A demonstration of the application of STXS to an EFT fit is given in LHCHXSWG-INT-2017-001. The full equations are available below. A few of the important details are:

- the equations directly use the HEL parameters except in the case of cG and cA, which are multiplied by 16pi^2 so that their coefficients are of the same order as the others (these parameters in the files correspond to c'_g' and c'_y in the above note).

- when fitting we recommend to redefine the parameters as Wilson coefficients ci/Lambda^2 by taking out the prefactors. Then the linear terms should give the dominant contribution to the fit, and the quadratic terms can be used to check the effect of higher powers of 1/Lambda.

- the HEL implementation includes redundant parameters that should be accounted for in any fit.

- STXS bins are defined as cross section x B4l, so fits to STXS measurements must combine the production equations with the equations for HZZto4l and the total width.

The EFT/SM ratios for production are crosssections.txt and for decay are decays.txt. General questions about the generation of the equations should be directed to Gabija Zemaityte.

-- ChristopherHays - 2017-12-11

Topic attachments
I Attachment History Action Size Date Who Comment
Texttxt crosssections.txt r1 manage 25.0 K 2017-12-11 - 12:32 ChristopherHays sigma_EFT/sigma_SM for STXS cross sections
Texttxt decays.txt r1 manage 3.2 K 2017-12-11 - 12:33 ChristopherHays EFT/SM for decay widths or their ratios
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Topic revision: r1 - 2017-12-11 - ChristopherHays
 
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