scholarly journals NLO QCD+EW predictions for tHj and tZj production at the LHC

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Davide Pagani ◽  
Ioannis Tsinikos ◽  
Eleni Vryonidou
Keyword(s):  
Cross Sections ◽  
Top Quark ◽  
Parton Shower ◽  
Specific Production ◽  
Final State ◽  
Realistic Estimate ◽  
Single Top ◽  
The Cross ◽  
Theory Uncertainty ◽  
Production Channel

Abstract In this work we calculate the cross sections for the hadroproduction of a single top quark or antiquark in association with a Higgs (tHj) or Z boson (tZj) at NLO QCD+EW accuracy. In the case of tZj production we consider both the case of the Z boson undecayed and the complete final state tℓ+ℓ−j, including off-shell and non-resonant effects. We perform our calculation in the five-flavour-scheme (5FS), without selecting any specific production channel (s-, t- or tW associated). Moreover, we provide a more realistic estimate of the theory uncertainty by carefully including the differences between the four-flavour-scheme (4FS) and 5FS predictions. The difficulties underlying this procedure in the presence of EW corrections are discussed in detail. We find that NLO EW corrections are in general within the NLO QCD theory uncertainties only if the flavour scheme uncertainty (4FS vs. 5FS) is taken into account. For the case of tℓ+ℓ−j production we also investigate differences between NLO QCD+EW predictions and NLO QCD predictions matched with a parton shower simulation including multiple photon emissions.

scholarly journals Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix ElementVtb

2015 ◽  
Vol 115 (15) ◽  
Author(s):  
T. Aaltonen ◽  
V. M. Abazov ◽  
B. Abbott ◽  
B. S. Acharya ◽  
M. Adams ◽  
...  
Keyword(s):  
Cross Sections ◽  
Top Quark ◽  
Single Top

scholarly journals Differences in fully differential cross section of single top quark production and its subsequent decay process depending on various anomalous Wtb couplings.

2019 ◽  
Vol 222 ◽  
pp. 04007
Author(s):  
Edward Boos ◽  
Viacheslav Bunichev
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Top Quark ◽  
Fully Differential ◽  
Subsequent Decay ◽  
Single Top ◽  
Quark Spin ◽  
Top Quark Production ◽  
Quark Production ◽  
Fully Differential Cross Section

The fully differential cross sections of t-channel production of a single top quark with its subsequent decay are compared for the case of contributions involving anomalous Wtb couplings. It is shown that the most noticeable differences, for cases corresponding to different anomalous couplings, appear in the shape of two-dimensional distributions, where one of the variables is the energy of a charged lepton and the other is one of the t-quark spin orientation angles.

scholarly journals Soft-gluon corrections in top-quark production

2018 ◽  
Vol 33 (25) ◽  
pp. 1830021 ◽  
Author(s):  
Nikolaos Kidonakis
Keyword(s):  
Cross Sections ◽  
Top Quark ◽  
Z Bosons ◽  
New Physics ◽  
Higgs Bosons ◽  
Soft Gluon ◽  
Total Cross Sections ◽  
Single Top ◽  
Top Quark Production ◽  
Quark Production

I review calculations of soft-gluon corrections for top-quark production in hadron collisions. I describe theoretical formalisms for their resummation and for finite-order expansions. I show that soft-gluon corrections are dominant for a large number of top-quark processes. I discuss top–antitop pair production as well as single-top production, including total cross sections and differential distributions, and compare with data from the LHC and the Tevatron. I also discuss top-quark production in association with charged Higgs bosons, Z bosons and other particles in models of new physics.

scholarly journals Test of QCD at large Q2 with exclusive hadronic processes

2014 ◽  
Vol 31 ◽  
pp. 1460304
Author(s):  
Chengping Shen ◽  
Keyword(s):  
Perturbative Qcd ◽  
Cross Sections ◽  
Branching Fractions ◽  
Center Of Mass ◽  
Axial Vector ◽  
Hadronic Decays ◽  
Final States ◽  
Final State ◽  
The Cross ◽  
Using Data

My report consists of two parts: (1). Using samples of 102 million ϒ(1S) and 158 million ϒ(2S) events at Belle, we study 17 exclusive hadronic decays of these two bottomonium resonances to some Vector-Pseudoscalar (VP), Vector-Tensor (VT) and Axial-vector-Pseudoscalar (AP) processes and their final states. Branching fractions are measured for all the processes. The ratios of the branching fractions of ϒ(2S) and ϒ(1S) decays into the same final state are used to test a perturbative QCD (pQCD) prediction for OZI-suppressed bottomonium decays. (2). Using data samples of 89 fb-1, 703 fb-1, and 121 fb-1 collected at center-of-mass (CMS) energies 10.52, 10.58, and 10.876 GeV, respectively, we measure the cross sections of e+e- → ωπ0, [Formula: see text], and [Formula: see text]. The energy dependence of the cross sections is presented.

ASSOCIATED PRODUCTION OF LIGHT PSEUDOSCALAR BOSON η WITH TOP QUARK PAIRS IN THE SLH MODEL AT THE ILC

2011 ◽  
Vol 26 (21) ◽  
pp. 1577-1586 ◽  
Author(s):  
JINZHONG HAN ◽  
DAPENG YANG ◽  
XUELEI WANG
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Cross Sections ◽  
Top Quark ◽  
Linear Collider ◽  
International Linear Collider ◽  
Quark Pairs ◽  
Associated Production ◽  
The Standard Model ◽  
The Cross

The light pseudoscalar boson η is the typical particle predicted by the Simplest Little Higgs (SLH) model. In this paper, we investigate some processes of the associated production of a light pseudoscalar boson η with a pair of top quarks in the SLH model at the International Linear Collider (ILC), i.e. [Formula: see text] and [Formula: see text]. We find that the cross-sections of these two processes could reach [Formula: see text] fb in the favorite parameter space in the SLH model, which is consistent with the results of the cross-section of [Formula: see text] in the standard model and the cross-section of [Formula: see text] in the minimal supersymmetric standard model. It should be clear that hundreds to thousands of η can be produced at the ILC per year, these processes of [Formula: see text] are really interesting in testing the standard model and searching the signs of the SLH model.

Sign in / Sign up

Export Citation Format

Share Document