We provide a study of the parameter space of the complex 2-Higgs doublet model (C2HDM), focusing on signs of large C P -violating couplings of the 125 GeV Higgs boson with the fermions. The study is performed utilizing machine learning (ML) techniques developed recently for parameter space exploration, including an evolutionary strategy algorithm and novelty reward. We give particular attention to the electron electric dipole moment (eEDM). We confirm that the recently found kite diagrams are crucial for the outcome of the analysis. Moreover, their use also mitigates the dependence of the results on the scale and scheme choice of the masses in the loop diagrams. We furthermore point out that, already at the current level of experimental precision, the Barr-Zee diagrams with charm quark loops must be taken into account. The combined use of kite diagrams and ML techniques allows for the resurrection of large fermion C P -odd couplings for type II and flipped C2HDM when the 125 GeV Higgs coincides with the second lightest neutral scalar. This arises due to cancellations, typically of the per-mil order, which, moreover, will still be possible for a foreseeable eEDM precision down to 10 − 33 e. cm. For these cases, the constraints on the C P -odd couplings arises from the precision LHC measurements.
We present a unified framework for the discussion of black hole thermodynamics of d -dimensional static black holes with spherical or compact hyperbolic horizon topology satisfying g t t g r r = − 1 in Schwarzschild gauge. To that end, we consider any such black hole as a solution to an integrable two-dimensional effective dilaton theory and thereby as a vacuum solution to a generalized notion of d -dimensional quasitopological gravity. We show that the generating function determining f ( r ) = − g t t in the integrated equation of motion provides the thermodynamic mass in a generalized first law with entropy computed as the Wald entropy. The framework presented here can be applied to singular and regular black holes with flat or anti–de Sitter asymptotics.
Rovibrational transitions in the hydrogen and antihydrogen molecular ions H 2 + and H ¯ 2 − offer the possibility of testing Lorentz and C P T symmetry to extremely high precision, in principle attaining O ( 10 − 17 ) . In this paper, the third in a series, we give a comprehensive derivation of the rovibrational spectrum of H 2 + and H ¯ 2 − in the standard model extension (SME), an effective quantum field theory incorporating Lorentz and C P T violation. New developments described here include a complete analysis of the molecular dynamics from first principles in terms of the spherical tensor representation of the SME couplings, the systematic extension of our previous results to the nonminimal SME, a full description of the quantum number dependence of the rovibrational energy levels in the spherical tensor formalism with both high and low background magnetic fields, and an extended discussion of sidereal and annual variations of transition frequencies arising from both rotations and Lorentz boosts. The resulting sensitivity of the rovibrational spectrum to an extended range of SME couplings, together with the ability to isolate their individual effects using the quantum number dependence of the transition frequencies, enhances the opportunities to detect Lorentz and C P T symmetry breaking through rovibrational spectroscopy of H 2 + and H ¯ 2 − .
In multibody decays of heavy mesons, conventional charge-parity ( C P ) asymmetry observables obtained by integrating over the full phase space are insensitive to the higher-order wave expansion contributions in the decay amplitude squared and consequently fail to retain information on interference effects among different resonances. To overcome this limitation, one can introduce a phase-space partitioning scheme based on the zeros of Legendre polynomials, supplemented by a sign-function weighting procedure. On such a basis, two observables are defined, namely, an asymmetry observable A ± asy , l and the corresponding C P asymmetry A CP asy , l . We further separate the observables into interference and noninterference parts and analyze their respective roles. As an application, the decay channel B ± → π ± π + π − are analyzed in the region near the ρ 0 ( 1450 ) resonance. Using the LHCb data, the results show that odd- l schemes are particularly effective in isolating interference contributions, while even- l schemes are more sensitive to noninterference terms. This new assignment scheme has the potential to be extended to other decay processes, thus enriching the available physical observables.
We extend the concept study of a storage ring-based millihertz gravitational wave (GW) detector of our previous work by estimating the terrestrial gravity noise (TGN) for a singly charged di-uranium ion circulating in a model storage ring with the circumference of the Large Hadron Collider (LHC). In our estimate, we consider solely seismic activity originating from Rayleigh waves, which are one of the most dominant source of TGN. Our first result is an analytical calculation of the time delay caused by the gravitational pull of a mass fluctuation in the vicinity of such a storage ring that a particle builds up compared to the unperturbed circulation time. Furthermore we simulate a Rayleigh wave field in a homogeneous half space scaled with the Peterson low noise model and compute the gravitational forces acting on the particle stored in the model ring. We relate our analytical considerations to the numerical results for the time delay by solving the geodesic equations for a storage ring and a conservative background potential and analytically derive the function of the time delay from the result. By performing a Fourier transform we compute the characteristic noise strain numerically and analytically. Based on the results we conclude that the terrestrial gravity noise in a storage ring-based gravitational wave detector is weak compared to the GW signature. However, we expect that seismic perturbations of the storage ring structure leading to a shaking of the experimental apparatus can cause a very large noise contribution. This noise, however, is mitigable in principle—in contrast to the TGN.
C P 4 3 HDM is a curious version of the three-Higgs-doublet model built upon a C P symmetry of order 4 (dubbed C P 4 ). When extended to fermions, C P 4 leads to unusually tight correlations between the scalar and Yukawa sectors and induces tree-level flavor changing neutral couplings. Still, viable scenarios exist, in which quark flavor changing signals remain within experimental limits. In this work, we extend C P 4 to the lepton sector and investigate whether the lepton-Higgs couplings and lepton flavor violating (LFV) signals can also be kept under control. We consider two classes of LFV processes: tree-level leptonic decays of the 125 GeV Higgs boson and the muon decays μ → e γ and μ → 3 e . For each C P 4 -invariant lepton Yukawa scenario, we perform a focused Yukawa sector scan that uses physical lepton properties as input and suppresses LFV effects. We identify a promising C P 4 3 HDM scenario compatible with the present-day experimental constraints, show that it can accommodate the recent CMS hint of a 146 GeV scalar decaying to e μ , and argue that this interpretation can be tested at future colliders through the search of comparably strong e e and μ μ signals.
Building on the earlier work by Araki and Tanii, Aschieri , and Buratti , we demonstrate that every model for self-dual nonlinear electrodynamics in four dimensions has a U ( 1 ) duality-invariant extension to 4 p > 4 dimensions, and construct new self-dual nonlinear theories for a gauge ( 2 p − 1 )-form. We present a family of models for self-dual nonlinear ( 2 p − 1 )-form electrodynamics in which the trace of the energy-momentum tensor determines the flow with respect to a duality-invariant deformation parameter. Finally, we propose the interesting problem of computing the so-called induced action in the case that self-dual ( 2 p − 1 )-form electrodynamics is coupled to dilaton and axion fields, and the compact duality group U ( 1 ) is enhanced to the noncompact group SL ( 2 , R ) .
We present the first computation of next-to-next-to-leading order (NNLO) pure QED and mixed QCD ⊗ QED corrections to unpolarized and polarized semi-inclusive deep-inelastic scattering (SIDIS). Building on our previous NNLO QCD results, these corrections are crucial for improving the theoretical precision. The coefficient functions are derived within the QCD factorization framework using dimensional regularization, with consistent renormalization and mass factorization. A detailed phenomenological analysis shows that the NNLO QED and QCD ⊗ QED terms enhance perturbative stability and reduce scale uncertainties. These results are essential for high-precision SIDIS predictions at future facilities such as the Electron-Ion Collider.
A new technique is developed to identify dielectrons ( e + e − ) with Lorentz boost γ L > 20 that produce one single merged cluster in the electromagnetic calorimeter of the CMS detector. The identification uses two multivariate models: one for the case where both electron tracks are reconstructed, and another where only one of the tracks is reconstructed. The efficiency is determined using proton-proton collision data collected at a center-of-mass energy of 13 TeV. Boosted J / ψ mesons decaying into e + e − pairs are used to estimate the efficiency of the model with two tracks, yielding an overall efficiency of 80%. The Z → μ + μ − γ events, where the photon converts into a collimated dielectron, are used for the model with a single track, yielding an efficiency of about 60%. A dedicated energy correction for dielectron candidates is also developed using B ± → J / ψ K ± → e + e − K ± data.
Future gravitational-wave detectors, such as the Einstein Telescope and Laser Interferometer Gravitational Wave Observatory (LIGO) Voyager, are planned to implement cryogenic technology. For the Kamioka gravitational wave detector, where cryogenics has already been adopted, issues related to the growth of an ice layer on mirror surfaces were reported. Further studies have confirmed the presence of nanometric layers in cryogenic experiments in which ice led to an increase in optical loss and to oscillations of the mirror reflectance. In this study, we investigate the mechanical loss of an ice layer grown on a silicon substrate. The results show that the total mechanical loss increases over time with the thickness of the ice layer, indicating that even a few nanometers of ice can impact the sensitivity of gravitational-wave detectors.
More than one dark sector particle transforming under the same symmetry provides one stable dark matter (DM) component, which undergoes coannihilation with the heavier particle(s) decaying to DM. Specific assumptions on the kinematics and on the coupling parameters may render the heavier component(s) stable and contribute as DM. The choices of the charges of the dark sector fields under transformation play a crucial role in the resultant phenomenology. In this paper, we systematically address the possibility of obtaining two scalar DM components under Z N symmetry. We consider both the possibilities of DM being weakly interacting massive particles (WIMPs) or pseudofeebly interacting massive particles (pFIMPs). We elaborate upon the Z 3 symmetric model, confronting the relic density-allowed parameter space with the recent most direct and indirect search bounds and prospects. We also highlight the possible distinction of the allowed parameter space in single component and two-component cases as well as between WIMP-WIMP and WIMP-pFIMP scenarios.
We present a quotient-space Bayesian formulation for DESI-era anomaly interpretation. Given a pattern-labeled catalog with map i↦(i), the induced posterior p(| D), sector inclusion probabilities P_α, co-activation probabilities P_αβ, and grouped Bayes factors B_α(D) are exact summaries over predeclared physical activation events. Pairwise comparisons such as versus remain ordinary Bayes-factor tests between specified families; the quotient construction addresses the coarser question of which physical sector carries posterior support when different sectors are represented by unequal numbers of catalog elements. We derive a sector-resolved DESI-CMB-SN likelihood specification for late-time background, early-time ruler, supernova calibration, perturbation, and gravitational-wave propagation sectors. The construction includes an Alcock-Paczynski/isotropic-scale BAO decomposition, a pure-ruler projection, analytic marginalization of low-rank supernova calibration modes, Fisher-normalized sector priors, inactive-sector leakage tests, log-evidence uncertainty propagation, and prior/sector-partition diagnostics. The result is a quantitative procedure for reporting model-comparison support at the level of physically interpretable sectors.
In this paper, we revisit the smoothness of the classical limit of inclusive observables in the formalism developed by Kosower, Maybee and O’Connell (KMOC). Building on the earlier work, we prove that the classical limit of three classes of inclusive observables, namely scattering angle, radiative field, and angular impulse is smooth and does not suffer from any so-called superclassical divergences at all orders in perturbation. We use scalar QED as a model. Our analysis goes some way in showing that KMOC formalism can be used to compute classical radiation by simply focusing on all the terms that scale as ℏ 0 , as all the terms that scale with inverse power of ℏ vanish. Through this analysis, we have successfully isolated the classes of terms that contribute to the classical limit, thereby allowing direct and more efficient computations of physical observables.
We explore the sensitivity of the Sudbury Neutrino Observatory (SNO) experiment to light dark matter particles χ with spin-dependent interactions with nucleons. We show that the pair-production of MeV scale dark matter is possible in heavy water (CANDU (Canada Deuterium Uranium)) reactors via D ( n , χ χ ¯ ) He 3 , and calculate the expected rate within the simplest models of χ -nucleon interactions. Owing to a sizable Q -value for this reaction, a large fraction of dark matter (DM) particles produced this way are above the threshold for deuteron disintegration, D ( χ , χ ) n p , which adds to the SNO neutral current signal. Evaluating the CANDU-to-SNO scheme for the production and detection of DM, we derive novel constraints for the χ -nucleon spin-dependent cross sections, showing that cross sections above σ χ p ∼ 10 − 33 cm 2 are generally excluded if m χ ≤ 1.5 MeV . An isospin-mirror reaction will occur in the Sun, and for the kinematically allowed region it excludes a portion of parameter space with cross sections on the order 10 − 37 cm 2 . We also evaluate the potential sensitivity of small “near” detectors placed in close proximity to a CANDU reactor to search for a coherent nuclear recoil, finding subdominant sensitivity.
We develop a semiclassical framework to determine scaling dimensions of neutral composite operators in scalar conformal field theories. For the critical Ising λ ϕ 4 theory in d = 4 − ε , we obtain the full spectrum of composite operators built out of n fields transforming according to the various Lorentz representations to next-to-leading order in the double-scaling limit n → ∞ and λ → 0 with λ n fixed. At any given order, the semiclassical expansion resums an infinite number of Feynman diagrams. Combining our results with existing perturbative computations further yields the complete five-loop scaling dimensions in the ε -expansion for the family of ϕ n operators. Finally, extrapolating the semiclassical results to three dimensions leads to a competitive alternative to existing methodologies.
A systematic way to constructing optimized interpolating operators for two-hadron systems is developed by incorporating interhadron spatial wave functions. The wave functions can be obtained from an iterative process with an appropriate initial guess. To implement these operators, a novel quark smearing technique utilizing Z 3 noise vectors is proposed, which allows for effectively incorporating interhadron spatial wave functions at the source without using all-to-all quark propagators. Proof-of-principle application to the Ω c c c Ω c c c system using physical-point lattice configurations with a large size L a ≃ 8.1 fm demonstrates that optimized operators outperform combinations of limited plane wave operators in the variational analysis, enabling clear identification of states around 2 m Ω c c c ≃ 9700 MeV with the energy gap as narrow as ∼ 5 MeV . A comparison on correlation functions, effective energies, and HAL QCD potentials between unoptimized operators and optimized operators is given, with a special emphasis on the effects from nearby elastic scattering states. Potential applicability of the optimized operator to various two-hadron systems and its relation to the variational method are also discussed.
