Changes between Version 3 and Version 4 of FAQ-NewPhysics-1


Ignore:
Timestamp:
04/13/12 18:50:15 (8 years ago)
Author:
omatt
Comment:

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  • FAQ-NewPhysics-1

    v3 v4  
    33== How can I implement a new physics model in MadGraph / MadEvent ? ==
    44
    5 === The "old" way : using
    6 {{{
    7 USRMOD
    8 }}}
    9 v1 ===
    10 This is "traditional" way to create a new physics model in MadGraph / MadEvent v4. You should use the
    11 {{{
    12 USRMOD
    13 }}}
    14 template directory present in the
    15 {{{
    16 Models
    17 }}}
    18 directory. The full procedure to follow is extensively described [http://cp3wks05.fynu.ucl.ac.be/Manual/usrmod.html here].
     5=== The "old" way : using **USRMOD v1** ===
     6This is "traditional" way to create a new physics model in MadGraph / MadEvent v4. You should use the **USRMOD**
     7template directory present in the **Models** directory. The full procedure to follow is extensively described [http://cp3wks05.fynu.ucl.ac.be/Manual/usrmod.html here].
    198
    209This method has been successfully used over the past to create several new Physics models. However, it presents two important disadvantages:
    2110   * The base model is always the SM and the possible modifications are restricted (e.g. removing a particle is not possible). This was due to the important structural differences in the original BSM models provided with MadGraph / MadEvent v4.
    2211   * Feynman rules should be computed by hand.
    23 To address these issues, two new methods are now available and should be preferentially used (starting from the future version 4.6, old models files, including those produced with the
    24 {{{
    25 USRMOD
    26 }}}
    27 v1, will only be passively supported).
     12To address these issues, two new methods are now available and should be preferentially used (starting from the version 5.0, old models files, including those produced with the
     13**USRMOD v1** will only be passively supported).
    2814
    29 === The "new" way : using [http://feynrules.phys.ucl.ac.be FeynRules] and/or
    30 {{{
    31 USRMOD
    32 }}}
    33 v2 ===
     15=== The "new" way : using [http://feynrules.phys.ucl.ac.be FeynRules] and/or **USRMOD v2** ===
    3416
    3517==== [http://feynrules.phys.ucl.ac.be FeynRules] ====
     
    4022Thanks to its high capabilities, including a user friendly interface, the automatized model generation for arbitrary QFT physics theories and robust validation procedures, [http://feynrules.phys.ucl.ac.be FeynRules] and the corresponding interface will be the default tool to generate important MadGraph / MadEvent models starting from version 4.6.
    4123
    42 ====
    43 {{{
     24==== **USRMOD** v2 ====
     25In order to keep the
    4426USRMOD
    45 }}}
    46 v2 ====
    47 In order to keep the
    48 {{{
     27approach flexibility with the new models produced by the [http://feynrules.phys.ucl.ac.be FeynRules] package, a new independent version of the
    4928USRMOD
    50 }}}
    51 approach flexibility with the new models produced by the [http://feynrules.phys.ucl.ac.be FeynRules] package, a new independent version of the
    52 {{{
     29scripts, called
    5330USRMOD
    54 }}}
    55 scripts, called
    56 {{{
    57 USRMOD
    58 }}}
    5931v2, has been released. The "philosophy" remains the same, i.e. starting from a base model, the user add/remove/modify particles, interactions and/or parameters, then run the script and finally edit the relevant coupling expressions.
    6032
    6133Compare to the first version, it has the following advantages:
    6234   * Fully compatible with (and ''only'' with) all models produced by [http://feynrules.phys.ucl.ac.be FeynRules], so the base model can be the SM but also any other model previously produced, including those produced by the
    63 {{{
    6435USRMOD
    65 }}}
    6636v2 itself!
    6737   * No limitation for the possible modifications. The
    68 {{{
    6938USRMOD
    70 }}}
    7139v2 propose to first save a "copy" of the base model and adjust all files to reflects the user changes.
    7240   * Safer thanks to additional internal consistency checks