Lattice QCD Calculation of Electroweak Box Contributions to Superallowed Nuclear and Neutron Beta Decays.

We present the first lattice QCD calculation of the universal axial γW-box contribution □_{γW}^{VA} to both superallowed nuclear and neutron beta decays. This contribution emerges as a significant component within the theoretical uncertainties surrounding the extraction of |V_{ud}| from superallowed decays. Our calculation is conducted using two domain wall fermion ensembles at the physical pion mass. To construct the nucleon four-point correlation functions, we employ the random sparsening field technique. Furthermore, we incorporate long-distance contributions to the hadronic function using the infinite-volume reconstruction method. Upon performing the continuum extrapolation, we arrive at □_{γW}^{VA}=3.65(7)_{lat}(1)_{PT}×10^{-3}. Consequently, this yields a slightly higher value of |V_{ud}|=0.973 86(11)_{exp}(9)_{RC}(27)_{NS}, reducing the previous 2.1σ tension with the CKM unitarity to 1.8σ. Additionally, we calculate the vector γW-box contribution to the axial charge g_{A}, denoted as □_{γW}^{VV}, and explore its potential implications.

Lattice QCD Calculation of π

We extend the application of lattice QCD to the two-photon-mediated, order α^{2} rare decay π^{0}→e^{+}e^{-}. By combining Minkowski- and Euclidean-space methods we are able to calculate the complex amplitude describing this decay directly from the underlying theories (QCD and QED) which predict this decay. The leading connected and disconnected diagrams are considered; a continuum limit is evaluated and the systematic errors are estimated. We find ReA=18.60(1.19)(1.05) eV, ImA=32.59(1.50)(1.65) eV, a more accurate value for the ratio (ReA/ImA)=0.571(10)(4), and a result for the partial width Γ(π^{0}→γγ)=6.60(0.61)(0.67) eV. Here the first errors are statistical and the second systematic. This calculation is the first step in determining the more challenging, two-photon-mediated decay amplitude that contributes to the rare decay K→µ^{+}µ^{-}.

Nucleon Transversity Distribution in the Continuum and Physical Mass Limit from Lattice QCD.

We report a state-of-the-art lattice QCD calculation of the isovector quark transversity distribution of the proton in the continuum and physical mass limit using large-momentum effective theory. The calculation is done at four lattice spacings a={0.098,0.085,0.064,0.049} fm and various pion masses ranging between 220 and 350 MeV, with proton momenta up to 2.8 GeV. The result is nonperturbatively renormalized in the hybrid scheme with self-renormalization, which treats the infrared physics at large correlation distance properly, and extrapolated to the continuum, physical mass, and infinite momentum limit. We also compare with recent global analyses for the nucleon isovector quark transversity distribution.

Lattice QCD Calculation of the Pion Mass Splitting.

We use the infinite volume reconstruction method to calculate the charged and neutral pion mass difference. The hadronic tensor is calculated using lattice QCD and then combined with an analytic photon propagator, and the mass splitting is calculated with exponentially suppressed finite-volume errors. The calculation is performed using six gauge ensembles generated with 2+1-flavor domain wall fermions, and five ensembles are at the physical pion mass. Both Feynman and Coulomb gauges are adopted in the calculation and agree well when the lattice spacing approaches zero. After performing the continuum extrapolation and examining the residual finite-volume effects, we obtain the pion mass splitting Δm_{π}=4.534(42)_{stat}(43)_{sys} MeV, which agrees well with experimental measurements.

Lattice QCD Calculation of the Two-Photon Exchange Contribution to the Muonic-Hydrogen Lamb Shift.

We develop a method for lattice QCD calculation of the two-photon exchange contribution to the muonic-hydrogen Lamb shift. To demonstrate its feasibility, we present the first lattice calculation with a gauge ensemble at m_{π}=142 MeV. By adopting the infinite-volume reconstruction method along with an optimized subtraction scheme, we obtain with statistical uncertainty ΔE_{TPE}=-28.9(4.9) µeV+93.72 µeV/fm^{2}·⟨r_{p}^{2}⟩, or ΔE_{TPE}=37.4(4.9) µeV, which is consistent with the previous theoretical results in a range of 20-50 µeV.

Hadronic Light-by-Light Scattering Contribution to the Muon Anomalous Magnetic Moment from Lattice QCD.

We report the first result for the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment with all errors systematically controlled. Several ensembles using 2+1 flavors of physical mass Möbius domain-wall fermions, generated by the RBC and UKQCD collaborations, are employed to take the continuum and infinite volume limits of finite volume lattice QED+QCD. We find a_{µ}^{HLbL}=7.87(3.06)_{stat}(1.77)_{sys}×10^{-10}. Our value is consistent with previous model results and leaves little room for this notoriously difficult hadronic contribution to explain the difference between the standard model and the BNL experiment.

First-Principles Calculation of Electroweak Box Diagrams from Lattice QCD.

We present the first realistic lattice QCD calculation of the γW-box diagrams relevant for beta decays. The nonperturbative low-momentum integral of the γW loop is calculated using a lattice QCD simulation, complemented by the perturbative QCD result at high momenta. Using the pion semileptonic decay as an example, we demonstrate the feasibility of the method. By using domain wall fermions at the physical pion mass with multiple lattice spacings and volumes, we obtain the axial γW-box correction to the semileptonic pion decay, □_{γW}^{VA}|_{π}=2.830(11)_{stat}(26)_{syst}×10^{-3}, with the total uncertainty controlled at the level of ∼1%. This study sheds light on the first-principles computation of the γW-box correction to the neutron decay, which plays a decisive role in the determination of |V_{ud}|.

Light-Neutrino Exchange and Long-Distance Contributions to 0ν2ß Decays: An Exploratory Study on ππ→ee.

We present an exploratory lattice QCD calculation of the neutrinoless double beta decay ππ→ee. Under the mechanism of light-neutrino exchange, the decay amplitude involves significant long-distance contributions. The calculation reported here, with pion masses m_{π}=420 and 140 MeV, demonstrates that the decay amplitude can be computed from first principles using lattice methods. At unphysical and physical pion masses, we obtain that amplitudes are 24% and 9% smaller than the predication from leading order chiral perturbation theory. Our findings provide the lattice QCD inputs and constraints for effective field theory. A follow-on calculation with fully controlled systematic errors will be possible with adequate computational resources.

Proton Isovector Helicity Distribution on the Lattice at Physical Pion Mass.

We present a state-of-the-art calculation of the isovector quark-helicity Bjorken-x distribution in the proton using lattice-QCD ensembles at the physical pion mass. We compute quasidistributions at proton momenta P_{z}∈{2.2,2.6,3.0} GeV on the lattice and match them systematically to the physical parton distribution using the large-momentum effective theory. We reach an unprecedented precision through high statistics in simulations, large-momentum proton matrix elements, and control of excited-state contamination. The resulting distribution with combined statistical and systematic errors is in agreement with the latest phenomenological analysis of the spin-dependent experimental data, in particular, Δu[over ¯](x)>Δd[over ¯](x).

Connected and Leading Disconnected Hadronic Light-by-Light Contribution to the Muon Anomalous Magnetic Moment with a Physical Pion Mass.

We report a lattice QCD calculation of the hadronic light-by-light contribution to the muon anomalous magnetic moment at a physical pion mass. The calculation includes the connected diagrams and the leading, quark-line-disconnected diagrams. We incorporate algorithmic improvements developed in our previous work. The calculation was performed on the 48^{3}×96 ensemble generated with a physical pion mass and a 5.5 fm spatial extent by the RBC and UKQCD Collaborations using the chiral, domain wall fermion formulation. We find a_{µ}^{HLbL}=5.35(1.35)×10^{-10}, where the error is statistical only. The finite-volume and finite lattice-spacing errors could be quite large and are the subject of ongoing research. The omitted disconnected graphs, while expected to give a correction of order 10%, also need to be computed.

Inconsistency between physicians' attitudes and behaviors toward TCM: A questionnaire survey in Chengdu.

Although Western Medicine is considered as the mainstream medicine in China, Traditional Chinese Medicine (TCM) still has its own advantages and characteristics. The attitudes and behaviors to TCM are divided, some West Medicine Doctors prefer TCM during treatment, while others consider it not effective. The objective of this study is to find out the attitudes and treatment behaviors of Chengdu physicians toward TCM, and identify factors associated with their attitude and behaviors. A representative sample of 2049 Chengdu physicians were recruited online to investigate their attitudes and behaviors toward TCM. During this research, previous Integrative Medicine Attitude Questionnaire were referred and modified, and adjusted questionnaire was made based on the actual situation of TCM in Chengdu. This questionnaire contains 3 distinct parts. The first part aimed at the attitudes of respondents toward TCM, and contains 15 questions in 3 sections, Holism, Knowledge, and Evidence. The second part tried to determine the behaviors toward TCM in terms of self-use, recommendations, as well as prescriptions. In addition, 6 modalities including Chinese Patent Medicine, Chinese Herbal Medicine, Acupuncture, Massage & Bone Setting, Qigong, and TCM diet were introduced in the behavioral part. In the third part, we aimed to collect personal, professional, and structural factors that may significantly influence TCM attitudes and behaviors. Physicians hold positive attitudes toward TCM in general, all the mean/highest possible subscales scores value of Holism (90.53%), Knowledge (63.77%), and Evidence (62.73%) domain were over 60%. On the other hand, physicians were more positive on self-use (49.40%) and recommendation (55.98%) of TCM than giving TCM prescriptions (36.60%) to patients. The attitudes and behaviors toward may not be consistent, which means physicians may not give prescriptions to patients even they have good attitudes to TCM. Education and self-use of TCM are important positive factors that influence the behaviors of physicians.

Efficacy and safety of Danggui Niantong Decoction in patients with gout: a systematic review and meta-analysis.

Background: This study aims to evaluate the efficacy and safety of Danggui Niantong Decoction (DGNT) systematically on gout treating. Methods: This study was registered in PROSPERO, and the registration number was CRD42021271607. By the end of December, 2022, literature research was conducted among eight electronic databases. Main results of this study were blood uric acid (BUA) and Creactive protein (CRP). Secondary outcomes were erythrocyte sedimentation rate (ESR), serum creatinine (Scr), urinary protein quantified at 24 h (Upro), and interleukin-8 (IL-8). Study screening, data collection, as well as quality assessment were performed by two reviewers independently, and analysis was completed using Stata (SE15.0) and Review Manager (5.4). Results: A total number of 13 studies were included in our meta-analysis (n = 1,094 participants). Results showed DGNT combined with conventional western medicine (CWM) was more effective than WM alone in BUA (weighted mean differences (WMD) = -3.49, 95% confidence interval (CI) [-50.36, -32.59], p = 0.000), CRP (WMD = -41.48, 95% CI [-4.32, -2.66], p = 0.017), ESR (WMD = -6.23, 95% CI [-9.28, -3.17], p = 0.019), Scr (WMD = -18.64, 95% CI [-23.09, -14.19], p = 0.001), Upro (WMD = -0.72, 95% CI [-0.91, -0.53], p = 0.000), and IL-8 (WMD = -4.77, 95% CI [-11.48, 1.94], p = 0.000). None of the adverse effects noted were severe, and no life-threatening event was reported. Conclusion: This study shows that DGNT combined with CWM seems to have an effective clinical therapeutic potential. In addition, it also provides a scientific basis for better clinical application of DGNT in the future. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021271607; Identifier: PROSPERO, CRD42021271607.