Analytic Model for the QCD Running Coupling with Universal {bar {alpha}}{sub {ital s}} (0) Value
- Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Moscow Region, 141980 (Russia)
We discuss the new model expression {bar {alpha}}{sub an}( Q{sup 2}) recently obtained for the QCD running coupling with a regular ghost-free behavior in the {open_quotes}low Q{sup 2} {close_quotes} region. Being deduced from the standard {open_quotes}asymptotic-freedom{close_quotes} expression by imposing the Q{sup 2} analyticity{emdash}without any adjustable parameters{emdash}it has nice features: (i)The universal limiting value {bar {alpha}}{sub an}( 0)=4{pi}/{beta}{sub 0} expressed only via group symmetry factors and independent of experimental estimates on the running coupling {bar {alpha}}{sub s}(Q{sup 2}) (of QCD scale parameter {Lambda} ). This value is stable with respect to higher order corrections. (ii)Stability of IR behavior with respect to higher-loop effects. (iii)Coherence between the experimental {bar {alpha}}{sub an}( M{sup 2}{sub {tau}}) value and integral information on IR {bar {alpha}}{sub s}(Q{sup 2}) behavior as extracted from jet physics data. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 538595
- Journal Information:
- Physical Review Letters, Vol. 79, Issue 7; Other Information: PBD: Aug 1997
- Country of Publication:
- United States
- Language:
- English
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