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pegasus:overview [23/04/2020 10:27] – lipatovpegasus:overview [15/04/2024 10:14] (current) – lipatov
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 ====== Overview ====== ====== Overview ======
  
-Here we give a some information and explanations about the important features of PEGASUS.+Here we give some information and explanations about the important features of PEGASUS.
  
 ===== Physical problem and solution ===== ===== Physical problem and solution =====
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 However, theoretical description of a number of high energy processes proceeding with large momentum  However, theoretical description of a number of high energy processes proceeding with large momentum 
 transfer and containing multiple hard scales needs for transverse momentum dependent (TMD) parton (quark transfer and containing multiple hard scales needs for transverse momentum dependent (TMD) parton (quark
-or gluon) distributions in a proton. These quantities encode the nonperturbative information on proton structure, including transverse momentum and polarization degrees of freedom and satisfy the +or gluon) distributions in a proton and nuclei. These quantities encode the nonperturbative information on hardon structure, including transverse momentum and polarization degrees of freedom and satisfy the 
 Balitsky-Fadin-Kuraev-Lipatov (BFKL) or Catani-Ciafaloni-Fiorani-Marchesini (CCFM) evolution equations. Balitsky-Fadin-Kuraev-Lipatov (BFKL) or Catani-Ciafaloni-Fiorani-Marchesini (CCFM) evolution equations.
 The hadron-level Monte-Carlo event generator [[https://cascade.hepforge.org|CASCADE]] and The hadron-level Monte-Carlo event generator [[https://cascade.hepforge.org|CASCADE]] and
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 PEGASUS is a newly developed parton-level Monte-Carlo event generator PEGASUS is a newly developed parton-level Monte-Carlo event generator
 designed to calculate cross sections for a wide range of hard QCD processes,  designed to calculate cross sections for a wide range of hard QCD processes, 
-which incorporates the TMD gluon dynamics in a proton.+which incorporates the TMD gluon dynamics in a proton and nuclei.
 It provides all necessary components, including  It provides all necessary components, including 
 off-shell (dependent on the transverse momenta) production off-shell (dependent on the transverse momenta) production
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 extremely user friendly interface, which allows one  extremely user friendly interface, which allows one 
 to easily implement various kinematical cuts into the calculations. to easily implement various kinematical cuts into the calculations.
-Generated events (weighted or unweighted) can be stored in the  +Generated events (weighted or unweighted) can be stored in the [[https://arxiv.org/abs/hep-ph/0609017|Les Houches Event]] file or presented "on the fly" with convenient
-Les Houches Event file or presented "on the fly" with convenient+
 built-in tool [[pegasus:plotter|PEGASUS Plotter]]. built-in tool [[pegasus:plotter|PEGASUS Plotter]].
  
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 The calculations using PEGASUS include a few general steps common for all of the processes. The calculations using PEGASUS include a few general steps common for all of the processes.
-When PEGASUS is running, one can select the colliding particles, proton-proton or proton-antiproton,  +When PEGASUS is running, one can select the colliding particles, proton-proton, proton-antiproton, proton-nucleus or electron-proton,  
-and set their center-of-mass energy. The default setting corresponds to the LHC Run II setup.+and set beam energies. The default setting corresponds to the LHC Run II setup.
 Then one can select factorization scheme (TMD or collinear one) for each of the colliding particles, choose corresponding parton density function and set the parameters, important  Then one can select factorization scheme (TMD or collinear one) for each of the colliding particles, choose corresponding parton density function and set the parameters, important 
 for further Monte-Carlo simulation, namely, number of iterations and number of simulated events per iteration. for further Monte-Carlo simulation, namely, number of iterations and number of simulated events per iteration.
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   * The user-defined setup for any process (total center-of-mass energy, selected parton densities, kinematical restrictions, binnings etc) can be saved to a configuration file in some internal format (''*.pegasus''). This can be done via the main menu (using //File -> Save// or //File -> Save As// options) or via the popup menu available on right mouse button click or via appropriate button in the button panel. Of course, the configuration file can be loaded and a user-defined setup can be used in further applications. This can be done via main menu (with //File -> Open// option) or via popup menu or via //Open// button on the button panel.    * The user-defined setup for any process (total center-of-mass energy, selected parton densities, kinematical restrictions, binnings etc) can be saved to a configuration file in some internal format (''*.pegasus''). This can be done via the main menu (using //File -> Save// or //File -> Save As// options) or via the popup menu available on right mouse button click or via appropriate button in the button panel. Of course, the configuration file can be loaded and a user-defined setup can be used in further applications. This can be done via main menu (with //File -> Open// option) or via popup menu or via //Open// button on the button panel. 
   * Weighted or unweighted events can be generated. This option is available via main menu //Edit -> Settings -> Generated events// or via popup menu.   * Weighted or unweighted events can be generated. This option is available via main menu //Edit -> Settings -> Generated events// or via popup menu.
-  * If one needs to generate the Les Houches Event file, one has to mark corresponding option before the calculation starts. Note that this option affects the speed of the calculations.+  * If one needs to generate the [[https://arxiv.org/abs/hep-ph/0609017|Les Houches Event]] file, one has to mark corresponding option before the calculation starts. Note that this option affects the speed of the calculations.
   * The calculation will start by choosing the corresponding option in main menu (//Calculation -> Start//), popup menu or pressing //Start// button on the button panel. The numerical results for requested observables will be immediately presented "on the fly" with built-in tool [[pegasus:plotter|PEGASUS Plotter]]. The calculations can be paused or even stopped (using main menu options //Calculation -> Pause//, //Calculation -> Stop//, corresponding buttons on the button panel or options in popup menu).   * The calculation will start by choosing the corresponding option in main menu (//Calculation -> Start//), popup menu or pressing //Start// button on the button panel. The numerical results for requested observables will be immediately presented "on the fly" with built-in tool [[pegasus:plotter|PEGASUS Plotter]]. The calculations can be paused or even stopped (using main menu options //Calculation -> Pause//, //Calculation -> Stop//, corresponding buttons on the button panel or options in popup menu).
   * If there are several contributing subprocesses, there is a possibility to immediately jump to the next one (via //Calculation -> Next// option in main menu or appropriate button on button panel or popup menu) during the calculations.   * If there are several contributing subprocesses, there is a possibility to immediately jump to the next one (via //Calculation -> Next// option in main menu or appropriate button on button panel or popup menu) during the calculations.
  
-The generated events can be accumulated in Les Houches Event (''*.lhe'') file and/or presented in [[pegasus:plotter|PEGASUS Plotter]]. Using the latter, one can save the results in a some internal format (''*.pplot'') or as a simple plain data (compatible, for example, with [[http://www.gnuplot.info|Gnuplot]] package) or export them to an image (''*.pdf'', ''*.png'', ''*.jpg'' or ''*.bmp'').+The generated events can be accumulated in a Les Houches Event (''*.lhe'') file and/or presented in [[pegasus:plotter|PEGASUS Plotter]]. Using the latter, one can save the results in a some internal format (''*.pplot'') or as a simple plain data (compatible, for example, with [[http://www.gnuplot.info|Gnuplot]] package) or export them to an image (''*.pdf'', ''*.png'', ''*.jpg'' or ''*.bmp'').
  
 ===== Implemented TMD gluon densities in a proton ===== ===== Implemented TMD gluon densities in a proton =====
  
 ^ Set      ^  Order of a<sub>s</sub>      ^  N<sub>f</sub>  ^  QCD scale [MeV]  ^  Reference  ^ ^ Set      ^  Order of a<sub>s</sub>      ^  N<sub>f</sub>  ^  QCD scale [MeV]  ^  Reference  ^
 +| LLM (CCFM)  |  2  |  4  |  200  |  [[https://arxiv.org/abs/2211.03727|A.V. Lipatov, G.I. Lykasov, M.A. Malyshev]]  |
 | A0 (CCFM)  |  1  |  4  |  250  |  [[https://arxiv.org/abs/hep-ph/0411287|H. Jung]]  | | A0 (CCFM)  |  1  |  4  |  250  |  [[https://arxiv.org/abs/hep-ph/0411287|H. Jung]]  |
 | B0 (CCFM)  |  1  |  4  |  250  |  [[https://arxiv.org/abs/hep-ph/0411287|H. Jung]]  | | B0 (CCFM)  |  1  |  4  |  250  |  [[https://arxiv.org/abs/hep-ph/0411287|H. Jung]]  |
 | JH'2013 set 1 (CCFM)  |  2  |  4  |  200  |  [[https://arxiv.org/abs/1312.7875|F. Hautmann, H. Jung]]  | | JH'2013 set 1 (CCFM)  |  2  |  4  |  200  |  [[https://arxiv.org/abs/1312.7875|F. Hautmann, H. Jung]]  |
 | JH'2013 set 2 (CCFM)  |  2  |  4  |  200  |  [[https://arxiv.org/abs/1312.7875|F. Hautmann, H. Jung]]  | | JH'2013 set 2 (CCFM)  |  2  |  4  |  200  |  [[https://arxiv.org/abs/1312.7875|F. Hautmann, H. Jung]]  |
-| KMR (MMHT'2014)  |  1  |  5  |  211  |  [[https://arxiv.org/abs/hep-ph/9911379|M.A. Kimber, A.D. Martin, M.G. Ryskin]] \\ [[https://arxiv.org/abs/hep-ph/0306169|G. Watt, A.D. Martin, M.G. Ryskin]]   | +| KLSZ'2020 (KMR)  |  1  |  4  |  143  |  [[https://arxiv.org/abs/1911.01445|A.V. Kotikov, A.V. Lipatov, B.G. Shaikhatdenov, P. Zhang]]   | 
-| KMR (NNPDF3.1)  |  1  |  5  |  167  |  [[https://arxiv.org/abs/hep-ph/9911379|M.A. Kimber, A.D. Martin, M.G. Ryskin]] \\ [[https://arxiv.org/abs/hep-ph/0306169|G. Watt, A.D. Martin, M.G. Ryskin]]   | +| PB NLO set 1  |  2  |  4  |  118  |  [[https://arxiv.org/abs/1804.11152|F. Hautmann, H. Jung, A. Lelek, V. Radescu, R. Zlebcik]]   | 
-| KMR (DAS set 1)  |  1  |  4  |  143  |  [[https://arxiv.org/abs/1911.01445|A.V. Kotikov, A.V. Lipatov, B.G. Shaikhatdenov, P. Zhang]]   | +| PB NLO set 2  |  2  |  4  |  118  |  [[https://arxiv.org/abs/1804.11152|F. Hautmann, H. Jung, A. Lelek, V. Radescu, R. Zlebcik]]   |
-| KMR (DAS set 2)  |  1  |  4  |  143  |  [[https://arxiv.org/abs/1911.01445|A.V. Kotikov, A.V. Lipatov, B.G. Shaikhatdenov, P. Zhang]]   | +
-| PB NLO set 1  |  2  |  4  |  118  |  [[https://arxiv.org/abs/1704.01757|F. Hautmann, H. Jung, A. Lelek, V. Radescu, R. Zlebcik]]   | +
-| PB NLO set 2  |  2  |  4  |  118  |  [[https://arxiv.org/abs/1704.01757|F. Hautmann, H. Jung, A. Lelek, V. Radescu, R. Zlebcik]]   |+
  
 The A0+, A0-, B0+, B0-, JH'2013 set 1(2)+ and JH'2013 set 1(2)- distributions, needed The A0+, A0-, B0+, B0-, JH'2013 set 1(2)+ and JH'2013 set 1(2)- distributions, needed
 to estimate the scale uncertainties of the CCFM-based calculations, are not shown in the Table. to estimate the scale uncertainties of the CCFM-based calculations, are not shown in the Table.
 +In principle, any other TMD gluon density in a proton could be used: 
 +one just have to upload it from the separate data file prepared in the standard [[https://arxiv.org/abs/1407.5935|uPDFevolv]] routine format.
  
 ===== Strong coupling and masses of particles ===== ===== Strong coupling and masses of particles =====
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 with respect to the number of active flavors and QCD scale. with respect to the number of active flavors and QCD scale.
 This choice is done automatically with the choice of the TMD and/or conventional This choice is done automatically with the choice of the TMD and/or conventional
-parton densities in a proton. There is no possibility to change it manually since this setup is essential for determination of corresponding parton distributions.+parton densities. There is no possibility to change it manually since this setup is essential for determination of corresponding parton distributions.
  
 The masses of all particles (quarks, gauge bosons, heavy quarkonia etc), The masses of all particles (quarks, gauge bosons, heavy quarkonia etc),
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   * Polarization information is not preserved.   * Polarization information is not preserved.
   * A parton carries a tag according to the standard [[http://pdg.lbl.gov/|Particle Data Group]] numbering scheme.   * A parton carries a tag according to the standard [[http://pdg.lbl.gov/|Particle Data Group]] numbering scheme.
-  * Conventional (collinear) parton densities in a proton are numbered according to the [[https://lhapdf.hepforge.org|LHAPDF]] scheme, while TMD parton distributions are numbered according to the [[https://tmdlib.hepforge.org|TMDLib]] package.+  * Conventional (collinear) parton densities in a proton and nuclei are numbered according to the [[https://lhapdf.hepforge.org|LHAPDF]] scheme, while TMD parton distributions are numbered according to the [[https://tmdlib.hepforge.org|TMDLib]] package.
  
-The produced ''*.lhe'' file can then be processed with an external program to introduce some peculiar event selection, to include parton showers, to hadronize the final particles, etc. It is found+The produced ''*.lhe'' file can then be processed with an external program to introduce some peculiar event selection, [[pegasus:showering| to include parton showers, to hadronize the final particles]], etc. It is found
 to be compatible with such Monte Carlo generators as [[http://home.thep.lu.se/Pythia|PYTHIA 8.2]] and [[https://cascade.hepforge.org|CASCADE]]. to be compatible with such Monte Carlo generators as [[http://home.thep.lu.se/Pythia|PYTHIA 8.2]] and [[https://cascade.hepforge.org|CASCADE]].
  
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 We are also grateful to Maria Mikova, Natalia Ovechkina and Anastasia Zotova for their support and help for the design of the program. We are also grateful to Maria Mikova, Natalia Ovechkina and Anastasia Zotova for their support and help for the design of the program.
  
-Contributions to the physics in PEGASUS were provided by Anatoly Kotikov (JINR, Dubna) and  +Contributions to the physics in PEGASUS were provided by Anatoly Kotikov (JINR, Dubna),   
-Nizami Abdulov (MSU, Moscow). We thank Vladimir Lyubushkin (JINR, Dubna),  +Gennady Lykasov (JINR, Dubna) and Nizami Abdulov. We thank Vladimir Lyubushkin (JINR, Dubna) and Alsu Bagdatova (LPI, Moscow), who contributed significantly to the functionality and stability of PEGASUS.
-who contributed significantly to the functionality and stability of PEGASUS.+
  
 We are especially grateful to Nikolai Zotov, who guided and supervised our first steps in High Energy Physics,  We are especially grateful to Nikolai Zotov, who guided and supervised our first steps in High Energy Physics, 
 who encouraged our progress in k<sub>t</sub>-factorization and whose enthusiasm consolidated our group. Nikolai Zotov passed away on January 2016. Our work is dedicated to his memory. who encouraged our progress in k<sub>t</sub>-factorization and whose enthusiasm consolidated our group. Nikolai Zotov passed away on January 2016. Our work is dedicated to his memory.
  
pegasus/overview.1587626859.txt.gz · Last modified: 23/04/2020 10:27 by lipatov