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Related papers: QCD parameters and SM-high precision from $e^+e^-$…

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We present the estimates of the order $O(\alpha^{4}_{s})$ QCD corrections to $R(s)$, $R_{\tau}$ and to the deep-inelastic scattering sum rules, namely to the non-polarized and polarized Bjorken sum rules and to the Gross-Llewellyn Smith sum…

High Energy Physics - Phenomenology · Physics 2008-02-03 A. L. Kataev , V. V. Starshenko

(Abridged) Many-multiplet (MM) method applied to three inhomogeneous samples of Keck/HIRES quasar absorption spectra gives a shift in the value of the fine-structure constant of Delta alpha/alpha = (-5.4+/-1.2) 10^{-6} in the redshift range…

Astrophysics · Physics 2017-08-23 Sergei A. Levshakov

The thorough analysis of the ALEPH data on hadronic tau-decay is performed in the framework of QCD. The perturbative calculations are performed in 3 and 4-loop approximations. The terms of the operator product expansion (OPE) are accounted…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. V. Geshkenbein , B. L. Ioffe , K. N. Zyablyuk

We summarize the results obtained for the quark masses (u,d,s,c, and b) in Refs.~\cite{AlamKhan:2023ili,AlamKhan:2023kgs} and strong coupling ($\alpha_s$) using renormalization group (RG) improvement of the theoretical expressions and…

High Energy Physics - Phenomenology · Physics 2023-11-20 M. S. A. Alam Khan

The muon anomalous magnetic moment exhibits a 3.6 \sigma discrepancy between experiment and theory. One explanation requires the existence of a light vector boson, Z_d (the dark Z), with mass 10 - 500 MeV that couples weakly to the…

High Energy Physics - Phenomenology · Physics 2015-06-05 Hooman Davoudiasl , Hye-Sung Lee , William J. Marciano

The well-known problem of the unknown power corrections within QCD improved factorisation leaves the interpretation of the so-called LHCb anomalies in the angular observables of B-->K* mu+ mu- as an open problem. In order to contribute to…

High Energy Physics - Phenomenology · Physics 2017-08-02 V. G. Chobanova , T. Hurth , F. Mahmoudi , D. Martinez Santos , S. Neshatpour

Motivated by recent progress of theory and experiment on the anomalous magnetic moment of the electron, a_e, we update the hadronic contributions to a_e. Using our up-to-date compilation of e^+ e^- \to hadrons data, we find the leading…

High Energy Physics - Phenomenology · Physics 2015-06-11 Daisuke Nomura , Thomas Teubner

We compute the renormalization mismatch displayed in 1--loop approximation by classically equivalent 4-quark operators and coming from different possible definitions of the $\gamma_5$ matrix in dimensional regularization. The result is then…

High Energy Physics - Phenomenology · Physics 2009-10-28 L. -E. Adam , K. G. Chetyrkin

A comprehensive as of November 2003 and evaluated data compilation on sigma_tot(e+ e- --> hadrons) was used to estimate the lowest order hadronic contribution to the muon anomalous magnetic moment. The preliminary result is a_mu(had, LO) =…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. V. Ezhela , S. B. Lugovsky , O. V. Zenin

We present new compact integrated expressions of SU3 breaking corrections to QCD spectral functions of heavy-light molecules and four-quark XYZ-like states at lowest order (LO) of perturbative (PT) QCD and up to d=8 condensates of the OPE.…

High Energy Physics - Phenomenology · Physics 2018-07-04 R. Albuquerque , S. Narison , D. Rabetiarivony , G. Randriamanatrika

Based on recent HQET sum rule and lattice calculations we present updated Standard Model predictions for the mass differences of neutral $B$ mesons: $\Delta M_s^{\rm SM} = \left(18.4^{+0.7}_{-1.2} \right) \mbox{ps}^{-1}$ and $\Delta…

High Energy Physics - Phenomenology · Physics 2019-12-13 Luca Di Luzio , Matthew Kirk , Alexander Lenz , Thomas Rauh

The $\mu\nu$SSM is a highly predictive alternative model to the MSSM. In particular, the electroweak sector of the model can explain the longstanding discrepancy between the experimental result for the anomalous magnetic moment of the muon,…

High Energy Physics - Phenomenology · Physics 2021-09-29 Sven Heinemeyer , Essodjolo Kpatcha , Iñaki Lara , Daniel E. López-Fogliani , Carlos Muñoz , Natsumi Nagata

The muon anomalous $g$ value, $a_\mu=(g-2)/2$, is calculated up to one-loop level in noncommutative QED. We argue that relativistic muon in E821 experiment nearly always stays at the lowest Landau level. So that spatial coordinates of muon…

High Energy Physics - Theory · Physics 2009-11-07 Xiao-Jun Wang , Mu-Lin Yan

We investigate the muon anomalous magnetic dipole moment (MDM), the muon electric dipole moment (EDM) and the lepton-flavour-violating decays of the $\tau-$lepton, $\tau \to \mu \gamma$ and $\tau\to 3\mu$, in the CP-violating Minimal…

High Energy Physics - Phenomenology · Physics 2009-11-10 Tai-Fu Feng , Tao Huang , Xue-Qian Li , Xin-Min Zhang , Shu-Min Zhao

The hadronic vacuum-polarization contribution to the muon anomalous magnetic moment a_{mu}(hadr) and to the value of the eleectromagnetic coupling constant at q^2 = M^2_z are determined more precisely in connection with a new more exact…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. V. Geshkenbein

We review in some detail the QCD corrections to the measurement of the forward-backward charge asymmetry of heavy quarks in the $\mathrm{e^+e^-\rightarrow Q\overline{Q}(g)}$ process at the Z pole. We show that the size of these corrections…

High Energy Physics - Phenomenology · Physics 2021-05-03 Juan Alcaraz Maestre

Corrections of order $\alpha_s^4$ for the axial singlet contributions for the decay rates of the $Z$-boson into hadrons are evaluated in the limit of the heavy top quark mass. Combined with recently finished ${\cal O}(\alpha_s^4)$…

High Energy Physics - Phenomenology · Physics 2015-06-03 P. A. Baikov , K. G. Chetyrkin , J. H. Kühn , J. Rittinger

We present a complete calculation of the QCD corrections (of the order $\alpha_s$) to the width of the decay $H^+ \to t \bar{b}$ within the Minimal Supersymmetric Standard Model. We find that the QCD corrections are quite important, and…

High Energy Physics - Phenomenology · Physics 2011-01-13 A. Bartl , H. Eberl , K. Hidaka , T. Kon , W. Majerotto , Y. Yamada

We show that the leading $SU(3)$-breaking corrections to the $\Delta S = 1$ $f_1$ vector form factors of hyperons are $O(m_s)$ and $O(m_s^{3/2})$, and are expected to be $\sim 20$--$30\%$ by dimensional analysis. This is consistent with the…

High Energy Physics - Phenomenology · Physics 2009-10-22 Jeffrey Anderson , Markus A. Luty

The problem of determination of $\alpha_{s}$ and the condensates from the moments of invariant mass distribution in the semileptonic tau decays is considered. It is investigated how the extracted values of alpha_s(m^{2}_{tau}) and the…

High Energy Physics - Phenomenology · Physics 2009-10-30 P. A. Raczka