Search results for "Bottom"

DandDSdecay constants from QCD duality at three loops

2005

Using special linear combinations of finite energy sum rules which minimize the contribution of the unknown continuum spectral function, we compute the decay constants of the pseudoscalar mesons B and Bs. In the computation, we employ the recent three loop calculation of the pseudoscalar two-point function expanded in powers of the running bottom quark mass. The sum rules show remarkable stability over a wide range of the upper limit of the finite energy integration. We obtain the following results for the pseudoscalar decay constants: fB = 178±14 MeV and fBs = 200±14 MeV. The results are somewhat lower than recent predictions based on Borel transform, lattice computations or HQET. Our sum …

A Measurement of the Bbbar Forward-backward Asymmetry Using the Semileptonic Decay Into Muons

1992

Weak Quark Mixing and the CKM Matrix

2003

Weak quark mixing and the Cabibbo-Kobayashi-Maskawa (CKM) matrix are outlined in this chapter.

Simultaneous Measurement of the RatioR=B(t→Wb)/B(t→Wq)and the Top-Quark Pair Production Cross Section with the D0 Detector ats=1.96  TeV

2008

We present the first simultaneous measurement of the ratio of branching fractions, R = B(t --> Wb)/B(t --> Wq), with q being a d, s, or b quark, and the top-quark pair production cross section sigma(t (t) over bar) in the lepton plus jets channel using 0.9 fb(-1) of p (p) over bar collision data at root s = 1.96 TeV collected with the D0 detector. We extract R and sigma(t (t) over bar) by analyzing samples of events with 0, 1, and >= 2 identified b jets. We measure R = 0.97(-0.08)(+0.09) (stat + syst) and sigma(t (t) over bar) = 8.18(-0.84)(+0.90) (stat + syst) +/- 0.50(lumi) pb, in agreement with the standard model prediction.

Quark and lepton mixing in weak interactions

1986

The coupling strength of weak interactions between quarks of different flavour shows a clear pattern: couplings between members of the same family are much stronger than the ones between neighbour families and couplings between first and third family haye escaped detection so far. The coupling strength between different families decreases with increasing quark mass, but a theoretical explanation of this pattern is still missing. On the other side, lepton mixing and neutrino oscillations have not been seen in experiments yet. An analysis of experimental data in the framework of simultaneous oscillations of three neutrino fluxes yields limits on the three mixing angles which are about as rest…

Experimental analysis of weak mixing angles between three or four quark generations

1987

New data on weak quark decays and on weak heavy quark production are used to obtain the allowed ranges of elements of the quark mixing matrix for three or four generations of sequential quarks. The analysis yields allowed ranges for the three mixing angles in the six-quark case and for the six mixing angles in the eight-quark case.

Bottom-up construction of dynamic density functional theories for inhomogeneous polymer systems from microscopic simulations

2020

We propose and compare different strategies to construct dynamic density functional theories (DDFTs) for inhomogeneous polymer systems close to equilibrium from microscopic simulation trajectories. We focus on the systematic construction of the mobility coefficient, $\Lambda(r,r')$, which relates the thermodynamic driving force on monomers at position $r'$ to the motion of monomers at position $r$. A first approach based on the Green-Kubo formalism turns out to be impractical because of a severe plateau problem. Instead, we propose to extract the mobility coefficient from an effective characteristic relaxation time of the single chain dynamic structure factor. To test our approach, we study…

Basal heat improves adventitious root quality in Plumeria (Plumeria rubra L.) stem cuttings of different sizes

2014

Root development of hardwood cuttings of Plumeria rubra was investigated in relation to basal heat and the size of cuttings. Terminal cuttings of a clone grown in Sicily were trimmed to various lengths, ranging from 10 to 26 cm. To verify the cutting rooting response to basal heat, half of the cuttings were placed on a basal heated bench (28 ± 3°C, constant temperature) while the remaining were placed on an unheated bench (16-18°C during the night and 20-22°C during the day). Percent rooting and cutting survival were not affected by basal heat and cutting length. However, basal heat positively affected number of roots, length of longest root and bud growth. Increases in the length of the cu…

Microfluidics and Macromolecules: Top-Down Analytics and Bottom-Up Engineering of Soft Matter at Small Scales

2016

Microfluidics is the art of creating and manipulating small portions of fluids. A typical variant of this art is fluid transport within small channels, either in form of laminar co-flow of miscible streams or in form of segmented-flow dripping and jetting of immiscible streams. Either method provides means to expose components of interest to defined local conditions such as spatially controlled concentration profiles that could not be established without the microfluidic auxiliaries. This ability renders microfluidics uniquely useful as both a method for advanced analytics and synthesis. This article sheds a spotlight on the use and utility of this method in macromolecular chemistry and phy…

Evaluation of FASP, SP3, and iST Protocols for Proteomic Sample Preparation in the Low Microgram Range

2017

Efficient and reproducible sample preparation is a prerequisite for any robust and sensitive quantitative bottom-up proteomics workflow. Here, we performed an independent comparison between single-pot solid-phase-enhanced sample preparation (SP3), filter-aided sample preparation (FASP), and a commercial kit based on the in-StageTip (iST) method. We assessed their performance for the processing of proteomic samples in the low μg range using varying amounts of HeLa cell lysate (1-20 μg of total protein). All three workflows showed similar performances for 20 μg of starting material. When handling sample sizes below 10 μg, the number of identified proteins and peptides as well as the quantitat…