Measurement of the effective Bs0→J/ψKS0 lifetime

This paper reports the first measurement of the effective B0 s → J /ψK0 S lifetime and an updated mea- surement 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: τ eff J /ψK0 S = 1.75 ± 0.12 (stat) ± 0.07 (syst) ps and B(B0 s → J /ψK0 S ) = (1.97 ± 0.23) × 10−5. For the latter measurement, the uncertainty includes both statistical and systematic sources

Measurements of the Λb0→J/ψΛ decay amplitudes and the Λb0 polarisation in pp collisions at s=7 TeV

An angular analysis of Λ0 b → J /ψΛ decays is performed using a data sample corresponding to 1.0 fb−1 collected in pp collisions at √s = 7 TeV with the LHCb detector at the LHC. A parity violating asymmetry parameter characterising the Λ0 b → J /ψΛ decay of 0.05 ± 0.17 ± 0.07 and a Λ0 b transverse production polarisation of 0.06 ± 0.07 ± 0.02 are measured, where the first uncertainty is statistical and the second systemati

Search for D(s)+→π+μ+μ- and D(s)+→π-μ+μ+ decays

A search for non-resonant D+ (s) → π +μ+μ− and D+ (s) → π −μ+μ+ decays is performed using proton- proton collision data, corresponding to an integrated luminosity of 1.0 fb−1, at √s = 7 TeV recorded by the LHCb experiment in 2011. No signals are observed and the 90% (95%) confidence level (CL) limits on the branching fractions are found to be B(D+ → π +μ+μ−) < 7.3 (8.3) × 10−8, B(D+ s → π +μ+μ−) < 4.1 (4.8) × 10−7, B(D+ → π −μ+μ+) < 2.2 (2.5) × 10−8, B(D+ s → π −μ+μ+) < 1.2 (1.4) × 10−7. These limits are the most stringent to dat

Search for direct CP violation in D0→h-h+ modes using semileptonic B decays

A search for direct CP violation in D0 → h−h+ (where h = K or π ) is presented using data corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by LHCb in pp collisions at a centre-of-mass energy of 7 TeV. The analysis uses D0 mesons produced in inclusive semileptonic b-hadron decays to the D0μX final state, where the charge of the accompanying muon is used to tag the flavour of the D0 meson. The difference in the CP-violating asymmetries between the two decay channels is measured to be ACP = ACP (K − K +) − ACP (π −π +) = (0.49 ± 0.30 (stat) ± 0.14 (syst))%

Differential branching fraction and angular analysis of the decay B 0 → K ∗0 μ + μ -

The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions

Search for the rare decay D0→μ+μ-

A search for the rare decay D0 → μ+μ− is performed using a data sample, corresponding to an integrated luminosity of 0.9 fb−1, of pp collisions collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The observed number of events is consistent with the background expectations and corresponds to an upper limit of B(D0 → μ+μ−) < 6.2 (7.6) × 10−9 at 90% (95%) confidence level. This result represents an improvement of more than a factor twenty with respect to previous measurement

Measurement of the CKM angle γ from a combination of B±→Dh± analyses

A combination of three LHCb measurements of the CKM angle γ is presented. The decays B± → D K ± and B± → Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K + K −, π+π−, K ±π∓, K ±π∓π±π∓, K0 Sπ+π−, or K0 S K + K − final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B± → D K ± decays alone a best-fit value of γ = 72.0◦ is found, and confidence intervals are set γ ∈ [56.4, 86.7] ◦ at 68% CL, γ ∈ [42.6, 99.6] ◦ at 95% CL. The best-fit value of γ found from a combination of results from B± → Dπ± decays alone, is γ = 18.9◦, and the confidence intervals γ ∈ [7.4, 99.2] ◦ ∪ [167.9, 176.4] ◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K ± and B± → Dπ± decays gives a best-fit value of γ = 72.6◦ and the confidence intervals γ ∈ [55.4, 82.3] ◦ at 68% CL, γ ∈ [40.2, 92.7] ◦ at 95% C

A study of the Z production cross-section in pp collisions at s√=7 TeV using tau final states

A measurement of the inclusive Z → ττ cross-section in pp collisions at s√=7TeV is presented based on a dataset of 1.0 fb−1 collected by the LHCb detector. Candidates for Z → τ τ decays are identified through reconstructed final states with two muons, a muon and an electron, a muon and a hadron, or an electron and a hadron. The production cross-section for Z bosons, with invariant mass between 60 and 120 GeV/c 2, which decay to τ leptons with transverse momenta greater than 20 GeV/c and pseudorapidities between 2.0 and 4.5, is measured to be σ pp→Z→ττ = 71.4 ± 3.5 ± 2.8 ± 2.5 pb; the first uncertainty is statistical, the second is systematic, and the third is due to the uncertainty on the integrated luminosity. The ratio of the cross-sections for Z → τ τ to Z → μμ is determined to be 0.93 ± 0.09, where the uncertainty is the combination of statistical, systematic, and luminosity uncertainties of the two measurements

Measurement of relative branching fractions of B decays to ψ(2S) and J/ψ mesons

The relative rates of B-meson decays into J/ψ and ψ(2S) mesons are measured for the three decay modes in pp collisions recorded with the LHCb detector. The ratios of branching fractions ( B) are measured to be where the third uncertainty is from the ratio of the ψ(2S) and J/ψ branching fractions to μ + μ −

Terrestrial Very-Long-Baseline Atom Interferometry:Workshop Summary

This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions