Transverse momentum resummation for s -channel single top quark production at the LHC

Abstract

We study the soft gluon radiation effects for the s-channel single top quark production at the LHC. By applying the transverse momentum dependent factorization formalism, the large logarithms about the small total transverse momentum (q ⊥ ) of the single-top plus one-jet final state system, are resummed to all orders in the expansion of the strong interaction coupling at the accuracy of Next-to-Leading Logarithm (NLL). We compare our numerical results with PYTHIA and find that both the q ⊥ and φ * observables from PYTHIA are consistent with our prediction. Furthermore, we point out the soft gluon radiation effects from the final state become significant in this process, especially for the boosted kinematical region.

Les Houches 2021—physics at TeV colliders: report on the standard model precision wishlist

“…NLO QCD for single topquark production in association with two jets [841]. NLO QCD matched to parton shower for single top-quark production in association with a jet in the MINLO method [842]; Soft-gluon resummation at NLL for single-top production in the tchannel [843] and the s-channel modes [844].…”

Reduction of planar double-box diagram for single-top production via auxiliary mass flow

“…For all above three channels, the next-to-leading order (NLO) QCD corrections have been investigated [26][27][28][29][30][31][32][33][34][35][36][37]. For the next-to-next-to-leading order (NNLO) corrections, many approximate results based on soft gluon resummation have been obtained [38][39][40][41][42][43][44][45][46]. The NNLO QCD correction to t-channel under structure function approximation have been calculated in [47].…”

Probing Ztt¯ couplings using Z boson polarization in ZZ production at hadron

“…The top quark often plays a key role in triggering electroweak symmetry breaking (EWSB) in many NP models, and as a result, the gauge couplings of top quarks, e.g., Wtb and Ztt, may largely deviate from the SM predictions [1][2][3][4][5]. The Wtb couplings have been well measured in both the single top quark production and the top-quark decay [6][7][8][9][10][11][12][13][14][15][16][17]; the Ztt coupling can be measured in ttZ and tjZ productions [18][19][20][21][22][23][24][25] which are, unfortunately, difficult to separately determine the vector and axial-vector components of the Ztt coupling. The chiral structure of the Ztt coupling would reveal the gauge structure of NP models [21,26], therefore, measuring and distinguishing the vector and axial vector components of the Ztt coupling is in order.…”