scholarly journals The renormalised $$\mathrm{O}(a)$$ improved vector current in three-flavour lattice QCD with Wilson quarks

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Jochen Heitger ◽  
◽  
Fabian Joswig
Keyword(s):  
Lattice Qcd ◽  
Gauge Coupling ◽  
Vector Current ◽  
Tree Level ◽  
Renormalisation Constant ◽  
Local Vector ◽  
The One ◽  
Smooth Dependence ◽  
Typical Range

AbstractWe present the results of a non-perturbative determination of the improvement coefficient $$c_\mathrm{V}$$ c V and the renormalisation factor $$Z_\mathrm{V}$$ Z V , which define the renormalised vector current in three-flavour $$\mathrm{O}(a)$$ O ( a ) improved lattice QCD with Wilson quarks and tree-level Symanzik-improved gauge action. In case of the improvement coefficient, we consider both lattice descriptions of the vector current, the local as well as the conserved (i.e., point-split) one. Our improvement and normalisation conditions are based on massive chiral Ward identities and numerically evaluated in the Schrödinger functional setup, which allows to eliminate finite quark mass effects in a controlled way. In order to ensure a smooth dependence of the renormalisation constant and improvement coefficients on the bare gauge coupling, our computation proceeds along a line of constant physics, covering the typical range of lattice spacings $$0.04\,\mathrm{fm}\lesssim a\lesssim 0.1\,\mathrm{fm}$$ 0.04 fm ≲ a ≲ 0.1 fm that is useful for phenomenological applications. Especially for the improvement coefficient of the local vector current, we report significant differences between the one-loop perturbative estimates and our non-perturbative results.

scholarly journals Ward identity determination of $$Z_{\mathrm {S}}/Z_{\mathrm {P}}$$ for $$N_{\mathrm {f}}=3$$ lattice QCD in a Schrödinger functional setup

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Jochen Heitger ◽  
Fabian Joswig ◽  
Anastassios Vladikas
Keyword(s):  
Lattice Qcd ◽  
Large Volume ◽  
Ward Identity ◽  
Tree Level ◽  
Quark Masses ◽  
Axial Variation ◽  
Functional Boundary ◽  
Functional Boundary Conditions ◽  
Typical Range

Abstract We derive chiral Ward identities for lattice QCD with Wilson quarks and $$N_{\mathrm{f}}\ge 3$$Nf≥3 flavours, on small lattices with Schrödinger functional boundary conditions and vanishingly small quark masses. These identities relate the axial variation of the non-singlet pseudoscalar density to the scalar one, thus enabling the non-perturbative determination of the scale-independent ratio $$Z_{\mathrm {S}}/Z_{\mathrm {P}}$$ZS/ZP of the renormalisation parameters of these operators. We obtain results for $$N_{\mathrm{f}}=3$$Nf=3 QCD with tree-level Symanzik-improved gluons and Wilson-Clover quarks, for bare gauge couplings which cover the typical range of large-volume $$N_{\mathrm{f}}= 2+1$$Nf=2+1 simulations with Wilson fermions at lattice spacings below $$0.1\,$$0.1fm. The precision of our results varies from 0.3 to 1%, except for the coarsest lattice, where it is 2%. We discuss how the $$Z_{\mathrm {S}}/Z_{\mathrm {P}}$$ZS/ZP ratio can be used in the non-perturbative calculations of $${\mathrm {O}}(a)$$O(a) improved renormalised quark masses.

scholarly journals Non-perturbative determination of cV, ZV and ZS/ZP in Nf = 3 lattice QCD

2018 ◽  
Vol 175 ◽  
pp. 10004 ◽  
Author(s):  
Jochen Heitger ◽  
Fabian Joswig ◽  
Anastassios Vladikas ◽  
Christian Wittemeier
Keyword(s):  
Lattice Qcd ◽  
Quark Mass ◽  
Numerical Evaluation ◽  
Vector Current ◽  
Tree Level ◽  
Gauge Action ◽  
Renormalization Factor ◽  
Preliminary Results ◽  
Renormalization Constants

We report on non-perturbative computations of the improvement coefficient cV and the renormalization factor ZV of the vector current in three-flavour O(a) improved lattice QCD with Wilson quarks and tree-level Symanzik improved gauge action. To reduce finite quark mass effects, our improvement and normalization conditions exploit massive chiral Ward identities formulated in the Schrödinger functional setup, which also allow deriving a new method to extract the ratio ZS/ZP of scalar to pseudoscalar renormalization constants. We present preliminary results of a numerical evaluation of ZV and cV along a line of constant physics with gauge couplings corresponding to lattice spacings of about 0:09 fm and below, relevant for phenomenological applications.

scholarly journals Determination of the charm quark mass in lattice QCD with 2 + 1 flavours on fine lattices

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Jochen Heitger ◽  
Fabian Joswig ◽  
Simon Kuberski
Keyword(s):  
Lattice Qcd ◽  
Quark Mass ◽  
Charm Quark ◽  
Renormalisation Group ◽  
Tree Level ◽  
Lattice Action ◽  
Group Invariant ◽  
Quark Masses ◽  
Charm Quark Mass

Abstract We present a determination of the charm quark mass in lattice QCD with three active quark flavours. The calculation is based on PCAC masses extracted from Nf = 2 + 1 flavour gauge field ensembles at five different lattice spacings in a range from 0.087 fm down to 0.039 fm. The lattice action consists of the O(a) improved Wilson-clover action and a tree-level improved Symanzik gauge action. Quark masses are non-perturbatively O(a) improved employing the Symanzik-counterterms available for this discretisation of QCD. To relate the bare mass at a specified low-energy scale with the renormalisation group invariant mass in the continuum limit, we use the non-pertubatively known factors that account for the running of the quark masses as well as for their renormalisation at hadronic scales. We obtain the renormalisation group invariant charm quark mass at the physical point of the three-flavour theory to be Mc = 1486(21) MeV. Combining this result with five-loop perturbation theory and the corresponding decoupling relations in the $$ \overline{\mathrm{MS}} $$ MS ¯ scheme, one arrives at a result for the renormalisation group invariant charm quark mass in the four-flavour theory of Mc(Nf = 4) = 1548(23) MeV, where effects associated with the absence of a charmed, sea quark in the non-perturbative evaluation of the QCD path integral are not accounted for. In the $$ \overline{\mathrm{MS}} $$ MS ¯ scheme, and at finite energy scales conventional in phenomenology, we quote $$ {m}_{\mathrm{c}}^{\overline{\mathrm{MS}}} $$ m c MS ¯ ($$ {m}_{\mathrm{c}}^{\overline{\mathrm{MS}}} $$ m c MS ¯ ; Nf = 4) = 1296(19) MeV and $$ {m}_{\mathrm{c}}^{\overline{\mathrm{MS}}} $$ m c MS ¯ (3 GeV; Nf = 4) = 1007(16) MeV for the renormalised charm quark mass.

scholarly journals Determination of $c_A$ in three-flavour lattice QCD with Wilson fermions and tree-level improved gauge action

2014 ◽  
Author(s):  
Christian Wittemeier ◽  
Michele Della Morte ◽  
John Bulava ◽  
Jochen Heitger
Keyword(s):  
Lattice Qcd ◽  
Tree Level ◽  
Gauge Action ◽  
Wilson Fermions

scholarly journals Non-perturbative determination of improvement b-coefficients in Nf = 3

2018 ◽  
Vol 175 ◽  
pp. 10008 ◽  
Author(s):  
Giulia Maria de Divitiis ◽  
Maurizio Firrotta ◽  
Jochen Heitger ◽  
Carl Christian Köster ◽  
Anastassios Vladikas
Keyword(s):  
Boundary Conditions ◽  
Lattice Qcd ◽  
Tree Level ◽  
Gauge Action ◽  
The Past ◽  
Functional Boundary ◽  
Functional Boundary Conditions ◽  
Mass Dependent ◽  
B Coefficients

We present our preliminary results of the non-perturbative determination of the valence mass dependent coefficients bA - bP and bm as well as the ratio ZPZm=ZA entering the flavour non-singlet PCAC relation in lattice QCD with Nf = 3 dynamical flavours. We apply the method proposed in the past for quenched approximation and Nf = 2 cases, employing a set of finite-volume ALPHA configurations with Schrödinger functional boundary conditions, generated with O(a) improved Wilson fermions and the tree-level Symanzik-improved gauge action for a range of couplings relevant for simulations at lattice spacings of about 0.09 fm and below.

Two-Stage Procedure for the Quantitative Determination of Autoprothrombin III Concentration and Some Applications

1967 ◽  
Vol 18 (01/02) ◽  
pp. 198-210 ◽  
Author(s):  
Ronald S Reno ◽  
Walter H Seegers
Keyword(s):  
Prothrombin Time ◽  
Factor Vii ◽  
Two Stage ◽  
Pronounced Increase ◽  
One Stage ◽  
Assay Procedure ◽  
Bovine Plasma ◽  
The One ◽  
Autoprothrombin C

SummaryA two-stage assay procedure was developed for the determination of the autoprothrombin C titre which can be developed from prothrombin or autoprothrombin III containing solutions. The proenzyme is activated by Russell’s viper venom and the autoprothrombin C activity that appears is measured by its ability to shorten the partial thromboplastin time of bovine plasma.Using the assay, the autoprothrombin C titre was determined in the plasma of several species, as well as the percentage of it remaining in the serum from blood clotted in glass test tubes. Much autoprothrombin III remains in human serum. With sufficient thromboplastin it was completely utilized. Plasma from selected patients with coagulation disorders was assayed and only Stuart plasma was abnormal. In so-called factor VII, IX, and P.T.A. deficiency the autoprothrombin C titre and thrombin titre that could be developed was normal. In one case (prethrombin irregularity) practically no thrombin titre developed but the amount of autoprothrombin C which generated was in the normal range.Dogs were treated with Dicumarol and the autoprothrombin C titre that could be developed from their plasmas decreased until only traces could be detected. This coincided with a lowering of the thrombin titre that could be developed and a prolongation of the one-stage prothrombin time. While the Dicumarol was acting, the dogs were given an infusion of purified bovine prothrombin and the levels of autoprothrombin C, thrombin and one-stage prothrombin time were followed for several hours. The tests became normal immediately after the infusion and then went back to preinfusion levels over a period of 24 hrs.In other dogs the effect of Dicumarol was reversed by giving vitamin K1 intravenously. The effect of the vitamin was noticed as early as 20 min after administration.In response to vitamin K the most pronounced increase was with that portion of the prothrombin molecule which yields thrombin. The proportion of that protein with respect to the precursor of autoprothrombin C increased during the first hour and then started to go down and after 3 hrs was equal to the proportion normally found in plasma.

SIMPLIFIED DEXAMETHASONE SUPPRESSION TEST

1969 ◽  
Vol 61 (2) ◽  
pp. 219-231 ◽  
Author(s):  
V. H. Asfeldt
Keyword(s):  
Cushing’S Syndrome ◽  
Normal Subjects ◽  
Cushing's Syndrome ◽  
Dexamethasone Suppression Test ◽  
Clinical Value ◽  
Suppression Test ◽  
The One ◽  
Steroid Excretion ◽  
Dexamethasone Suppression

ABSTRACT This is an investigation of the practical clinical value of the one mg dexamethasone suppression test of Nugent et al. (1963). The results, evaluated from the decrease in fluorimetrically determined plasma corticosteroids in normal subjects, as well as in cases of exogenous obesity, hirsutism and in Cushing's syndrome, confirm the findings reported in previous studies. Plasma corticosteroid reduction after one mg of dexamethasone in cases of stable diabetes was not significantly different from that observed in control subjects, but in one third of the insulin-treated diabetics only a partial response was observed, indicating a slight hypercorticism in these patients. An insufficient decrease in plasma corticosteroids was observed in certain other conditions (anorexia nervosa, pituitary adenoma, patients receiving contraceptive or anticonvulsive treatment) with no hypercorticism. The physiological significance of these findings is discussed. It is concluded that the test, together with a determination of the basal urinary 17-ketogenic steroid excretion, is suitable as the first diagnostic test in patients in whom Cushing's syndrome is suspected. In cases of insufficient suppression of plasma corticosteroids, further studies, including the suppression test of Liddle (1960), must be carried out.

A Validated 2D-LC-UV Method for Simultaneous Determination of Imatinib and N-demethylimatinib in Plasma and Its Clinical Application for Therapeutic Drug Monitoring with GIST Patients

2020 ◽  
Vol 17 ◽  
Author(s):  
Houli Li ◽  
Di Zhang ◽  
Xiaoliang Cheng ◽  
Qiaowei Zheng ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
One Dimension ◽  
Therapeutic Drug ◽  
Plasma Samples ◽  
Column Temperature ◽  
Injection Volume ◽  
Target Analytes ◽  
The One ◽  
Middle Column

Background: The trough concentration (Cmin) of Imatinib (IM) is closely related to the treatment outcomes and adverse reactions of patients with gastrointestinal stromal tumors (GIST). However, the drug plasma level has great interand intra-individual variability, and therapeutic drug monitoring (TDM) is highly recommended. Objective: To develop a novel, simple, and economical two-dimensional liquid chromatography method with ultraviolet detector (2D-LC-UV) for simultaneous determination of IM and its major active metabolite, N-demethyl imatinib (NDIM) in human plasma, and then apply the method for TDM of the drug. Method: Sample was processed by simple protein precipitation. Two target analytes were separated on the one-dimension column, captured on the middle column, and then transferred to the two-dimension column for further analysis. The detection was performed at 264 nm. The column temperature was maintained at 40˚C and the injection volume was 500 μL. Totally 32 plasma samples were obtained from patients with GIST who were receiving IM. Method: Sample was processed by simple protein precipitation. Two target analytes were separated on the one-dimension column, captured on the middle column, and then transferred to the two-dimension column for further analysis. The detection was performed at 264 nm. The column temperature was maintained at 40˚C and the injection volume was 500 μL. Totally 32 plasma samples were obtained from patients with GIST who were receiving IM. Conclusion: The novel 2D-LC-UV method is simple, stable, highly automated and independent of specialized technicians, which greatly increases the real-time capability of routine TDM for IM in hospital.

scholarly journals Interplay of New Physics effects in (g − 2)ℓ and h → ℓ+ℓ− — lessons from SMEFT

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Svjetlana Fajfer ◽  
Jernej F. Kamenik ◽  
M. Tammaro
Keyword(s):  
Closed Operator ◽  
Higgs Doublet ◽  
New Physics ◽  
Effective Field ◽  
Tree Level ◽  
Electroweak Symmetry ◽  
Scalar Leptoquark ◽  
Doublet Model ◽  
The One ◽  
Two Higgs Doublet Model

Abstract We explore the interplay of New Physics (NP) effects in (g− 2)ℓ and h→ℓ+ℓ− within the Standard Model Effective Field Theory (SMEFT) framework, including one-loop Renormalization Group (RG) evolution of the Wilson coefficients as well as matching to the observables below the electroweak symmetry breaking scale. We include both the leading dimension six chirality flipping operators including a Higgs and SU(2)L gauge bosons as well as four-fermion scalar and tensor operators, forming a closed operator set under the SMEFT RG equations. We compare present and future experimental sensitivity to different representative benchmark scenarios. We also consider two simple UV completions, a Two Higgs Doublet Model and a single scalar LeptoQuark extension of the SM, and show how tree level matching to SMEFT followed by the one-loop RG evolution down to the electroweak scale can reproduce with high accuracy the (g−2)ℓ and h→ℓ+ℓ− contributions obtained by the complete one- and even two-loop calculations in the full models.

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