Search results for "aska"
showing 10 items of 568 documents
A solution to the strong CP problem transforming the theta angle to the KM CP-violating phase
2010
It is shown that in the scheme with a rotating fermion mass matrix (i.e. one with a scale-dependent orientation in generation space) suggested earlier for explaining fermion mixing and mass hierarchy, the theta angle term in the QCD action of topological origin can be eliminated by chiral transformations, while giving still nonzero masses to all quarks. Instead, the effects of such transformations get transmitted by the rotation to the CKM matrix as the KM phase giving, for theta of order unity, a Jarlskog invariant typically of order 10(-5), as experimentally observed. Strong and weak CP violations appear then as just two facets of the same phenomenon.
Kl3Semileptonic Form Factor from (2+1)-Flavor Lattice QCD
2008
We present the first results for the ${K}_{l3}$ form factor from simulations with $2+1$ flavors of dynamical domain wall quarks. Combining our result, namely, ${f}_{+}(0)=0.964(5)$ with the latest experimental results for ${K}_{l3}$ decays leads to $|{V}_{us}|=0.2249(14)$, reducing the uncertaintity in this important parameter. For the $O({p}^{6})$ term in the chiral expansion we obtain $\ensuremath{\Delta}f=\ensuremath{-}0.013(5)$.
Weak Mixing, CP Violation and the Standard Model
1990
These lectures summarize experimental information on weak couplings of quark flavours from weak decays and weak production of heavy flavours and the relation of the observed direct CP violation to a non-trivial phase in the quark mixing matrix. The interest in this field is twofold: on the one side, we can measure precisely the parameters of the standard model in its own framework; on the other side, any inconsistency amongst these measurements or evidence for any process forbidden in the standard model will lead beyond that model. The outline of these lectures is the following: 1. Weak Mixing of Quarks 1.1 Kobayashi-Maskawa-Matrix 1.2 Experimental Constraints on the KM Matrix 1.3 Allowed R…
Precision Measurement of the RatioB(t→Wb)/B(t→Wq)and Extraction ofVtb
2011
We present a measurement of the ratio of top quark branching fractions R = B(t -> Wb)/B(t -> Wq), where q can be a d, s or b quark, in the lepton+jets and dilepton ttbar final states. The measurement uses data from 5.4 fb-1 of ppbar collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure R = 0.90 +/- 0.04, and we extract the CKM matrix element |Vtb| as |Vtb| = 0.95 +/- 0.02, assuming unitarity of the 3x3 CKM matrix.
Evidence forB0→ρ0ρ0Decays and Implications for the Cabibbo-Kobayashi-Maskawa Angleα
2007
We search for the decays B(0) --> rho(0)rho(0), B(0) --> rho(0)f(0)(980), and B(0) --> f(0)(980)f(0)(980) in a sample of about 384 x 10(6) Upsilon(4S) --> BB[over] decays collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at Stanford Linear Accelerator Center. We find evidence for B(0) --> rho(0)rho(0) with 3.5 sigma significance and measure the branching fraction B = (1.07 +/- 0.33 +/- 0.19) x 10(-6) and longitudinal polarization fraction f(L) = 0.87 +/- 0.13 +/- 0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix unitarity angle alpha due to penguin contributio…
Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element Vtb
2015
et al.
Approximation of Baskakov type Pólya–Durrmeyer operators
2017
In the present paper we propose the Durrmeyer type modification of Baskakov operators based on inverse Polya-Eggenberger distribution. First we estimate a recurrence relation by using hypergeometric series. We give a global approximation theorem in terms of second order modulus of continuity, a direct approximation theorem by means of the Ditzian-Totik modulus of smoothness and a Voronovskaja type theorem. Some approximation results in weighted space are obtained. Also, we show the rate of convergence of these operators to certain functions by illustrative graphics using the Maple algorithms.
Elektroniskās darba laika uzskaites sistēmas tīmekļa vietnes, lietotnes saskarnes izstrāde un ārējo NFC lasītāju sasaiste ar sistēmas lietotnes kontr…
2018
Darbā aprakstīta lietotāja saskarnes izstrāde un ārējā NFC lasītāja sasaiste ar “Elektronisko darba laika uzskaites sistēmu”, jeb EDLUS, kas ir jau pastāvošs produkts, kas jau tiek izmantota Latvijā esošu būvobjektu darba laika uzskaitē. Darba izstrādes mērķis bija: uzlabot šīs sistēmas tīmekļa saites pārskatāmību, pielāgot vietnes izskatu mobilajām ierīcēm ar responsīvu dizainu, uzlabot vietnes paziņojumu attēlošanu un izstrādāt risinājumu ārējo USB NFC lasītāju sasaistei ar sistēmu. Šis risinājums jau tiek izmantots sistēmas Android lietotnes izstrādē un izstrādātā lietotāju saskarne tiek pielietota gatavajā produktā.
Eisüberlastung in Daugava: Rembat (13.04.1904.)
1904
K. B. Dosa 1904. gada 13. aprīlī fotografētie ledus sastrēgumi Daugavā pie Rembates ar aprakstu. Foto 1: Ledus bloki (daļa kāda ledus "mūra") Daugavas labajā krastā pirms otrā strauta " mutes" lejpus dzirnavām pie Rembates. Skats augšup. Foto 2: Tā sauktās "Maskavas ielas" plūdi ar Daugavas ledu. Lejup Rembates, skats uz leju. (LU Muzeja Botānikas un mikoloģijas kolekcija M1613/288)
Rotaļlietas kā līdzeklis 4-5 gadu vecu bērnu valodas attīstībai
2021
Darba autore –Linda Feldmane teorētiski analizē un pēta, vai rotaļlietas palīdz 4-5 gadu veciem bērniem attīstīt valodas prasmes. Pētījumā pierādās, ka bērni labprāt rotaļājas un veido sarunas savā starpā, kas veicina viņu valodas attīstību. Rotaļlietas kā līdzeklis 4 līdz 5 gadu vecu bērnu valodas attīstībai, veicina bērna pareizu skaņu apguvi, jo bērns māk raksturot rotaļlietu un paplašināt vārdu krājumu. Darba autore pēc empīriskā novērojuma, var secināt, ka bērniem no 4 līdz 5 gadu vecumam liela loma valodas apguvē un pilnveidē veicina pareiza rotaļlietu izvēle un to regulāra mainīšana, un dažādošana. Kvalifikācijas darbā pētījuma metodes ir literatūras avotu analīze, bērnu novērošana u…