On the impact of non-factorisable corrections in VBF single and double Higgs production

  • PDF / 856,367 Bytes
  • 30 Pages / 595.276 x 841.89 pts (A4) Page_size
  • 72 Downloads / 168 Views

DOWNLOAD

REPORT


Springer

Received: June 5, Revised: September 3, Accepted: September 14, Published: October 21,

2020 2020 2020 2020

Fr´ ed´ eric A. Dreyer, Alexander Karlberg and Lorenzo Tancredi Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, U.K.

E-mail: [email protected], [email protected], [email protected] Abstract: We study the non-factorisable QCD corrections, computed in the eikonal approximation, to Vector-Boson Fusion single and double Higgs production and show the combined factorisable and non-factorisable corrections for both processes at O(αs2 ). We investigate the validity of the eikonal approximation with and without selection cuts, and carry out an in-depth study of the relative size of the non-factorisable next-to-next-toleading order corrections compared to the factorisable ones. In the case of single Higgs production, after selection cuts are applied, the non-factorisable corrections are found to be mostly contained within the factorisable scale uncertainty bands. When no cuts are applied, instead, the non-factorisable corrections are slightly outside the scale uncertainty band. Interestingly, for double Higgs production, we find that both before and after applying cuts, non-factorisable corrections are enhanced compared to the single Higgs case. We trace this enhancement to the existence of delicate cancellations between the various leading-order Feynman diagrams, which are partly spoiled by radiative corrections. All contributions studied here have been implemented in proVBFH v1.2.0 and proVBFHH v1.1.0. Keywords: NLO Computations, QCD Phenomenology ArXiv ePrint: 2005.11334

c The Authors. Open Access, Article funded by SCOAP3 .

https://doi.org/10.1007/JHEP10(2020)131

JHEP10(2020)131

On the impact of non-factorisable corrections in VBF single and double Higgs production

Contents 1 Introduction

1

2 QCD corrections in VBF Higgs production 2.1 Factorisable corrections 2.2 Non-factorisable corrections

4 4 5 14 14 15 16 16 17

4 Results for di-Higgs VBF production 4.1 Validity of the eikonal approximation 4.2 Fiducial results

18 19 20

5 Conclusions

23

A Analytic results for one-loop integrals

24

1

Introduction

Following the discovery of the Higgs boson in 2012 [1, 2], it has become a primary focus of the experimental program of the Large Hadron Collider (LHC) to measure its properties and in particular its couplings to itself and to the other Standard Model particles [3]. One of the key channels for studying the Higgs boson is the Vector-Boson Fusion (VBF) production mode, where the Higgs boson is produced together with two (typically) hard and forward jets. This process has been the focus of several recent fixed order theoretical calculations [4–10]. A common point between all these calculations is that they are performed in the factorised approximation, which corresponds to the limit where partons from the two colliding protons are treated as coming from two identical copies o