We present a lattice QCD determination of the Bs → Dsℓν scalar and vector form factors over the full physical range of momentum transfer. The result is derived from correlation functions computed ...using the highly improved staggered quark (HISQ) formalism, on the second generation MILC gluon ensembles accounting for up, down, strange and charm contributions from the sea. We calculate correlation functions for three lattice spacing values and an array of unphysically light b -quark masses, and extrapolate to the physical value. Using the HISQ formalism for all quarks means that the lattice current coupling to the W can be renormalized nonperturbatively, giving a result free from perturbative matching errors for the first time. Our results are in agreement with, and more accurate than, previous determinations of these form factors. From the form factors we also determine the ratio of branching fractions that is sensitive to violation of lepton universality: R (Ds) = B (Bs → Dsτντ) /B (Bs → Dsℓνl), where ℓ is an electron or a muon. We find R (Ds) = 0.2993 (46) , which is also more accurate than previous lattice QCD results. Combined with a future measurement of R (Ds), this could supply a new test of the Standard Model. We also compare the dependence on heavy quark mass of our form factors to expectations from heavy quark effective theory.
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All lattice-QCD calculations of the hadronic-vacuum-polarization contribution to the muon's anomalous magnetic moment to date have been performed with degenerate up- and down-quark masses. Here we ...calculate directly the strong-isospin-breaking correction to a_{μ}^{HVP} for the first time with physical values of m_{u} and m_{d} and dynamical u, d, s, and c quarks, thereby removing this important source of systematic uncertainty. We obtain a relative shift to be applied to lattice-QCD results obtained with degenerate light-quark masses of δa_{μ}^{HVP,m_{u}≠m_{d}}=+1.5(7)%, in agreement with estimates from phenomenology.
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Perfluoroalkyl substances (PFAS), including two most commonly studied compounds perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are widely distributed environmental pollutants, ...used extensively earlier. Due to their toxicological effects the use of PFAS is now regulated. Based on earlier studies on PFOA's distribution in bone and bone marrow in mice, we investigated PFAS levels and their possible link to bone microarchitecture of human femoral bone samples (n = 18). Soft tissue and bone biopsies were also taken from a 49-year old female cadaver for PFAS analyses. We also studied how PFOA exposure affects differentiation of human osteoblasts and osteoclasts. PFAS were detectable from all dry bone and bone marrow samples, PFOS and PFOA being the most prominent. In cadaver biopsies, lungs and liver contained the highest concentrations of PFAS, whereas PFAS were absent in bone marrow. Perfluorononanoic acid (PFNA) was present in the bones, PFOA and PFOS were absent. In vitro results showed no disturbance in osteogenic differentiation after PFOA exposure, but in osteoclasts, lower concentrations led to increased resorption, which eventually dropped to zero after increase in PFOA concentration. In conclusion, PFAS are present in bone and have the potential to affect human bone cells partly at environmentally relevant concentrations.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We analysed floor dust samples from 65 children's bedrooms in Finland collected in 2014/2015 for 62 different per- and polyfluoroalkyl substances (PFASs) with a simple and highly efficient method. ...Validation results from the analysis of standard reference material (SRM) 2585 were in good agreement with literature data, while 24 PFASs were quantified for the first time. In the dust samples from children's bedrooms, five perfluoroalkyl carboxylic acids (PFCAs) and perfluorooctane sulfonic acid (PFOS) were detected in more than half of the samples with the highest median concentration of 5.26 ng/g for perfluorooctanoic acid (PFOA). However, the dust samples were dominated by polyfluoroalkyl phosphoric acid esters (PAPs) and fluorotelomer alcohols (FTOHs) (highest medians: 53.9 ng/g for 6:2 diPAP and 45.7 ng/g for 8:2 FTOH). Several significant and strong correlations (up to ρ = 0.95) were found among different PFASs in dust as well as between PFASs in dust and air samples (previously published) from the same rooms. The logarithm of dust to air concentrations (log Kdust/air) plotted against the logarithm of the octanol-air partition coefficient (log Koa) resulted in a significant linear regression line with R2 > 0.88. Higher dust levels of PFOS were detected in rooms with plastic flooring material in comparison to wood (p < 0.05). Total estimated daily intakes via dust (EDIdust) and air (EDIair) of perfluoroalkyl acids (PFAA), including biotransformation of precursors to PFAAs, were calculated for 10.5-year-old children. The total EDIdust for PFOA and PFOS were estimated to be 0.007 ng/kg bw/day and 0.006 ng/kg bw/day, respectively, in an intermediate exposure scenario. The sum of the total EDIs for all PFAAs was slightly higher for dust than air (0.027 and 0.019 ng/kg bw/day). Precursor biotransformation was generally important for total PFOS intake, while for the PFCAs, FTOH biotransformation was estimated to be important for air, but not for dust exposure.
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•PAPs and FTOHs were the predominant PFASs in children's bedroom floor dust.•Linear regression was obtained between log Kdust/air and log Koa (r = 0.94, R2 > 0.88).•PFOS dust levels were higher in rooms with plastic than wooden floor material.•PFCA intake via dust was driven by direct intake and not by precursor intake.•53 PFASs were detected in the dust standard reference material (SRM) 2585.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The quark-line disconnected diagram is a potentially important ingredient in lattice QCD calculations of the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon. It ...is also a notoriously difficult one to evaluate. Here, for the first time, we give an estimate of this contribution based on lattice QCD results that have a statistically significant signal, albeit at one value of the lattice spacing and an unphysically heavy value of the u/d quark mass. We use HPQCD's method of determining the anomalous magnetic moment by reconstructing the Adler function from time moments of the current-current correlator at zero spatial momentum. Our results lead to a total (including u, d and s quarks) quark-line disconnected contribution to amu of -0.15% of the u/d hadronic vacuum polarization contribution with an uncertainty which is 1% of that contribution.
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We determine the contribution to the anomalous magnetic moment of the muon from the αQED2 hadronic vacuum polarization diagram using full lattice QCD and including u/d quarks with physical masses for ...the first time. We use gluon field configurations that include u, d, s and c quarks in the sea at multiple values of the lattice spacing, multiple u/d masses and multiple volumes that allow us to include an analysis of finite-volume effects. We obtain a result for aμHVP,LO of 667(6)(12)×10−10, where the first error is from the lattice calculation and the second includes systematic errors from missing QED and isospin-breaking effects and from quark-line disconnected diagrams. Our result implies a discrepancy between the experimental determination of aμ and the Standard Model of 3σ.
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We describe a new technique to determine the contribution to the anomalous magnetic moment of the muon coming from the hadronic vacuum polarization using lattice QCD. Our method reconstructs the ...Adler function, using Pade approximants, from its derivatives at q super(2) = 0 obtained simply and accurately from time-moments of the vector current-current correlator at zero spatial momentum. We test the method using strange quark correlators on large-volume gluon field configurations that include the effect of up and down (at physical masses), strange and charm quarks in the sea at multiple values of the lattice spacing and multiple volumes and show that 1% accuracy is achievable. For the charm quark contributions we use our previously determined moments with up, down and strange quarks in the sea on very fine lattices. We find the (connected) contribution to the anomalous moment from the strange quark vacuum polarization to be (ProQuest: Formulae and/or non-USASCII text omitted), and from charm to be (ProQuest: Formulae and/or non-USASCII text omitted). These are in good agreement with flavor-separated results from nonlattice methods, given caveats about the comparison. The extension of our method to the light quark contribution and to that from the quark-line disconnected diagram is straightforward.
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We derive the operator product expansion whose vacuum expectation value gives the time moments of the pseudoscalar heavy-light current-current correlator up to and including terms in αs2 multiplying ...⟨ψ¯ψ⟩/M3 and terms in αs multiplying ⟨αsG2⟩/M4, where M is the heavy quark mass. Using lattice QCD results for heavy-strange correlators obtained for a variety of heavy quark masses on gluon field configurations including u, d and s quarks in the sea at three values of the lattice spacing, we are able to show that the contribution of the strange-quark condensate to the time moments is very substantial. We use our lattice QCD time moments and the operator product expansion to determine a value for the condensate, fitting the fourth, sixth, eighth and tenth time moments simultaneously. Our result, ⟨s¯s⟩MS¯(2 GeV)=−(296(11) MeV)3, agrees well with HPQCD's earlier, more direct, lattice QCD determination C. McNeile et al. (HPQCD Collaboration), Phys. Rev. D 87, 034503 (2013). As well as confirming that the s quark condensate is close in value to the light quark condensate, this demonstrates clearly the consistency of the operator product expansion for fully nonperturbative calculations of matrix elements of short-distance operators in lattice QCD.
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Studies show evidence of longitudinal brain volume decreases in schizophrenia. We studied brain volume changes and their relation to symptom severity, level of function, cognition, and antipsychotic ...medication in participants with schizophrenia and control participants from a general population based birth cohort sample in a relatively long follow-up period of almost a decade. All members of the Northern Finland Birth Cohort 1966 with any psychotic disorder and a random sample not having psychosis were invited for a MRI brain scan, and clinical and cognitive assessment during 1999-2001 at the age of 33-35 years. A follow-up was conducted 9 years later during 2008-2010. Brain scans at both time points were obtained from 33 participants with schizophrenia and 71 control participants. Regression models were used to examine whether brain volume changes predicted clinical and cognitive changes over time, and whether antipsychotic medication predicted brain volume changes. The mean annual whole brain volume reduction was 0.69% in schizophrenia, and 0.49% in controls (p = 0.003, adjusted for gender, educational level, alcohol use and weight gain). The brain volume reduction in schizophrenia patients was found especially in the temporal lobe and periventricular area. Symptom severity, functioning level, and decline in cognition were not associated with brain volume reduction in schizophrenia. The amount of antipsychotic medication (dose years of equivalent to 100 mg daily chlorpromazine) over the follow-up period predicted brain volume loss (p = 0.003 adjusted for symptom level, alcohol use and weight gain). In this population based sample, brain volume reduction continues in schizophrenia patients after the onset of illness, and antipsychotic medications may contribute to these reductions.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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