Related papers: Optimal Spin Basis in Polarized Photon Linear Coll…
Processes with creation of a pair charged particles with emission of hard photon and two pairs of charged particles are considered for colliding partially polarized photon photon beams. The effects of circular and linear polarization of the…
We describe the off-diagonal spin basis for observing angular correlations in top quark pair production events at the Fermilab Tevatron. For events initiated by quark-antiquark annihilation, the top and antitop quark spins are 100%…
The degree of top polarization and strength of $t\bar{t}$ correlation are dependent on production dynamics, decay mechanism, and choice of the observables. At the LHC, measurement of the top polarization and spin correlations in $t\bar{t}$…
Search for new-physics through possible anomalous t tbar gamma, tbW and gamma gamma H couplings which are generated by SU(2) X U(1) gauge-invariant dimension-6 effective operators is discussed, using energy and angular distributions of…
We present the first analysis of top spin polarizations, $t \bar t$ spin correlations, and $t \bar t$ spin entanglement at the LHC in the context of the Standard Model Effective Field Theory, that goes beyond Leading Order QCD accuracy. The…
Cross section measurements of top quark production in association with a vector boson in proton-proton collisions at $\sqrt{s}=13\,\mathrm{TeV}$ at the CERN LHC provide an important probe of the electroweak top quark couplings. In this…
The proton is a composite object with spin one-half, understood to contain highly relativistic spin one-half quarks exchanging spin-one gluons, each possibly with significant orbital angular momenta. While their fundamental interactions are…
correlation, assuming that the spin of the top quark is either correlated with the spin of the anti-top quark as predicted by the standard model or is uncorrelated. For the first time we use a matrix-element-based approach to study ttbar…
The polarization dependent momentum distributions of top quarks and their decay products are calculated for $t\bar t$ production at future $e^+e^-$ colliders with polarized beams. The Green function formalism is applied to this reaction…
Correlations are fundamental in describing many body systems - not only in natural sciences. However, in experiments, correlations are notoriously difficult to assess on the microscopic scale, especially for electron spins. Here, we…
Top quark production in association with a photon offers a unique test ground for the standard model predictions, as it is sensitive to the top-photon coupling. These processes are rare when compared to standard top pair production, however…
We study nonperturbative multiphoton electron-positron pair creation in ultrastrong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the…
The weak decay of a polarized top quark has a rich structure of angular correlations among its decay products. We describe some of the noteworthy features of such decays. We then examine the three modes of single top production, with an…
We discussed the photoproduction of pair of charged particles $a\bar{a}\quad (a=e,\mu,\pi)$ as well as the double photon emission processes off an electron accounting for the polarization of colliding particles. In the kinematics when all…
Colliding beams of 70% polarized protons at up to $\sqrt{s}$=500 GeV, with high luminosity, L=2$\times10^{{\rm 32}}$ cm$^{-2}$sec$^{-1}$, will represent a new and unique laboratory for studying the proton. RHIC-Spin will be the first…
We investigate the production of Higgs particles in association with the supersymmetric scalar partners of the top quark at proton colliders. In the minimal supersymmetric extension of the Standard Model, the cross sections for the…
We present a measurement of the correlation between the spins of t and tbar quarks produced in proton-antiproton collisions at the Tevatron Collider at a center-of-mass energy of 1.96 TeV. We apply a matrix element technique to dilepton and…
We report on recent calculations of the differential cross section for top-quark pair production at hadron colliders. The results are differential with respect to the top-pair invariant mass and to the partonic scattering angle. In these…
We study azimuthal asymmetries in heavy quark pair production in unpolarized electron-proton and proton-proton collisions, where the asymmetries originate from the linear polarization of gluons inside unpolarized hadrons. We provide cross…
The polarization of a top quark can be sensitive to new physics beyond the standard model. Since the charged lepton from top quark decay is maximally correlated with the top quark spin, it is common to measure the polarization from the…