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00008 #include "HepPDT/defs.h"
00009 #include "HepPDT/ResonanceStructure.hh"
00010
00011 namespace HepPDT {
00012
00013 Measurement ResonanceStructure::lifetime( ) const
00014 {
00015
00016 static double epsilon = 1.0e-25;
00017 static double hbar = 6.58211889e-25;
00018 double life, err;
00019 if( itsTotalWidth.value() < epsilon ) {
00020
00021 return Measurement( 0., 0.);
00022 }
00023 life = hbar / itsTotalWidth.value();
00024 if( itsTotalWidth.sigma() < epsilon ) {
00025 err = 0.;
00026 } else {
00027 err = ( itsTotalWidth.sigma()/ itsTotalWidth.value() ) * life;
00028 }
00029 return Measurement( life, err );
00030 }
00031
00032 }