Search results for " Neutral"
showing 10 items of 654 documents
Observation of the Baryonic Flavor-Changing Neutral Current Decay Λb0→Λμ+μ-
2011
8 páginas, 2 figuras, 4 tablas.-- PACS numbers: 13.30.Ce, 12.15.Mm, 14.20.Mr.-- CDF Collaboration: et al.
Dynamical Casimir-Polder potentials in non-adiabatic conditions
2014
In this paper we review different aspects of the dynamical Casimir¿Polder potential between a neutral atom and a perfectly conducting plate under nonequilibrium conditions. In order to calculate the time evolution of the atom¿wall Casimir¿Polder potential, we solve the Heisenberg equations describing the dynamics of the coupled system using an iterative technique. Different nonequilibrium initial states are considered, such as bare and partially dressed states. The partially dressed states considered are obtained by a sudden change of a physical parameter of the atom or of its position relative to the conducting plate. Experimental feasibility of detecting the considered dynamical effects i…
Search for flavor changing neutral currents via quark–gluon couplings in single top quark production using 2.3 fb−1 of pp¯ collisions
2010
We present a search for flavor changing neutral currents via quark-gluon couplings in a sample of single top quark final states corresponding to 2.3 fb(-1) of integrated luminosity collected with the DO detector at the Fermilab Tevatron Collider. We select events containing a single top quark candidates with an additional jet, and obtain separation between signal and background using Bayesian neural networks. We find consistency between background expectation and observed data, and set limits on flavor changing neutral current gluon couplings of the top quark to up quarks (tgu) and charm quarks (tgc). The cross section limits at the 95% C.L. are sigma(tgu) gu) gc) < 3.9 x 10(-3).
Search for Production of Single Top Quarks ViatcgandtugFlavor-Changing-Neutral-Current Couplings
2007
We search for the production of single top quarks via flavor-changing neutral current couplings of a gluon to the top quark and a charm ($c$) or up ($u$) quark. We analyze 230 pb$^{-1}$ of lepton + jets data from $\ppbar$ collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters $\kappacLambda$ and $\kappauLambda$, where $\kappag$ define the strength of $tcg$ and $tug$ couplings, and $\Lambda$ defines the scale of new physics. The limits at 95% C.L. are: $\kappacLambda < 0.15 \rm TeV^{-1}$ and $\kappauLam…
Measurement of the quadratic slope parameter in the K-L -> 3 pi(0) decay Dalitz plot
2001
A value of (-6.1 +- 0.9_{stat} +- 0.5_{syst})*10^{-3} is obtained for the quadratic slope parameter h in the K_L -> 3\pi^0 decay Dalitz plot at the NA48 experiment at the CERN SPS. The result is based on 14.7*10^6 fully reconstructed K_L -> 3\pi^0 -> 6\gamma decays. This is the most precise measurement of any of the Dalitz plot slope parameters in the charged and neutral kaon decays so far.
Na+ -dependent neutral amino acid transporters A, ASC, and N of the blood-brain barrier: mechanisms for neutral amino acid removal.
2004
Four Na+-dependent transporters of neutral amino acids (NAA) are known to exist in the abluminal membranes (brain side) of the blood-brain barrier (BBB). This article describes the kinetic characteristics of systems A, ASC, and N that, together with the recently described Na+-dependent system for large NAA (Na+-LNAA), provide a basis for understanding the functional organization of the BBB. The data demonstrate that system A is voltage dependent (3 positive charges accompany each molecule of substrate). Systems ASC and N are not voltage dependent. Each NAA is a putative substrate for at least one system, and several NAA are transported by as many as three. System A transports Pro, Ala, His,…
Safety and efficacy of novel dermal and epidermal microneedle delivery systems for rabies vaccination in healthy adults.
2010
International audience; In the present pilot study, intradermal ID delivery systems with a BD microneedle from 1 to 3mm in length, and epidermal delivery (BD skin abrader) through abraded skin surface relative to standard intramuscular injection were evaluated. Circulating neutralizing antibodies were measured against the rabies virus after the Vero cells rabies vaccine was administered at D0, D7, D21 and D49. This clinical evaluation in 66 healthy volunteers shows that ID delivery using BD microneedle technology of 1/4 the IM antigen dose is safe, efficient and reliable, resulting in a protective seroconversion rate. In contrast, the epidermal delivery route did not produce an immune respo…
Computational and experimental investigation of intermolecular states and forces in the benzene-helium van der Waals complex
2003
A study of the intermolecular potential-energy surface (IPS) and the intermolecular states of the perprotonated and perdeuterated benzene–He complex is reported. From a fit to ab initio data computed within the coupled cluster singles and doubles including connected triples model for 280 interaction geometries, an analytic IPS including two- to four-body atom–atom terms is obtained. This IPS, and two other Lennard-Jones atom–atom surfaces from the literature, are each employed in dynamically exact (within the rigid-monomer approximation) calculations of J = 0 intermolecular states of the isotopomers. Rotational constants and Raman-scattering coefficients for intermolecular vibrational trans…
Raman spectroscopy and crystal-field split rotational states of photoproducts CO and H2 after dissociation of formaldehyde in solid argon
2012
Raman signal is monitored after 248 nm photodissociation of formaldehyde in solid Ar at temperatures of 9–30 K. Rotational transitions J = 2 ← 0 for para-H2 fragments and J = 3 ← 1 for ortho-H2 are observed as sharp peaks at 347.2 cm−1 and 578.3 cm−1, respectively, which both are accompanied by a broader shoulder band that shows a split structure. The rovibrational spectrum of CO fragments has transitions at 2136.5 cm−1, 2138.3 cm−1, 2139.9 cm−1, and 2149 cm−1. To explain the observations, we performed adiabatic rotational potential calculations to simulate the Raman spectrum. The simulations indicate that the splitting of rotational transitions is a site effect, where H2 molecules can resi…
Impact of the environmental taxes on reduction of emission from transport in Latvia
2021
Transport has a significant contribution to climate change and many post-Soviet republics, including Latvia, struggle to decrease these emissions to reach carbon neutrality by 2050. In this paper, ...