Iskanje po katalogu digitalne knjižnice

Opis: Z modernizacijo se je spremenil način življenja ljudi. Vedno več je tudi cest, katere nam omogočajo da živimo »moderni« način življenja, ki pa je tudi vse hitrejši. Posledično vse več ljudi uporablja avtomobile, saj tako hitreje pridejo do željenega cilja. Zato je še toliko bolj pomembno, da ne pozabimo strmeti k temu, da bodo tudi prehodi za kolesarje in pešce čim bolj varni. Naloga predstavlja štiri naključno izbrane prehode za pešce v Mariboru, ki so premalo osvetljeni in tako nevarni za pešce. Prikazuje tudi kako bi se z majhnim vložkom povečanja osvetljenosti, varnost prehodov povečala in posledično zmanjšala možnost nastanka prometne nezgode zaradi slabe vidljivosti. Na koncu diplomske naloge je izračunan tudi dejanski strošek povečanja osvetljenosti teh prehodov.
Ključne besede: promet, prehod za pešce, osvetljenost, varnost pešcev, označitev prehodov, analiza stroškov osvetljenosti, javna razsvetljava
Objavljeno v DKUM: 28.09.2017; Ogledov: 2235; Prenosov: 403
Celotno besedilo (1,34 MB)

Opis: We report an observation of the $B^{\pm } \to J/\psi \eta K^{\pm }$ and $B^0 \to J/\psi \eta K^0_S$ decays using $772\times 10^{6}B\overline {B}$ pairs collected at the $\Upsilon (4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We obtain the branching fractions ${\mathcal B}(B^{\pm }\rightarrow J/\psi \eta K^{\pm })=(1.27\pm 0.11(\hbox {stat.})\pm 0.11(\hbox {syst.}))\times 10^{-4}$ and ${\mathcal B}(B^0\to J/\psi \eta K^0_S)=(5.22 \pm 0.78 (\hbox {stat.}) \pm 0.49 (\hbox {syst.}))\times 10^{-5}$. We search for a new narrow charmonium(-like) state $X$ in the $ J/\psi \eta$ mass spectrum and find no significant excess. We set upper limits on the product of branching fractions, ${\mathcal B}(B^\pm \to XK^\pm){\mathcal B}(X \to J/\psi \eta)$, at $3872\,\hbox {MeV}\,c^{-2}$ where a $C$-odd partner of $X(3872)$ may exist, at $\psi (4040)$ and $\psi (4160)$ assuming their known mass and width, and over a range from 3.8 to $4.8\,\hbox {GeV}\,c^{-2}$. The obtained upper limits at 90% confidence level for $X^{C\hbox {-}{\rm odd}}(3872)$, $\psi (4040)$, and $\psi (4160)$ are $3.8\times 10^{-6}$, $15.5\times 10^{-6}$, and $7.4\times 10^{-6}$, respectively.
Ključne besede: C07, C21, particle properties, lepton collider experiments, experimental particle physics
Objavljeno v DKUM: 21.07.2017; Ogledov: 1540; Prenosov: 232
Celotno besedilo (372,20 KB)
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Opis: We report a measurement of the amplitude ratio $r_S$ of $B^0 \to D^0K^{\ast 0}$ and $B^0 \to \bar {D^0}K^{\ast 0}$ decays with a Dalitz analysis of $D\to K_S^0\pi ^+\pi ^-$ decays, for the first time using a model-independent method. We set an upper limit $r_S < 0.87$ at the 68% confidence level, using the full data sample of $711\,{\rm fb}^{-1}$ corresponding to $772\times 10^6$ $B\bar {B}$ pairs collected at the $\Upsilon (4S)$ resonance with the Belle detector at the KEKB $e^+e^-$ collider. This result is obtained from observables $x_- = +0.4 ^{+1.0 +0.0}_{-0.6 -0.1} \pm 0.0$, $y_- = -0.6 ^{+0.8 +0.1}_{-1.0 -0.0} \pm 0.1$, $x_+ = +0.1 ^{+0.7 +0.0}_{-0.4 -0.1} \pm 0.1$, and $y_+ = +0.3 ^{+0.5 +0.0}_{-0.8 -0.1} \pm 0.1$, where $x_\pm = r_S \cos (\delta _S \pm \phi _3)$, $y_\pm = r_S \sin (\delta _S \pm \phi _3)$, and $\phi _3\ (\delta _S)$ is the weak (strong) phase difference between $B^0 \to D^0K^{\ast 0}$ and $B^0 \to \bar {D^0}K^{\ast 0}$.
Ključne besede: CO2, CO3, Cabibbo-Kobayashi-Maskawa quark-mixing matrix, CP violation, experimental particle physics
Objavljeno v DKUM: 21.07.2017; Ogledov: 1788; Prenosov: 289
Celotno besedilo (555,01 KB)
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Opis: We are preparing a major upgrade of the KEKB electron-positron collider, the Super KEK B factory (SuperKEKB) – a project that could detect new phenomena arising from physics beyond the Standard Model by using a large amount of data, corresponding to the integrated luminosity of 50 ab-1. This data set will allow studies of rare processes in B meson decays, D meson decays and τ lepton decays with an unprecedented sensitivity. To achieve the goal of this ambitious project, the design luminosity of the SuperKEKB is 8 mid 1035 cm-2s-1 – 50 times larger than that of the present KEKB collider. The current Belle detector will also be upgraded to take a full advantage of the high collider luminosity. The new detector, SuperBelle, is designed in such a way that it should perform at least as well as the present Belle spectrometer, despite the substantial increase in beam-induced backgrounds.
Ključne besede: KEKB, SuperKEKB, B mesons, B factories, SuperBelle
Objavljeno v DKUM: 30.06.2017; Ogledov: 1214; Prenosov: 374
Celotno besedilo (1,04 MB)
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Opis: We present a measurement of the time-dependent CP violation parameters in B0 → η′K0 decays. The measurement is based on the full data sample containing 772 × 10^6 BB pairs collected at the Υ(4S) resonance using the Belle detector at the KEKB asymmetric-energy e+e− collider. The measured values of the mixing-induced and direct CP violation parameters are: sin⁡ 2ϕ1eff=+0.68±0.07±0.03, Aη′K0=+0.03±0.05±0.04, where the first uncertainty is statistical and the second is systematic. The values obtained are the most accurate to date. Furthermore, these results are consistent with our previous measurements and with the world-average value of sin 2ϕ1 measured in B0 → J/ψK0 decays.
Ključne besede: CP violation, CKM angle beta, e+-e- Experiments, B physics
Objavljeno v DKUM: 27.06.2017; Ogledov: 1539; Prenosov: 379
Celotno besedilo (448,79 KB)
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