95,002 research outputs found
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
The 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
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
First 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)
Measurement of the time-dependent CP asymmetry in B0 -> J/ψ KS0 decays
This 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 branching fraction
The 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
A marine systematic conservation plan for Rodrigues Island, Western Indian Ocean
Includes abstract.Includes bibliographical references (p. 53-59).In 2007 the local government of Rodrigues gazetted four marine reserves in the north of the island based on knowledge and insights from stakeholders, mainly from the fishing community. In order to verify the stakeholder-based design, a marine reserve network was designed using Marxan, a systematic conservation planning programme
Eliane Rodrigues and Jose-Maria Martinez Pinzolas, Preliminaries Phase I, 5th Van Cliburn Competition (1977)
Keyboard partita no. 6 in E minor, BWV 830. Toccata / J. S. Bach ; Piano sonata no. 17 in D minor, op. 31, no. 2. Largo - Allegro / Beethoven ; Ballade no. 2 in F major, op. 38 / Chopin (Rodrigues) -- Ballade no. 4 in F minor, op. 52 / Chopin ; Piano sonata no. 8 in C minor, op. 13. Grave - Allegro di molto e con brio / Beethoven (PARTIAL) ; Piano sonata no. 8 in C minor, op. 13. Rondo: Allegro / Beethoven (Pinzolas)
Eliane Rodrigues and Jose-Maria Martinez Pinzolas, Preliminaries Phase I, 5th Van Cliburn Competition (1977)
Keyboard partita no. 6 in E minor, BWV 830. Toccata / J. S. Bach ; Piano sonata no. 17 in D minor, op. 31, no. 2. Largo - Allegro / Beethoven ; Ballade no. 2 in F major, op. 38 / Chopin (Rodrigues) -- Ballade no. 4 in F minor, op. 52 / Chopin ; Piano sonata no. 8 in C minor, op. 13. Grave - Allegro di molto e con brio / Beethoven (PARTIAL) ; Piano sonata no. 8 in C minor, op. 13. Rondo: Allegro / Beethoven (Pinzolas)
Observations of Bºs→ψ(2S)η and Bº(s)→ψ(2S)π+π- decays
First observations of the B0s
→ψ(2S)η, B0 →ψ(2S)π
+
π
− and B0s
→ψ(2S)π
+
π
− decays are made
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
√
s = 7 TeV. The ratios of the branching fractions
of each of the ψ(2S) modes with respect to the corresponding J/ψ decays are
B(B0s
→ψ(2S)η)
÷
B(B0s
→J/ψη)
= 0.83± 0.14 (stat)±0.12 (syst) ±0.02 (B),
;
B(B0→ψ(2S)π
+
π
−
)
÷
B(B0→J/ψπ
+
π
−
)
= 0.56± 0.07 (stat)±0.05 (syst)± 0.01 (B),
;
B(B0s
→ψ(2S)π
+
π
−
)
÷
B(B0s
→J/ψπ
+
π
−
)
= 0.34± 0.04 (stat)±0.03 (syst)± 0.01 (B),
where the third uncertainty corresponds to the uncertainties of the dilepton branching fractions of the J/ψ
and ψ(2S) meson decays
Letter from J. E. Gavin to Louis C. Cramton regarding Sale of Bright Angel Trail
Letter from J. E. Gavin to Louis C. Cramton regarding the Bright Angel Trail controversy, including newspaper clipping
Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays
Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of prime importance in probing new physics. Here 7421 +/- 105 signal events from the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A time-dependent fit to the data yields a value of phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard Model expectation. No evidence of direct CP violation is found
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