Recent High-precision Measurements Research Articles

Dielectric loss due to charged-defect acoustic phonon emission

The coherence times of state-of-the-art superconducting qubits are limited by bulk dielectric loss, yet the microscopic mechanism leading to this loss is unclear. Here, we propose that the experimentally observed loss can be attributed to the presence of charged defects that enable the absorption of electromagnetic radiation by the emission of acoustic phonons. Our explicit derivation of the absorption coefficient for this mechanism allows us to derive a loss tangent of 7.2 × 10−9 for Al2O3, in good agreement with recent high-precision measurements [Read et al., Phys. Rev. Appl. 19, 034064 (2023)]. We also find that for temperatures well below ∼0.2 K, the loss should be independent of temperature, which is also in agreement with observations. Our investigations show that the loss per defect depends mainly on properties of the host material, and a high-throughput search suggests that diamond, cubic BN, AlN, and SiC are optimal in this respect.

W boson mass in singlet-triplet scotogenic dark matter model

The recent high precision measurement of [Formula: see text] boson mass by CDF-II collaboration points to the contribution(s) of new physics beyond the Standard Model (SM). One of the minimalistic ways to account for the anomalous [Formula: see text] boson mass is by introducing a hyperchargeless real [Formula: see text] triplet scalar whose vacuum expectation value (VEV) explicitly contributes to the [Formula: see text] boson mass at the tree level while the [Formula: see text] boson mass remains the same. Such a triplet can be naturally embedded in a singlet-triplet scotogenic model for one-loop neutrino mass generated by dark sector particles running in the loop. We discuss the detailed phenomenology of the model, obtaining the parameter space consistent with the CDF-II [Formula: see text] boson mass measurements. The dark matter as well as the constraints comings from [Formula: see text], [Formula: see text], [Formula: see text] parameters are also analyzed.

CDF-II W-boson mass anomaly in the canonical Scotogenic neutrino–dark matter model

The CDF-II collaboration’s recent high-precision measurement of [Formula: see text]-boson mass indicates new physics contribution(s) beyond the Standard Model. We investigate the possibility of the well-known canonical Scotogenic model to explain the CDF-II measurement. The Scotogenic model is a popular scenario beyond the Standard Model that induces neutrino masses at the one-loop level and includes a viable dark matter candidate, either scalar or fermionic. For both scalar and fermionic dark matter possibilities, we simultaneously examine the constraints coming from (a) neutrino mass, oscillation, neutrinoless double beta decay and lepton flavor violation experiments, (b) from LEP and LHC, (c) from dark matter relic density and direct detection experiments, (d) from the oblique [Formula: see text] parameter values consistent with CDF-II [Formula: see text]-boson measurement. We demonstrate that the new CDF-II measurement rules out the feasible parameter space of the scalar dark matter in the high mass regions ([Formula: see text]), while still allowing the intermediate mass regions [Formula: see text]. We also showed that the fermionic dark matter candidate in the canonical Scotogenic model, in the range [Formula: see text], can simultaneously explain all the aforementioned issues. Furthermore, we investigated how the recent findings from ATLAS 2023 impact this study.

Extraction of spin-averaged rovibrational transition frequencies in HD+ for the determination of fundamental constants

We present a comprehensive analysis of all currently available high-accuracy frequency measurements of rotational and rovibrational transitions in the hydrogen molecular ion . Our analysis utilises the theoretically calculated hyperfine structure to extract the values of three spin-averaged transition frequencies through a global linear least-squares adjustment that takes into account theory-induced correlations between the different transitions. We subsequently use the three spin-averaged transition frequencies as input data in a second adjustment which employs precise theoretical expressions for the transition frequencies, written as a function of the proton, deuteron and electron relative atomic masses, the Rydberg constant, and the proton and deuteron charge radii. Our analysis shows that the data may significantly improve the value of the electron relative atomic mass and the proton-electron mass ratio, in particular if combined with recent high-precision measurements of particle atomic masses and mass ratios obtained from Penning traps.

Relativistic coupled-cluster analysis of the second-order effects on the hyperfine structure in Cs133

Using the single and double approximated relativistic coupled-cluster method, we calculate the first-order hyperfine structure constants for the $6{p}_{3/2}, 8{p}_{3/2}, 6{d}_{3/2}, 7{d}_{3/2}$, and $7{d}_{5/2}$ states in $^{133}\mathrm{Cs}$, and also evaluate the second-order magnetic dipole--magnetic dipole, magnetic dipole--electric quadrupole effects caused by the off-diagonal hyperfine interaction. With these calculations, we reanalyze some recent high-precision experimental measurements of the hyperfine splitting intervals of $^{133}\mathrm{Cs}$. We find that the second-order magnetic dipole--magnetic dipole effects are especially sizable at the order of kHz in the $B$ constant for the ${d}_{3/2,5/2}$ states. Our calculations can provide a reference for future higher precision experimental measurements.

Scrutinizing a hidden SM-like gauge model with corrections to oblique parameters

In view of the recent high precision measurement of the Standard Model W boson mass at the CDF II detector, we compute the contributions to the oblique parameters S, T and U coming from the two additional Higgs doublets (one inert and one hidden) as well as the hidden neutral dark gauge bosons and extra heavy fermions in the gauged two-Higgs-doublet model (G2HDM). While the effects from the hidden Higgs doublet and new heavy fermions are found to be minuscule, the hidden gauge sector SU(2)_H times U(1)_X with gauge coupling strength gtrsim 10^{-2} and gauge boson mass gtrsim 100 GeV can readily explain the W boson mass anomaly but is nevertheless excluded by the dilepton high-mass resonance searches at the Large Hadron Collider. On the other hand, the new global fits to the oblique parameters due to the new W boson mass measurement can give discernible impacts on the mass splitting and mixing angle for the inert Higgs doublet in G2HDM. We also study the impact on the signal strength of diphoton mode of the 125 GeV Higgs boson h rightarrow gamma gamma and the detectability of the yet to be observed process h rightarrow Z gamma at the High Luminosity Large Hadron Collider. Current constraints for the dark matter candidate W^prime including the dark matter relic density, dark matter direct detections and invisible Higgs decays are also taken into account in this study.

Exploring and exploiting various regimes within the jet shower

The last few years have seen community-wide excitement in the study of jet substructure derived from the inner workings of clustering algorithms. Such efforts have resulted in the design of new observables which are related to partonic processes from final state hadrons. Since jets are multi-scale objects, they necessarily encode information about both the perturbative (pQCD) parton shower and non-perturbative (npQCD) physics including hadronization. Recent high precision measurements of jet substructure in proton-proton (pp) collisions have pushed the theoretical community into extending their predictions to higher orders resulting in the observation of large theoretical uncertainties from the non-perturbative regime of the calculations. We emphasize the importance of understanding a jet shower from a multidimensional point of view and highlight a recent measurement focused on distinguishing the pQCD vs. npQCD regimes within a jet shower. We introduce and discuss the utility of the formation time evaluated at varying stages of the jet shower in pp collisions. Finally, we present a monte-carlo study of the formation time of charged particles within the jet to gain a handle on hadronization mechanisms including stringbreaking, and outline a path forward for such observables in heavy ion collisions.

The Curious Stellar System M22

AbstractIn the context of hierarchical galaxy assembly, globular clusters and dwarf galaxies are indispensable probes of the formation of our Milky Way. M22 is a stellar system with chemical abundances reminiscent of an accreted dwarf galaxy such as ω Centauri but disc-like kinematics suggesting a Milky Way origin. Curiously, M22 contains a population of stars enhanced in slow neutron-capture (s-)process elements due to pollution from low-mass AGB stars. Recently, the original in-situ population stars of the Milky Way disc has been revealed to be enhanced in s-process elements. This provides a tantalizing link between the in-situ Milky Way population and the formation of M22. This talk discussed how recent high-precision chemical abundance measurements suggest that M22 may be coeval with this in-situ component, and what the formation mechanisms of this s-process population can tell us about the chemical evolution of our Galaxy before the establishment of the disc.

W boson mass tension caused by its right-handed gauge coupling at high energies?

The CDF collaboration's recent high-precision measurement of the W mass is in 7.0σ disagreement with the Standard Model expectation. This tension will be relieved if the W boson has a non-trivial right-handed gauge coupling at high energies. At TeV scales, the SM gauge symmetric four-fermion interactions induce a right-handed gauge coupling, and SM fermions compose massive composite particles. We investigate the top-quark mass produced by spontaneous symmetry breaking and compute the W and Z boson propagators and decays. The right-handed coupling corrections to their masses and widths are consistent with experimental measurements. We discuss how SM gauge bosons and composite particles can restore parity-preserving gauge symmetries at TeV scales.

Correlating W-Boson Mass Shift with Muon g-2 in the Two Higgs Doublet Model.

We show an interesting correlation between the recent high precision measurement of the W-boson mass by the CDF Collaboration and the muon (g-2) anomaly in the context of the two Higgs doublet model. One-loop diagrams involving the exchange of neutral scalar bosons can explain the muon (g-2), which, however, requires significant mass splittings among members of the second Higgs doublet. These splittings also generate a positive shift in the mass of the W boson, consistent with the recent CDF measurement. The charged and neutral scalars of the model cannot be heavier than about 600GeV for a simultaneous explanation of the two anomalies. The entire parameter space of the model can be tested at the LHC by a combination of same sign dimuon signals in pp→(μ^{+}μ^{+}jj+E_{T}) and pp→(μ^{+}μ^{-}τ^{+}τ^{-}+X) signals.

Higgs physics confronts the MW anomaly

The recent high-precision measurement of the W mass by the CDF collaboration is in sharp tension with the Standard Model prediction as obtained by the electroweak fit. If confirmed, this finding can only be explained in terms of new physics effects. In this work, we point out a generic connection between the MW anomaly and Higgs physics observables such as h→γγ,Zγ and the ratio h→ZZ/WW. Moreover, we systematically classify new physics scenarios which can address the MW anomaly via a tree-level contribution to the Tˆ parameter. These include a real scalar triplet, a scalar quadruplet with the same hypercharge of the Higgs doublet, a Z′ boson, a vector triplet with unit hypercharge and a vector boson with the gauge quantum numbers of the Higgs doublet. These solutions to the MW anomaly are characterized by new physics states which are typically too heavy to be discovered in direct searches, but which might leave their imprints in Higgs physics.

Dibaryons: Molecular versus compact hexaquarks * *This work has been supported by DFG (CL 214/3-3). H. Cl. appreciates the support by the Munich Institute for Astro- and Particle Physics (MIAPP) which is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy – EXC-2094 - 390783311

Hexaquarks constitute a natural extension of complex quark systems, just as tetra- and pentaquarks do. To this end, the current status of in both experiment and theory is reviewed. Recent high-precision measurements in the nucleon-nucleon channel and analyses thereof have established as an indisputable resonance in the long-sought dibaryon channel. Important features of this state are its narrow width and deep binding relative to the threshold. Its decay branchings favor theoretical calculations predicting a compact hexaquark nature of this state. We review the current status of experimental and theoretical studies on as well as new physics aspects it may bring in future. In addition, we review the situation at the and thresholds, where evidence for a number of resonances of presumably molecular nature has been found – similar to the situation in charmed and beauty sectors. Finally, we briefly discuss the situation of dibaryon searches in the flavored quark sectors.

Anomalous thermodynamic properties of quantum critical superconductors

Recent high-precision measurements employing different experimental techniques have unveiled an anomalous peak in the doping dependence of the London penetration depth which is accompanied by anomalies in the heat capacity in iron-pnictide superconductors at the optimal composition associated with the hidden antiferromagnetic quantum critical point. We argue that finite temperature effects can be a cause of observed features. Specifically we show that quantum critical magnetic fluctuations under superconducting dome can give rise to a nodal-like temperature dependence of both specific heat and magnetic penetration depth in a fully gapped superconductor. In the presence of line nodes in the superconducting gap fluctuations can lead to the significant renormalization of the relative slope of $T$-linear penetration depth which is steepest at the quantum critical point. The results we obtain are general and can be applied beyond the model we use.

Addition of the line list for carbon disulfide to the HITRAN database: line positions, intensities, and half-widths of the 12C32S2, 32S12C34S, 32S12C33S, and 13C32S2 isotopologues

A new ro-vibrational line list for the 12C32S2, 32S12C34S, 32S12C33S, and 13C32S2 isotopologues of carbon disulfide, including line positions, intensities, and linewidths, has been produced as part of the HITRAN2020 project. The carbon disulfide line list covers the range from about 0 to 6470 cm−1 (1.55 µm). The calculations of the line positions and intensities were performed by applying the PGOPHER program using a large set of measured line positions available in the literature, including the most recent high-precision dual-comb laser spectroscopy measurements and transition dipole moments for each measured band. The bands which did not have available intensity measurements were scaled to the experimental cross-sections from the PNNL database. Semi-empirical models for rotational dependence of air- and self-broadened half widths are developed based on the available experimental data.A total of 94992 transitions corresponding to 423 cold and hot bands of the 12C32S2, 32S12C34S, 32S12C33S, and 13C32S2 isotopologues up to a maximum rotational angular momentum J=150 have been calculated. The CS2 line list has been generated in HITRAN format and is provided as supplementary material and will be a part of the next edition of the HITRAN database distributed through https://www.hitran.org. This list will be useful in the fields of atmospheric environmental chemistry, medical diagnostics and planetary atmospheres.

High-precision analysis of Feshbach resonances in a Mott insulator

We show that recent high-precision measurements of relative on-site interaction energies $\Delta U$ in a Mott insulator require a theoretical description beyond the standard Hubbard-model interpretation, when combined with an accurate coupled-channels calculation. In contrast to more sophisticated lattice models, which can be elaborate especially for parameter optimization searches, we introduce an easy to use effective description of $U$ valid over a wide range of interaction strengths modeling atomic pairs confined to single lattice sites. This concise model allows for a straightforward combination with a coupled-channels analysis. With this model we perform such a coupled-channels analysis of high-precision $^7$Li spectroscopic data on the on-site interaction energy $U$, which spans over four Feshbach resonances and provide an accurate and consistent determination of the associated resonance positions. Earlier experiments on three of the Feshbach resonances are consistent with this new analysis. Moreover, we verify our model with a more rigorous numerical treatment of the two atom system in an optical lattice.

Potassium isotope fractionation during chemical weathering of basalts

Non-traditional stable isotopes (e.g., Li, Mg, and Si) are increasingly used as tracers for studying Earth's surface processes. The isotopes of potassium (K), a highly soluble and mobile element during weathering, could be a promising new tracer for continental weathering; however, the K isotopic variations in weathering profile has not been directly studied due to previous analytical difficulties. Recent high-precision measurements revealed that K isotopes in global river waters are fractionated from the Bulk Silicate Earth (BSE) value, indicating they are influenced by chemical weathering of the crust. Isotopic fractionation during chemical weathering is one of several processes that could ultimately lead to ∼0.6‰ difference of δ41K between the BSE and modern seawater. In order to determine the direction and controlling factors of K isotopic fractionation during basalt weathering, especially under intense weathering conditions, we measured K isotopic compositions in two sets of bauxite developed on the Columbia River Basalts, together with fresh parental basalt and aeolian deposit samples using a recently developed high-precision method. Results show that K isotopic variations among fresh basalts and aeolian dust are limited, close to the BSE value. Extreme K depletion (>99%) and K isotopic fractionation (δ41K up to 0.5 ‰) are observed in bauxite drill cores due to intense chemical weathering. The top of the weathering profiles shows less depletion in K abundances and the δ41K values are closer to those of the fresh basalts and aeolian dusts, likely due to addition of aeolian dust at the tops of both profiles. The weathered products are generally depleted in heavy K isotopes, which is consistent with heavier K isotopic compositions observed in river water and seawater. The δ41K in bauxites displays a positive correlation with K2O contents as well as δ7Li, indicating the behaviors of K and Li isotopes are comparable during chemical weathering. This study shows that K concentrations and its isotopic compositions are sensitive tracers of chemical weathering and could be good weathering proxies over Earth's history.

Rayleigh scattering formalism for the tune-out wavelength: Application to the 2 3 S state of helium

SynopsisThe tune-out wavelength for an atom interacting with an incident laser beam is reformulated as a zero in the Rayleigh scattering cross section instead of the dynamic polarizability (or AC Stark shift). The two pictures are equivalent in lowest order, but not when higher-order retardation effects are taken into account. Detailed high-precision calculations in Hylleraas coordinates will be presented for the tune-out wavelength of helium at 413 nm near the 2 3 S – 33 P optical transition, including D-wave retardation corrections, and compared with recent high-precision measurements.

Determination of the Scalar and Vector Polarizabilities of the Cesium 6s^{2}S_{1/2}→7s^{2}S_{1/2} Transition and Implications for Atomic Parity Nonconservation.

Using recent high-precision measurements of electric dipole matrix elements of atomic cesium, we make an improved determination of the scalar (α) and vector (β) polarizabilities of the cesium 6s^{2}S_{1/2}→7s^{2}S_{1/2} transition calculated through a sum-over-states method. We report values of α=-268.82(30)a_{0}^{3} and β=27.139(42)a_{0}^{3} with the highest precision to date. We find a discrepancy between our value of β and the past preferred value, resulting in a significant shift in the value of the weak charge Q_{w} of the cesium nucleus. Future work to resolve the differences in the polarizability will be critical for interpretation of parity nonconservation measurements in cesium, which have implications for physics beyond the standard model.

QCD evolution of superfast quarks

Recent high-precision measurements of nuclear deep inelastic scattering at high x and moderate 6 < Q$^2$ < 9GeV$^2$ give a rare opportunity to reach the quark distributions in the {\it superfast} region, in which the momentum fraction of the nucleon carried by its constituent quark is larger than the total fraction of the nucleon at rest, x>1. We derive the leading-order QCD evolution equation for such quarks with the goal of relating the moderate-Q$^2$ data to the two earlier measurements of superfast quark distributions at large 60 < Q$^2$ < 200~GeV$^2$. Since the high-Q$^2$ measurements gave strongly contradictory estimates of the nuclear effects that generate superfast quarks, relating them to the high-precision, moderate-Q$^2$ data through QCD evolution allows us to clarify this longstanding issue. Our calculations indicate that the moderate-Q$^2$ data at $x\lesssim 1.05$ are in better agreement with the high-Q$^2$ data measured in (anti)neutrino-nuclear reactions which require substantial high-momentum nuclear effects in the generation of superfast quarks. Our prediction for the high-Q$^2$ and x>1.1 region is somewhat in the middle of the neutrino-nuclear and muon-nuclear scattering data.

On the small-scale clustering of quasars: constraints from the MassiveBlack II simulation

Abstract We examine recent high-precision measurements of small-scale quasar clustering (at z ∼ 0.5–2 on scales of ${\sim }25~\mathrm{kpc}\, h^{-1}$) from the SDSS in the context of the MassiveBlack II (MBII) cosmological hydrodynamic simulation and conditional luminosity function (CLF) modelling. At these high luminosities (g &amp;lt; 20.85 quasars), the MBII simulation volume ($100~\mathrm{cMpc}\, h^{-1}$ comoving boxsize) has only three quasar pairs at distances of 1–4 Mpc. The black hole masses for the pairs range between $M_{\rm bh}\sim 1{\, \rm and\, }3\times 10^{9}~\mathrm{M}_{\odot }\, h^{-1}$ and the quasar hosts are haloes of $M_{\rm h}\sim 1\hbox{--}3\times 10^{14}~\mathrm{M}_{\odot }\, h^{-1}$. Such pairs show signs of recent major mergers in the MBII simulation. By modelling the central and satellite AGN CLFs as lognormal and Schechter distributions, respectively (as seen in MBII AGNs), we arrive at CLF models which fit the simulation predictions and observed luminosity function and the small-scale clustering measured for the SDSS sample. The small-scale clustering of our mock quasars is well-explained by central--satellite quasar pairs that reside in $M_{\rm h}\gt 10^{14}~\mathrm{M}_{\odot }\, h^{-1}$ dark matter haloes. For these pairs, satellite quasar luminosity is similar to that of central quasars. Our CLF models imply a relatively steep increase in the maximum satellite luminosity, $L^*_{\mathrm{sat}}$, in haloes of $M_{\rm h}\gt 10^{14}~\mathrm{M}_{\odot }\, h^{-1}$ with associated larger values of $L^*_{\mathrm{sat}}$ at higher redshift. This leads to increase in the satellite fraction that manifests itself in an enhanced clustering signal at ≲1 Mpc h−1. For the ongoing eBOSS-CORE sample, we predict ∼200–500 quasar pairs at z ∼ 1.5 (with $M_{\rm h} \gtrsim 10^{13}~\mathrm{M}_{\odot }\, h^{-1}$ and $M_{\rm bh} \gtrsim 10^{8}~\mathrm{M}_{\odot }\, h^{-1}$) at ∼25 kpc scales. Such a sample would be ≳ 10 times larger than current pair samples.