Results and Future Plans on Central Exclusive Production with the LHCb Detector

The LHCb detector and LHC running conditions are ideally suited to measuring central exclusive production. Several recent measurements of exclusive dimuon, single and double charmonia are reviewed. The potential for future measurements across a broad range of physics channels is discussed.Comment: Invited contribution to a special edition of the International Journal of Modern Physics A (IJMPA) devoted to Central Exclusive Production in Hadron Collision

The determination of the spin and parity of a vector-vector system

We present a construction of the reaction amplitude for the inclusive production of a resonance decaying to a pair of identical vector particles such as $J/\psi J/\psi$, $\rho\rho$, $\phi\phi$, or $ZZ$. The method provides the possibility of determining the spin and parity of a resonance in a model-independent way. A test of the methodology is demonstrated using the Standard Model decay of the Higgs boson to four leptons.Comment: 8 pages, 7 figure

Inclusive photoproduction of vector quarkonium in ultra-peripheral collisions at the LHC

We explore the possibility of using ultra-peripheral proton-lead collisions at the LHC to study inclusive vector-quarkonium photoproduction, that occurs when a quasi-real photon emitted by a fully stripped lead ion breaks a proton to produce a vector quarkonium. Owing to the extremely large energies of the colliding hadrons circulating in the LHC, the range of accessible photon-nucleon centre-of-mass energies, W_gamma+p, largely exceeds what has been and will be studied at lepton-hadron colliders, HERA and the EIC. We perform a tune to HERA photoproduction data, use this tune to predict the yields of photoproduced J/psi, and estimate the corresponding transverse-momentum reach at LHC experiments. We also model the hadroproduction background and demonstrate that inclusive photoproduction can be isolated at the LHC from such background by imposing constraints on the hadronic activity in the lead-going direction at mid, forward, or far-forward rapidities depending on the capability of the detector under consideration. We find that the resulting cross sections are large enough to be measured by ALICE, ATLAS, CMS, and LHCb. We estimate the background-to-signal ratio after isolation to be of the order of 0.001 and 0.1 in the low and large transverse-momentum regions, respectively. In addition, we propose and assess the Jacquet-Blondel method to reconstruct the photon-nucleon centre-of-mass energy and the fractional energy of the quarkonium with respect to the photon.LaTeX, 34 pages, 26 figures, 9 tables uses svjour3.cls, svglov3.clo and svepjc3.clo (provided

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 $\phi^*_\eta$

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

The Effects of Cone-Beam Computed Tomography Imaging Guidance on Patient Radiation Exposure in Trans-Arterial Chemoembolisation for Hepatocellular Carcinoma

This study investigated the effects of cone-beam computed tomography (CBCT) guidance in trans-arterial chemoembolisation (TACE) procedures on the number of digital subtraction angiography (DSA) runs acquired and total patient radiation exposure in patients with hepatocellular carcinoma (HCC). A retrospective, analytical cross-sectional, single institution, study was conducted. Dose data were compared across the control (DSA guidance alone) and study (DSA and CBCT guidance) groups. A total of 122 procedures were included within the study. There was a significant reduction in the number of DSA runs (3 vs 5, p < 0.001) and DSA air kerma-area product (PKA) (3077.3 vs 4276.6 μGym2, p = 0.042) for the study group when compared to the control group. Total procedural PKA and total procedural reference air kerma (Ka,r) were shown to be 50 and 73% higher, respectively, for the study group when compared to the control group. CBCT imaging guidance does reduce the number of DSA runs and DSA PKA required to complete the TACE procedure for patients diagnosed with HCC; however, a substantial increase in total procedural PKA is to be expected and it is thus important that this increased dose is carefully considered and justified

PDF4LHC recommendations for LHC Run II

We provide an updated recommendation for the usage of sets of partondistribution functions (PDFs) and the assessment of PDF and PDF+$\alpha_s$uncertainties suitable for applications at the LHC Run II. We reviewdevelopments since the previous PDF4LHC recommendation, and discuss and comparethe new generation of PDFs, which include substantial information fromexperimental data from the Run I of the LHC. We then propose a new prescriptionfor the combination of a suitable subset of the available PDF sets, which ispresented in terms of a single combined PDF set. We finally discuss tools whichallow for the delivery of this combined set in terms of optimized sets ofHessian eigenvectors or Monte Carlo replicas, and their usage, and provide someexamples of their application to LHC phenomenology

An innovative food system approach to diversifying protein intake: &lt;scp&gt;Protein‐I&lt;/scp&gt; : Shared Island sustainable healthy nutrition

There is a need to transform our current food system if we are to feed the rapidly expanding global population while maintaining planetary health. Within the island of Ireland, there is an urgent need to diversify the foods that currently contribute to our populations' protein intake. A Shared Island Innovative Food System approach is required to achieve this in a manner that is sustainable and provides benefits to producers, consumers and other supply chain participants. The Protein-I project employs such an approach, with the paradigm focusing on production of plant food through to human health, while paying particular attention to the development of the rural bioeconomy. Using an interdisciplinary approach, the team will develop strategies to maximise sustainable plant protein production in a traceable/transparent fashion and assess the impact of changes to existing value chains and the development of new value chains for the rural economy. A smart supply chain technology solution tailored to the needs of the agri-food industry will be developed and tested. Additionally, we will co-design consumer-led approaches to diversify plant protein intake, model the impact of changes at the population level and perform human interventions to demonstrate efficacy in terms of achieving adequate nutrition and improved health. Comprehensive engagement with stakeholders is embedded throughout the whole project to embrace the multi-actor approach. Overall, the project will be a key step towards future-proofing our food system on the island of Ireland and moving towards protecting planetary and population health, within the context of a just transition.<br/