292 research outputs found
LHCb RMS-R3 — new radiation hard system for on-line monitoring of beam and background conditions in Run 3
No full textDuring Run 3, the LHCb experiment will collect data at a higher luminosity with respect to the previous decade of data taking. The Radiation Monitoring System (RMS-R3) will display the interaction rate of the LHC’s beams along with its background in LHCb. The RMS-R3 comprises four detector modules based on the Metal-Foil Detectors radiation hard technology that can withstand fluences up to 1020 MIPs/cm2 or radiation doses of up to a GGy, during its entire lifespan. The modules are placed symmetrically around the beam pipe very close to the Interaction Point at LHCb at a distance of about 2.2 m, while covering a backward acceptance of 7–14 degrees. The readout electronics provide a continuous relative luminosity measurement for LHCb and observations of background evolutions during the various stages of the beam preparation towards collisions. The RMS-R3 detector's performance has shown good response reproducibility of about 1% and excellent linearity
LHCb RMS-R3, new radiation hard system for on-line monitoring of beam and background conditions in Run 3
No full textDuring Run 3, the LHCb experiment will collect data at a higher luminosity with respect to the previous decade of data taking. The Radiation Monitoring System (RMS-R3), functionally designed for reliable long-run performance, will display the interaction rate of the LHC’s beams along with its background in LHCb. The RMS-R3 comprises 4 detector modules based on the Metal-Foil Detectors radiation hard technology that can withstand fluences up to 10 MIPs/cm or radiation doses of up to a GGy, during its entire lifespan. The modules are placed symmetrically around the beam pipe remarkably close to the interaction point at LHCb at about 2.2 m, while covering a backward acceptance of 7-14 degrees. The readout electronics provide a continuous relative luminosity measurement for LHCb and observations of background evolutions during the various stages of the beam preparation towards collisions. The RMS-R3 detector’s performance has shown good response reproducibility of about 1% and excellent linearity, making it a robust and reliable complementary detector for beam induced background and luminosity measurement at LHCb
Etude des désintégrations radiatives du méson B^0_s et du système de détection des radiations avec détecteur LHCb
No full textLe travail présenté a été accompli dans le cadre de l'expérience LHCb. La thèse comporte deux parties : le développement et la mise en route du Radiation Monitoring System (RMS) et l'étude des performances attendues pour la mesure de la désintégration radiative Bs-> g. Une surveillance en ligne du bruit de fond lié à l accélérateur est indispensable pour la sécurité du détecteur et pour collecter des données de bonne qualité pour la physique. La technologie dite Métal Foil Detector a été choisie pour la surveillance en ligne de la radiation. Son temps de réponse est rapide, elle est sensible dans la plage de radiation correspondant aux conditions nominales de fonctionnement pour LHCb, elle est robuste et la quantité de matière qu'elle ajoute reste modérée. Le système de lecture et son intégration dans l architecture de LHC ont été menés à bien. Les résultats obtenus avec le RMS sont en accord avec ceux d'autres systèmes de mesure de bruit de fond et ont montré que le RMS était sensible aux collisions pp et capable de détecter des augmentations inattendues dans le taux de radiation. La deuxième partie de la thèse est consacrée à l étude des performances attendues pour la mesure de la désintégration radiative Bs-> g. L'optimisation des critères de sélection a été effectuée avec une simulation Monte-Carlo complète du détecteur. La simulation des événements de signal a été complétée par celle des principaux bruits de fond. Dans les conditions nominales de fonctionnement, on attend pour un an environ 9000 candidats Bs-> g enregistrés, reconstruits et sélectionnés. Le niveau de bruit de fond attendu est estimé à B/S g. The online monitoring of the background related to the accelerator is mandatory for the safety of the detector and for high quality data taking. The Metal Foil Detector technology was chosen for the radiation online monitoring. It is characterized by a fast time response and is sensitive to irradiation range corresponding to the conditions expected for nominal LHCb operation. It is robust and yields a moderate amount of material. The readout system and its integration in the LHC architecture have been realized. The results obtained with the RMS are in agreement with those from other systems that measure accelerator backgrounds. It has been shown that the RMS is sensitive to the pp collisions and is able to detect unexpected increase in the radiation rate. The second part of the thesis is dedicated to the study of the expected performances for the measurement of the radiative decay Bs-> g. The selection criteria optimization has been realized with a full Monte Carlo simulation of the detector. The signal events simulation has been complemented by the detailed background studies. In nominal operation conditions, about 9000 signal events are expected to be recorded, reconstructed and selected. The background level is estimated to be B/S < 2.9@90% CL.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF
Observations of Bºs→ψ(2S)η and Bº(s)→ψ(2S)π+π- decays
No full textFirst 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
Prompt charm production in pp collisions at √<span style="text-decoration:overline">s</span>=7 TeV
No full textCharm production at the LHC in pp collisions at s√=7 TeV is studied with the LHCb detector. The decays D0→K−π+, D+→K−π+π+, D⁎+→D0(K−π+)π+, D+s→ϕ(K−K+)π+, Λ+c→pK−π+, and their charge conjugates are analysed in a data set corresponding to an integrated luminosity of 15 nb−1. Differential cross-sections dσ/dpT are measured for prompt production of the five charmed hadron species in bins of transverse momentum and rapidity in the region 0<pT<8 GeV/c and 2.0<y<4.5. Theoretical predictions are compared to the measured differential cross-sections. The integrated cross-sections of the charm hadrons are computed in the above pT-y range, and their ratios are reported. A combination of the five integrated cross-section measurements gives
σ(cc¯)pT<8 GeV/c,2.0<y<4.5=1419±12(stat)±116(syst)±65(frag) μb,
where the uncertainties are statistical, systematic, and due to the fragmentation functions
Observation of J/ψ-pair production in pp collisions at √s=7 TeV
No full textThe production of J/ψ pairs in proton–proton collisions at a centre-of-mass energy of 7 TeV has been observed using an integrated luminosity of 37.5 pb−1 collected with the LHCb detector. The production cross-section for pairs with both J/ψ in the rapidity range 2 < yJ/ψ < 4.5 and transverse momentum pJ/ψ T <10 GeV/c is σJ/ψJ/ψ =5.1±1.0±1.1 nb, where the first uncertainty is statistical and the second systematic
India's product patent protection regime: Less or more of "pills for the poor"?
No full textThe year 2005 marks the end of transition period for many developing countries with competent pharmaceutical sectors that competed in supplying generic versions of patented drugs to LDCs before, thereby inducing price competition and enhancing access to medicines. In a post-2005 scenario, the critical issue is whether LDCs without adequate manufacturing capabilities can make use of compulsory licensing expeditiously to induce price competition and secure lower prices. This paper uses empirical evidence collected during a firm-level survey of the Indian pharmaceutical sector to generate evidence on emerging strategies of firms. It shows that the vigour of compulsory licensing as a price-leveraging instrument post-2005 is incumbent mainly on its economic feasibility. It shows that Indian firms view the market potential (in terms of market size and profits involved in such supply, especially if they have to make specific technological investments to produce the drug) of the mechanism much more severely than before, and may be less inclined to engage in such production if their commercial expectations are grossly unmet. The analysis assesses implications of emerging strategies of firms in the Indian pharmaceutical sector for access to medicines both domestically and internationally, and highlights the challenges involved.product patents, Indian pharmaceuticals, generics, access
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)
Measurement of the effective B_s^0 -> J/ψ K_S^0 lifetime
No full textThis paper reports the first measurement of the effective B_s^0 -> J/{\psi} K_S^0 lifetime and an updated measurement of its time-integrated branching fraction. Both measurements are performed with a data sample, corresponding to an integrated luminosity of 1.0 fb^{-1} of pp collisions, recorded by the LHCb experiment in 2011 at a centre-of-mass energy of 7 TeV. The results are: tau_J/{\psi}K_S^0 = 1.75 +/- 0.12 (stat) +/- 0.07 (syst) and BR(B_s^0 -> J/{\psi} K_S^0) = (1.97 +/- 0.23) X 10^{-5}.
For the latter measurement, the uncertainty includes both statistical and systematic sources
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
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