Extractionofresonanceparametersfrommesonnstar共振參數提取的介子PPT學習教案

1、會計學1Extractionofresonanceparametersfrommesonnstar共振參數提取的介子共振參數提取的介子Excited baryon resonance in N, *N reactions Structure of resonance : mass, form factor, branching ratio第1頁/共15頁Mass, Width,ElectromagneticN-N* form factorsLattice QCDHadron ModelsDynamical Coupled-Channels Analysis EBACReaction Data第

2、2頁/共15頁Resonances: poles of the scattering amplitudescharacterize resonances Pole position mass, width Residue Form factorsForm Factor第3頁/共15頁N*NVPI/GWBW,Pole(AC)BWCMB,Pitt-ANLBW,Pole(AC)Bonn-GatchinaBW,Pole(AC)BW,Pole(AC)GiessenBW,Pole(SP)BWJlab/YerevanBWMAIDBWDMTBW,Pole(SP)JuelichPole(AC)EBACPole(

3、AC)BW,Pole(AC)Extraction of Resonance ParametersBW Breit-Wigner, SP speed-plot, AC Analytic continuation Dynamical model第4頁/共15頁Dynamical Model of meson production reactionCoupled channels model with N three-body unitarityG0(W): MB Green function N* Green function: mass N* vertex : form factor 第5頁/共

4、15頁Resonance Pole on unphysical sheetIm WRe WScatteringPhysical SheetBound stateResonanceUn-physical sheetNeed to examine T(W) for complex W, un-physical sheetMulti-sheets for coupled channel Ex: 2ch pp uu up pu (Kato 65,.) Resonance第6頁/共15頁Analytic continuation of T(W) T(W) : obtained by solving Li

5、ppman-Schwinger EquationlChoose appropriate path for phys/un-phys sheets (Pearce-Gibson 89)lV(p,p) must be analytic in the region of path deformation=W-planeRe WIm WRe pExample: T for un-physical sheet above thresholdp-planeIm p第7頁/共15頁Green functions with unstable particleW-planeExample: for un-phy

6、s and p-plane(Pearce Afnan 84)第8頁/共15頁Toy model N* couple with only S-wave, non-rela : analytic solution第9頁/共15頁P33Im WRe WResults from EBAC model (preliminary)Contour plot of |T(W)|MwidthRphiArndt0612119952-47Hoehler93120910050-48Cutkosly80121010053-47Doring0912189047-37第10頁/共15頁P11Pole trajectory1

7、23Multi-poles associated with single resonancein coupled channelpreliminarypolesours1357 - i 761364 - i 105R. A. Arndt et al. 1359 - i 821388 - i 83M. Doring et al.1387 - i 147/21387 - i 71第11頁/共15頁Pole of T matrix gives resonance information Mass and width from pole position, form factors from resi

8、dueA method to extract resonance parameters using analytic continuation of the scattering amplitude is developed.Applied for N scattering amplitude of EBAC current model P33, P11 resonance poles are extractedExtracting resonance form factor is in progress.第12頁/共15頁Resonance MassResonance Form Factor (complex number)第13頁/共15頁PDG 08: BW and Pole Example P11BWPoleArnt06 (AC)1485 284i/21354 162i/2Cutkosky80(AC)1440 340i/21375 180i/2Vrana00 (AC)1479 490i