validphys.photon package
Submodules
validphys.photon.alpha module
Module that implements the alpha running
- class validphys.photon.alpha.Alpha(theory, q2max)[source]
Bases:
object
Class that solves the RGE for alpha_qed
- alpha_em(q)[source]
Compute the value of the running alphaem.
- Parameters
q (float) – value in which alphaem is computed
- Returns
alpha_em – electromagnetic coupling
- Return type
numpy.ndarray
- alphaem_fixed_flavor_exa(q, alphaem_ref, qref, nf, nl)[source]
Compute numerically the running alphaem for nf fixed.
- alphaem_fixed_flavor_trn(q, alphaem_ref, qref, nf, nl)[source]
Compute the running alphaem for nf fixed at, at least, NLO, using truncated method. In this case the RGE for alpha_em is solved decoupling it from the RGE for alpha_s (so the mixed terms are removed). alpha_s will just be unused.
- compute_alphaem_at_thresholds()[source]
Compute and store alphaem at thresholds to speed up the calling to alpha_em inside fiatlux: when q is in a certain range (e.g. thresh_c < q < thresh_b) and qref in a different one (e.g. thresh_b < q < thresh_t) we need to evolve from qref to thresh_b with nf=5 and then from thresh_b to q with nf=4. Given that the value of alpha at thresh_b is always the same we can avoid computing the first step storing the values of alpha in the threshold points. It is done for qref in a generic range (not necessarly qref=91.2).
validphys.photon.compute module
Module that calls fiatlux to add the photon PDF.
- class validphys.photon.compute.Photon(theoryid, lux_params, replicas)[source]
Bases:
object
Photon class computing the photon array with the LuxQED approach.
- compute_photon_array(replica)[source]
Compute the photon PDF for every point in the grid xgrid.
- Parameters
replica (int) – replica id
- Returns
compute_photon_array – photon PDF at the fitting scale Q0
- Return type
numpy.array
- property error_matrix
Generate error matrix to be used in generate_errors.
- generate_errors(replica)[source]
Generate LUX additional errors according to the procedure described in sec. 2.5 of https://arxiv.org/pdf/1712.07053.pdf
validphys.photon.constants module
validphys.photon.structure_functions module
- class validphys.photon.structure_functions.F2LO(pdfs, theory)[source]
Bases:
StructureFunction
Analytically compute the structure function F2 at leading order.
- class validphys.photon.structure_functions.FLLO[source]
Bases:
StructureFunction
Analytically compute the structure function FL at leading order., i.e. return zero.
- class validphys.photon.structure_functions.InterpStructureFunction(path_to_fktable, pdfs)[source]
Bases:
StructureFunction
Compute an interpolated structure function convoluting an FKtable with a PDF.