The aim of the LHCb Upgrade II is to operate at a luminosity of up to 1.5 x $10^{34}cm^{-2}s^{-1}$ . The required substantial modifications of the current LHCb ECAL due to high radiation doses in the central region and increased particle densities are referred to as PicoCal. An enhancement already during LS3 will reduce the occupancy and mitigate substantial ageing effects in the central region after Run 3. R&D on several scintillating sampling ECAL technologies is currently being performed: SpaCal with garnet scintillating crystals and tungsten absorber, SpaCal with scintillating plastic fibres and tungsten or lead absorber, and Shashlik with polystyrene tiles, lead absorber and fast WLS fibres. Time resolutions of better than 20 ps at high energy were observed in test beam measurements of prototype SpaCal and Shashlik modules. The presentation will also cover results from detailed simulations to optimise the design and physics performance of the PicoCal.

The LHCb experiment will undergo its high luminosity detector upgrade in 2033-2034 to operate at a maximal instantaneous luminosity of 1.5 × 1034cm-2s-1. This increase in instantaneous luminosity poses a challenge to the tracking system to achieve proper track reconstruction with a tenfold higher occupancy. Here we focus on foreseen solutions for the new tracking stations after the magnet, called Mighty Tracker. It is of hybrid nature, comprising silicon pixels in the inner region and scintillating fibres in the outer region. The silicon pixels provide the necessary granularity and radiation tolerance to handle the high track density expected in the central region, while the scintillating fibres are well suited for the peripheral acceptance region. New R&D activities are needed in both technologies to cope with the highest instantaneous luminosity and the drastic increase in the radiation environment. An overview of the current status of the Mighty Tracker project will be presented.

The LHCb (Large Hadron Collider Beauty) experiment will undergo its high-luminosity detector upgrade (known as Upgrade~II) in the long shutdown 4 of the LHC (2033-2034) to operate at a maximal instantaneous luminosity of $\rm 1.5~\times~10^{34}{cm}^{-2}{s}^{-1}$ in Runs~5 and~6, ten times higher than in previous data taking periods. This increase in instantaneous luminosity poses a challenge to the tracking system to achieve proper track reconstruction with a tenfold higher occupancy. In this abstract we focus on foreseen solutions for the tracking stations after the magnet, currently performed by the Scintillating Fibre (SciFi) Tracker. The SciFi Tracker is composed of mats of staggered scintillating fibres with a silicon photomultiplier (SiPM) readout system to detect charged particles. In Upgrade~II, the inner region of the SciFi will be instrumented with an HV-CMOS pixel detector to cope with the high occupancy in this region. For the outer SciFi region, adding timing information to the track reconstruction is currently being evaluated in a dedicated simulation study to understand its role in reducing the occupancy, minimising ghost tracks (reconstructed tracks not produced by real charged particles) and decreasing the track computation time. Additionally to the higher instantaneous luminosity, the integrated luminosity will also increase in the future data taking periods, with an aim to collect a total of $\rm 240~fb^{-1}$. This will lead to a drastic increase in the radiation environment and thus in the SiPM's dark count rate (DCR), making cryogenic cooling and novel detector technologies necessary to maintain single photon detection capabilities. This also requires an update of the front-end electronics to operate at such a large temperature range and to maximise charge collection.

The LHCb detector underwent a major upgrade in the past years. The modifications enable the detector to operate at an increased instantaneous luminosity and to read out data at the LHC bunch crossing rate of 40MHz. The new operating conditions required the replacement of the complete tracking system. The main tracking stations are replaced by the SciFi Tracker, a large high granularity scintillating fibre tracker read out by arrays of silicon photomultipliers (SiPMs). A custom ASIC is used to digitise the SiPM signals at 40MHz using three comparators per channel. Further digital electronics perform clustering and data-compression before the data is sent via optical links to the DAQ system. The comparator thresholds are calibrated using a dedicated light injection system. The commissioning of this system, calibration results, and latest performance measurements are presented in this poster. The SciFi Tracker has three stations with four detection layers each and uses the BCAM system for real-time 3D monitoring. Originally developed for the ATLAS experiment, BCAM uses opto-electronic sensors to monitor the detector geometry detecting shifts or deformations caused by factors like LHCb magnet powering cycles, SciFi detector powering, or environmental variations. Preliminary results highlight BCAM's micron-level sensitivity (10-20 microns) and its effectiveness in monitoring the impact of magnetic fields and operational conditions on the detector alignment.

The search for the decay B→µνɣ at LHCb using Run 2 data is reported. This channel is considered the golden mode to probe the B meson substructure and allows to probe the first inverse moment of the B-meson light-cone distribution amplitude. Reconstruction of this decay is very challenging at the LHC and deemed impossible. Using photon conversions to an e+e- pair in the vertex locator the reconstruction of the displaced B vertex is possible. This also allows to correct for the missing neutrino momentum and get a signal peak in corrected B invariant mass. The upcoming result has the potential to prove once again that LHCb can perform B physics analyses that were thought to be impossible at a hadron machine.

The LHCb Detector has undergone a series of major upgrades during the LHC LS2. In the first stages of data taking an Early Measurements Task Force is being carried out in order to understand the early detector performance and provide the first physics results of Run 3. In this poster we present the first results of the decays B+→J/ψK+ and B+→ψ(2S) K+, with the charmonia resonances decaying into a dielectron pair, using 2022 and 2023 data from the upgraded LHCb detector. This result represents a critical milestone towards future analysis involving electrons in the final state in Run 3, including Lepton Flavour Universality measurements

Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of the tracking detectors. The curvature biases present at the LHCb detector are studied in $pp$ collision data recorded at $\sqrt{s}=13$~TeV from 2016 to 2018. The biases are determined using the pseudomass method with $Z\to\mu^+\mu^-$ decays in intervals defined by the data-taking period, magnet polarity and muon direction in the detector. Correcting for these biases, typically at the $10^{-4}$~GeV$^{-1}$ level, improves the $Z\to\mu^+\mu^-$ mass resolution by roughly 20\% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass.

One of the privileged ways to search for signs of New Physics (NP) beyond the Standard Model (SM), is the study of b\\rightarrow s\\ell^{+}\\ell^{-}b→sℓ+ℓ− (\\ellℓ\= electron or muon) transitions which involve Flavour Changing Neutral Currents (FCNC) via box or loop diagrams. The aim of this work is to perform an angular analysis on B\_s^0 \\rightarrow \\phi e^+e^-Bs0→ϕe+e− in the low dielectron mass region to provide the measurement of the photon polarization in b -> s gamma transitions.

The identification of helium nuclei at LHCb is achieved using a method primarily based on measurements of ionisation losses in the silicon sensors. It is developed using pp collision data at √s = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5/fb. A total of around $10^5$ helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background misidentification probability of down to O(10−12). The method is validated with the observation of 107±11 hypertritons and antihypertritons, which are reconstructed via their two-body decay 3ΛH ⭢ 3He + π- and its charge conjugate. These observations open the door to a rich programme of precise measurements of QCD and astrophysics interest to be performed on the available data.

In order to increase the event rate and operate at a larger instantaneous luminosity, the LHCb detector has undergone a big upgrade for the new data-taking period in Run 3. An important part of the upgrade is the improvement of the trigger system, which is now fully software-based, and performs an offline-quality track reconstruction. A precise knowledge of the position and orientation of all LHCb sub-detectors in real-time is crucial to maximize the trigger efficiency and obtain the best-quality data for physics analyses. This poster summarizes the foreseen real-time alignment and calibration procedure, with a focus on the alignment of the LHCb tracker, which has a large impact on the reconstructed track \chi^2, affecting the number of tracks that can be reconstructed as well as the primary and secondary vertex resolution and the track momentum resolution. These are all quantities employed by most of the trigger lines for the selection of events. Results from the Run 3 commissioning period are presented, showing the impact of the VELO and SciFi alignment on the vertex and track resolution. The improvements seen on the reconstructed mass distributions of \K^{0}_s and \Lambda^0 hadrons between two different stages of the LHCb alignment are also shown as an example.