Wilson Coefficient Research Articles

Measurement and correlation of coumarin solubility in aqueous solution of acidic deep eutectic solvents based on choline chloride

The solubility of coumarin in three aqueous solutions of acidic deep eutectic solvents (DESs) based on choline chloride (ChCl) as hydrogen bond acceptor (HBA) with some carboxilic acids (propionic acid, lactic acid and acetic acid) as hydrogen bond donors (HBD) have been measured using the shake flask method at T = (298.15 to 313.15) K. According to obtained results, the solubility of coumarin increases with increasing the weight fraction of ChCl/propionic acid more than 100-fold. The experimental solubility data were correlated by electrolyte Nonrandom Two-Liquid (e-NRTL),Wilson and UNIQUAC activity coefficient models. Then, the dissolution thermodynamic properties, enthalpy, Gibbs free energy and entropy were calculated based on Gibbs and van't Hoff equations to investigate the solvation behavior of coumarin in the aqueous DES solutions.

Sensitivity of EDM experiments in paramagnetic atoms and molecules to hadronic CP violation

Experiments searching for the electric dipole moment (EDM) of the electron $d_e$ utilise atomic/molecular states with one or more uncompensated electron spins, and these paramagnetic systems have recently achieved remarkable sensitivity to $d_e$. If the source of $CP$ violation resides entirely in the hadronic sector, the two-photon exchange processes between electrons and the nucleus induce $CP$-odd semileptonic interactions, parametrised by the Wilson coefficient $C_{SP}$, and provide the dominant source of EDMs in paramagnetic systems instead of $d_e$. We evaluate the $C_{SP}$ coefficients induced by the leading hadronic sources of $CP$ violation, namely nucleon EDMs and $CP$-odd pion-nucleon couplings, by calculating the nucleon-number-enhanced $CP$-odd nuclear scalar polarisability, employing chiral perturbation theory at the nucleon level and the Fermi-gas model for the nucleus. This allows us to translate the ACME EDM limits from paramagnetic ThO into novel independent constraints on the QCD theta term $|\bar \theta| < 3 \times 10^{-8}$, proton EDM $|d_p| < 2 \times 10^{-23}\,e\,{\rm cm}$, isoscalar $CP$-odd pion-nucleon coupling $|\bar g^{(1)}_{\pi NN}| < 4 \times 10^{-10}$, and colour EDMs of quarks $|\tilde d_u - \tilde d_d| < 2 \times 10^{-24}\,{\rm cm}$. We note that further experimental progress with EDM experiments in paramagnetic systems may allow them to rival the sensitivity of EDM experiments with neutrons and diamagnetic atoms to these quantities.

Vapor–liquid equilibrium at 94 kPa and surface tension at 298.15 K for hexane + ethanol + cyclopentyl methyl ether mixture

Vapor-liquid equilibrium (VLE) and surface tension (ST) for the hexane + ethanol + cyclopentyl methyl ether mixture have been measured and modeled. VLE determinations are carried out in a dynamic Guillespie type cell at the isobaric condition of 94 kPa, whereas the dependence of ST on concentration is measured in a maximum differential bubble pressure tensiometer at atmospheric pressure and 298.15 K.The thermodynamical consistent VLE data exhibit positive deviation from ideal behavior without ternary azeotropy and are well correlated by Redlich–Kister expansion and predicted by the binary nonrandom two-liquid, Wilson and universal quasichemical activity coefficient models. The ST data exhibit negative deviation from the linear behavior and are smoothed using the Myers-Scott expansion, showing no ternary aneotropic behavior.The experimental data of VLE and ST are accurately characterized by applying the square gradient theory to the Peng–Robinson Stryjek–Vera equation of state (EoS) appropriately extended to mixtures employing the modified Huron–Vidal mixing rule. This theoretical framework shows that experimental VLE and ST data can be fully predicted by only using binary contributions within a global average absolute deviation of 1.25% for VLE and 6.1% for ST. The theoretical approach also provides a route to explore the concentration distribution of species in the interfacial region, where it is possible to conclude that hexane exhibits both adsorption and desorption; ethanol displays strong positive adsorption whereas CPME does not exhibit surface activity.

General neutrino interactions with sterile neutrinos in light of coherent neutrino-nucleus scattering and meson invisible decays

In this work we study the current bounds from the CEνNS process and meson invisible decays on generic neutrino interactions with sterile neutrinos in effective field theories. The interactions between quarks and left-handed SM neutrinos and/or right-handed neutrinos are first described by the low-energy effective field theory (LNEFT) between the electroweak scale and the chiral symmetry breaking scale. We complete the independent operator basis for the LNEFT up to dimension-6 by including both the lepton-number-conserving (LNC) and lepton-number-violating (LNV) operators involving right-handed neutrinos. We translate the bounds on the LNEFT Wilson coefficients from the COHERENT observation and calculate the branching fractions of light meson invisible decays. The bounds on LNEFT are then mapped onto the SM effective field theory with sterile neutrinos (SMNEFT) to constrain new physics above the electroweak scale. We find that the meson invisible decays can provide the only sensitive probe for τ neutrino flavor component and s quark component in the quark-neutrino interactions involving two (one) active neutrinos and for the effective operators without any active neutrino fields. The CEνNS process places the most stringent bound on all other Wilson coefficients. By assuming one dominant Wilson coefficient at a time in SMNEFT and negligible sterile neutrino mass, the most stringent limits on the new physics scale are 2.7–10 TeV from corresponding dipole operator in LNEFT and 0.5–1.5 TeV from neutrino-quark operator in LNEFT.

Model-independent bounds on new physics effects in non-leptonic tree-level decays of B-mesons

We present a considerably improved analysis of model-independent bounds on new physics effects in non-leptonic tree-level decays of B-mesons. Our main finding is that contributions of about ±0.1 to the Wilson coefficient of the colour-singlet operator Q2 of the effective weak Hamiltonian and contributions in the range of ±0.5 (both for real and imaginary part) to Q1 can currently not be excluded at the 90% C.L. . Effects of such a size can modify the direct experimental extraction of the CKM angle γ by up to 10° and they could lead to an enhancement of the decay rate difference ∆Γd of up to a factor of 5 over its SM value — a size that could explain the D0 dimuon asymmetry. Future more precise measurements of the semi-leptonic asymmetries {a}_{sl}^q and the lifetime ratio τ (Bs)/τ (Bd) will allow to shrink the bounds on tree-level new physics effects considerably. Due to significant improvements in the precision of the non-perturbative input we update all SM predictions for the mixing obervables in the course of this analysis, obtaining: ∆Ms = (18.77 ± 0.86) ps−1, ∆Md = (0.543 ± 0.029) ps−1, ∆Γs = (9.1 ± 1.3) · 10−2 ps−1, ∆Γd = (2.6 ± 0.4) · 10−3 ps−1, {a}_{sl}^q = (2.06 ± 0.18) · 10−5 and {a}_{sl}^d = (−4.73 ± 0.42) · 10−4.

Predictions for B_s rightarrow {bar{K}}^* ell ,ell in non-universal Z' models

The lepton flavor universality violating (LFUV) measurements R_K and R_{K^*} in B meson decays can be accounted for in non-universal Z' models. We constrain the couplings of these Z' models by performing a global fit to correlated b rightarrow s ell ell and b rightarrow d ell ell processes, and calculate their possible implications for B_s rightarrow {bar{K}}^*ell ell observables. For real new physics (NP) couplings, the 1sigma favored parameters allow the corresponding LFUV ratio R_{K^*}^{(s)} in B_s rightarrow {bar{K}}^*ell ell to range between 0.8 and 1.2 at low q^2. Complex NP couplings improve the best fit only marginally, however they allow a significant enhancement of the branching ratio, while increasing the range of R_{K^*}^{(s)} at low q^2 to 0.8–1.8. We find that NP could cause zero-crossing in the forward–backward asymmetry A_{FB} to shift towards lower q^2 values, and enhancement in the magnitude of integrated A_{FB}. The CP asymmetry A_{CP} may be suppressed and even change sign. The simultaneous measurements of integrated R_{K^*}^{(s)} and A_{CP} values to 0.1 and 1% respectively, would help in constraining the effective NP Wilson coefficient C_9 in b rightarrow d mu mu interactions.

Experimental analysis of vapour-liquid phase equilibria for binary systems of diethyl carbonate with methyl, ethyl, isopropyl, n-butyl and isoamyl acetates at 95 kPa

Experimental analysis of vapour-liquid phase equilibrium (VLE) for five binary pairs of diethyl carbonate (DEC) with methyl acetate, ethyl acetate, isopropyl acetate, n-butyl acetate and isoamyl acetate was carried out in this study. VLE data were generated experimentally at local atmospheric pressure of 95 kPa in a glass dynamic recirculation still. Reliability of data was checked with the thermodynamic consistency tests by Van Ness, infinite dilution, pure component and mean absolute deviation test. Experimental data was found to be thermodynamically consistent with all tests and data was regressed with Wilson, NRTL and UNIQUAC activity coefficient models to determine binary interaction parameters. Binary pair of DEC with n-butyl acetate has shown azeotropic behaviour with minimum boiling azeotrope and a close-boiling behaviour through-out the composition range. No azeotropic behaviour was observed for the rest of the binary pairs.

On renormalons of static QCD potential at u = 1/2 and 3/2

We investigate the u=1/2left[mathcal{O}left({Lambda}_{mathrm{QCD}}right)right] and u=3/2left[mathcal{O}left({Lambda}_{mathrm{QCD}}^3right)right] renormalons in the static QCD potential in position space and momentum space using the OPE of the potential-NRQCD effective field theory. This is an old problem and we provide a formal formulation to analyze it. In particular we present detailed examinations of the u = 3/2 renormalons. We clarify how the u = 3/2 renormalon is suppressed in the momentum-space potential in relation with the Wilson coefficient VA(r). We also point out that it is not straightforward to subtract the IR renormalon and IR divergences simultaneously in the multipole expansion. Numerical analyses are given, which clarify the current status of our knowledge on the perturbative series. The analysis gives a positive reasoning to the method for subtracting renormalons used in recent αs(MZ ) determination from the QCD potential.

Experimental Vapor–Liquid Phase Equilibrium Analysis of the Binary Systems of Aniline with Xylene Isomers at 93.13 kPa

In the present work, vapor–liquid phase equilibrium (VLE) analyses of binary systems of aniline with four isomers of xylene, comprising p-xylene, m-xylene, o-xylene, and ethylbenzene, are reported at 93.13 kPa. The experimental VLE data was generated in a dynamic circulating vapor–liquid, and the data was found thermodynamically consistent using the Van Ness point-to-point consistency test. The experimental VLE data was regressed with the Wilson, NRTL, and UNIQUAC activity coefficient models to obtain the binary interaction parameters. No azeotropic or close-boiling behavior was observed in any of the binary pair, and these pairs were found suitable for separation through a conventional distillation method.

Probing flavor nonuniversal theories through Higgs physics at the LHC and future colliders

We explored the possibility that Higgs coupling to new physics violates flavor universality. In particular, we parameterize such models with dimension-six effective operators which modify the coupling between the first generation quarks, Higgs boson, and $Z$ boson. Through the use of boosted Higgsstrahlung events at both the HL-LHC and potential future hadron colliders, as well as existing ATLAS data for background estimates, we projected constraints on the scale of new physics as a function of the Wilson coefficient. The high energy $Zh$ process will provide unique information about these class of operators, and the sensitivity is competitive with the LEP electroweak precision measurements. We include different scenarios of the overall systematic uncertainties and the PDF uncertainties when presenting the projected sensitivities. We also discuss the constraints from FCNCs to these flavor-violating models and the complementarity of the exotic Higgs decay to the $Zh$ process.

Experimental isobaric vapour-liquid equilibrium data for binary systems of {sec-butyl acetate (SBAC) + acetamide} and {sec-butyl alcohol (SBA) + acetamide} and the ternary system of (SBAC + SBA + acetamide) at 101.3 kPa

Isobaric vapour - liquid equilibrium (VLE) data for the binary systems of sec-butyl acetate (SBAC) + acetamide and sec-butyl alcohol (SBA) + acetamide and the ternary system of SBAC + SBA + acetamide were measured at 101.3 kPa using a modified Othmer still. The thermodynamic consistency tests for the experimental data were checked by Van Ness point test and Wisniak’s L-W method. The experimental VLE data of the binary systems were correlated with NRTL, Wilson and UNIQUAC activity coefficient models. The results indicate that the binary and ternary VLE data predicted by the three models agree well with the experimental data. And the ‘pseudo-azeotropic’ phenomenon of sec-butyl acetate + sec-butyl alcohol mixture can be eliminated by acetamide.

What can black holes teach us about the IR and UV?

Combining insights from both the effective field theory of quantum gravity and black hole thermodynamics, we derive two novel consistency relations to be satisfied by any quantum theory of gravity. First, we show that a particular combination of the number of massless (light) fields in the theory must take integer values. Second, we show that, once the massless spectrum is fixed, the Wilson coefficient of the Kretschmann scalar in the low-energy effective theory is fully determined by the logarithm of a single natural number.

The three-loop single mass polarized pure singlet operator matrix element

We calculate the massive polarized three-loop pure singlet operator matrix element AQq(3),PS in the single mass case in the Larin scheme. This operator matrix element contributes to the massive polarized three-loop Wilson coefficient HQq(3),PS in deep-inelastic scattering and constitutes a three-loop transition matrix element in the variable flavor number scheme. We provide analytic results in Mellin N and in x space and study the behaviour of this operator matrix element in the region of small and large values of the Bjorken variable x.

O new physics, where art thou? A global search in the top sector

We provide a comprehensive global analysis of Run II top measurements at the LHC in terms of dimension-6 operators. A distinctive feature of the top sector as compared to the Higgs-electroweak sector is the large number of four-quark operators. We discuss in detail how they can be tested and how quadratic terms lead to a stable limit on each individual Wilson coefficient. Predictions for all observables are computed at NLO in QCD. Our SFitter analysis framework features a detailed error treatment, including correlations between uncertainties.

New physics in brightarrow sell ell transitions at one loop

We investigate new-physics contributions to brightarrow s ell ell transitions in the context of an effective field theory extension of the Standard Model, including operator mixing at one loop. We identify the few scenarios where a single Wilson coefficient, C/Lambda ^2 sim 1/mathrm{TeV}^2, induces a substantial shift in the lepton flavour universality ratios R_K and R_{K^*} at one loop, while evading Z-pole precision tests, collider bounds, and other flavour constraints. Novel fits to the present data are achieved by a left-handed current operator with quark-flavour indices (2, 2) or (3, 3). Interestingly, the running of the Standard Model Yukawa matrices gives the dominant effect for these scenarios. We match the favoured effective-theory scenarios to minimal, single-mediator models, which are subject to additional stringent constraints. Notably, we recognise three viable instances of a leptoquark with one coupling to fermions only. If the anomalies were confirmed, it appears that one-loop explanations have good prospects of being directly tested at the LHC.

Investigation of effects of new physics in Λb→Λcτν¯τ decay

Recent experimental results of ${\cal R}(D^{(*)})$ deviate from the standard model (SM) by $3.1\sigma$, suggesting a new physics (NP) that affects the $b\to c \tau \bar\nu_\tau$ transition. Motivated by this, we investigate the possible NP effects in the $\Lambda_b\to\Lambda_c \tau\bar\nu_\tau$ decay. For this purpose, assuming the neutrinos are left-handed, we calculate in detail the helicity amplitudes of $\Lambda_b\to\Lambda_c \ell\bar\nu_\ell$ decays with all possible four-fermion operators. Within the latest results of $\Lambda_b\to\Lambda_c$ form factors from lattice QCD calculations, we study these decays in a model-independent manner. The differential and total branching fractions and other observables are calculated. In SM, we obtain the ratio ${\cal R}(\Lambda_c)=0.33\pm0.01$. Supposing that NP only affects the third generation fermions, we present the correlations among ${\cal R}(D)$, ${\cal R}(D^*)$ and ${\cal R}(\Lambda_c)$. We perform a minimum $\chi^2$ fit of the wilson coefficient of each operator to the latest experimental data of different observables. It is found that the left-handed scalar operator ${\cal O}_{SL}$ affects the branching fraction remarkably, and the ratio ${\cal R}(\Lambda_c)$ can be enhanced by $30\%$. For other operators, the ratio amounts to $0.38\pm0.02$, which is larger than prediction of SM by $20\%$. Using the fitted values of the wilson coefficients of the single NP operators, we also give a prognosis for the physical observables of $\Lambda_b\to\Lambda_c \tau\bar\nu_\tau$. Furthermore, we also study the effects of three typical NP models on $\Lambda_b\to\Lambda_c \tau\bar\nu_\tau$. We hope our results can be tested in the current LHCb experiment and the future high energy experiments.

MEASUREMENTS AND THERMODYNAMIC MODELING OF VAPOR-LIQUID EQUILIBRIA FOR BINARY SYSTEMS OF ISOPROPYL CHLOROACETATE WITH CYCLOHEXANE, ISOPROPANOL AND BENZENE AT 101.3 kPa

Abstract In this work, the vapor-liquid equilibrium experimental data for the systems of isopropyl chloroacetate + isopropanol, isopropyl chloroacetate + cyclohexane and isopropyl chloroacetate + benzene were measured by a modified Rose-type recirculating still under the pressure of 101.3 kPa. The thermodynamic consistency of the measured data was verified by the Herington and van Ness methods, respectively. The experimental data were correlated by the NRTL, Wilson, and UNIQUAC activity coefficient models, and the corresponding interaction parameters of the three models were obtained. The root-mean-square deviations between the experimental data and calculated results for the temperature and the mole fraction of the vapor phase were less than 0.58 K and 0.0066, respectively. In addition, the excess Gibbs energy was calculated for the three systems.

Direct detections of Majorana dark matter in vector portal

In this paper we investigate the direct detections of Majorana dark matter (MDM) in vector portal. Considering that the tree-level scattering cross sections in these models are either dark matter velocity suppressed or spin-dependent, we calculate radiative corrections to the spin-independent cross section in effective field theory approach. Wilson coefficients of effective MDM-quark interactions are calculated at the one-loop level, and the Wilson coefficient of the effective MDM-gluon interaction is derived at the two-loop level. Numerical results show that current constraints can rule out a narrow mass range of MDM when tree-level contributions are considered, and the spin-independent cross section from radiative corrections is a few orders of magnitude smaller than the tree-level contributions.

Soft bootstrap and effective field theories

The soft bootstrap program aims to construct consistent effective field theories (EFT’s) by recursively imposing the desired soft limit on tree-level scattering amplitudes through on-shell recursion relations. A prime example is the leading two-derivative opera­ tor in the EFT of SU(N) x SU(N)/SU(N) nonlinear sigma model (NLSM), where \U0001d4aa(p2 ) amplitudes with an arbitrary multiplicity of external particles can be soft-bootstrapped. We extend the program to \U0001d4aa(p4) operators and introduce the “soft blocks,” which are the seeds for soft bootstrap. The number of soft blocks coincides with the number of independent operators at a given order in the derivative expansion and the incalculable Wilson coefficient emerges naturally. We also uncover a new soft-constructible EFT involving the “multi-trace” operator at the leading two-derivative order, which is matched to SO(N + 1) /SO(N) NLSM. In addition, we consider Wess-Zumino-Witten (WZW) terms, the existence of which, or the lack thereof, depends on the number of flavors in the EFT, after a novel application of Bose symmetry. Remarkably, we find agreements with group­ theoretic considerations on the existence of WZW terms in SU(N) NLSM for N ≥ 3 and the absence of WZW terms in SO(N) NLSM for N ≠ 5.

The Higgs width in the SMEFT

We calculate the total and partial inclusive Higgs widths at leading order in the Standard Model Effective Field Theory (SMEFT). We report results incorporating SMEFT corrections for two and four body Higgs decays through vector currents in this limit. The narrow width approximation is avoided and all phase space integrals are directly evaluated. We explain why the narrow width approximation fails more significantly in the SMEFT compared to the SM, despite the narrowness of the observed SU(2) × U(1) bosons in both theories. Our results are presented in a manner that allows various input parameter schemes to be used, and they allow the inclusive branching ratios and decay widths of the Higgs to be numerically determined without a Monte Carlo generation of phase space for each Wilson coefficient value chosen.