Using improved operator product expansion in Borel–Laplace sum rules with ALEPH $$\tau $$ decay data, and determination of pQCD coupling

نویسندگان

چکیده

We use improved truncated Operator Product Expansion (OPE) for the Adler function, involving two types of terms with dimension $D=6$, in double-pinched Borel-Laplace Sum Rules and Finite Energy V+A channel strangeless semihadronic $\tau$ decays. The generation higher order perturbative QCD $D=0$ part function is carried out using a renormalon-motivated ansatz incorporating leading UV renormalon first IR renormalons. trunacted evaluated by variants fixed-order perturbation theory (FO), Principal Value Borel resummation (PV), contour-improved (CI). For experimental spectral we ALEPH $\tau$-decay data. point that FO PV evaluation methods account correctly structure Rules, while this not case CI evaluation. extract value ${\overline {\rm MS}}$ coupling $\alpha_s(m_{\tau}^2) = 0.3235^{+0.0138}_{-0.0126}$ [$\alpha_s(M_Z^2)=0.1191 \pm 0.0016$] average method, which consider as our main result. If included also extraction, would be 0.3299^{+0.0232}_{-0.0225}$ [$\alpha_s(M_Z^2)=0.1199^{+0.0026}_{-0.0028}$]. This work an extension improvement previous [Eur.Phys.J.C81 (2021) 10, 930] where used OPE more naive (and widely used) form extracted values $\alpha_s(M_Z^2)$ were somewhat lower.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

data mining rules and classification methods in insurance: the case of collision insurance

assigning premium to the insurance contract in iran mostly has based on some old rules have been authorized by government, in such a situation predicting premium by analyzing database and it’s characteristics will be definitely such a big mistake. therefore the most beneficial information one can gathered from these data is the amount of loss happens during one contract to predicting insurance ...

15 صفحه اول

Chiral sum rules and vacuum condensates from tau-lepton decay data

QCD finite energy sum rules, together with the latest updated ALEPH data on hadronic decays of the tau-lepton are used in order to determine the vacuum condensates of dimension d = 2 and d = 4. These data are also used to check the validity of the Weinberg sum rules, and to determine the chiral condensates of dimension d = 6 and d = 8, as well as the chiral correlator at zero momentum, proporti...

متن کامل

Determination of pion-baryon coupling constants from QCD sum rules.

We evaluate the πNN , πΣΣ and πΣΛ coupling constants using QCD sum rules based on pion-to-vacuum matrix elements of correlators of two interpolating baryon fields. The parts of the correlators with Dirac structure k/γ5 are used, keeping all terms up to dimension 5 in the OPE and including continuum contributions on the phenomenological side. The ratios of these sum rules to baryon mass sum rule...

متن کامل

Operator product expansion and analyticity

We discuss the current use of the operator-product expansion in QCD calculations. Treating the OPE as an expansion in inverse powers of an energy-squared variable (with possible exponential terms added), approximating the vacuum expectation value of the operator product by several terms and assuming a bound on the remainder along the euclidean region, we observe how the bound varies with increa...

متن کامل

Operator product expansion and confinement

Operator product expansion technique is analyzed in abelian and nonabelian field theoretical models with confinement. Special attention is paid to the regimes where nonzero virtuality of vacuum fields is felt by external currents. It is stressed that despite the physics of confinement is sometimes considered as being caused by " soft " fields, it can exhibit the pronounced " hard " effects in OPE.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: European Physical Journal C

سال: 2022

ISSN: ['1434-6044', '1434-6052']

DOI: https://doi.org/10.1140/epjc/s10052-022-10298-w