ekore.operator_matrix_elements.polarized.space_like package

The polarized, space-like OME.

ekore.operator_matrix_elements.polarized.space_like.A_singlet(matching_order, n, nf, L)[source]

Compute the tower of the singlet OME.

Parameters:
  • matching_order (tuple(int,int)) – perturbative matching order

  • n (complex) – Mellin variable

  • nf (int) – number of active flavor below threshold

  • L (float) – :math:\ln(\mu_F^2 / m_h^2)

Returns:

singlet OME

Return type:

numpy.ndarray

ekore.operator_matrix_elements.polarized.space_like.A_non_singlet(matching_order, n, L)[source]

Compute the tower of the non-singlet OME.

Parameters:
  • matching_order (tuple(int,int)) – perturbative matching order

  • n (complex) – Mellin variable

  • L (float) – :math:\ln(\mu_F^2 / m_h^2)

Returns:

non-singlet OME

Return type:

numpy.ndarray

Submodules

ekore.operator_matrix_elements.polarized.space_like.as1 module

The NLO OME in the polarized case for the matching conditions in the VFNS.

Heavy quark contribution for intrinsic evolution are not considered for the polarized case. The matching conditions for the VFNS at \(\mu_F^2 \neq m_H^2\) are provided in [BBlumleinDF+23]. In the paper, the fraction \(\mu_F^2 / m_H^2\) inside the log is inverted, yielding an additional factor of (-1) wherever L has an odd power. Additionally, a different convention for the anomalous dimensions is used, yielding a factor 2 in the OME’s wherever they are present. The anomalous dimensions and beta function with the addition ‘hat’ have the form \(\hat\gamma = \gamma^{(nf+1)} - \gamma^{(nf)}\).

ekore.operator_matrix_elements.polarized.space_like.as1.A_hg(n, L)[source]

Compute the NLO heavy-gluon OME \(A_{Hg}^{S,(1)}\).

Implements 104 of [BBlumleinDF+23].

Parameters:
  • n (complex) – Mellin moment

  • L (float) – \(\ln(\mu_F^2 / m_h^2)\)

  • nf (int) – Number of active flavors

Returns:

NLO heavy-gluon OME \(A_{Hg}^{S,(1)}\)

Return type:

complex

ekore.operator_matrix_elements.polarized.space_like.as1.A_gg(L)[source]

Compute the NLO gluon-gluon OME \(A_{gg,H}^{S,(1)}\).

Implements 186 of [BBlumleinDF+23].

Parameters:

L (float) – \(\ln(\mu_F^2 / m_h^2)\)

Returns:

NLO gluon-gluon OME \(A_{gg,H}^{S,(1)}\)

Return type:

complex

ekore.operator_matrix_elements.polarized.space_like.as1.A_singlet(n, L)[source]

Compute the NLO singlet OME.

\[\begin{split}A^{S,(1)} = \left(\begin{array}{cc} A_{gg,H}^{S,(1)} & 0 & 0\\ 0 & 0 & 0 \\ A_{hg}^{S,(1)} & 0 & 0 \end{array}\right)\end{split}\]
Parameters:
  • n (complex) – Mellin moment

  • L (float) – \(\ln(\mu_F^2 / m_h^2)\)

Returns:

NLO singlet OME \(A^{S,(1)}\)

Return type:

numpy.ndarray

ekore.operator_matrix_elements.polarized.space_like.as2 module

Contains the NNLO OME in the polarized case for the matching conditions in the VFNS.

The equations are given in [BBlumleinDF+23]. As in the NLO OME, in the paper, an additional factor 2 can be found in front of the anomalous dimensions and factor (-1) for odd powers of L. The anomalous dimensions and beta function with the addition ‘hat’ are defined as in the NLO case.

ekore.operator_matrix_elements.polarized.space_like.as2.beta_0hat = -0.6666666666666666

This is the lowest order beta function with the addition ‘hat’ defined as above.

ekore.operator_matrix_elements.polarized.space_like.as2.A_qq_ns(n, cache, L)[source]

Compute NNLO light-light non-singlet OME \(A_{qq,H}^{NS,(2)}\).

Implements 133 of [BBlumleinDF+23].

Parameters:
Returns:

NNLO light-light non-singlet OME \(A_{qq,H}^{NS,(2)}\)

Return type:

complex

ekore.operator_matrix_elements.polarized.space_like.as2.A_hq_ps(n, cache, L, nf)[source]

Compute NNLO heavy-light pure-singlet OME \(A_{Hq}^{PS,(2)}\).

Implements 138 of [BBlumleinDF+23].

Parameters:
  • n (complex) – Mellin moment

  • cache (numpy.ndarray) – Harmonic sum cache

  • L (float) – \(\ln(\mu_F^2 / m_h^2)\)

  • nf (int) – Number of active flavors

Returns:

NNLO heavy-light pure-singlet OME \(A_{Hq}^{PS,(2)}\)

Return type:

complex

ekore.operator_matrix_elements.polarized.space_like.as2.A_hg(n, cache, L)[source]

Compute NNLO heavy-gluon OME \(A_{Hg}^{S,(2)}\).

Implements 111 of [BBlumleinDF+23].

Parameters:
Returns:

NNLO heavy-gluon OME \(A_{Hg}^{S,(2)}\)

Return type:

complex

ekore.operator_matrix_elements.polarized.space_like.as2.A_gq(n, cache, L)[source]

Compute NNLO gluon-quark OME \(A_{gq,H}^{S,(2)}\).

Implements 174 of [BBlumleinDF+23].

Parameters:
Returns:

NNLO gluon-quark OME \(A_{gq,H}^{S,(2)}\)

Return type:

complex

ekore.operator_matrix_elements.polarized.space_like.as2.A_gg(n, cache, L)[source]

Compute NNLO gluon-gluon OME \(A_{gg,H}^{S,(2)}\).

Implements 187 of [BBlumleinDF+23].

Parameters:
Returns:

NNLO gluon-gluon OME \(A_{gg,H}^{S,(2)}\)

Return type:

complex

ekore.operator_matrix_elements.polarized.space_like.as2.A_singlet(n, cache, L, nf)[source]

Compute the NNLO singlet OME.

\[\begin{split}A^{S,(2)} = \left(\begin{array}{cc} A_{gg, H}^{S,(2)} & A_{gq, H}^{S,(2)} & 0 \\ 0 & A_{qq,H}^{NS,(2)} & 0\\ A_{hg}^{S,(2)} & A_{hq}^{PS,(2)} & 0\\ \end{array}\right)\end{split}\]
Parameters:
  • n (complex) – Mellin moment

  • cache (numpy.ndarray) – Harmonic sum cache

  • L (float) – \(\ln(\mu_F^2 / m_h^2)\)

  • nf (int) – Number of active flavors

Returns:

NNLO singlet OME \(A^{S,(2)}(N)\)

Return type:

numpy.ndarray

ekore.operator_matrix_elements.polarized.space_like.as2.A_ns(n, cache, L)[source]

Compute the NNLO non-singlet OME.

\[\begin{split}A^{NS,(2)} = \left(\begin{array}{cc} A_{qq,H}^{NS,(2)} & 0 \\ 0 & 0 \\ \end{array}\right)\end{split}\]
Parameters:
Returns:

NNLO non-singlet OME \(A^{NS,(2)}\)

Return type:

numpy.ndarray