Extraction of resonance parameters from meson star 共振參數(shù)提取的介子 NSTAR

1、extraction of resonance parameters from meson production reactionst. sato (osaka u.)collaborators: n. suzuki(osaka) t.-s. h. lee(anl) and b. julia-diaz(barcelona), h. kamano(jlab), a. matsuyama(shizuoka) suzuki, sato, lee prc 79 (2009) 025205 motivation dynamical model of meson production reaction e

2、xtraction of resonance parameters, (analytic continuation of scattering amplitudes) p33 and p11 from current ebac model summary excited baryon resonance in n, *n reactions structure of resonance : mass, form factor, branching ratiomass, width,electromagneticn-n* form factorslattice qcdhadron modelsd

3、ynamical coupled-channels analysis ebacreaction dataresonanceresonances: poles of the scattering amplitudescharacterize resonances pole position mass, width residue form factorsform factorn*nvpi/gwbw,pole(ac)bwcmb,pitt-anlbw,pole(ac)bonn-gatchinabw,pole(ac)bw,pole(ac)giessenbw,pole(sp)bwjlab/yerevan

4、bwmaidbwdmtbw,pole(sp)juelichpole(ac)ebacpole(ac)bw,pole(ac)extraction of resonance parametersbw breit-wigner, sp speed-plot, ac analytic continuation dynamical modeldynamical model of meson production reactioncoupled channels model with n three-body unitarityg0(w): mb green function n* green functi

5、on: mass n* vertex : form factor 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,.) resonanceanalytic continuation of t(w) t(w) :

6、obtained by solving lippman-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 pgreen functions with unstable particlew-planeexamp

7、le: for un-phys and p-plane(pearce afnan 84)toy model n* couple with only s-wave, non-rela : analytic solutionp33im wre wresults from ebac model (preliminary)contour plot of |t(w)|mwidthrphiarndt0612119952-47hoehler93120910050-48cutkosly80121010053-47doring0912189047-37p11pole trajectory123multi-pol

8、es 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 71summarypole of t matrix gives resonance information mass and width from pole position, form factors from residuea method t

9、o 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.resonance massresonance form factor (complex number)pdg 08: bw and pole example p11bwpolearnt06 (ac)1485 284i/21354 162i/2cutkosky80(ac)1440 340i/21375 180i/