相关论文: Effective theories and constraints on new phyhsics
We study the $W$ boson associated single top quark production at the Large Hadron Collider (LHC) to probe anomalous chromo-magnetic and chromo-electric moments of the top quark with the help of polarization and spin correlation observables…
We investigate the constraints on the anomalous quartic $ZZ\gamma\gamma$ couplings through the process $p p\to p\gamma p\to p \gamma q Z X$ at the LHC. Taking into consideration various forward detector acceptances and integrated LHC…
We study the possibility for the process $pp \rightarrow p\gamma p \rightarrow pW^-t(W^+\bar t)X$ with anomalous Wtb couplings in a model independent effective Lagrangian approach at the LHC. We find 95% confidence level bounds on the…
We study the process $e^+e^- \rightarrow W^+W^- \gamma$ at high-energy $e^+ e^-$ colliders to investigate the effect of genuine quartic $W^+W^-\gamma\gamma$ and $W^+W^- Z\gamma$ anomalous couplings on the cross section. Deviations from the…
The angular and energy distributions of the final lepton in e ebar t tbar --> l^{+-} X at next linear colliders (NLC) are analyzed a model-independent way for arbitrary longitudinal beam polarizations as sensitive tests of possible…
We study the T odd correlations induced by CP violating anomalous top-quark couplings at both production and decay level in the process gg --> t t_bar --> (b mu+ nu_mu) (b_bar mu- nu_mu_bar). We consider several counting asymmetries at the…
The production of $\nu \bar{\nu} \gamma \gamma$ in high-energy $e^+e^-$ collisions offers a window on anomalous quartic gauge boson couplings. We investigate the effect of two possible anomalous couplings on the cross section for $\nu…
We investigate the possibility that an imaginary anomalous $tbW$ coupling can be measured in the process $e^-p \to \nu_e \overline t X$ by means of T-odd observables. One such observable considered here is the polarization of the top…
We describe the reaches on quartic $\gamma \gamma \gamma \gamma$, $\gamma \gamma WW$, $\gamma \gamma ZZ$, $\gamma \gamma \gamma Z$, $\gamma \gamma t \bar{t}$ anomalous couplings at the LHC using intact protons in the final state measured in…
We work out in the forward limit and up to order $e^6$ in perturbation theory the collinear divergences. In this kinematical regime we discover new collinear divergences that we argue can be only cancelled using quantum interference with…
We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in gamma+gamma -> t+tbar -> lX/bX for various beam polarizations in order to study possible anomalous t-tbar-gamma, tbW and gamma-gamma-H…
By reanalyzing the influence of the anomalous $Z\bar t t$ couplings on the $Z\rightarrow b\bar b$ decay process, we pointed out the ambiguity in the conventional treatment of the effective Lagrangian approach, because of the possible…
The investigation of flavour-changing neutral current transitions(FCNC) involving the top quark are only possible with new theoretical frameworks that extend the Standard Model(SM), given that these transitions are almost entirely…
The rates and corresponding jet distributions for the decay $Z\to b\bar bg$ and the process $e^+e^-\to t\bar tg$ may be sensitive to anomalous dipole-like couplings of heavy quarks to the photon and $Z$. In the $b$-quark case, after…
We study the process pp->QVX (where Q=t,b and V=g,gamma,Z) through the anomalous interactions of the new heavy quarks at the LHC. Considering the present limits on the masses and mixings, the signatures of the heavy quark anomalous…
We study the deep inelastic scattering and photo-production modes of $t\overline{t}$ pairs at the proposed LHeC and its potential to probe the electromagnetic and weak dipole moments (MDM and EDM for $tt\gamma$) of the top quark. A…
In this paper, we investigate the contributions of anomalous quartic gauge couplings (aQGCs) to $Z\gamma jj$ production at the Large Hadron Collider (LHC) in the context of Standard Model effective theory (SMEFT). When energy scale is…
We examine loop-mediated effects of new heavy quarks Q=(t',b') on t tbar production at hadron colliders, using a phenomenological model with flavor off-diagonal couplings of charged and neutral scalars phi=(phi^+-,phi^0) to Q. We show that…
The top quark could provide very important information for the Standard Model extentions due to its large mass close to the electroweak symmetry breaking scale. In this work, anomalous single top production is studied by using gamma…
Bounds on the absorptive (imaginary) parts of the top quark chromomagnetic $\hat{\mu}_t$ and chromoelectric $\hat{d}_t$ dipole moments are obtained by reinterpreting the most recent LHC data in top quark pair production. It is found that…