A bstract The shape of the Higgs potential is modified by the presence of additional scalar fields, as predicted in many Beyond-Standard-Model (BSM) scenarios. In such cases, deviations in the Higgs self-interactions — in particular the trilinear Higgs couplings — could serve to disentangle the physics beyond the Standard Model (SM). While the SM predicts only one trilinear Higgs coupling, extended scalar sectors allow for additional self-interactions that can manifest themselves in Higgs pair production, via the s -channel contribution of a heavy 𝒞𝒫-even scalar H . We present the first sensitivity study to such a BSM trilinear scalar coupling using machine learning. Specifically, we train a neural network on the invariant mass distributions of Higgs pair production at the HL-LHC to extract $$ {\xi}_H^t\times {\lambda}_{hhH} $$ ξ H t × λ hhH , i.e. the product of the resonant H top-Yukawa coupling and the trilinear coupling of H to the two SM-like Higgses in the final state, hh . Assuming a hypothetical H mass of 450 GeV, we show that, depending on future experimental efficiencies and uncertainties, a determination of $$ {\xi}_H^t\times {\lambda}_{hhH} $$ ξ H t × λ hhH at the 10–20% level may be achievable by the end of the HL-LHC. We present a simple and more efficient alternative to classical statistical methods, proving the efficiency of neural networks for both hypothesis testing and parameter estimation, which outperforms conventional maximum likelihood methods in this context.

The large hadron collider beauty (LHCb) experiment is a forward spectrometer, designed to study beauty and charm quarks physics at the large hadron collider (LHC). To exploit of the higher luminosity that will be delivered during Run3, the full experiment needed a substantial upgrade, from the detector to the data acquisition (DAQ) and high level trigger (HLT). In this article, we will focus on the new DAQ system for the LHCb experiment that represents a substantial paradigm shift compared to the previous one, and to similar systems used by similar experiments in the past and present times. To overcome the inefficiencies introduced by a local selection implemented directly with the readout hardware, the Run3 system is designed to perform a full software reconstruction of all the produced events. To achieve this, both the DAQ and the HLT need to process the $\sim $ 30 MHz full event-rate. In particular, this article will introduce the final design of the system; it will provide a focus on the hardware and software design of the event building (EB) and how we integrated technologies designed for the high performance computing (HPC) world — like InfiniBand HDR (200 Gb/s) — into the DAQ system; we will present performance measurements of the full EB system under different operational conditions; and we will provide a feedback from EB operation during the beginning of the data-taking.

This paper evaluates the real-time distribution of data over Ethernet for the upgraded LHCb data acquisition cluster at CERN. The system commissioning ends in 2021 and its total estimated input throughput is 32 Terabits per second. After the events are assembled, they must be distributed for further data selection to the filtering farm of the online trigger. High-throughput and very low overhead transmissions will be an essential feature of such a system. In this work RoCE (Remote Direct Memory Access over Converged Ethernet) high-throughput Ethernet protocol and Ethernet flow control algorithms have been used to implement lossless event distribution. To generate LHCb-like traffic, a custom benchmark has been implemented. It was used to stress-test the selected Ethernet networks and to check resilience to uneven workload distribution. Performance tests were made with selected evaluation clusters. 100 Gb/s and 25 Gb/s links were used. Performance results and overall evaluation of this Ethernet-based approach are discussed.

Consistent detector description is an integral part of all modern experiments and also the main motivation behind the creation of DD4hep, which tries to address detector description in a broad sense including for, example, geometry and the materials used in the device, additional parameters describing e.g. the detection techniques, constants required for alignment and calibration, description of the readout structures and conditions data. A central component of DD4hep is DDG4 which is a mechanism that converts arbitrary DD4hep detector geometries to Geant4 and provides access to all Geant4 action stages. In addition to that DDG4 also offers a comprehensive plugins suite that includes handling of different IO formats, Monte Carlo truth linking and a large set of segmentation and sensitive detector classes, allowing the simulation of a wide variety of detector technologies. One of the last remaining open issues of detector description was support for drawings from civil engineers for passive detector components. In this proceedings we highlight recent developments in DD4hep/DDG4 that enable support for CAD drawings and generic tessellated shapes and through the help of the library assimp enable the import of a wide variety of CAD formats, thus eliminating the need for writing complex re-implementations of CAD drawings in source code. In addition, we present other developments such as support for a new output format called EDM4hep and developments for a more unified and easier handling of units.

Detector description is an essential component in simulation, reconstruction and analysis of data resulting from particle collisions in high energy physics experiments and for the detector development studies for future experiments. Current detector description implementations of running experiments are mostly specific implementations. DD4hep [1] is an open source toolkit created in 2012 to serve as a generic detector description solution. The main motivation behind DD4hep is to provide the community with an integrated solution for all these stages and address detector description in a broad sense, including the geometry and the materials used in the device, and additional parameters describing e.g. the detection techniques, constants required for alignment and calibration, description of the readout structures and conditions data. In these proceedings, we will give an overview of the project and discuss recent developments in DD4hep as well as showcase adaptions of the framework by LHC and upcoming accelerator projects together with the road map of future developments.

LHCb is one of the 4 experiments at the LHC accelerator at CERN. During the upgrade phase of the experiment, several new electronic boards and Front End chips that perform the data acquisition for the experiment will be added by the different sub-detectors. These new devices will be controlled and monitored via a system composed of GigaBit Transceiver (GBT) chips that manage the bi-directional slow control traffic to the Slow Control Adapter(s) (SCA) chips. The SCA chips provide multiple field buses to interface the new electronics devices (I2C, GPIO, etc). These devices will need to be integrated in the Experiment Control System (ECS) that drives LHCb. A set of tools was developed that provide an easy integration of the control and monitoring of the devices in the ECS. A server (GbtServ) provides the low level communication layer with the devices via the several user buses in the GBT-SCA chip and exposes an interface for control to the experiment SCADA (WinCC OA), the fwGbt component provides the interface between the SCADA and the GbtServ and the fwHw component, a tool that allows the abstraction of the devices models into the ECS. Using the graphical User Interfaces or XML files describing the structure and registers of the devices it creates the necessary model of the hardware as a data structure in the SCADA. It allows then the control and monitoring of the defined registers using their name, without the need to know the details of the hardware behind. The fwHw tool also provides the facility of defining and applying recipes - named sets of configurations which can be used to easily configure the hardware according to specific needs.

DD4hep is an open-source software toolkit that provides comprehensive and complete generic detector descriptions for high energy physics (HEP) detectors. The Compact Muon Solenoid collaboration (CMS) has recently evaluated and adopted DD4hep to replace its custom detector description software. CMS has demanding software requirements as a very large, longrunning experiment that must support legacy geometries and study many possible upgraded detector designs of a constantly evolving detector that will be taking data for many years to come. CMS has chosen DD4hep since it is a high-quality, community-supported solution that will benefit from continuing modernization and maintenance. This presentation will discuss the issues of DD4hep adoption, the advantages and disadvantages of the various design choices, performance results, and the integration of the plugin systems from CMS and Gaudi, another open-source software framework. Recommendations about DD4hep based upon the CMS use cases will also be presented.

The first untagged decay-time-integrated amplitude analysis of $B^{0}_{s} rightarrow K^{0}_{textrm{S}} K^{pm}pi^{mp}$ decays is performed using a sample corresponding to $3.0,$fb$^{-1}$ of $pp$ collision data recorded with the LHCb detector during 2011 and 2012. The data are described with an amplitude model that contains contributions from the intermediate resonances $K^{*}(892)^{0,+}$, $K^*_2(1430)^{0,+}$ and $K^*_0(1430)^{0,+}$, and their charge conjugates. Measurements of the branching fractions of the decay modes $B^{0}_{s} rightarrow K^{*}(892)^{pm}K^{mp}$ and $B^{0}_{s} rightarrow K^{*}(892)^{0}kern 0.2emoverline{kern -0.2em K}{}^{0}, kern 0.2emoverline{kern -0.2em K}{}^{*}(892)^{0}K^{0}$ are in agreement with, and more precise than, previous results. The decays $B^{0}_{s} rightarrow K^*_0(1430)^{pm} K^{mp}$ and $B^{0}_{s} rightarrow K^{*}_{0}(1430)^{0}kern 0.2emoverline{kern -0.2em K}{}^{0}, kern 0.2emoverline{kern -0.2em K}{}^{*}_{0}(1430)^{0}K^{0}$ are observed for the first time, each with significance over 10 standard deviations.

The LHCb experiment uses a custom made C++ detector and geometry description toolkit, integrated with the Gaudi framework, designed when the LHCb software was first implemented. With the LHCb upgrade scheduled for 2021, it is necessary for the experiment to review this choice and adapt to the evolution of software and computing (in terms of e.g multi-threading support or vectorization) The Detector Description Toolkit for High Energy Physics (DD4hep) is a good candidate for the replacement for LHCb’s geometry description framework: it is possible to integrate it with the LHCb core software framework and its features theoretically match the requirements: in terms of geometry and detector description but also concerning the possibility to add detector alignment parameters and the integration with simulation tools. In this paper we report on detailed studies undertaken to compare the feature set proposed by the DD4hep toolkit, to what is needed by LHCb. We show not only how the main description could be migrated, but also how to integrate the LHCb real-time alignment tools in this toolkit, in order to identify the main obstacles to the migration of the experiment to DD4hep.

LHCb is one of the 4 experiments at the LHC accelerator at CERN, specialized in B-physics. During the next long shutdown period, the LHCb experiment will be upgraded to a trigger-less readout system with a full software trigger in order to be able to record data with a much higher instantaneous luminosity. To achieve this goal, the upgraded systems for Timing and Fast Control (TFC) and Data Acquisition (DAQ) will have new electronic boards and a new software stack will be introduced for data acquisition. In the development stage, all these components are housed in servers named MiniDAQ. These new components will need to be integrated in an upgraded Experiment Control System (ECS) based on the WinCC OA SCADA and the CERN JCOP framework. The ECS provides full monitoring and control for all these subsystems and many important features like configuration recipes and automated actions. This paper describes the implementation of the upgraded ECS and its component fwMiniDAQ, which integrates all the new developments and can be easily distributed to the sub-detector developers and configured for their various setups.

For a successful experiment, it is of utmost importance to provide a consistent detector description. This is also the main motivation behind DD4hep, which addresses detector description in a broad sense including the geometry and the materials used in the device, and additional parameters describing, e.g., the detection techniques, constants required for alignment and calibration, description of the readout structures and conditions data. An integral part of DD4hep is DDG4 which is a powerful tool that converts arbitrary DD4hep detector geometries to Geant4 and provides access to all Geant4 action stages. It is equipped with a comprehensive plugins suite that includes handling of different IO formats; Monte Carlo truth linking and a large set of segmentation and sensitive detector classes, allowing the simulation of a wide variety of detector technologies. In the following, recent developments in DD4hep/DDG4 like the addition of a ROOT based persistency mechanism for the detector description and the development of framework support for DDG4 are highlighted. Through this mechanism an experiment’s data processing framework can interface its essential tools to all DDG4 actions. This allows for simple integration of DD4hep into existing experiment frameworks.

A search for charge-parity (CP) violation in Cabibbo-suppressed Ds+→KS0π+, D+→KS0K+, and D+→ϕπ+ decays is reported using proton-proton collision data, corresponding to an integrated luminosity of 3.8  fb-1, collected at a center-of-mass energy of 13 TeV with the LHCb detector. High-yield samples of kinematically and topologically similar Cabibbo-favored D(s)+ decays are analyzed to subtract nuisance asymmetries due to production and detection effects, including those induced by CP violation in the neutral kaon system. The results areACP(Ds+→KS0π+)=(1.3±1.9±0.5)×10-3,ACP(D+→KS0K+)=(-0.09±0.65±0.48)×10-3,ACP(D+→ϕπ+)=(0.05±0.42±0.29)×10-3,where the first uncertainties are statistical and the second systematic. They are the most precise measurements of these quantities to date, and are consistent with CP symmetry. A combination with previous LHCb measurements, based on data collected at 7 and 8 TeV, is also reported.

The doubly Cabibbo-suppressed decay Ξ$_{c}^{+}$  → pϕ with ϕ → K$^{+}$K$^{−}$ is observed for the first time, with a statistical significance of more than fifteen standard deviations. The data sample used in this analysis corresponds to an integrated luminosity of 2 fb$^{−1}$ recorded with the LHCb detector in pp collisions at a centre-of-mass energy of 8 TeV. The ratio of branching fractions between the decay Ξ$_{c}^{+}$  → pϕ and the singly Cabibbo-suppressed decay Ξ$_{c}^{+}$  → pK$^{−}$π$^{+}$ is measured to be $ frac{mathrm{mathcal{B}}left({varXi}_c^{+}to pphi right)}{mathrm{mathcal{B}}left({varXi}_c^{+}to p{K}^{-}{pi}^{+}right)}=left(19.8pm 0.7pm 0.9pm 0.2right)times {10}^{-3}, $

Decays of $B_{s}^{0}$ and $overline{B}{}_{s}^{0}$ mesons into $J/psipi^+pi^-$ final states are studied in a data sample corresponding to 1.9 fb$^{-1}$ of integrated luminosity collected with the LHCb detector in 13 TeV $pp$ collisions. A time-dependent amplitude analysis is used to determine the final-state resonance contributions, the $CP$-violating phase $phi_s=-0.057pm 0.060pm 0.011$ rad, the decay-width difference between the heavier mass $B_{s}^{0}$ eigenstate and the $B^{0}$ meson of $-0.050pm 0.004pm 0.004$ ps$^{-1}$, and the $CP$-violating parameter $|lambda|=1.01_{-0.06}^{+0.08}pm0.03$, where the first uncertainty is statistical and the second systematic. These results are combined with previous LHCb measurements in the same decay channel using 7 TeV and 8 TeV $pp$ collisions obtaining $phi_s =0.002pm0.044pm0.012$ rad, and $|lambda| =0.949pm0.036pm0.019$.

The detector description is an essential component to analyze data resulting from particle collisions in high energy physics experiments. The interpretation of data from particle collisions typically requires auxiliary data which describe in detail the state of the experiment. These accompanying data include alignment parameters, parameters describing the electronics as well as calibration- and environmental constants. We present a mechanism to manage such data in multiple simultaneous versions depending on their validity. The detector conditions data are made available to the physics algorithms through a number of transient objects grouped to collections. Such a collection represents a coherent slice of all conditions data necessary to process one or several events depending on the valid interval of the slice being the intersection of the individual conditions. A multi-threaded application may hold several such collections in parallel depending on the time-stamps of the events currently processed. Once prepared, these collections are read-only and can easily be shared between threads with minimal requirements for locking and hence minimal overhead. We deliberately restrained ourselves from providing a persistent data solution, which in the past were fields of expertise of the experiments, but rather provided the necessary hooks to populate the conditions cache. We will present the use-cases that have driven the development, the main design choices and details of the implementation.

A search for the rare leptonic decay $B^{+} rightarrow {mu}^{+}{mu}^{-}{mu}^{+}{nu}_{{mu}}$ is performed using proton-proton collision data corresponding to an integrated luminosity of $4.7$ fb$^{-1}$ collected by the LHCb experiment. The search is carried out in the region where the lowest of the two ${mu}^{+}{mu}^{-}$ mass combinations is below $980$MeV/c$^{2}$. The data are consistent with the background-only hypothesis and an upper limit of $1.6 times 10^{-8}$ at 95% confidence level is set on the branching fraction in the stated kinematic region.

The first observation of the Bs0→D¯*0ϕ decay is reported, with a significance of more than seven standard deviations, from an analysis of pp collision data corresponding to an integrated luminosity of 3  fb-1, collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. The branching fraction is measured relative to that of the topologically similar decay B0→D¯0π+π- and is found to be B(Bs0→D¯*0ϕ)=(3.7±0.5±0.3±0.2)×10-5, where the first uncertainty is statistical, the second systematic, and the third from the branching fraction of the B0→D¯0π+π- decay. The fraction of longitudinal polarization in this decay is measured to be fL=(73±15±4)%. The most precise determination of the branching fraction for the Bs0→D¯0ϕ decay is also obtained, B(Bs0→D¯0ϕ)=(3.0±0.3±0.2±0.2)×10-5. An upper limit, B(B0→D¯0ϕ)u003c2.0 (2.3)×10-6 at 90% (95%) confidence level is set. A constraint on the ω-ϕ mixing angle δ is set at |δ|u003c5.2° (5.5°) at 90% (95%) confidence level.