Abstract
We consider soft gluon emission corrections to the production of a top-antitop pair in association with a W boson at the Large Hadron Collider. We obtain a soft-gluon resummation formula for this production process which is valid up to next-to-next-to-leading logarithmic accuracy. We evaluate the soft gluon resummation formula in Mellin space by means of an in-house parton level Monte Carlo code which allows us to obtain predictions for the total cross section as well as for several differential distributions. We study the impact of the soft-gluon resummation corrections in comparison to fixed order calculations.
Highlights
Some of us applied Soft Collinear Effective Theory (SCET) methods1 in order to study the associated production of a top pair and a Higgs boson in the SM beyond NLO [8]
We evaluate the resummation formulas in Mellin space, along the lines of what was done in the case of top-pair production in the context of an approach based on SCET methods in [23, 24]
By combining the information encoded in the NLO hard function and soft function with the solution of the renormalization group (RG) equations that they satisfy, it is possible to resum logarithms of the ratio between the hard scale μh and the soft scale μs up to next-to-next-to leading logarithmic (NNLL) accuracy
Summary
The partonic process underlying the associated production of a top pair and a W boson at the LHC can be written as i(p1) + j(p2) −→ t(p3) + t(p4) + W ±(p5) + X ,. In order to carry out resummation, one needs to know the soft anomalous dimension ΓH, defined through the renormalization-group equation satisfied by the hard function. These anomalous dimensions do not depend on the nature of the color-neutral boson in the final state. One needs to subtract the residual IR poles from the color decomposed one-loop amplitudes in order to be able to assemble the hard functions since they are finite quantities This is done by means of appropriate IR subtraction counterterms [27, 28], following the same procedure employed in [29] for the top-quark pair production case. Results have been cross-checked by means of GoSam in combination with Ninja [20, 30, 31]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
