JPCam: A 1.2Gpixel camera for the J-PAS survey

JPCam is a 14-CCD mosaic camera, using the new e2v 9k-by-9k 10microm-pixel 16-channel detectors, to be deployed on a dedicated 2.55m wide-field telescope at the OAJ (Observatorio Astrofisico de Javalambre) in Aragon, Spain. The camera is designed to perform a Baryon Acoustic Oscillations (BAO) survey of the northern sky. The J-PAS survey strategy will use 54 relatively narrow-band (~13.8nm) filters equi-spaced between 370 and 920nm plus 3 broad-band filters to achieve unprecedented photometric red-shift accuracies for faint galaxies over ~8000 square degrees of sky. The cryostat, detector mosaic and read electronics is being supplied by e2v under contract to J-PAS while the mechanical structure, housing the shutter and filter assembly, is being designed and constructed by a Brazilian consortium led by INPE (Instituto Nacional de Pesquisas Espaciais). Four sets of 14 filters are placed in the ambient environment, just above the dewar window but directly in line with the detectors, leading to a mosaic having ~10mm gaps between each CCD. The massive 500mm aperture shutter is expected to be supplied by the Argelander-Institut fur Astronomie, Bonn. We will present an overview of JPCam, from the filter configuration through to the CCD mosaic camera. A brief outline of the main J-PAS science projects will be included.Comment: 11 pages and 9 figure

A specific amino acid motif of HLA-DRB1 mediates risk and interacts with smoking history in Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disease in which genetic risk has been mapped to HLA, but precise allelic associations have been difficult to infer due to limitations in genotyping methodology. Mapping PD risk at highest possible resolution, we performed sequencing of 11 HLA genes in 1,597 PD cases and 1,606 controls. We found that susceptibility to PD can be explained by a specific combination of amino acids at positions 70-74 on the HLA-DRB1 molecule. Previously identified as the primary risk factor in rheumatoid arthritis and referred to as the "shared epitope" (SE), the residues Q/R-K/R-R-A-A at positions 70-74 in combination with valine at position 11 (11-V) is highly protective in PD, while risk is attributable to the identical epitope in the absence of 11-V. Notably, these effects are modified by history of cigarette smoking, with a strong protective effect mediated by a positive history of smoking in combination with the SE and 11-V (P = 10-4; odds ratio, 0.51; 95% confidence interval, 0.36-0.72) and risk attributable to never smoking in combination with the SE without 11-V (P = 0.01; odds ratio, 1.51; 95% confidence interval, 1.08-2.12). The association of specific combinations of amino acids that participate in critical peptide-binding pockets of the HLA class II molecule implicates antigen presentation in PD pathogenesis and provides further support for genetic control of neuroinflammation in disease. The interaction of HLA-DRB1 with smoking history in disease predisposition, along with predicted patterns of peptide binding to HLA, provide a molecular model that explains the unique epidemiology of smoking in PD

Observation of a New Excited Ds+ Meson in B0 →d-D+K+π-Decays

Using pp collision data corresponding to an integrated luminosity of 5.4 fb−1 collected with the LHCb detector at a center-of-mass energy of 13 TeV, the B0 → D−DþKþπ− decay is studied. A new excited Dþ s meson is observed decaying into the DþKþπ− final state with large statistical significance. The pole mass and width, and the spin parity of the new state are measured with an amplitude analysis to be mR ¼ 2591 6 7 MeV, ΓR ¼ 89 16 12 MeV, and JP ¼ 0−, where the first uncertainty is statistical and the second systematic. Fit fractions for all components in the amplitude analysis are also reported. The new resonance, denoted as Ds0ð2590Þþ, is a strong candidate to be the Dsð21 S0Þþ state, the radial excitation of the pseudoscalar ground-state Dþ s meson

Observation of Multiplicity Dependent Prompt χc1 (3872) and ψ (2S) Production in pp Collisions

The production of χc1(3872) and ψ(2S) hadrons is studied as a function of charged particle multiplicity in pp collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 2 fb−1 . For both states, the fraction that is produced promptly at the collision vertex is found to decrease as charged particle multiplicity increases. The ratio of χc1(3872) to ψ(2S) cross-sections for promptly produced particles is also found to decrease with multiplicity, while no significant dependence on multiplicity is observed for the equivalent ratio of particles produced away from the collision vertex in b-hadron decays. This behavior is consistent with a calculation that models the χc1(3872) structure as a compact tetraquark. Implications for the binding energy of the χc1(3872) state are discussed

Measurement of CP observables in B± → D(*)K± and B± → D(*) π ± decays using two-body D final states

Measurements of CP observables in B± → D(∗)K± and B± → D(∗)π ± decays are presented, where D(∗) indicates a neutral D or D∗ meson that is an admixture of meson and anti-meson states. Decays of the D(∗) meson to the Dπ0 and Dγ final states are partially reconstructed without inclusion of the neutral pion or photon. Decays of the D meson are reconstructed in the K±π ∓, K+K−, and π +π − final states. The analysis uses a sample of charged B mesons produced in proton-proton collisions and collected with the LHCb experiment, corresponding to integrated luminosities of 2.0, 1.0, and 5.7 fb−1 taken at centre-of-mass energies of 7, 8, and 13 TeV, respectively. The measurements of partially reconstructed B± → D(∗)K± and B± → D(∗)π ± with D → K∓π ± decays are the first of their kind, and a first observation of the B± → (Dπ0 )D∗ π ± decay is made with a significance of 6.1 standard deviations. All CP observables are measured with world-best precision, and in combination with other LHCb results will provide strong constraints on the CKM angle

Search for CP violation in D(s)+→h+π0 and D(s)+→h+η decays

Searches for CP violation in the two-body decays D + (s) → h +π 0 and D + (s) → h +η (where h + denotes a π + or K+ meson) are performed using pp collision data collected by the LHCb experiment corresponding to either 9 fb−1 or 6 fb−1 of integrated luminosity. The π 0 and η mesons are reconstructed using the e +e −γ final state, which can proceed as three-body decays π 0 → e +e −γ and η → e +e −γ, or via the two-body decays π 0 → γγ and η → γγ followed by a photon conversion. The measurements are made relative to the control modes D + (s)→ K0 S h + to cancel the production and detection asymmetries. The CP asymmetries are measured to b

Observation of the decay Λb0 → χc1pπ−

The Cabibbo-suppressed decay Λ 0 b → χc1pπ − is observed for the first time using data from proton-proton collisions corresponding to an integrated luminosity of 6 fb−1 , collected with the LHCb detector at a centre-of-mass energy of 13 TeV. Evidence for the Λ 0 b → χc2pπ − decay is also found. Using the Λ 0 b → χc1pK− decay as normalisation channel, the ratios of branching fractions are measured to be B Λ 0 b → χc1pπ − B Λ0 b → χc1pK− = (6.59 ± 1.01 ± 0.22) × 10−2 , B Λ 0 b → χc2pπ − B Λ0 b → χc1pπ− = 0.95 ± 0.30 ± 0.04 ± 0.04 , B Λ 0 b → χc2pK− B Λ0 b → χc1pK− = 1.06 ± 0.05 ± 0.04 ± 0.04 , where the first uncertainty is statistical, the second is systematic and the third is due to the uncertainties in the branching fractions of χc1,2 → J/ψγ decays. Keywords: B physics, Branching fraction, Hadron-Hadron scattering (experiments), QCD, Qua

First measurement of the CP-violating phase in B0s→J/ψ( → e+e−)ϕ decays

A flavour-tagged time-dependent angular analysis of B0 s → J/ψφ decays is presented where the J/ψ meson is reconstructed through its decay to an e +e − pair. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1 . The CP-violating phase and lifetime parameters of the B0 s system are measured to be φs = 0.00 ± 0.28 ± 0.05 rad, ∆Γs = 0.115 ± 0.045 ± 0.011 ps−1 and Γs = 0.608 ± 0.018 ± 0.011 ps−1 where the first uncertainty is statistical and the second systematic. This is the first time that CP-violating parameters are measured in the B0 s → J/ψφ decay with an e +e − pair in the final state. The results are consistent with previous measurements in other channels and with the Standard Model predictions

Angular analysis of B0→D∗−D∗+s with D∗+s→D+sγ decays

The first full angular analysis of the B0 → D∗−D∗+ s decay is performed using 6 fb−1 of pp collision data collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The D∗+ s → D+ s γ and D∗− → D 0 π − vector meson decays are used with the subsequent D+ s → K+K−π + and D 0 → K+π − decays. All helicity amplitudes and phases are measured, and the longitudinal polarisation fraction is determined to be fL = 0.578±0.010±0.011 with world-best precision, where the first uncertainty is statistical and the second is systematic. The pattern of helicity amplitude magnitudes is found to align with expectations from quark-helicity conservation in B decays. The ratio of branching fractions [B(B0 → D∗−D∗+ s ) × B(D∗+ s → D+ s γ)]/B(B0 → D∗−D+ s ) is measured to be 2.045 ± 0.022 ± 0.071 with world-best precision. In addition, the first observation of the Cabibbo-suppressed Bs → D∗−D+ s decay is made with a significance of seven standard deviations. The branching fraction ratio B(Bs → D∗−D+ s )/B(B0 → D∗−D+ s ) is measured to be 0.049 ± 0.006 ± 0.003 ± 0.002, where the third uncertainty is due to limited knowledge of the ratio of fragmentation fractions

Study of Bs0 → J/ψπ+π−K+K− decays

The decays Bs0 → J/ψπ+π−K+K− are studied using a data set corresponding to an integrated luminosity of 9 fb−1, collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The decays Bs0 → J / ψK∗ 0K ¯ ∗ 0 and Bs0 → χc1(3872)K+K−, where the K+K−pair does not originate from a ϕ meson, are observed for the first time. Precise measurements of the ratios of branching fractions between intermediate χc1(3872)ϕ, J / ψK∗ 0K ¯ ∗ 0, ψ(2S)ϕ and χc1(3872)K+K− states are reported. A structure, denoted as X(4740), is observed in the J/ψϕ mass spectrum and, assuming a Breit-Wigner parameterisation, its mass and width are determined to be mX(4740)=4741±6±6MeV/c2,ΓX(4740)=53±15±11MeV, where the first uncertainty is statistical and the second is systematic. In addition, the most precise single measurement of the mass of the Bs0 meson is performed and gives a value of mBs0=5366.98±0.07±0.13MeV/c