| 30 | === Code changes === |
| 31 | |
| 32 | A few changes are made in the code to have access to more information about the particles in the event sample produced in `LPAIR`, especially to distinguish the muons from the exclusive production from the remnants from the proton break up. Then, two changes are made in the file //ilpair-cms-pp.f// in order to store information from `JetSet` in the `HBOOK` files: |
| 33 | |
| 34 | 1. particle status code, //ks//, at line 246; and |
| 35 | |
| 36 | 2. particle parentage, //icode//, at line 248. |
| 37 | |
| 38 | Also, taking advantage for the fact that `LPAIR` performs the theoretical calculation in terms of Q^2^, the p,,T,, cut is internally applied by means of a Q^2^ cut in file //peripp.f// at line 29. |
| 39 | |
| 40 | |
75 | | 2. Parametrization by Fiore et al. |
76 | | |
77 | | To be added |
| 86 | 2. Parametrization by Fiore et al [[http://epja.epj.org/articles/epja/abs/2002/10/100500505/100500505.html|Eur. Phys. J. A 15, 505-515 (2002)]]. |
| 87 | |
| 88 | >**Abstract**: An explicit model realizing parton-hadron duality and fitting the data is suggested. Complex nonlinear Regge trajectories are important ingredients of the |
| 89 | >model. The inclusion of ∆ and N^∗^ trajectories should account for all resonances in the direct channel. The exotic trajectory is responsible for the smooth background. |
| 90 | |
| 91 | This parametrization is meant to fit the data for the low Q^2^ region, reproducing the resonances of low-mass mesons. The figure below shows the distribution F,,2,, vs. `x` for Q^2^ = 0.5 GeV^2^: |
| 92 | |
| 93 | [[Image(source:/trunk/plots/FIORE_F2_x.png, 500px)]] |
| 94 | |
| 95 | === Variables === |
| 96 | |
| 97 | The final-state kinematics is used to make the distributions in terms of the variables of the interacting particles, like the photon virtuality, Q^2^, by: |
| 98 | |
| 99 | > Q^2^ = [P,,p,,(E)-p,,rem,,(E)]^2^-[P,,p,,(x)-p,,rem,,(x)]^2^-[P,,p,,(y)-p,,rem,,(y)]^2^-[P,,p,,(z)-p,,rem,,(z)]^2^ |
| 100 | |
| 101 | and the momentum fraction of the proton carried by the photon, x, by |
| 102 | |
| 103 | > x = Q^2^/(M,,X,,^2^-M,,p,,^2^+Q^2^), |
| 104 | |
| 105 | with ξ given by |
| 106 | |
| 107 | > ξ=`log`,,10,,(x) |
| 108 | |
220 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_etapair_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_etapair_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
221 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_etarem_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_etarem_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
222 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_invm_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_invm_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
223 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_invmlarge_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_invmlarge_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
224 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_mx_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_mx_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
225 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_mx_zoom_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_mx_zoom_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
226 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_mx_zoom2_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_mx_zoom2_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
227 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_mx2_zoom_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_mx2_zoom_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
228 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_mx2_zoom2_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_mx2_zoom2_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
229 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_ptpair_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_ptpair_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
230 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_ptpairlarge_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_ptpairlarge_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
231 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_Q2_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_Q2_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
232 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_Q2large_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_Q2large_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
233 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_x_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_x_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
234 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_xi_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_xi_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
235 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_xilog_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_xilog_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
236 | | || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_SURI:cuts-nocuts_1Mevt_ypair_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || [[Image(source:/trunk/plots/exp_cuts/ratio_MXmax_300GeV/RATIO_GRV:cuts-nocuts_1Mevt_ypair_Q2_nocut_exp_accp_MXmax_300.png, 500px)]] || |
| 252 | |||| to be added || |
| 253 | |