Probe anomalous tqγ couplings through single top photoproduction at the LHC

Abstract

In this work we study the constraints on the anomalous tqγ (q=u, c) couplings by photon-produced leading single top production and single top jet associated production through the main reaction pp → pγp → pt → pW(→ ℓν ℓ )b + X and pp → pγp → ptj → pW(→ ℓν ℓ )bj + X assuming a typical LHC multipurpose forward detectors in a model independent effective lagrangian approach. Our results show that: for the typical detector acceptance 0.0015 < ξ 1 < 0.5, 0.1 < ξ 2 < 0.5 and 0.0015 < ξ 3 < 0.15 with a luminosity of 2 fb −1 , the lower bounds of κ tqγ through leading single top channel (single top jet channel) are 0.0130 (0.0156), 0.0218 (0.0206) and 0.0133 (0.01655), respectively, correspond to Br(t → qγ) ∼ 3 × 10 −5 . With a luminosity of 200 fb −1 , the lower bounds of κ tqγ are 0.0041 (0.0048), 0.0069 (0.0064) and 0.0042 (0.0051), respectively, correspond to Br(t → qγ) ∼ 4 × 10 −6 . We conclude that both channels can be used to detect such anomalous tqγ couplings and the detection sensitivity on κ tqγ is obtained.

Light-by-light scattering with intact protons at the LHC: from standard model to new physics

“…Previous studies using proton-tagging at the LHC for New Physics searches can be found in refs. [3,4,[9][10][11][12][13][14][15][16][17][18][19]. We refer to [20] for a study of light-by-light scattering at the LHC without proton tagging.…”

Search for the RS model with a small curvature through photon-induced process at the LHC

“…In our case η max = 2.4. Taking into account the cut imposed on the transverse momenta of the muons, |p t | > p t,min , one can transform inequality (32) into the bound on the scattering angle of the muons in the c.m.s of two photons…”

NLO QCD corrections to Single Top and W associated photoproduction at the LHC with forward detector acceptances

“…In this case, SM Wt photoproduction turns to its irreducible background. Moreover, a lot of studies are performed at the γp colliders, i.e., testing anomalous gauge boson couplings [37][38][39][40][41][42] or probing flavour changing neutral currents (FCNC) through Single Top photoproduction [43,44], etc. In cases like these, SM Wt photoproduction turns to be a most important reducible background that needs precise measurement and analysis.…”

“…Many phenomenological studies on photon induced processes are summarized here involve: standard model productions [56], supersymmetry [57][58][59][60][61][62], extra dimensions [63][64][65][66], unparticle physics [67], top triangle moose model [68], gauge boson self-interactions [37][38][39][40][41][42][69][70][71][72], neutrino electromagnetic properties [73][74][75], the top quark physics [23,24,36,43,44], dark matter searches [76] and triplet Higgs production [77], etc.…”