42,238 research outputs found
Fast methods for training Gaussian processes
No full textThis submission includes a simplified version of some code we have been developing for fast training of Gaussian processes. We also include a sample data set, which is NOAA tidal data from Woods Hole in the US, downloaded from http://tidesandcurrents.noaa.gov/ .
The code and data included here were used to produce the numerical results in the following paper:
[1] Fast methods for training Gaussian processes, C. J. Moore, A. J. K. Chua, C. P. L. Berry, and J. R. Gair (2016), submitted to RSOS
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Fast methods for training Gaussian processes
No full textThis submission includes a simplified version of some code we have been developing for fast training of Gaussian processes. We also include a sample data set, which is NOAA tidal data from Woods Hole in the US, downloaded from http://tidesandcurrents.noaa.gov/ . The code and data included here were used to produce the numerical results in the following paper: [1] Fast methods for training Gaussian processes, C. J. Moore, A. J. K. Chua, C. P. L. Berry, and J. R. Gair (2016), submitted to RSOS.Moore, Christopher J; Chua, Alvin J K; Berry, Christopher P L; Gair, Jonathan R. (2016). Fast methods for training Gaussian processes, [software]. http://dx.doi.org/10.7488/ds/1343
Measurement of the B0–B0 oscillation frequency Δmd with the decays B0→D−π+ and B0→ J/ψK∗0
No full textThe B
0
–B
0
oscillation frequency Δmd is measured by the LHCb experiment using a dataset corresponding
to an integrated luminosity of 1.0 fb−1
of proton–proton collisions at √
s = 7 TeV, and is found to be
Δmd
=0.5156±0.0051 (stat.)±0.0033 (syst.) ps−1
. The measurement is based on results from analyses
of the decays B
0
→ D
−π
+ (D
−
→ K
+π
−π
−) and B
0
→ J/ψK
∗0
(J/ψ →μ
+μ
−,K
∗0
→ K
+π
−) and
their charge conjugated modes
Observation of the Lambda(0)(b) -> J/psi p pi(-) decay
No full textThe first observation of the Cabibbo-suppressed decay Λ b → J/ψpπ is reported using a data sample of proton-proton collisions at 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1. A prominent signal is observed and the branching fraction relative to the decay mode Λ b → J/ψpK is determined to be B (Λb → J / ψp π-/ B Λ b → J / ψp K- = 0.0824 ± 0.0025 stat ± 0.0042 syst. A search for direct CP violation is performed. The difference in the CP asymmetries between these two decays is found to be A CP (Λb → J / ψp π-) - A CP (Λb → J / ψp K-) = + 5.7 ± 2.4 stat ± 1.2 syst %, which is compatible with CP symmetry at the 2.2σ level. [Figure not available: see fulltext.] © 2014 The Author(s)
DISEÑO DE OSCILADORES CAÓTICOS DE CHUA EN MATLAB, MULTISIM Y DSP-BUILDER (DESIGN OF A CHAOTIC OSCILLATORS OF CHUA IN MATLAB, MULTISIM AND DSP-BUILDER)
No full textResumenEste artículo presenta la metodología de diseño del sistema caótico de Chua, en los programas de software Matlab, Multisim y DSP-Builder. La simulación del circuito caótico en Multisim va acompañada del cálculo de cada uno de los componentes electrónicos y las conexiones correspondientes. También se hace uso del software Matlab/Simulink para recrear las ecuaciones diferenciales que representan del sistema de Chua, creando un programa mediante el que se pueden obtener las salidas del sistema, visualizarlas gráficamente y comparar los resultados. De la misma manera se muestran los resultados de la implementación en DSP-FPGA específicamente en un DSP-FPGA Cyclone III Edition de Altera, visualizándose las secuencias y los enrollamientos resultantes en un osciloscopio.Palabras Clave: Caos, DSP-Builder, Matlab, Multisim, Oscilador de Chua. AbstractThis article presents the design methodology of a Chua chaotic system, using the software programs Matlab, Multisim and DSP-Builder. The simulation of the chaotic circuit on Multisim is accompanied by the calculation of each of the electronic components and the corresponding connections. Matlab/Simulink software is also used to represent the differential equations that describe the Chua system, generating a program through the outputs signals can be obtained, graphically visualized and compared the results. In the same way the results of implementation into an DSP-FPGA Cyclone III Edition, Altera, visualizing the output sequences and scrolls.Keywords: Chaos, Chua oscillator, DSP-Builder, Matlab, Multisim
Measurement of the branching fraction
No full textThe B
0
s
→ J/ψK
0
S
branching fraction is measured in a data sample corresponding to 0.41 fb−1
of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to
the penguin contributions affecting the sin 2β measurement from B
0
→ J/ψK
0
S
. The time-integrated
branching fraction is measured to be B(B
0
s
→ J/ψK
0
S
) = (1.83±0.28)×10−5
. This is the most precise
measurement to date
Numerical investigation on compact multimode dielectric resonator antennas of very high permittivity
No full textTwo well known numerical techniques, the Finite Element Method (FEM) and the Finite Integration in Time Domain (FIT), have been applied to study a low volume high permittivity dielectric resonator antenna. The paper demonstrates that the design of a compact size and wide frequency coverage dielectric resonator antenna (DRA) for ISM band is possible by proper selection of the resonator shape in combination with appropriate resonant modes. Numerical results for one particular antenna design are reported
Measurement of the time-dependent CP asymmetry in B0 -> J/ψ KS0 decays
No full textThis Letter reports a measurement of the CP violation observables SJ/ψK0S and CJ/ψK0S in the decay channel B0→J/ψK0S performed with 1.0 fb−1 of pp collisions at s√=7 TeV collected by the LHCb experiment. The fit to the data yields SJ/ψK0S=0.73±0.07(stat)±0.04(syst) and CJ/ψK0S=0.03±0.09(stat)±0.01(syst). Both values are consistent with the current world averages and within
expectations from the Standard Model
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
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