The roots of scientific cooperation between Latvia and CERN stretch as far back the early 1990s, when researchers from the University of Latvia (UL) Institute of Solid-State Physics (ISSP) contributed to the scintillating crystal studies for the electromagnetic calorimeter of the Compact Muon Solenoid (CMS) experiment. In the following two decades sporadic yet significant cooperation continued...
Lithuanian scientists began their collaboration with CERN in 1993 by joining research on radiation-induced defects in semiconductors and their impact on the performance of silicon detectors. Since then, the scope and scale of Lithuania’s participation in CERN experiments have grown substantially. This progress was significantly facilitated, first, by Lithuania becoming an Associate Member...
Since 2022, with the active work of CERN Baltic Group in close collaboration with Next Ion Medical Machine Study (NIMMS) group of the European Organization for Nuclear Research (CERN), an initiative has been started for the development of an innovative particle therapy center in the Baltic States - “Advanced Particle Therapy center for the Baltic States” (APTCB). A dedicated working group was...
The RIANA project, funded by Horizon Europe and coordinated by German Electron Synchrotron DESY, is designed to advance nanoscience and nanotechnology research. At its heart is the ARIE (Analytical Research Infrastructures in Europe) network, which consists of seven European networks of top-tier research infrastructures.
RIANA offers a single-entry point for researchers to access 69 advanced...
Artificial Intelligence has transformed from a theoretical concept to an indispensable force shaping our world. This presentation will embark on a comprehensive journey through AI's rich history, exploring its foundational milestones and the visionaries who paved the way. We will then examine the current landscape of AI, highlighting its diverse applications and the profound impact it has on...
The battle against cancer remains a top priority for society, with an urgent need to develop therapies capable of targeting challenging tumours while preserving patient’s quality of life. Hadron Therapy (HT), which employs accelerated beams of protons, carbon ions, and other charged particles, represents a significant frontier in cancer treatment.
The potential of protons was first...
Introduction: Due to steep dose gradients of the Bragg peak, proton and ion beam therapy is more sensitive to treatment uncertainties compared to conventional radiotherapy. With overall range uncertainty of ~3 – 5%, ensuring robustness of treatment delivery reduces dose conformality – hindering full potential of these modalities.
Apart from conventional strategies, range verification...
The FLASH effect is a promising advance in radiation therapy, reducing normal tissue toxicity without compromising tumor control when ionizing radiation is delivered at ultra-high dose rates (UHDRs) [1]. Preclinical studies support this benefit, yet mechanisms remain incompletely understood. Proposed explanations include radiolytic oxygen depletion, radical–radical recombination, and...
When antimatter and matter annihilated themselves shortly after the Big Bang, a tiny amount of matter was leftover. This is what all planets, stars and galaxies of the known universe are made of. While processes are known for decades that violate the symmetry between matter and antimatter, they are by far insufficient to explain what happened in the early universe. The talk will discuss...
Renormalization of mixing matrices is still a rather open question in particle physics. Previously, we have devised a renormalization scheme which satisfies all the mixing renormalization requirements (UV finiteness, gauge-independence, etc.) trivially. In this presentation we showcase our renormalization scheme of mixing matrices by computing the hadronic $W$ decay widths in the Standard...
An improved perturbative QCD approach is developed that addresses
the pattern of hadron multiplicity fluctuations in quark and gluon jets produced in e+e- annihilation, LHC and elsewhere.
Two seemingly unrelated puzzling phenomena recently observed by ATLAS and CMS experiments may have a common origin (RSE, the rattlesnake effect).
A careful study of the physical content of field dynamics reveals that different field content might actually correspond to the same physical system. This is the basic case for dualities between different theories. Some recent results are reviewed, with the emphasis that this situation corresponds to simple path integral identities. This holds true for the S-dual in Maxwell-Chern-Simons...
We present the decayrates of neutrinos in the Grimus-Neufeld model as a background to the question, in which sense the model is still consistent with Cosmological observations.
The LHCb (Large Hadron Collider beauty) experiment at CERN is a dedicated detector designed to study the decays of heavy-flavor hadrons containing bottom and charm quarks. Operating at the Large Hadron Collider, LHCb provides unique sensitivity to processes involving flavor physics, CP violation, and rare decays, enabling precise tests of the Standard Model and searches for physics beyond it....
As the heaviest particle in the Standar Model (SM) and due to its large Yukawa coupling, the top quark plays a crucial role in the electroweak sector of the SM. Beyond direct measurements of the top quark mass, which depend on precise modelling of the parton shower and hadronization process, and cross-section measurements, sensitive to various sources of uncertainty, an alternative approach...
We present a measurement of the substructure of bottom quark jets originating from $t\bar{t}$ decays in proton--proton collisions at the CMS experiment. In particular, we study the $b$-fragmentation function and the dead cone effect using dilepton $t\bar{t}$ events from Run 3 data collected at $\sqrt{s}=13.6$ TeV. The $b$-fragmentation function, which describes how a $b$ quark fragments into a...
Since the discovery of the Higgs boson in 2012 by the CMS and ATLAS collaborations, many properties of this once elusive particle and key component of the Standard Model of particle physics (SM) have since been measured. One of the remaining properties still to check is the self coupling of the Higgs boson deeply linked to the Higgs mechanism and the underlying Higgs potential.
Double Higgs...
Over the last five decades, many outstanding questions in particle physics have been answered, leading to the Standard Model (SM) and its spectacular confirmation with the discovery of the Higgs boson in 2012, which would supply the heart to this theory. Now the hunt is for a deeper theory of reality. To answer this question, Europe, Japan, the US and China have proposed plans for building new...
The LHCb Upgrade II (“Mighty” upgrade) pushes operation to an order-of-magnitude higher luminosity and demands a downstream tracker that withstands extreme hit rates, radiation, and continuous 40 MHz streaming while maintaining high efficiency and resolution. This challenge is met by the Mighty Tracker that adopts a hybrid layout: radiation-hard silicon pixels in the innermost,...
In preparation for the CMS Phase-2 upgrade targeting the High-Luminosity LHC (HL-LHC), significant progress has been made in the production and assembly of the MIP Timing Detector (MTD). The goal of this sub-system is to provide the CMS detector with precise 4D vertexing capability, enabling time resolution of $\sigma \sim 35\,\text{ps}$ for charged tracks, thus helping mitigate the effects of...
The High-Luminosity Large Hadron Collider (HL-LHC) will provide a dataset much larger than in previous runs, but it will also create more challenging conditions for detectors. To prepare for this, the CMS detector will undergo a Phase-2 upgrade, which will improve tracking, muon, and calorimeter performance.
The Drell-Yan production of lepton pairs is an important process for testing the...
Quenches are a major issue for superconducting magnets because of their high current density which translates to high stored magnetic energy and eventually heat dissipation that may cause irreversible damage if left unadressed. The objective of this work is to describe the experimental demonstration of a novel quench detection and protection principle, combining a superconducting coil with a...
Accelerator projects aimed at enhancing technological innovations are a necessity for the accelerator community to build the future machines for research and industrial applications. Additive manufacturing (AM), as a promising tool to provide larger design freedom than conventional manufacturing techniques, has been explored already several years. Riga Technical University (RTU) experience,...
Fundamental research in high-energy physics (HEP) requires the distribution, processing and storage of a truly huge amount of data collected by the large experiments situated at the Large Hadron Collider (LHC) at CERN. Furthermore, the statistical nature of this research requires an equally vast amount of Monte-Carlo (MC) sample generation. To cope with the immense computing resource demands...
In this report I’ll tell about our activities within a project supported from Latvian Council of Sciences “Laser Photodetchment Threshold Spectroscopy of Negative Ions“. Within our project the participation in 3 different experiments from the list of active experiments on ISOLDE. Firstly Electron Affinity measurements on Clorine [1], and Polonium [2] as next. And latr we joined the parity non...
*On behalf of CRIS collaboration
Isotope Separator On Line DEvice (ISOLDE) at CERN is a unique source of low-energy beams of radioactive nuclides. Collinear Resonance Ionization Spectroscopy (CRIS) is one of the ongoing experiments located at the ISOLDE facility and one of the frontiers in the search for physics beyond standard model.
Francium, (particularly its 7S1/2 → 6D3/2,5/2...
Low Gain Avalanche Detectors (LGADs) are the technology of choice for the timing detectors of the upcoming ATLAS and CMS upgrades at the High-Luminosity Large Hadron Collider (HL-LHC) due to their good timing resolution and signal-to-noise (S/N) ratio. Their performance, however, is limited for low-penetrating particles in p-type devices, since the charge multiplication mechanism differs for...
In this work, we report the experimental results of studies aimed at producing electrodes for glass-based micropatterned detectors, employing selective laser etching. Femtosecond laser technologies allow for achieving multi-photon absorption in optically transparent materials such as fused silica (glass) due to their extremely high peak power and short pulse durations. The laser-affected...
FLUKA is a general-purpose Monte Carlo code used for modeling particle transport and interactions across diverse applications including accelerator design, radiation protection, medical physics, and cosmic-ray studies. The code's accuracy depends critically on large nuclear data collections: levels, half-lives, spins/parities, decays that have historically been encoded in a monolithic FLUKA4...
A first International Cooperation Agreement (ICA) between Estonia and CERN was signed in 1996. The Protocol to the ICA, signed in 2004, assured the funding required for the particle physics community in Estonia.
After joining the CMS Collaboration in 1997, Estonia’s high-energy particle physics community has been reinforced by the return of expatriate scientists, by new students and by direct...
Scintillators are widely applied, from advanced medical imaging to high-energy physics experiments. Cerium-activated garnets such as YAG:Ce are particularly attractive because of their high photoluminescence efficiency and relatively fast response time. Nevertheless, the fabrication of bulk single crystals or transparent ceramics remains costly, which restricts large-scale implementation. To...
In this study, a fully integrated Gas Electron Multiplier (GEM) detector system was employed for high-resolution X-ray imaging. The detector is based on a triple-GEM foil configuration, each with an active area of 10×10cm², housed within a sealed gas chamber. The GEM foils are fabricated from copper foil, featuring a dense array of microscopic holes that enable avalanche multiplication of...
Accurate range control remains a key challenge in particle therapy. Ion radiography promises to tackle this by estimating relative stopping power along particle trajectory, yielding 2-dimensional water-equivalent-path-length (WEPL) projections – improved tissue differentiation and quantitative information for patient alignment compared to X-ray imaging. Among different modalities, use of...
Beam monitoring in ultra-high dose rate (UHDR) radiotherapy, also known as FLASH RT, presents significant challenges, as conventional detectors exhibit saturation and nonlinearities at dose rates ≥40 Gy/s due to charge recombination and signal quenching effects. Ionization chambers and silicon-based solid-state detectors, widely employed in conventional RT, are therefore unsuitable for UHDR...
Plastic scintillating optical fibers are widely used in high-energy particle detectors due to their short scintillation decay times, high energy output, flexibility, small diameter, and low cost. Since 2021, they have become an important part of the LHCb (Large Hadron Collider beauty) experiment, when the SciFi (Scintillating Fibre) particle tracker based on them was put into operation. This...
To enhance the performance of a high-gain, fast-timing micro-pattern gaseous detector (MPGD) using a gas electron multiplier (GEM), new manufacturing methods and materials are essential. The cylindrical symmetry of microholes in perforated electrodes improves detector sensitivity and stability by concentrating electric field lines [1]. However, high gain increases the likelihood of discharge...
The neutron time-of-flight facility (n_TOF) at CERN, in operation since 2001, is a pulsed spallation neutron source designed for precision measurements of neutron-induced reactions. In the n-TOF facility, neutrons can be generated in an energy range from the meV up to GeV, enabling experiments in astrophysics, advanced nuclear technologies, and medical applications. There are three...
CERN has developed a 40T solenoid concept for the Muon Collider final cooling stage of the muon beam. The concept proposes modular solenoid with central bore aperture of 50mm, which provides a 40T magnetic field with 1% uniformity over a length of 0.5m. The solenoid employs non-insulated Rare earth Barium Copper Oxide (ReBCO) high temperature superconductor windings, operated at 4.2 K.
This...
Radiation effects in optical materials for EUROfusion applications (LiF, MgF2, LiAlO2, LaAlO3 etc) as well as in some relevant scintillators for high-energy physics (BaFr, Y3Al5O12 and Gd3Ga5O12) irradiated by swift heavy ions (Kr, E=147 MeV and Xe, E=132 MeV with fluencies ranging from 6·1010 to 2·1014 ions/cm2 have been studied. A stable strong induced absorption observed in the visible...
Low Gain Avalanche Detectors (LGADs) are pivotal for high-precision timing in particle physics experiments, particularly in high-radiation environments like particle colliders. This study investigates the performance degradation of LGADs irradiated with 24 GeV/c relativistic protons, a prevalent radiation source in particle colliders. Implementing the Transient Current Technique (TCT), we...
