Hadronic contribution to the running QED coupling at the Z-boson mass scale

نویسندگان

چکیده

An update is described of a model independent method to determine the hadronic contribution QED running coupling at Zboson mass scale, ∆αHAD(M2 Z ). The major source uncertainty from light quark vector current correlator zero momentum. This substantially reduced using recently improved lattice QCD results for this correlator. result ) = 274.13(0.73) × 10−4

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود 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

Top quark contribution to hadronic decays of the Z - boson at α 2 s in QCD

We evaluate the effect of a virtual top quark on the coefficient of α2s in the decay rates Γ(Z → hadrons) and Γ(Z → bb). We treat the dependence on the top quark mass exactly instead of using a large mass expansion. The present work completes the evaluation of the α2s contributions to these quantities. The calculation uses both the MS and Collins-Wilczek-Zee renormalization prescriptions. The r...

متن کامل

Study of Hadronic Decays of the Z Boson at Lep

Each of the four LEP experiments has recorded around 4 million hadronic Z decays, mostly in the period between 1990 and 1995. The analysis of the main physics topics on this subject has been essentially completed, but a few specific points are still under investigation, especially in the QCD sector. This report summarizes four recent papers on the characteristics of the hadronic decays of the Z...

متن کامل

A determination of the QED coupling at the Z pole

We critically examine the evaluation of the hadronic contribution to the running of the QED coupling, α, from Q 2 = 0 to Q 2 = M 2 Z. Using data for e + e − → hadrons we find that α(M 2 Z) −1 = 128.99 ± 0.06, as compared to the existing value of 128.87 ± 0.12.

متن کامل

A determination of the QED coupling at the Z poleA

We critically examine the evaluation of the hadronic contribution to the running of The improvement in the measurements of electroweak quantities allows high precision tests of the Standard Model in which the measured Z boson mass is related to other ob-servables (see, for example, the recent reviews in Refs. 1, 3]). Surprisingly, out of the three accurately measured quantities (, G F , M Z) wh...

متن کامل

QED Radiative Corrections to Z Boson Production and the Forward Backward Asymmetry at Hadron Colliders

The O(α) radiative corrections to the process p p (−) → γ∗, Z → `+`− (` = e, μ) are calculated. Factorizing the collinear singularity associated with initial state photon bremsstrahlung into the parton distribution functions, we find that initial state corrections have a much smaller effect than final state radiative corrections. Due to mass singular logarithmic terms associated with photons em...

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: Revista Mexicana De Fisica

سال: 2023

ISSN: ['0035-001X', '2683-2224']

DOI: https://doi.org/10.31349/revmexfis.69.020801