
Change Log
----------
**********
1.1 => 1.2
**********

Physics
-------



Usage
-----

- new environment variable URQMD_TAB to find tables.dat
  if you use different platforms we suggest to set
  export URQMD_TAB=tables.`uname`

- complete rewrite of gnuranf. There have been some problems with
  genranf.f on Linux machines. gnuranf.f is now default for Linux. 


Bugs
----

- redirection of OSCAR output via was ftn19 missing
- wrong sign for angular distributions 
- changes to support SunOS


**********
1.2 => 1.3
**********

Physics
-------

Low energy (E-lab<2 GeV) strangeness production now modeled more accurately.
For details see PhD thesis of H. Weber, Uni Frankfurt (2003).

Bug fixes
---------

Nucleus initialization for cascade mode had an unphysical peak on the outer
edges of the distribution. Now a correct Woods-Saxon shape is used.

**********
1.3 => 2.3
**********

Physics
-------

Pythia 6.409 has been implemented to allow for pQCD scatterings.
This is influences ALL observables above SPS energies.
Coherent scattering is important at high energies but not properly included, it is
mimicked by a reduced leading particle cross section.	

s-channel resonance formation below sqrt s=3 GeV, is not
treated as string anymore, instead the formed object is projected onto
a resonance state. Here the highest mass resonance is choosen and the
decay branching are extrapolated to m=sqrt s.
This leads to increased flow at all energies. 

Slight refit of mulitplicities in pp to incorporate new data.
	
The intermediate versions 2.0-2.1 are described in more detail in 
E. Bratkovskaya et al, Phys.Rev.C69:054907,2004. 
This paper also compares UrQMD 1.3 with the UrQMD 2.0/2.1.
UrQMD 2.3 includes only minor modifications compared to version 2.1 and 2.2.
	

!!! output format has been changed for files 13,14,16 !!!
!!! this might create problems with analysis tools    !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
This was necessary to allow for PDG particle ID.
PDG IDs are shifted by 1000 (OSCAR output however has the proper PDG-IDs).
	
Format changes:         
old: 201  format(9e16.8,i5,2i3,i6,i5,i4)
new: 201  format(9e16.8,i11,2i3,i9,i5,i4)
--        
old: 210  format(9e16.8,i5,2i3,i6,i5,i10,3e16.8,i8)
new: 210  format(9e16.8,i11,2i3,i9,i5,i10,3e16.8,i8)
--
old: 213  format(9e16.8,i5,2i3,i6,i5,i4,8e16.8)
new: 213  format(9e16.8,i11,2i3,i9,i5,i4,8e16.8)
--
old: 501  format(i5,9e16.8,i5,2i3,i6,i5,i3,i15)
new: 501  format(i5,9e16.8,i11,2i3,i9,i5,i3,i15)
--
old: 503  format(9e15.7,i5,2i3,i6,i5,i4,2i4)
new: 503  format(9e15.7,i11,2i3,i9,i5,i4,2i4)
--
old: 302  format (a7,i9,a13,i12,a9,a20,i4,a20,f7.3)
new: 302  format (a7,i9,a13,i12,a9,a20,i7,a20,f11.3)
	
Replaced total cross sections from CERN-HERA by Regge cross
sections. This changes the cross section (in line with data) 
for ultra-high energetic interactions (E_cm>500 GeV).

Includes new FAST Woods-Saxin initialisation (Switch on 
with CTOption 24 =2). This is very important for speed-up in 
Cosmic Ray simulations!
	
Some small bugfixes.

**********
2.3 => 3.3
**********

Physics
-------

Charm rescattering
Implementation of charmed hadrons with the following itype's:
D (133), D* (134), J/Psi (135), Psi' (136), chi_c (137)

Rescattering cross sections with pions and rho's included as well, both elastic
and inelastic D+pi -> D*, rho + J/Psi -> D+\bar{D} and rho + J/Psi -> D*+ \bar{D*}

Cross sections have been parameterized from work done by Zi-Wei Lin:
Nucl.Phys.A689:965-979,2001 and Phys.Rev.C62:034903,2000

UrQMD + Hydro
It is possible to run UrQMD with a hydrodynamic evolution for the hot and dense
stage of the heavy ion reaction. Default calculations are still the cascade
mode calculations. For the physics changes please refer to arXiv:0806.1695. The
hydrodynamic evolution is calculated via the SHASTA algorithm. 

* New files 1fluid.f, bessel.f, defs.f, uhmerge.f and new directory with tables
  for the equation of state (eosfiles) have been added

* output.f: new entry f15outhy is implemented to generate output in f15 if
  hydro is called. $nin$ is set to 9 and one header line and nine particle
  lines at the beginning and in the end of the hydrodynamic evolution is
  printed consisting only of zeroes except of the time information.

* New options and parameters:
  - CTOption(45)=1 : hydro mode (default is cascade calculation)
  - CTOption(47)=2 : hadron gas EoS (default)
  - CTOption(47)=3 : Bag model EoS
  - CTOption(47)=5 : chiral + hadron gas EoS 
  - CTOption(48)=N : flag for only  N timesteps of hydro evolution (test case)
  - CTOption(49): spectator switch: 0 (default)$\rightarrow$spectators are
                  propagated seperately; 1 $\rightarrow$ spectators are also
                  put on the hydro grid
  - CTOption(50)=1: (additional) f14/f19-output directly after hydro evolution;
                    time is equal to $t_{\rm hydrostart}$ because of back
                    propagation, resonances decay immediately
  - CTOption(52): freeze-out switch: 0 (default) $\rightarrow$ isochronous
                  transverse slices; 1 $\rightarrow$ completely isochronous
                  freeze-out os the whole system 
  - CTOption(53): switch for improved momentum generation, default is zero and
                  any other number leads to old prescription with in any case
                  high enough maxima
  - CTParam(61)= 0.2 fm : dx is the cell size for the hydro code
  - CTParam(62)= 200 : ngr is the grid size of the hydro code
  - CTParam(63)= 1. fm : is the minimal $t_{\rm hydrostart}$
  - CTParam(64)= 5 is the factor for the freezeout criterium ($x*\epsilon_0$)
  - CTParam(65)= 1 is multiplied with $t_{\rm hydrostart}$
  - CTParam(66)=1.d10 is the rapidity cut for the matter that is put on the
                      hydrodynamic grid, necessary for calculations at higher
                      energies than $E_{\rm}=160A~$GeV. 
* Output in timesteps according to tim statement in inputfile is not
  consistently possible during the hydrodynmic evolution 

* The option for test cases cto 48 does not work when using the bag model
  equation of state. 

* Cut in uhmerge.f to stabilize the Cooper-Frye Monte Carlo has been
  introduced. 

* f15-output has been adjusted. There is now one collision entry before the
  hydro evolution with npart ingoing particles and no outgoing particles and
  the opposite after the hydro evolution. Therfore the format 502 of the header
  line has been changed from format(i1,i8,i4,i7,f8.3,4e12.4) to
  format(i8,i8,i4,i7,f8.3,4e12.4). Since there is now an interaction with 0
  ingoing particles which was the signal for a new event, the header-line of a
  new event starts now with a -1.

Bug Fixes
* Completely new makefile is written. Please use "make help" for information.
* anndec.f: New subroutine getbran which gives reasonable values back even if
  summed cross section is very small. 
* scatter.f: Disable elastic scattering for pp collisions now works stable
  (CTOption(7))
* blockres.f Branching ratios for hyperon resonances are adjusted in order to
  ensure that they sum up to one (thanks to Pasi Huovinen).
* CTParam(67) allows for testparticle calculations (default is one testparticle
  per real particle). If this parameter is used with a value different from one
  the variable ncollmax in colltab.f has to increased (by CTParam(67)/2) and
  AAmax should be set to 300*CTParam(67) in inputs.f. After that the code has
  to be recompiled and the file 'tables.dat' has to be removed and newly
  generated. The output does not account for the testparticles and has to be
  scaled accordingly. Furthermore, the computig time increases when using this
  parameter. 
* scatter.f: The freeze-out coordinates in position space are changed to take
  into account the formation times of particles produced in string
  fragmentation processes. Only formed hadrons are able to decouple from the
  system. 


************
3.3 => 3.3p1
************

Bugfix in output.f, concerning file f19 and charmed particles.


************
3.3p1 => 3.4
************

Physics
-------

* A new, more realistic, iso-energy density particlization hypersurface
 has been introduced (see arXiv:1206.3371).
* Tables for Hadron-Gas and Chiral+Deconfinement EoS have been extended to accommodate for
  energy densities up to 400 times nuclear ground state energy density. This is needed for
  LHC calculations.
* Charm rescattering has been reworked. The following particles are now included:
  D(133), D* (134), J/Psi (135), Chi_c (136), Psi'(137), D_s(138), D*_s(139). Additionally
  to elastic scattering the following processes are included: pi+D <-> rho+D*,
  pi+D* <-> rho+D, (phi,rho,K) + (J/Psi,Chi_c,Psi') <-> (D,D*,D_s,D*_s),
  (J/Psi,Chi_c,Psi') + Baryon -> Baryon. Cross-sections have been parametrized to fit
  results from [arXiv:nucl-th/0006086,nucl-th/9912046,nucl-ex/0612012,nucl-ex/0609039
  nucl-th/0301083]. Where no elastic cross-section was found, a constant 5 mb elastic
  cross-section is assumed.
* The meltpoint in Antibaryon + Meson collisions has been raised from 1.7~GeV to 2.18~GeV
  to account for the cross-section of resonances above the meltpoint, accidentally being
  lowered. Also the n + pi- meltpoint has been lowered to the p + pi+ meltpoint.

 
 
* New or changed Options and Parameters:
  -CTOption(52)=2 activates the iso-energy density particlization and is now default
  -CTOption(54) OSCAR 2008H output during hydro evolution; 0:(default) disabled
  -CTOption(55)=1 adjusts .f19 file for visualization output. (no longer OSCAR standard!)
                      fluidization (see arXiv:1104.3981)
  -CTParam(59) scaling factor for leading hadron cross section changed from 0.4 to 0.7 to
               account for new LHC data
  -CTParam(68) =1.d0 width 0f 3d Gaussian density calculations at fluidization
  -CTParam(69) =0.d0 quark density cut for fluidization (core-corona separation) in units
                     of three times the groundstate quark density (see arXiv:1104.3981)
  -CTParam(70) =1.d10 pseudorapidity cut to calculate the core density for core-corona at
  -CTParam(71) =2 (default) constructs the hypersurface at every second timestep
                1: enabled (full evolution)
                2: enabled (hyper surface)

Misc
----
* UrQMD can now be compiled for usage at LHC energies by entering 'make LHC'. This results
  in larger output files.
* New process identifiers 91 and 96 have been introduced to mark fluidization and
  particlization output to .f15
* The number of collisions on the Standard Output now counts also collisions before the
  Hydro phase
* UrQMD checks for many cases of physical, as well as numerical consistency during runtime.
  Should an inconsistency arise for any reason the code halts. In this case, UrQMD now
  returns "137" instead of "0" which is the default return value if no error occurred. This
  is useful to check automatically for aborted UrQMD runs.
* The current UrQMD version tag is now consistent in all output files. In all previous
  UrQMD versions, the string had been hard-coded to "1.2"
* Removed some non-critical warnings that were not useful for the user


Bug Fixes
---------
* In particlization, Bose-Einstein statistics instead of Boltzmann statistics is used fo K
  (ityp=±106) and K*_{893}(ityp=±108)
* A problem regarding isospin symmetry between meson-baryon and meson-antibaryon
  scattering as well as a false scaling factor for meson-antibaryon scattering has been
  fixed:
    -Previously, reactions like antiproton + pi- would be calculated using the n + pi-
    cross-section instead of the (proper) p + pi+ cross-section.
    -All resonant AntiBaryon+Meson scattering cross-sections were falsely reduced by a
    combinatorial factor of two which is needed for the scattering of strange mesons with
    strange antimesons of different type, e.g. Kbar + K*.
* A wrong assignment of the next collision partner happened in rare cases. Fixing this did
  not result in any changes in physics.
* Charmed particle are assigned correct charges now. Previously, UrQMD ostensibly did not
  conserve electric charge in some instances. This bug only affected the output. Charge in
  UrQMD is not a independent variable. All relevant quantum numbers have been, and
  always are, exactly conserved in UrQMD.
* The baryon density calculation in presence of anti-baryons is corrected. This is
  relevant when using the .f15 output to analyze baryon densities. The baryon-current
  restframe velocity was calculated wrongly depending on how many anti-baryons were
  present.
* In very rare cases of a pauli-blocked meson+baryon-string excitation, in which the
  string creates a baryon-antibaryon pair, the program threw a segmentation fault. This
  has been fixed.
* All MB interactions that could not do a quark/antiquark annihilation annihilation
  accidentally had a 12.5 mbarn cross section below the sighera meltpoint. This has been
  fixed.
* Xi+Kbar -> Omega violated detailed balance, since the Omega does not decay in UrQMD. Now
  this collision is treated as a string, which results mostly in Xi+Kbar -> Xi+Kbar+pi
* The symmetry coefficients were a factor of 2 too small for pi+pi0, pi-pi0, rho+rho0,
  rho-rho0 channels. This has been fixed.
* Mesons coming from the last string break got zero transverse momentum. We made the
  changes proposed by V.Uzhinsky [arXiv:1107.0374]
* In very rare cases nucleon resonances up to 5 GeV could be produced. This overpopulated
  the p+p and peripheral p+Au p_T spectra at p_T > 2 GeV at low collision energies. 

