magnitude lower than the predicted values. We also find that the hydrogen volume density of these clouds is ≲25 cm−3. In addition, we discuss the known IVMCs with previous 12CO detections in the context of the PDR models. Our analysis of these clouds indicates that the structure of molecular material in IVMCs is morphologically clumpy. These results motivate the need for future sensitive, on-the-fly searches (rather than targeted searches) for CO emission from IVMCs with resolutions on the order of ∼1′. High angular resolution (∼1′) H i and A v data will also be helpful to better constrain the structure and composition of IVMCs.

Primordial black holes in interferometry

If there is a population of black holes distributed randomly in space, light rays passing in their vicinity will acquire random phases. In the “two-slit” model of an interferometer this can, for a high density of black holes, lead to a diffusion in the phase difference between the two arms of the interferometer and thus to a loss of coherence or “visibility” in interferometric observations. Hence the existence of “fringe contrast” or “visibility” in interferometric observations can be used to put a limit on the possible presence of black holes along the flight path. We give a formula for this effect and consider its application, particularly for observations in cosmology. Under the assumption that the dark matter consists of primordial black holes, we consider sources at high [Formula: see text], up to the CMB. While the strongest results are for the CMB as the most remote source, more nearby sources at high [Formula: see text] lead to similar effects. The effect increases with the baseline, and in the limiting case of the CMB we find that with earth-size baselines a nonzero “visibility” would limit the mass of possible primordial black holes, to approximately [Formula: see text]. Although such limits would not appear to be as strong as those obtained, say from microlensing, they involve a much different methodology and are dominated by very early times (see Table 1 ). Longer baselines lead to more stringent limits and in principle with extreme lengths, the method could possibly find positive evidence for primordial black holes. In this case, however, all other kinds of phase averaging would have to be constrained or eliminated.

Impact of prechamber design and air–fuel ratio on combustion and fuel consumption in a SI engine equipped with a passive TJI

The increasing concern about Greenhouse Gas (GHG) emissions led the European Union to introduce increasingly stringent limits to the CO2 from road vehicles, with an impact on the sales of passenger cars. Vehicles equipped with Spark-Ignition (SI) engines became more numerous than those equipped with Compression-Ignition (CI) engines, due to the expensive aftertreatment system needed to comply with the restrictive European emission standards. However, SI engines provide lower efficiency than CI engines, due to the low compression ratio and the operation with a stoichiometric air–fuel ratio. Lean combustion can be a solution to increase SI engines' efficiency. Nevertheless, extremely lean mixtures lead to an increase in Cycle-to-Cycle Variability (CCV).The prechamber ignition concept, also known as Turbulent Jet Ignition (TJI), is an attractive solution for lean combustion, without its drawbacks. There are two ways to implement this concept: active TJI and passive TJI. In active TJI, there is an additional fuel supply system inside the prechamber, while passive TJI operates without additional injection. Therefore, passive TJI offers advantages in terms of simplicity, easy packaging, and low cost.In this work, the effects of passive TJI on combustion and performance are investigated by simulation analyses. Particularly, a 1-D engine model was developed to simulate the TJI combustion and validated against the experimental data. Furthermore, model simulations were carried out to assess how the prechamber geometry, in terms of A/V ratio, affects the jet performance, main chamber combustion, and fuel consumption, for different λ values.The analysis was conducted in a medium-to-high speed and load operating condition, namely 4500 rpm and 13 bar of Indicated Mean Effective Pressure (IMEP), under both stoichiometric and lean mixture. Simulation results demonstrated that the best jet performance and the highest engine efficiency are obtained for medium-to-high values of prechamber volume and large diameters, both in stoichiometric and lean-burn conditions, defining a common optimum prechamber design regardless of the λ level.

Neutrino search from γ-ray bursts during the prompt and X-ray afterglow phases using 10 years of IceCube public data

Neutrino emission from γ-ray bursts (GRBs) has been sought for a long time, and stringent limits on the most accredited GRB emission models have been obtained from IceCube. Multiwavelength GRB observations of the last decades have improved our knowledge of the GRB emission parameters, such as the Lorentz factor and the luminosity, which can vary from one GRB to another by several orders of magnitude. Empirical correlations among such parameters have been identified during the prompt phase, with direct implications on GRB models. In this work, we use the PSLab open-access code, developed for IceCube data analyses, to search for individual neutrino emission from the prompt and afterglow phases of selected GRBs, and for stacking emission from the ensemble of such GRBs. For the afterglow phase, we focus on GRBs with X-ray flares and plateaus in particular. While past stacking searches assumed the same GRB fluence at Earth, we present a stacking scheme based on physically motivated GRB weights. Moreover, we conceive a new methodology for the prompt phase that uses the empirical correlations to infer the GRB luminosity and Lorentz factor, when redshift measurements are not available. We do not observe any significant neutrino excess. Hence, we set constraints on the GRB neutrino fluxes and on relevant GRB parameters, including the magnetic field in the jet. Notably, the baryon loading is found to be less than ten for typical GRB jets.

Constraints on the Binarity of the WN3/O3 Class of Wolf–Rayet Stars* * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

The WN3/O3 Wolf–Rayet (WR) stars were discovered as part of our survey for WRs in the Magellanic Clouds. The WN3/O3s show the emission lines of a high-excitation WN star and the absorption lines of a hot O-type star, but our prior work has shown that the absorption spectrum is intrinsic to the WR star. Their place in the evolution of massive stars remains unclear. Here we investigate the possibility that they are the products of binary evolution. Although these are not WN3+O3 V binaries, they could still harbor unseen companions. To address this possibility, we have conducted a multiyear radial velocity study of six of the nine known WN3/O3s. Our study finds no evidence of statistically significant radial velocity variations, and allows us to set stringent upper limits on the mass of any hypothetical companion star: for probable orbital inclinations, any companion with a period less than 100 days must have a mass <2M ⊙. For periods less than 10 days, any companion would have to have a mass <1M ⊙. We argue that scenarios where any such companion is a compact object are unlikely. The absorption lines indicate a normal projected rotational velocity, making it unlikely that these stars evolved with the aid of a companion star that has since merged. The modest rotation also suggests that these stars are not the result of homogenous evolution. Thus it is likely that these stars are a normal but short-lived stage in the evolution of massive stars.

The Sword and the Shield: The Directive on Adequate Minimum Wages in the EU

Abstract This article contextualises the adoption of the Directive 2022/2041 (EU) on adequate minimum wages. The analysis considers wage adequacy, collective bargaining coverage, and the combat of in-work poverty as the main pillars on which the directive is built. The aim is to show the potential and limits of the directive’s approach to wage regulation, in the light of the stringent limits on EU competence deriving from EU treaties.

Search for heavy neutral leptons using tau lepton decays at BaBaR

This article presents a model-independent search for an additional, mostly sterile, heavy neutral lepton (HNL), that is capable of mixing with the Standard Model τ neutrino with a mixing strength of |Uτ4|2, corresponding to the absolute square of the extended Pontecorvo-Maki-Nakagawa-Sakata matrix element. Data from the BABAR experiment, with a total integrated luminosity of 424 fb−1, are analyzed using a kinematic approach that makes no assumptions on the model behind the origins of the HNL, its lifetime or decay modes. No significant signal is found. Upper limits on |Uτ4|2 at the 95% confidence level, depend on the HNL mass hypothesis and vary from 2.31×10−2 to 5.04×10−6 (with all uncertainties considered), across the mass range 100<m4<1300 MeV/c2; the more stringent limits being placed at higher masses.3 MoreReceived 21 July 2022Accepted 13 September 2022DOI:https://doi.org/10.1103/PhysRevD.107.052009Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBaryogenesis & leptogenesisExtensions of fermion sectorNeutrino interactionsNeutrino oscillationsParticle dark matterParticles & Fields

Dark Matter Dilution Mechanism through the Lens of Large-Scale Structure.

Entropy production is a necessary ingredient for addressing the overpopulation of thermal relics. It is widely employed in particle physics models for explaining the origin of dark matter. A long-lived particle that decays to the known particles, while dominating the universe, plays the role of the dilutor. We point out the impact of its partial decay to dark matter on the primordial matter power spectrum. For the first time, we derive a stringent limit on the branching ratio of the dilutor to dark matter from large scale structure observation using the sloan digital sky survey data. This offers a novel tool for testing models with a dark matter dilution mechanism. We apply it to the left-right symmetric model and show that it firmly excludes a large portion of parameter space for right-handed neutrino warm dark matter.

Experimental study on the effect of loading and regeneration for an optimized management of the DPF

Limits imposed by worldwide emission regulations on particulate emission from diesel engine exhaust resulted in the employment of filters to cut down pollutants to acceptable values after they are produced into the cylinders. The management of the entire system engine + aftertreatment demonstrated to play a fundamental role in order to ensure compliance with the increasingly stringent emission limits.This paper is devoted to investigate in detail the role of the engine operative conditions on the filter behavior during the loading phase and to analyze how the regeneration strategy affects the filter efficiency and its pressure drop during the subsequent loading phase. These aspects retain a relevant role in the light of the new limits for particle emission from the tailpipe related not only to the number of particles but also to the cut point for PN measurement, which will be lowered from the current 23 nm–10 nm (PN10).Testing was performed on a Euro6 engine; the results highlight that the specific engine operation deeply affects the filter loading process, with differences in the pressure drop trend (both in the shape and in the values) and in the DPF efficiency. The filter efficiency, once the regeneration event is completed, depends on the regeneration strategy: when the clean filter condition is restored, a slow increase of filtration efficiency is observed; when the regeneration event does not restore the clean filter status, the subsequent loading process is characterized by better filtration properties. The obtained findings represent additional useful information to account for in the procedure devoted to define the optimal strategy to manage the engine: the regeneration events should be planned not only by considering the pressure drop across the filter but accounting also for the filtration performance once the regeneration is completed, thus to define the optimal strategy to manage the engine + aftertreatment able to comply with the new stringent limits on tailpipe particles and to reduce fuel consumption and oil dilution.

Search for Dark-Matter-Nucleon Interactions via Migdal Effect with DarkSide-50.

Dark matter elastic scattering off nuclei can result in the excitation and ionization of the recoiling atom through the so-called Migdal effect. The energy deposition from the ionization electron adds to the energy deposited by the recoiling nuclear system and allows for the detection of interactions of sub-GeV/c^{2} mass dark matter. We present new constraints for sub-GeV/c^{2} dark matter using the dual-phase liquid argon time projection chamber of the DarkSide-50 experiment with an exposure of (12 306±184) kg d. The analysis is based on the ionization signal alone and significantly enhances the sensitivity of DarkSide-50, enabling sensitivity to dark matter with masses down to 40 MeV/c^{2}. Furthermore, it sets the most stringent upper limit on the spin independent dark matter nucleon cross section for masses below 3.6 GeV/c^{2}.

New constraint on neutrino magnetic moment and neutrino millicharge from LUX-ZEPLIN dark matter search results

Elastic neutrino-electron scattering represents a powerful tool to investigate key neutrino properties. In view of the recent results released by the LUX-ZEPLIN collaboration, we provide a first determination of the limits achievable on the neutrino magnetic moment and neutrino millicharge, whose effect becomes non-negligible in some beyond the Standard Model theories. In this context, we evaluate and discuss the impact of different approximations to describe the neutrino interaction with atomic electrons. The new LUX-ZEPLIN data allows us to set a very competitive limit on the neutrino magnetic moment when compared to the other laboratory bounds, namely ${\ensuremath{\mu}}_{\ensuremath{\nu}}^{\mathrm{eff}}&lt;1.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}{\ensuremath{\mu}}_{\mathrm{B}}$ at 90% C.L., which improves by a factor of 2.5 the Borexino collaboration limit and represents the second best world limit after the recent XENONnT result. Moreover, exploiting the so-called equivalent photon approximation, we obtain the most stringent limit on the neutrino millicharge, namely $|{q}_{\ensuremath{\nu}}^{\mathrm{eff}}|&lt;1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}{e}_{0}$ at 90% C.L., which represents a great improvement with respect to the previous laboratory bounds.