Jaana Kristiina Heikkilä

Abstract We present details on the new Level-1 Global Trigger at CMS for the upcoming high-luminosity operation of the LHC. Our focus is on the newly developed firmware, which employs a bottom-up generic approach to enhance menu adaptability and accommodate the increase in upstream data. We also highlight our efficient pipelining strategy that ensures excellent routability at 480 MHz. Furthermore, we discuss the firmware implementation for three prototypes targeting Serenity boards, together with their current and future testing and validation endeavours.

Abstract The CMS detector will be upgraded to maintain, or even improve, the physics acceptance under the harsh data taking conditions foreseen during the High-Luminosity LHC operations. In particular, the trigger system (Level-1 and High Level Triggers) will be completely redesigned to utilize detailed information from sub-detectors at the bunch crossing rate: the upgraded Global Trigger will use high-precision trigger objects to provide the Level-1 decision. Besides cut-based algorithms, novel machine-learning-based algorithms will also be included in the Global Trigger to achieve a higher selection efficiency and detect unexpected signals. Implementation of these novel algorithms is presented, focusing on how the neural network models can be optimized to ensure a feasible hardware implementation. The performance and resource usage of the optimized neural network models are discussed in detail.

The aim of this study was to investigate temporomandibular disorders (TMDs) and the symptoms and facial pain of professional symphony orchestra musicians. Results of questionnaires from musicians in Sinfonia Lahti and in The Finnish Radio Symphony Orchestra (n 1⁄4 73) showed that facial pain was common among orchestral musicians (30% of the musicians). The overall prevalence of the symptoms did not vary between the instrumentalist groups but indicated that the musicians playing different instruments had mixed susceptibilities to symptoms. In particular, night bruxism and sleep disturbances seemed to increase the number of symptoms of TMDs in wind players, whereas among string players sleep disturbances increased the occurrence of the symptoms. We conclude that unpleasant facial symptoms were prevalent in many of the professional musicians studied and, as such, may deserve attention as part of an occupational focus on health and wellness.

A new CMS tracker detector will be installed for operation at the High Luminosity LHC (HL-LHC). This detector comprises modules with two closely spaced parallel sensor plates and front-end ASICs capable of transmitting tracking information to the CMS Level-1 (L1) trigger at the 40 MHz beam crossing rate. The inclusion of tracking information in the L1 trigger decision will be essential for selecting events of interest efficiently at the HL-LHC. The CMS Binary Chip (CBC) has been designed to read out and correlate hits from pairs of tracker sensors, forming so-called track stubs. For the first time, a prototype irradiated module and a full-sized module, both equipped with the version 2 of the CBC, have been operated in test beam facilities. The efficiency of the stub finding logic of the modules for various angles of incidence has been studied. The ability of the modules to reject tracks with transverse momentum less than 2 GeV has been demonstrated. For modules built with irradiated sensors, no significant drop in the stub finding performance has been observed. Results from the beam tests are described in this paper.

Using the likelihood ratio test statistic, we present a method which can be employed to test the hypothesis of a single Higgs boson using the matrix of measured signal strengths. This method can be applied in the presence of incomplete data and takes into account uncertainties on the measurements. The p-value against the hypothesis of a single Higgs boson is defined from the expected distribution of the test statistic, generated using pseudo-experiments. The applicability of the likelihood-based test is demonstrated using numerical examples with uncertainties and missing matrix elements.

During the high-luminosity phase of the LHC (HL-LHC), planned to start in 2027, the accelerator is expected to deliver an instantaneous peak luminosity of up to 7.5×1034 cm−2 s−1. A total integrated luminosity of 0300 or even 0400 fb−1 is foreseen to be delivered to the general purpose detectors ATLAS and CMS over a decade, thereby increasing the discovery potential of the LHC experiments significantly. The CMS detector will undergo a major upgrade for the HL-LHC, with entirely new tracking detectors consisting of an Outer Tracker and Inner Tracker. However, the new tracking system will be exposed to a significantly higher radiation than the current tracker, requiring new radiation-hard sensors. CMS initiated an extensive irradiation and measurement campaign starting in 2009 to systematically compare the properties of different silicon materials and design choices for the Outer Tracker sensors. Several test structures and sensors were designed and implemented on 18 different combinations of wafer materials, thicknesses, and production technologies. The devices were electrically characterized before and after irradiation with neutrons, and with protons of different energies, with fluences corresponding to those expected at different radii of the CMS Outer Tracker after 0300 fb−1. The tests performed include studies with β sources, lasers, and beam scans. This paper compares the performance of different options for the HL-LHC silicon sensors with a focus on silicon bulk material and thickness.

In 2017 a new pixel detector was installed in the CMS detector. This so-called Phase-1 pixel detector features four barrel layers in the central region and three disks per end in the forward regions. The upgraded pixel detector requires an upgraded data acquisition (DAQ) system to accept a new data format and larger event sizes. A new DAQ and control system has been developed based on a combination of custom and commercial microTCA parts. Custom mezzanine cards on standard carrier cards provide a front-end driver for readout, and two types of front-end controller for configuration and the distribution of clock and trigger signals. Before the installation of the detector the DAQ system underwent a series of integration tests, including readout of the pilot pixel detector, which was constructed with prototype Phase-1 electronics and operated in CMS from 2015 to 2016, quality assurance of the CMS Phase-1 detector during its assembly, and testing with the CMS Central DAQ. This paper describes the Phase-1 pixel DAQ and control system, along with the integration tests and results. A description of the operational experience and performance in data taking is included.

A group of Early-Career Researchers (ECRs) has been given a mandate from the European Committee for Future Accelerators (ECFA) to debate the topics of the current European Strategy Update (ESU) for Particle Physics and to summarise the outcome in a brief document [1]. A full-day debate with 180 delegates was held at CERN, followed by a survey collecting quantitative input. During the debate, the ECRs discussed future colliders in terms of the physics prospects, their implications for accelerator and detector technology as well as computing and software. The discussion was organised into several topic areas. From these areas two common themes were particularly highlighted by the ECRs: sociological and human aspects; and issues of the environmental impact and sustainability of our research.

Using the likelihood ratio test statistic, we present a method which can be employed to test the hypothesis of a single Higgs boson using the matrix of measured signal strengths. This method can be applied in the presence of incomplete data and takes into account uncertainties on the measurements. The p-value against the hypothesis of a single Higgs boson is defined from the expected distribution of the test statistic, generated using pseudo-experiments. The applicability of the likelihood-based test is demonstrated using numerical examples with uncertainties and missing matrix elements.

Owing to our special genetic heritage, phenylketonuria is very rare in Finland, but the situation will change as the number of immigrants from populations with a larger incidence increases. In persons with this disorder, the enzyme phenylalanine hydroxylase, which metabolizes phenylalanine to tyrosine, is not functioning normally, leading to the accumulation phenylalanine within the body. High levels of phenylalanine are toxic to the central nervous system. A newborn affected with phenylketonuria is asymptomatic but will rapidly become disabled without therapy. The leading principle of the therapy is careful limitation of phenylalanine intake.

A search for a pseudoscalar Higgs boson A is performed, focusing on its decay into a standard model-like Higgs boson h and a Z boson. Decays of the h boson into a pair of tau leptons are considered along with Z boson decays into a pair of light leptons (electrons or muons). A data sample of proton-proton collisions collected by the CMS experiment at the LHC at √s= 13 TeV is used, corresponding to an integrated luminosity of 35 inverse femtobarns.The search uses the reconstructed mass distribution of the A boson as the discriminating variable. This analysis is the first of its kind to utilise the svFit algorithm while exploiting the possibility to apply a mass constraint of 125 GeV in the h→ττ four-vector reconstruction. The resolution of the reconstructed mass of the A boson is improved compared to the mass resolution obtained in previous analyses targeting the same final state.No excess above the standard model expectation is observed in data. Model-independent as well as model-dependent upper limits in the mA – tanβ plane for two minimal supersymmetric standard model benchmark scenarios are set at 95% confidence level. The model-independent upper limit on the product of the gluon fusion production cross section and the branching fraction for the A→Zh→llττ decay ranges from 27 fb at 220 GeV to 5 fb at 400 GeV. The observed model-dependent limits on the process σ(gg→A+bbA)B(A→Zh→llττ) in case of the hMSSM (low-tb-high) scenario exclude tanβ values from 1.6 (1.8) at mA= 220 GeV to 3.7 (3.8) at mA = 300 GeV, respectively.

Microdosimetry has been a fast growing field in dosimetry during the last years. We have measured and calculated microdosimetric quantities which are important in correlation between the energy deposited in microscopic volumes and the biological effect. We have measured the energy distribution spectra in volumes with diameters of 1 and 2 mum and calculated the dose mean of specific energy and the mean event number per unit absorbed dose for the radioisotopes: 60Co, 137Cs, 99Tcm, 125J and the beta emitter 90Sr.