Status and Physics Reach of LHCb

LHCb is the experiment at the Large Hadron Collider devoted to studies of new phenomena in CP violation and in rare decays. This review summarizes the status of the experiment in the imminence of the data taking, the prospects for the first measurements and highlights of its full physics program.Comment: Heavy Quarks and Leptons, Melbourne, 200

B Physics Prospects at LHC

Future Experiments at LHC will have the opportunity to pursue an extensive program on B Physics and CP violation. The expected performance are presented here.Comment: Presented at XXXXth Rencontres de Moriond, Electroweak Interaction and Unified Theories, March 5-12, 200

LHCb time-dependent results

This review reports preliminary results of time-dependent measurements of decays of B^0 mesons and B^0_s mesons coming from the analysis of about 36 pb^-1 of data collected by the LHCb experiment during the 2010 run of the Large Hadron Collider at sqrt(s)=7 TeV.Comment: 10 pages, 5 figures, The Ninth International Conference on Flavor Physics and CP Violation (FPCP 2011) Maale Hachamisha, Israel, May 23--27, 201

Lepton-flavour universality tests at LHCb

The Standard Model predictions about the universality of the gauge boson couplings to charged leptons have been tested in B meson semileptonic decays. Several measurements of charged-current and neutral current processes were performed with a data sample collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. This review presents recent results that manifest some anomalies challenging the SM paradigm. Prospects for future measurements to elucidate the origin of these anomalies are also discussed

First characterization of the Hamamatsu R11265 multi-anode photomultiplier tube

The characterization of the new Hamamatsu R11265-103-M64 multi-anode photomultiplier tube is presented. The sample available in our laboratory was tested and in particular the response to single photon was extensively studied. The gain, the anode uniformity and the dark current were measured. The tube behaviour in a longitudinal magnetic field up to 100 G was studied and the gain loss due to the ageing was quantified. The characteristics and performance of the photomultiplier tube make the R11265-103-M64 particularly tailored for an application in high energy physics experiments, such as in the LHCb Ring Imaging Cherenkov (RICH) detector at LHC

GNN for Deep Full Event Interpretation and hierarchical reconstruction of heavy-hadron decays in proton-proton collisions

The LHCb experiment at the Large Hadron Collider (LHC) is designed to perform high-precision measurements of heavy-hadron decays, which requires the collection of large data samples and a good understanding and suppression of multiple background sources. Both factors are challenged by a five-fold increase in the average number of proton-proton collisions per bunch crossing, corresponding to a change in the detector operation conditions for the LHCb Upgrade I phase, recently started. A further ten-fold increase is expected in the Upgrade II phase, planed for the next decade. The limits in the storage capacity of the trigger will bring an inverse relation between the amount of particles selected to be stored per event and the number of events that can be recorded, and the background levels will raise due to the enlarged combinatorics. To tackle both challenges, we propose a novel approach, never attempted before in a hadronic collider: a Deep-learning based Full Event Interpretation (DFEI), to perform the simultaneous identification, isolation and hierarchical reconstruction of all the heavy-hadron decay chains per event. This approach radically contrasts with the standard selection procedure used in LHCb to identify heavy-hadron decays, that looks individually at sub-sets of particles compatible with being products of specific decay types, disregarding the contextual information from the rest of the event. We present the first prototype for the DFEI algorithm, that leverages the power of Graph Neural Networks (GNN). This paper describes the design and development of the algorithm, and its performance in Upgrade I simulated conditions

Characterization of a Hamamatsu R7600 multi-anode photomultiplier tube with single photon signals

The characterization of the single photon response of the Hamamatsu R7600 multi-anode photomultiplier tube (MaPMT) is presented, in view of a possible application in Ring Imaging Cherenkov (RICH) detectors and high rate single photon counting applications in general. For most of the measurements the main source of single photons was a commercial blue LED biased with a small current of a few nA. The spectra obtained with this source match those obtained with Cherenkov light from a PbF2 crystal illuminated with a 22Na gamma source, confirming that the test signals are single photons. Dark current and cross-talk were measured at the single photoelectron level. The single photon response of the PMT was also studied as a function of the bias ratio between dynodes. The sensitivity to magnetic field up to 30 G and the effectiveness of three magnetic shields with different geometries were evaluated. Gain loss due to aging was also studied up to 2000 hours of operation at high counting rate

Aphanizomenon flos-aquae (AFA) Extract Prevents Neurodegeneration in the HFD Mouse Model by Modulating Astrocytes and Microglia Activation

Obesity and related metabolic dysfunctions are associated with neurodegenerative diseases, such as Alzheimer's disease. Aphanizomenon flos-aquae (AFA) is a cyanobacterium considered a suitable supplement for its nutritional profile and beneficial properties. The potential neuroprotective effect of an AFA extract, commercialized as KlamExtra®, including the two AFA extracts Klamin® and AphaMax®, in High-Fat Diet (HFD)-fed mice was explored. Three groups of mice were provided with a standard diet (Lean), HFD or HFD supplemented with AFA extract (HFD + AFA) for 28 weeks. Metabolic parameters, brain insulin resistance, expression of apoptosis biomarkers, modulation of astrocytes and microglia activation markers, and Aβ deposition were analyzed and compared in the brains of different groups. AFA extract treatment attenuated HFD-induced neurodegeneration by reducing insulin resistance and loss of neurons. AFA supplementation improved the expression of synaptic proteins and reduced the HFD-induced astrocytes and microglia activation, and Aβ plaques accumulation. Together, these outcomes indicate that regular intake of AFA extract could benefit the metabolic and neuronal dysfunction caused by HFD, decreasing neuroinflammation and promoting Aβ plaques clearanc

Aerogel at colliders

Recent progress in the application of silica aerogel as Cherenkov radiator for present and future collider experiments are reviewed. A complete characterization of the optical and physical properties of silica aerogel will be described, as well as robustness tests towards potentially aggressive experimental conditions such as high irradiation or exposed to fluorocarbons are reported. Finally, recent tests performed with a multilayer aerogel block will be presented and discussed