Search results for "Neutral Current"
showing 10 items of 301 documents
Search for the neutral current top quark decayt→Zcusing the ratio ofZ-boson+4 jetstoW-boson+4 jetsproduction
2009
We have used the Collider Detector at Fermilab (CDF II) to search for the flavor-changing neutral-current (FCNC) top quark decay t {yields} Zc using a technique employing ratios of W and Z production, measured in p{bar p} data corresponding to an integrated luminosity of 1.52 fb{sup -1}. The analysis uses a comparison of two decay chains, p{bar p} {yields} t{bar t} {yields} WbWb {yields} {ell}{nu}bjjb and p{bar p} {yields} t{bar t} {yields} ZcWb {yields} {ell}{ell}cjjb, to cancel systematic uncertainties in acceptance, efficiency, and luminosity. We validate the modeling of acceptance and efficiency for lepton identification over the multi-year dataset using another ratio of W and Z product…
QCD Jets at HERA II.O(? s 2 ) four-jet cross-sections
1989
We present exact expressions for theO(α s 2 ) tree graph four-jet cross-sections in neutral current and charged current deep inelasticep scattering initiated by quarks, antiquarks and gluons including lepton polarization effects. Using helicity amplitudes the partonic cross-sections are given in concise form including all colour, flavour and statistical factors. We explicate the electroweak coupling dependence and state how the partonic cross-sections are folded with the respective parton densities to obtain theep jet cross-sections toO(α s 2 ). We present some numerical results for the neutral current one-photon exchange case. We elaborate on the cut dependence of the jet rates and present…
First Observation of PeV-Energy Neutrinos with IceCube
2013
We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04 $\pm$ 0.16 and 1.14 $\pm$ 0.17 PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current $\nu_{e,\mu,\tau}$ ($\bar\nu_{e,\mu,\tau}$) or charged-current $\nu_{e}$ ($\bar\nu_{e}$) interactions within the IceCube detector. The events were discovered in a search for ultra-high energy neutrinos using data corresponding to 615.9 days effective livetime. The expected number of atmospheric background is $0.082 \pm 0.004 \text{(stat)}^{+0.041}_{-0.057} \text{(syst)}$. T…
"Table 1" of "A Measurement of the tau leptonic branching fractions"
1995
Axis error includes +- 0.23/0.23 contribution (Data statistics).
Relativistic multipole operators for semileptonic weak and electromagnetic nuclear reactions.
1989
We discuss multipole operators that arise in a relativistic analysis ofsemileptonic weak and electromagnetic interactions with nuclei. Thesesingle-particle operators are evaluated between relativistic nucleon boundstates that are solutions to the Dirac equation with potentials of the formproduced by the sigma-..omega.. model. The reduced matrix elements aregiven in terms of easily programmable radial integrals and can be applied to anumber of reactions such as elastic and inelastic electron scattering, realphoton processes, ..beta.. decay, and charged lepton capture as well as moreexotic interactions such as charged and neutral current neutrino reactions. Asa specific example, we calculate …
"Table 2" of "Flavour Separation of Helicity Distributions from Deep Inelastic Muon-Deuteron Scattering"
2010
Charged pion and kaon semi-inclusive asymmetries as functions of X.
A search for flavour changing neutral currents in top-quark decays in pp collision data collected with the ATLAS detector at root s=7 TeV
2012
A search for flavour changing neutral current (FCNC) processes in top-quark decays by the ATLAS Collaboration is presented. Data collected from pp collisions at the LHC at a centre-of-mass energy of √s = 7 TeV during 2011, corresponding to an integrated luminosity of 2.1 fb[superscript −1], were used. A search was performed for top-quark pair-production events, with one top quark decaying through the t → Zq FCNC (q = u, c) channel, and the other through the Standard Model dominant mode t → W b. Only the decays of the Z boson to charged leptons and leptonic W -boson decays were considered as signal. Consequently, the final-state topology is characterised by the presence of three isolated cha…
Muon-electron lepton-flavor-violating transitions : Shell-model calculations of transitions in 27Al
2018
In this paper we present the results of large-scale shell-model calculations of muon-to-electron lepton-flavorviolating transitions for the case of the target nucleus 27Al. We extend the previous shell-model calculations, done in the sd model space, by including also the p orbitals in order to see whether the negative-parity states produce any significant effect in the conversion rate. The analysis of the results shows the dominance of coherent transitions mediated by isovector operators and going by the ground state of the target, with practically null influence of excited positive- or negative-parity states. peerReviewed
Electroweak processes in nucleons and nuclei at intermediate energies
2014
263 páginas. Tesis Doctoral del Departamento de Física Teórica de la Universidad de Valencia y del Instituto de Física Corpuscular (IFIC).
Observation of the rare B(s)(0) + decay from the combined analysis of CMS and LHCb data.
2015
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported licence.-- et al.