Understanding digital events : process philosophy and causal autonomy

This paper argues that the ubiquitous digital networks in which we are increasingly becoming immersed present a threat to our ability to exercise free will. Using process philosophy, and expanding upon understandings of causal autonomy, the paper outlines a thematic analysis of diary studies and interviews gathered in a project exploring the nature of digital experience. It concludes that without mindfulness in both the use and design of digital devices and services we run the risk of allowing such services to direct our daily lives in ways over which we are increasingly losing control

A model-independent Dalitz plot analysis of B±→DK± with D→K0Sh+h− (h=π,K) decays and constraints on the CKM angle γ

A binned Dalitz plot analysis of B ±→DK ± decays, with D→KS0π+π- and D→KS0K+K-, is performed to measure the CP-violating observables x ± and y ± which are sensitive to the CKM angle γ. The analysis exploits 1.0 fb -1 of data collected by the LHCb experiment. The study makes no model-based assumption on the variation of the strong phase of the D decay amplitude over the Dalitz plot, but uses measurements of this quantity from CLEO-c as input. The values of the parameters are found to be x -=(0.0±4.3±1.5±0.6)×10 -2, y -=(2.7±5.2±0.8±2.3)×10 -2, x +=(-10.3±4.5±1.8±1.4)×10 -2 and y +=(-0.9±3.7±0.8±3.0)×10 -2. The first, second, and third uncertainties are the statistical, the experimental systematic, and the error associated with the precision of the strong-phase parameters measured at CLEO-c, respectively. These results correspond to γ=(44-38+43)°, with a second solution at γ→γ+180°, and r B=0.07±0.04, where r B is the ratio between the suppressed and favoured B decay amplitudes

Absolute luminosity measurements with the LHCb detector at the LHC

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ''van der Meer scan'' method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overal precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented

First evidence of direct CP violation in charmless two-body decays of Bs0 mesons

Using a data sample corresponding to an integrated luminosity of 0.35  fb-1 collected by LHCb in 2011, we report the first evidence of CP violation in the decays of Bs0 mesons to K±π∓ pairs, ACP(Bs0→Kπ)= 0.27±0.08(stat)±0.02(syst), with a significance of 3.3σ. Furthermore, we report the most precise measurement of CP violation in the decays of B0 mesons to K±π∓ pairs, ACP(B0→Kπ)=-0.088±0.011(stat)±0.008(syst), with a significance exceeding 6σ

Strong constraints on the rare decays Bs0 -> μ+μ- and B0 -> μ+μ-

A search for Bs0→μ+μ- and B0→μ+μ- decays is performed using 1.0  fb-1 of pp collision data collected at √s=7  TeV with the LHCb experiment at the Large Hadron Collider. For both decays, the number of observed events is consistent with expectation from background and standard model signal predictions. Upper limits on the branching fractions are determined to be B(Bs0→μ+μ-)<4.5(3.8)×10-9 and B(B0→μ+μ-)<1.0(0.81)×10-9 at 95% (90%) confidence level

Search for the rare decays B0s→μ+μ− and B0→μ+μ−

A search for the decays and B0→μ+μ− is performed with 0.37 fb−1 of pp collisions at collected by the LHCb experiment in 2011. The upper limits on the branching fractions are and B(B0→μ+μ−)<3.6×10−9 at 95% confidence level. A combination of these results with the LHCb limits obtained with the 2010 dataset leads to and B(B0→μ+μ−)<3.2×10−9 at 95% confidence level

Measurement of b-hadron branching fractions for two-body decays into charmless charged hadrons

Based on data corresponding to an integrated luminosity of 0.37 fb−1 collected by the LHCb experiment in 2011, the following ratios of branching fractions are measured: B(B0→π+π−)/B(B0→K+π−)=0.262±0.009±0.017,(fs/fd)⋅B(B0s→K+K−)/B(B0→K+π−)=0.316±0.009±0.019,(fs/fd)⋅B(B0s→π+K−)/B(B0→K+π−)=0.074±0.006±0.006,(fd/fs)⋅B(B0→K+K−)/B(B0s→K+K−)=0.018+0.008−0.007±0.009,(fs/fd)⋅B(B0s→π+π−)/B(B0→π+π−)=0.050+0.011−0.009±0.004,B(Λ0b→pπ−)/B(Λ0b→pK−)=0.86±0.08±0.05, where the first uncertainties are statistical and the second systematic. Using the current world average of B(B0→K+π−) and the ratio of the strange to light neutral B meson production f s /f d measured by LHCb, we obtain: B(B0→π+π−)=(5.08±0.17±0.37)×10−6,B(B0s→K+K−)=(23.0±0.7±2.3)×10−6,B(B0s→π+K−)=(5.4±0.4±0.6)×10−6,B(B0→K+K−)=(0.11+0.05−0.04±0.06)×10−6,B(B0s→π+π−)=(0.95+0.21−0.17±0.13)×10−6. The measurements of B(B0s→K+K−) , B(B0s→π+K−) and B(B0→K+K−) are the most precise to date. The decay mode B0s→π+π− is observed for the first time with a significance of more than 5σ