Related papers: Event Orientation in e+e- Annihilation
Flavour inclusive, udsc and b fragmentation functions in biased and unbiased jets and gluon fragmentation functions in biased jets are measured in e+e- annihilations using OPAL data collected at energies Ecms = 91.2 and 183-209 GeV.
We show that an anomalous CP-violating gamma-gamma-Z vertex gives rise to a novel asymmetry with transversely polarized electron and positron beams in the process e+e- -> gamma Z. This asymmetry, which is odd under naive time reversal, is…
We examine very general four-point interactions arising due to new physics contributing to the Higgs production process e+e- --> HZ. We write all possible forms for these interactions consistent with Lorentz invariance. We allow the…
We report the first observation of the polarization of $\Lambda/\bar{\Lambda}$ hyperons transverse to its production plane in $e^+e^-$ annihilation. We observe a significant polarization that rises with the fractional energy carried by the…
We report next-to-leading order perturbative QCD predictions of 4 jet event shape variables for the process e+e- \to 4 jets obtained using the general purpose Monte Carlo EERAD2. This program is based on the known `squared' one loop matrix…
For the processes e+e-\to \mu+\mu-, \tau+\tau-, b\bar{b} and c\bar{c} at a future e+e- collider with \sqrt{s}=0.5 TeV, we examine the sensitivity of the helicity cross sections to four-fermion contact interactions. If longitudinal…
The path-length dependence of jet quenching can help to constrain different jet quenching mechanisms in heavy-ion collisions. However, measuring an explicit value for this dependence has proven challenging. Traditional approaches, which…
We study angular observables in the $e^+e^-\to Z H\to \ell^+ \ell^-\,b\bar{b}$ channel at future circular $e^+ e^-$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we…
We study tunneling ionization of HeH+ in strong elliptical laser fields numerically and analytically. The calculated photoelectron momentum distribution (PMD) show two different offset angles corresponding to ionization events occurring in…
W bosons produced at high transverse momentum in hadron collisions can have polarization along the direction perpendicular to the production plane, which is odd under na$\ddot{\i}$ve-T-reversal where both the three-momenta and angular…
Measurements of alpha_s from e+e- annihilation experiments are reviewed and compared with measurements from other processes. Highlights are presented of recent QCD studies in e+e- annihilation at the Z0 resonance.
We proposed a new observable based on two particle azimuth correlation to study the away-side medium response in mid-central Au+Au collisions. We argue that a left/right asymmetry may appear at the away-side by selecting triggers separately…
The incident energy at which the azimuthal distributions in semi-central heavy ion collisions change from in-plane to out-of-plane enhancement, E_tran, is studied as a function of mass of emitted particles, their transverse momentum and…
The charged-particle multiplicity distribution and its moments have been measured, for all hadronic as well as for light-quark and b-quark events in e+e- collisions at the Z mass. The Hq moments derived from the charged-particle…
We present a complete calculation of the electroweak O(alpha^3 alpha_s) corrections to three-jet production and related event-shape observables at electron--positron colliders. The Z-boson resonance is described within the complex-mass…
We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment's second and third seasons of observations by searching for a possible systematic rotation of the polarization directions of…
Measurement of the helicity asymmetric cross section for semi-inclusive production of $\Lambda$-hyperons in $e^+e^-$ annihilation near the $Z^0$ resonance allows a complete determination of the spin-dependent fragmentation functions for the…
We propose event cuts in deep inelastic scattering, suitable for an examination of quark fragmentation universality. We compare the current hemisphere of the Breit frame with hemispheres in e+e- annihilation events, using Monte Carlo…
We present the leading unpolarized and single spin asymmetries in inclusive two-hadron production in electron-positron annihilation at the Z pole. The azimuthal dependence in the unpolarized differential cross section of almost back-to-back…
Polarizations of electromagnetic waves from distant galaxies are known to be correlated with the source orientations. These quantities have been used to search for signals of cosmological birefringence. We review and classify transformation…