Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userN^3LO fits to xF_3 data : $alpha_s$ vs 1/Q^2 contributions
44
0
0.0
(
0
)
Authors
A.L.Kataev
Ask ChatGPT about the research
No Arabic abstract
The results of approximate N$^$3LO and detailed NNLO fits to $xF_3$ data of the CCFR97 collaboration are presented. We demonstrate that $1/Q^2$ non-perturbative corrections to $xF_3$ modeled by three independent procedures are shadowed by perturbative QCD effects, starting at the NNLO. Special attention is paid to revealing the role of the recently calculated NNLO corrections to the anomalous dimensions and $N^3$LO corrections to the coefficient functions of odd moments of $xF_3$ with $nleq 13$. The related values of $alpha_s(M_Z)$ are extracted.
rate research
Read More
We briefly summarize the outcomes of our recent improved fits to the experimental data of CCFR collaboration for $xF_3$ structure function of $ u N$ deep-inelastic scattering at the next-to-next-to-leading order. Special attention is paid to the extraction of $alpha_s(M_Z)$ and the parameter of the infrared renormalon model for $1/Q^2$-correction at different orders of perturbation theory. The results can be of interest for planning similar studies using possible future data of Neutrino Factories.
The logarithmic contributions to the massive twist-2 operator matrix elements for deep-inelastic scattering are calculated to $O(alpha_s^3)$for general values of the Mellin variable $N$.
The twist--2 heavy flavor contributions to the polarized structure function $g_2(x,Q^2)$ are calculated. We show that this part of $g_2(x,Q^2)$ is related to the heavy flavor contribution to $g_1(x,Q^2)$ by the Wandzura--Wilczek relation to all orders in the strong coupling constant. Numerical results are presented.
The strong coupling constant $alpha_s$ and the heavy-quark masses, $m_c$, $m_b$, $m_t$ are extracted simultaneosly with the parton distribution functions (PDFs) in the updated ABM12 fit including recent data from CERN-SPS, HERA, Tevatron, and the LHC. The values of begin{eqnarray} onumber alpha_s(M_Z)&=&0.1147pm0.0008~({rm exp.)}, onumber m_c(m_c)&=&1.252pm 0.018~({rm exp.})~{rm GeV}, onumber m_b(m_b)&=&3.83pm0.12~({rm exp.})~{rm GeV}, onumber m_t(m_t)&=&160.9pm1.1~({rm exp.})~{rm GeV} end{eqnarray} are obtained with the $overline{MS}$ heavy-quark mass definition being employed throughout the analysis.
In the asymptotic limit $Q^2 gg m^2$, the heavy flavor Wilson coefficients for deep--inelastic scattering factorize into the massless Wilson coefficients and the universal heavy flavor operator matrix elements resulting from light--cone expansion. In this way, one can calculate all but the power corrections in $(m^2/Q^2)^k, k > 0$. The heavy flavor operator matrix elements are known to ${sf NLO}$. We present the last 2--loop result missing in the unpolarized case for the renormalization at 3--loops and first 3--loop results for terms proportional to the color factor $T_F^2$ in Mellin--space. In this calculation, the corresponding parts of the ${sf NNLO}$ anomalous dimensions cite{LARIN,MVVandim} are obtained as well.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
