Status and prospects for the LHCb upgrade

High-precision measurements performed by the LHCb collaboration have opened a new era in charm physics. Several crucial measurements, particularly in spectroscopy, rare decays and CP violation, can benefit from the increased statistical power of an upgraded LHCb detector. The upgrade of LHCb detector, its software infrastructure, and the impact on charm physics are discussed in detail.Comment: to appear in the proceedings of The 6th International Workshop on Charm Physics (CHARM 2013

The measurement of the production cross section ratio of identified hadrons and the calibration of the magnetic distortion in RICH1 at LHCb

Physics measurements at the LHC rely on the imulation of the proton-proton interaction to estimate detector performance and physics ackgrounds. Therefore, a good understanding of ll the processes involved is crucial to the final precision of any measurement. Monte Carlo event generators try to provide a realistic description of the proton-proton collision by combining the theoretical models describing different stages of the interaction process. Within this framework, the baryon number transport and the hadronisation mechanism are currently described by phenomenological models that need input from experimental data. This thesis investigates these subjects in the unique kinematic region covered by the LHCb detector. The production cross section ratios of identified hadrons (protons, kaons and pions) have been measured as a function of pseudorapidity and transverse momentum both at $sqrt{s} = 0.9$ TeV and $sqrt{s} = 7$ TeV collisions using 320 $mub^{-1}$ and 1.8 $nb^{-1}$ of data respectively. The measurements are then compared to the predictions from several tunings of the PYTHIA Monte Carlo generator. In general, current models do not give a satisfactory description of the hadronisation and tend to underestimate the transport of the baryon number into the final state. Critical to this analysis is the particle identification provided by the LHCb Ring Imaging Cherenkov (RICH) system. To ensure high performance, a proper calibration of the RICH photon detectors response is necessary. A system for the calibration of the magnetic distortion induced by the LHCb dipole magnet onto the photon detectors is described. The system currently provides calibration parameters used in the LHCb event reconstruction software and introduces a critical improvement to the overall particle identification performance

Gauging Airbnb review sentiments and critical key-topics by small area estimation

In literature, several researchers have discovered that the reviews written about Airbnb accommodation tend to be extremely positive than those published on other famous platforms, consequently, many negative experiences remain untracked. Leaving negative experiences underrepresented hampers hosts’ ability to improve their services. To overcome this gap, we employ Small Area Estimation to quantify negative sentiment in Airbnb reviews and the relative critical topics that characterize them. Our methodology involves a two-step process: frst, we employ sentiment analysis and topic modeling to identify negative sentiment and critical issues, followed by the application of a mixed efect random forest model to provide a granular analysis of Airbnb reviews in small sub-populations in the context of small area estimation. We focus on domains of the city of Rome defned by geographical areas and the presence of hosts and Superhosts. Our fndings reveal nuanced sentiment variations and critical topic proportions that traditional methods often overlook

Involving medical students in re-orienting health services: a photovoice study.

Abstract Introduction. Health promotion healthcare reorientation aims for health services focused not exclusively on diseases but also on prevention and health promotion. The implementation depends strongly on professionals’ willingness to actively participate in the reorientation. An effective strategy to boost reorientation is to reorient education and role definition of future professionals. This paper examines whether photovoice, a qualitative research method, can be suitable to i) increase future health professionals’ awareness of users’ needs and expectations; and ii) enable a process of critical reflection on role definition and health services organisation. Methods. One hundred and seventy-two medical students participated in the photovoice project. Participants were asked to produce one photo combined with an accompanying caption, responding to a pre-identified question: “What is, in your opinion, the main aspect affecting users' satisfaction/dissatisfaction in a healthcare facility?”. Participants discussed their photos in group discussions (n=16) and participated in data analysis sessions (n=4). Results. Participants' contributions revolved around how services were delivered (e.g., kindness, accessibility, attention to additional needs) rather than the service provided. The students showed their empathic side and proposed smart and inclusive solutions to improve users' overall experience. The proposals often implied a change in behaviour of professionals -their future selves- towards patients and low-cost improvements of organisational practices. Conclusions. This study demonstrated the value of using photovoice to reach medical students to integrate health promotion into their professional identities. The photovoice process, teamwork, and discussions opened a breach into traditional thinking about healthcare aspects often taken for granted or overlooked.  Our results confirm that a mix of advanced education and community-based participatory research activities has the potential to produce medical doctors responsive to users’ needs. This low-cost strategy should be considered for future interventions aimed at reorienting healthcare

Measurement of the forward Z boson production cross-section in pp collisions at s=13\sqrt{s} = 13 TeV

A measurement of the production cross-section of Z bosons in pp collisions at $\sqrt{s} = 13$ TeV is presented using dimuon and dielectron final states in LHCb data. The cross-section is measured for leptons with pseudorapidities in the range $2.0 \eta 4.5$, transverse momenta $p_\text{T} 20$ GeV and dilepton invariant mass in the range $60 m(\ell\ell) 120$ GeV. The integrated cross-section from averaging the two final states is \begin{equation*}\sigma_{\text{Z}}^{\ell\ell} = 194.3 \pm 0.9 \pm 3.3 \pm 7.6\text{ pb,}\end{equation*} where the first uncertainty is statistical, the second is due to systematic effects, and the third is due to the luminosity determination. In addition, differential cross-sections are measured as functions of the Z boson rapidity, transverse momentum and the angular variable $\phi^*_\eta$

Medusa, a multithread 4-body decay fitting and simulation software

We present a new C++14 compliant application to perform physics data analyses of generic 4-body decays in massively parallel platforms. Medusa is highly based on Hydra, a header-only library which hides most of the complexities of writing parallel code for different architectures. Medusa has been tested through the measurement of the CP-violating phase ϕsin b-hadron decays exploiting the data collected by the LHCb experiment. Medusa executes the optimization of the full model, running over 500000 events, until 330 times faster than a non-parallelized program. Medusa is freely available on GitHub under GPL v.3.0 license

Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of $t\overline{t}$, $W+b\overline{b}$ and $W+c\overline{c}$ is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 $\pm$ 0.02 \mbox{fb}^{-1}. The $W$ bosons are reconstructed in the decays $W\rightarrow\ell\nu$, where $\ell$ denotes muon or electron, while the $b$ and $c$ quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions