相关论文: Single top polarisation as a window to new physics
In the context of $SU(2)_L\times U(1)$ dimension six operators we study the potential of the LHeC to provide information on top quark effective interactions. We focus on single antitop production and how it is affected not only by the…
We investigate the prospects to observe effects of transverse polarization of top quarks in $pp,p\bar{p}\to t\bar{t}X$. QCD absorptive parts generate a polarization of top quarks and antiquarks transverse to the production plane in the…
We perform a model independent analysis of the flavour changing strong interaction vertices relevant to the LHC. In particular, the contribution of dimension six operators to single top production in various production processes is…
We report on a calculation of the full one-loop weak corrections through the order $\alpha_{\mathrm{S}}^2\alpha_{\mathrm{W}}$ to parton-parton scattering in all possible channels at the Relativistic Heavy Ion Collider (RHIC) running with…
We show that the polarization of hyperons observed in high energy collisions using unpolarized hadron beams and unpolarized nucleon or nuclear targets is closely related to the left-right asymmetries observed in single spin inclusive hadron…
Precision measurements of high energy top quarks at the LHC constitute a powerful probe of new physics. We study the effect of four fermion operators involving two tops and two light quarks on the high energy tail of the $t\bar t$ invariant…
We define three orthogonal axes to investigate the top quark polarization in the $t$-channel single top process. We provide expressions for the polarization in these axes in terms of anomalous $Wtb$ couplings. It is found that the…
We investigate the effects of top quark compositeness on various physical parameters, and obtain lower limits on the compositeness scale from electroweak precision data. We consider corrections to top quark decay rates and other physical…
The polarisation of top quarks produced in high energy processes can be a very sensitive probe of physics beyond the Standard Model. The kinematical distributions of the decay products of the top quark can provide clean information on the…
Fermion compositeness, and other types of new physics that can be described by the exchange of very massive particles, can manifest themselves as the result of an effective four-fermion contact interaction. In the case of the processes…
We study the sensitivity of the Large Hadron Collider (LHC) to top quark chromomagnetic (CMDM) and chromoelectric (CEDM) dipole moments and $Wtb$ effective couplings in single-top production in association with a $W^-$ boson, followed by…
Measuring top polarization is extremely important in understanding any new physics that couples to top quark. Here, we take up the task of extracting polarization of top quark coming from TeV-scale stop decay at the upgraded high luminosity…
Collisions of particles at the energy frontier can reveal new particles and forces via localized excesses. However, the initial observation may be consistent with a large variety of theoretical models, especially in sectors with new top…
We investigate the quantum properties of heavy-fermion pairs, such as $t\bar t$ or $\tau^+\tau^-$, produced in lepton-lepton collisions with polarised beams. Focusing on spin correlations, entanglement, Bell-inequality violation, and…
The recent observations of sizable transverse fractions of B-> phi K* are strongly contrary to the Standard Model expectation. We analyze all possible new-physics four-quark operators. We find that two classes of new-physics operators could…
The most general set of new physics effective operators contributing to the decay of an unpolarized top quark into a bottom quark and a W gauge boson are considered at next-to-leading order in QCD. We find that the dipole operator…
We consider top quark production and decay in the narrow width approximation and study if the polarisation effects, that manifest themselves in correlations of angular distributions of particles from top quark decays and final state jets in…
Fermion compositness, and other new physics which can be described by an exchange of very massive particles ($Z^\prime$ boson, leptoquarks, sparticles with R-parity violating couplings), can be manifest itself as the presence of a strong…
We study the sensitivity of the Large Hadron Collider (LHC) to top quark chromomagnetic (CMDM) and chromoelectric (CEDM) dipole moments and $Wtb$ effective couplings in single-top production in association with a $W^-$ boson, followed by…
Transverse $\Lambda$ polarization observed over four decades ago contradicted expectations from early leading-order perturbative QCD calculations. Measurements of $\Lambda$ polarization from unpolarized $pp$ and $p$A collisions have been…