Bugs fixing in UrQMD 1.3 and 2.3 Improvements of UrQMD model for simulation of PbarP and PbarA interactions A. Galoyan, V. Uzhinsky Bugs fixing in UrQMD 1.3 and 2.3 Stohastic interactions 1

2

Bug fixing in UrQMD 1.3 File make22.f 3 Determination of the c...get minimal masses * call getirg(i1,i1m,i1p) ! Uzhi call getirg(iabs(i1),i1m,i1p) ! Uzhi m1m=mminit(i1m) call getirg(i2,i2m,i2p) ! Uzhi call getirg(iabs(i2),i2m,i2p) ! Uzhi m2m=mminit(i2m) Determination of the range of possible baryon resonances. It was wrong For anti-baryons! File make22.f 3

Bug fixing in UrQMD 1.3 It has a low influence on the produced mesons 4

Bug fixing in UrQMD 2.3 There was the analogous mistake: File make22.f c...get minimal masses * call getirg(i1,i1m,i1p) ! Uzhi call getirg(iabs(i1),i1m,i1p) ! Uzhi m1m=mminit(i1m) call getirg(i2,i2m,i2p) ! Uzhi call getirg(iabs(i2),i2m,i2p) ! Uzhi m2m=mminit(i2m) Determination of the range of possible baryon resonances. It was wrong For anti-baryons! File make22.f Plus a new bug! c symmetrize or not angular distribution (depending on iline) c this data statements may be changed ... data symlog /14*.true., 1*.false., 6*.true., 7*.false., & 7*.true., 1*.false., 2*.true.,.false./ ! Uzhi ! & 7*.true., 1*.false., 2*.true./ ! Uzhi File angdis.f Angular distribution for a new PbarP reaction channel (39) was not determined! 5

Difference between UrQMD 1.3 and UrQMD 2.3 A new process (XX-> 1/2 strings) has been added in UrQMD 2.3 6

UrQMD 1.3 and UrQMD 2.3 There are some problems with baryon spectra. 7

UrQMD 1.3 and UrQMD 2.3 There are some problems with meson spectra. 8

UrQMD 1.3 and UrQMD 2.3 Meson spectra are too symmetric. There are too many heavy mesonic resonances in the annihilation. 9

UrQMD 1.3 and UrQMD 2.3 Strange peak in proton spectra at Pt=0 (diffraction?). 10

Improved UrQMD 1.3 in PandaRoot for Pbar A interactions Difference only 3 – 5 %. 11

Improved UrQMD 1.3 in PandaRoot for Pbar A interactions Difference in high energy tail. 12

Improved UrQMD 1.3 in PandaRoot for Pbar A interactions Difference is very small. 13

Improved UrQMD 1.3 in PandaRoot for Pbar A interactions Difference is very small. 14

Implementation of ΞΞbar production It is heavily to estimate and repeat calculations by A. Kaidalov and P.Volkovitsky (Z. Phys. C 63, 517-524 (1994) 15

Implementation of ΞΞbar production in every event of UrQMD+SMM model Thus, for estimation of the Nuclear re-scattering we assume 1. That Xi0 XiBar, Xi+, XiBar- are produced in each annihilation act. 2. The following propagation of the Xi is governed by UrQMD nucleon potentials (Skyrm, Yukawa, Pauli, Coulomb). 3. We are collecting and studying the corresponding references. There can be other potentials. They can be accounted. Algorithm 1. Changes in make22.f, urqmd.f, angdisnew.f, output.f files 2. We consider all possible annihi- lations of quarks. (Quarks of projectile can be changed during propagation before the annihilations). 3. We did not include Xi’s in nuclear residuals, though such events of capture take place. 16

Implementation of ΞΞbar production pbar + p at P_lab= 3GeV/c 17 Changes in angdisnew.f

Implementation of ΞΞbar production pbar + C at P_lab= 3GeV/c We did not considered clusterisation. J. Pochodzalla, Phys. Lett. B 669 (2008) 306, Exploring the potential of antihyperons in nuclei with antiprotons 18

Conclusion A lot of experimental data on inclusive PbarP interactions has been collected. 2. Bugs are fixed in UrQMD 1.3 and 2.3. An influence of the bugs on the results presented in Panda TPR is very small. 3. ΞΞbar production is implemented in UrQMD generator for PANDA hyper-nuclear program. The same can be done for charmed meson and baryon production. 19