LHCb Upgraded RICH 1 Engineering Design Review Report

During the Long Shutdown 2 of the LHC, the LHCb collaboration will replace the upstream Ring Imaging Cherenkov detector (RICH 1). The magnetic shield of the current RICH 1 will be modified, new spherical and plane mirrors will be installed and a new gas enclosure will be manufactured. New photon detectors (multianode photomultiplier tubes) will be used and these, together with their readout electronics, require a new mechanical support system. This document describes the new optical arrangement of RICH 1, its engineering design, installation and alignment. A summary of the project schedule and institute responsibilities is provided

LHCb Upgraded RICH 1 Engineering Design Review Report

During the Long Shutdown 2 of the LHC, the LHCb collaboration will replace the upstream Ring Imaging Cherenkov detector (RICH 1). The magnetic shield of the current RICH 1 will be modified, new spherical and plane mirrors will be installed and a new gas enclosure will be manufactured. New photon detectors (multianode photomultiplier tubes) will be used and these, together with their readout electronics, require a new mechanical support system. This document describes the new optical arrangement of RICH 1, its engineering design, installation and alignment. A summary of the project schedule and institute responsibilities is provided

Measurement of the kinematic variables of beauty particles produced in 350 GeV/c π−\pi^--Cu interactions

Using a sample of $26$ b\=b events, produced in $350\,\hbox{GeV}/c$ $\pi^-$ interactions in a copper target, which includes $13$ events where the decays of both $B$ and $\overline{B}$ are well reconstructed, we measure the differential distributions with respect to $x_F$ and $p_T^2$ as well as some two-particle kinematic variables. We also compare our results with a previous experiment and with predictions based on perturbative QCD

Azimuthal correlation between beauty particles produced in 350 GeV/c π−\pi^{-}-Cu interactions

Using a sample of $10^8$ triggered events, produced in $350\, \hbox{GeV}/c$ $\pi^-$ interactions in a copper target, we have identified $26$ b\=b events. These include $13$ events where the decays of both $B$ and $\overline{B}$ are well reconstructed. We measure the azimuthal \hbox{correlation} between beauty particles, and compare our result with predictions based on perturbative QCD

Made by hand

Although the mainstream animation industry has adopted digital production methods, the attraction of laborious hand-made methods for making animation persists in the independent sector. The chapter considers how ‘craftivist’ opposition to mechanical, technological and digital techniques is validated in this community of practice through ideas that haptic knowledge by skilled physical labour and an exploration of materiality, autographic mark-making and imperfection (Wabi-sabi) are guarantors of authenticity and individuality that can only be carried out by hand. Why is this? What ideas and assumptions can be seen to underpin the notions of craft and crafting? Tracing connections between craft and activism since the Industrial Revolution, this chapter critically reflects on discourses of craft and the handmade through reference to Ruskin (1851), Morris (1892), Hobsbawm (2000), Thompson (1980), Benjamin (1935), Krauss (2000) and Takahashi (2005). Whereas the experimental animation community privileges analogue, handmade processes that appear to oppose and critique commercial animation production, building upon Warburton (2016) and Frayling (2017) it is argued here that this approach is underpinned by nostalgia and often faked. What looks like a hand-painted animation could actually be a simulation that was ‘painted’ in a software package: a pastiche of manual labour. Aesthetics alone do not guarantee that a work of art opposes the mainstream. Instead of recycling the past to create ‘artistic’ animation, it is argued in the conclusion that contemporary practitioners can equally investigate issues of labour and materiality through digital tools and virtual materials such as in the ‘ugly’ CGI animation of Nikita Daikur (2017)

Differential branching fraction and angular analysis of the decay B0→K∗0μ+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

Opposite-side flavour tagging of B mesons at the LHCb experiment

The calibration and performance of the oppositeside flavour tagging algorithms used for the measurements of time-dependent asymmetries at the LHCb experiment are described. The algorithms have been developed using simulated events and optimized and calibrated with B + →J/ψK +, B0 →J/ψK ∗0 and B0 →D ∗− μ + νμ decay modes with 0.37 fb−1 of data collected in pp collisions at √ s = 7 TeV during the 2011 physics run. The oppositeside tagging power is determined in the B + → J/ψK + channel to be (2.10 ± 0.08 ± 0.24) %, where the first uncertainty is statistical and the second is systematic

Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

The $B_s^0\to J/\psi K_S^0$ 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 sin2$\beta$ measurement from $B^0\to J/\psi K_S^0$ The time-integrated branching fraction is measured to be $BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}$. This is the most precise measurement to date

Search for CP violation in D+→ϕπ+ and D+s→K0Sπ+ decays

A search for CP violation in D + → ϕπ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb−1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (−0.04 ± 0.14 ± 0.14)% for candidates with K − K + mass within 20 MeV/c 2 of the ϕ meson mass. A search for a CP -violating asymmetry that varies across the ϕ mass region of the D + → K − K + π + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+s→K0Sπ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%

Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays

A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity