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Titolo:
O(alpha(2)(s)) corrections to e(+)e(-)-> t(t)over-bar total and differential cross sections near threshold - art. no. 114014
Autore:
Nagano, T; Ota, A; Sumino, Y;
Indirizzi:
Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan Tohoku Univ Sendai Miyagi Japan 9808578 ys, Sendai, Miyagi 9808578, Japan
Titolo Testata:
PHYSICAL REVIEW D
fascicolo: 11, volume: 6011, anno: 1999,
pagine: 4014 -
SICI:
0556-2821(199912)6011:11<4014:OCTETT>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
QUARK PAIR PRODUCTION; PRODUCTION NEAR-THRESHOLD; TO-LEADING ORDER; QCD CORRECTIONS; T(T)OVER-BAR PRODUCTION; MOMENTUM DISTRIBUTIONS; E(+)E(-) ANNIHILATION; HEAVY; DECAY; WIDTH;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
--discip_EC--
Citazioni:
50
Recensione:
Indirizzi per estratti:
Indirizzo: Nagano, T Tohoku Univ, Dept Phys, Aoba Ku, Sendai, Miyagi 9808578, Japan Tohoku Univ Aoba Ku Sendai Miyagi Japan 9808578 i 9808578, Japan
Citazione:
T. Nagano et al., "O(alpha(2)(s)) corrections to e(+)e(-)-> t(t)over-bar total and differential cross sections near threshold - art. no. 114014", PHYS REV D, 6011(11), 1999, pp. 4014

Abstract

Recently full O(alpha(s)(2),alpha(s)beta,beta(2)) corrections to the threshold total cross section for e(+)e(-) --> t (t) over bar have been calculated, and the reported corrections turned out to be unexpectedly large. We study how to reduce the theoretical uncertainties of the cross section. We adopt a new mass definition proposed by Beneke, which incorporates a renormalon-pole cancellation in the total energy of a static quark-antiquark pair. This improves the convergence of the 1S resonance mass, while the normalization of the cross section scarcely changes. We argue that resummations of logarithms are indispensable, since two largely separated scales dictate theshape of the cross section. As a first step, we resum logarithms in the Coulombic part of the t (t) over bar potential, and observe a considerable improvement in the convergence of corresponding corrections. There still remain, however, large corrections, which arise from a 1/r(2) term in the t (t)over bar potential. We also calculate full O(alpha(s)(2),alpha(s)beta,beta(2)) corrections to the momentum distributions of top quarks in the threshold region. Corrections to the distribution shape are of moderate size over the whole threshold region. [S0556-2821(99)02321-8].

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Documento generato il 03/12/20 alle ore 15:50:51