Higgs production at hadron colliders: online calculators



  • Fixed order cross sections

    This online calculator evaluates the total cross section for the production of a SM Higgs boson in hadron collisions. Given the input parameters, the calculator returns the LO, NLO and NNLO [1] cross sections, computed by using the large-mtop approximation. The user can decide if the result should be strictly in the large-mtop limit, or if the exact mtop-dependent Born cross section should be used as normalization (in this case we use mtop=170.9 GeV). The bottom quark contribution is neglected.

  • Improved (resummed) cross sections

    This online calculator performs an improved computation of the total cross section. Given the input parameters, the calculator returns two numbers: an NNLO and an NNLL prediction. The user can choose two options for the calculation. In the first option (a) the NNLO result is obtained by evaluating the top quark contribution to the cross section up to NNLO in the large-mtop limit [1]. As for the bottom and top-bottom contributions, they are evaluated exactly [2] at NLO with the program HIGLU [3]. The result is finally corrected for EW contributions [4,5] according to [5]. The NNLL result is obtained as the NNLO but supplementing the top-quark contribution with the resummation of soft-gluons to all orders [6]. In this way the user can thus reproduce the NNLL cross sections presented in [7]. The online calculator now includes a second option (b) in which, as a further improvement, both the top and bottom quark loop contributions are treated exactly up to NLL+NLO.

    References

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    [2]C.Anastasiou, R.Boughezal, F.Petriello, JHEP 0904 (2009) 003.
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    A. Djouadi, M. Spira and P. M. Zerwas, Phys. Lett. B 264 (1991) 440;
    M. Spira, A. Djouadi, D. Graudenz and P. M. Zerwas, Nucl. Phys. B 453 (1995) 17.
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    [6]S. Catani, D. de Florian, M. Grazzini and P. Nason, JHEP 0307 (2003) 028.
    [7]D. de Florian, M. Grazzini, Phys.Lett. B674 (2009) 291.