Related papers: Atomic Parity Violation, Leptoquarks, and Contact …
Recent high-precision measurements of atomic parity-nonconserving transitions between the 6S and 7S states of cesium allow for a determination of the weak nuclear charge with a precision of 1.3%, providing an improved test of the standard…
We investigate the possibility that four-fermion contact interactions give rise to the observed deviation from the Standard Model prediction for the weak charge of Cesium, through one-loop contributions. We show that the presence of loops…
The parity violation in cesium atom is analysed in the framework of the models based on the SU(3)_C X SU(3)_L X U(1)_N gauge group. It is shown that in the minimal version, the main contribution to a deviation of weak charge \Delta Q_W due…
The most severe constraints on quark-lepton four-fermion contact interactions come from the agreement of atomic parity violation measurements with the Standard Model. In this letter I note that for contact interactions which arise in…
A new analysis of parity violation in atomic cesium has led to the improved value of the weak charge, $Q_W({\rm Cs}) = -72.06 \pm 0.46$. The implications of this result for constraining the Peskin-Takeuchi parameters S and T and for guiding…
We update the global constraint on four-fermion $ee q q$ contact interactions. In this update, we included the published data of H1 and ZEUS for the 94--96 run in the $e^+ p$ mode and the newly published data of H1 for the 1999 run in the…
We carry out high-precision calculation of parity violation in cesium atom, reducing theoretical uncertainty by a factor of two compared to previous evaluations. We combine previous measurements with our calculations and extract the weak…
We show that the two scenarios able to explain the HERA anomaly --- a new leptoquark coupling or a new contact interaction --- predict new contributions to atomic parity violation. These corrections are sufficiently large and different that…
Data from HERA, LEP and the Tevatron, as well as from low energy experiments are used to constrain the Yukawa couplings for scalar and vector leptoquarks in the Buchmuller-Ruckl-Wyler effective model. In the limit of very high leptoquark…
We have detected, by using stimulated emission, an Atomic Parity Violation (APV) in the form of a chiral optical gain of a cesium vapor on the 7S - 6P$_{3/2}$ transition,consecutive to linearly polarized 6S-7S excitation. We demonstrate the…
We review the progress made in the determination of the weak charge, Q\_w, of the cesium nucleus which raises the status of Atomic Parity Violation measurements to that of a precision electroweak test. Not only is it necessary to have a…
New data on parity violation in atomic cesium can be explained by a new neutral vector boson almost unmixed with Z, with a mass in the TeV range and sizeable couplings to the fermions. The properties of such additional Z' can be…
Exchange of two neutrinos (as well as other fermions) generates a long-range parity-violating (PV) potential of the form $\sim G^2/r^5$, with characteristic range $\hbar/(2m_\nu c)$. In atomic systems the corresponding matrix elements…
In a global analysis of the latest parity-violating electron scattering measurements on nuclear targets, we demonstrate a significant improvement in the experimental knowledge of the weak neutral-current lepton-quark interactions at low…
Recent reanalyses of the atomic physics effects on the weak charge in cesium have led to a value in much closer agreement with predictions of the Standard Model. We review precision electroweak tests, their implications for upper bounds on…
A concise review of atomic parity violation with a focus on the measurement and interpretation of parity violation in cesium.
Atomic parity violation has been observed in the 6s^2 1S0 - 5d6s 3D1 408-nm forbidden transition of ytterbium. The parity-violating amplitude is found to be two orders of magnitude larger than in cesium, where the most precise experiments…
The impact of atomic parity violation experiments on determination of the weak mixing parameter $\sin^2 \theta$ and the Peskin-Takeuchi parameters $S$ and $T$ is reassessed in the light of recent electroweak measurements at LEP, SLAC, and…
Recent advances in interpreting the most accurate to-date measurement of atomic parity violation in Cs are reviewed. The inferred nuclear weak charge, Q_W = - 72.65(28)_expt (36)_theor, agrees with the prediction of the standard model at 1…
Pair production of leptoquarks at future e+e- linear colliders is investigated for center-of-mass energies of 500 GeV and 800 GeV and an integrated luminosity of 500 fb^-1. Based on a Monte Carlo simulation we estimate the event rates for…