Fiducial cross sections for the lepton-pair-plus-photon decay mode in Higgs production up to NNLO QCD

The rare three-body decay of a Higgs boson to a lepton-antilepton pair and a photon is starting to become experimentally accessible at the LHC. We investigate how higher-order QCD corrections to the dominant gluon-fusion production process impact on the fiducial cross sections in this specific Higgs decay mode for electrons and muons. Corrections up to NNLO QCD are found to be sizeable. They are generally uniform in kinematical variables related to the Higgs boson, but display several distinctive features in the kinematics of its individual decay products.

Route measurements of natural surface radiation background in the Almaty region

Measurements of the spatial distribution of radon isotopes were carried out from April 2021 to August 2021 in the foothills of the Trans-Ili Alatau of the Tien Shan in the Almaty region at various heights above sea level: from 500 to 2500 meters. They were carried out using electronic radiometric equipment: beta-dosimeter “RKS-01B-SOLO”; gamma dosimeter “RKS-01G-SOLO”; radiometer of radon and its daughter decay products “RAMON- 02” in the field. As a result, preliminary assessment schemes were built for route measurements of the 222Rn radon isotope, beta and gamma radiation fields from natural daughter products of decay of radon isotopes and radionuclides located in the surface atmospheric layer.

INTERACTION OF IRON-CONTAINING NANOCLUSTER POLYOXOMETALATE WITH DOXORUBICIN

Актуальной проблемой в области адресной доставки лекарственных веществ являются аспекты, относящиеся к транспорту высокотоксичных препаратов, обладающих нежелательными побочными эффектами, в частности противоопухолевых. Были рассчитаны термодинамические параметры комплексообразования нанокластерного полиоксометаллата {MoFe}, перспективного в качестве средства адресной доставки лекарств, и широко применяемого в клинической практике цитостатика - доксорубицина. Взаимодействие доксорубицина с {Mo Fe} сопровождалось экзотермическим эффектом, что говорит об энергетически выгодном образовании комплекса. Кинетика процесса высвобождения доксорубицина из комплекса в буферном растворе с pH , соответствующим значению pH крови, была изучена методом люминесцентной спектроскопии. Были определены константы скорости процессов деструкции {Mo Fe} в комплексе, сопровождающейся высвобождением доксорубицина, и дальнейшего комплексообразования высвободившегося доксорубицина с продуктами распада {MoFe}. В будущем возможно управление скоростью высвобождения доксорубицина путем дополнительной стабилизации {Mo Fe}, например, путем его ассоциации с альбумином. Actual problem in the field of targeted drug delivery is transport of highly toxic drugs, with undesirable side effects, in particular antitumor medicine. The thermodynamic parameters of complexation between nanocluster polyoxometalate {MoFe}, promising as a means of targeted drug delivery, and a cytostatic agent - doxorubicin, widely used in clinical practice, were studied. The interaction of doxorubicin with {MoFe} was accompanied by an exothermic effect, which indicates an energetically favorable formation of the complex. The kinetics of the release of doxorubicin from the complex in a buffer solution with a pH corresponding to the pH value of blood was studied by fluorescence spectroscopy. The rate constants of destruction processes in the complex, accompanied by the release of doxorubicin, and further complexation of the released doxorubicin with decay products were determined. In the future, it is possible to slow down the release of doxorubicin by stabilizing the {MoFe}, for example, when it is associated with albumin.

An LGAD-Based Full Active Target for the PIONEER Experiment

PIONEER is a next-generation experiment to measure the charged pion branching ratios to electrons vs. muons Re/μ=Γπ+→e+ν(γ)Γπ+→μ+ν(γ) and pion beta decay (Pib) π+→π0eν. The pion to muon decay (π→μ→e) has four orders of magnitude higher probability than the pion to electron decay (π→eν). To achieve the necessary branching-ratio precision it is crucial to suppress the π→μ→e energy spectrum that overlaps with the low energy tail of π→eν. A high granularity active target (ATAR) is being designed to suppress the muon decay background sufficiently so that this tail can be directly measured. In addition, ATAR will provide detailed 4D tracking information to separate the energy deposits of the pion decay products in both position and time. This will suppress other significant systematic uncertainties (pulse pile-up, decay in flight of slow pions) to <0.01%, allowing the overall uncertainty in to be reduced to O (0.01%). The chosen technology for the ATAR is Low Gain Avalanche Detector (LGAD). These are thin silicon detectors (down to 50 μm in thickness or less) with moderate internal signal amplification and great time resolution. To achieve a 100% active region several emerging technologies are being evaluated, such as AC-LGADs and TI-LGADs. A dynamic range from MiP (positron) to several MeV (pion/muon) of deposited charge is expected, the detection and separation of close-by hits in such a wide dynamic range will be a main challenge. Furthermore, the compactness and the requirement of low inactive material of the ATAR present challenges for the readout system, forcing the amplifier chip and digitizer to be positioned away from the active region.

A Physiologically Based Pharmacokinetic Model for In Vivo Alpha Particle Generators Targeting Neuroendocrine Tumors in Mice

In vivo alpha particle generators have great potential for the treatment of neuroendocrine tumors in alpha-emitter-based peptide receptor radionuclide therapy (α-PRRT). Quantitative pharmacokinetic analyses of the in vivo alpha particle generator and its radioactive decay products are required to address concerns about the efficacy and safety of α-PRRT. A murine whole-body physiologically based pharmacokinetic (PBPK) model was developed for 212Pb-labeled somatostatin analogs (212Pb-SSTA). The model describes pharmacokinetics of 212Pb-SSTA and its decay products, including specific and non-specific glomerular and tubular uptake. Absorbed dose coefficients (ADC) were calculated for bound and unbound radiolabeled SSTA and its decay products. Kidneys received the highest ADC (134 Gy/MBq) among non-target tissues. The alpha-emitting 212Po contributes more than 50% to absorbed doses in most tissues. Using this model, it is demonstrated that α-PRRT based on 212Pb-SSTA results in lower absorbed doses in non-target tissue than α-PRRT based on 212Bi-SSTA for a given kidneys absorbed dose. In both approaches, the energies released in the glomeruli and proximal tubules account for 54% and 46%, respectively, of the total energy absorbed in kidneys. The 212Pb-SSTA-PBPK model accelerates the translation from bench to bedside by enabling better experimental design and by improving the understanding of the underlying mechanisms.

Next-to-leading-order QCD corrections and parton-shower effects for weakino+squark production at the LHC

We present a calculation of the next-to-leading order QCD corrections to weakino+squark production processes at hadron colliders and their implementation in the framework of the POWHEG-BOX, a tool for the matching of fixed-order perturbative calculations with parton-shower programs. Particular care is taken in the subtraction of on-shell resonances in the real-emission corrections that have to be assigned to production processes of a different type. In order to illustrate the capabilities of our code, representative results are shown for selected SUSY parameter points in the pMSSM11. The perturbative stability of the calculation is assessed for the pp →$$ {\tilde{\upchi}}_1^0{\tilde{d}}_L $$ χ ˜ 1 0 d ˜ L process. For the squark+chargino production process pp →$$ {\upchi}_1^{-}{\tilde{u}}_L $$ χ 1 − u ˜ L distributions of the chargino’s decay products are provided with the help of the decay feature of PYTHIA 8.

Opening the reheating box in multifield inflation

The robustness of multi-field inflation to the physics of reheating is investigated. In order to carry out this study, reheating is described in detail by means of a formalism which tracks the evolution of scalar fields and perfect fluids in interaction (the inflatons and their decay products). This framework is then used to establish the general equations of motion of the background and perturbative quantities controlling the evolution of the system during reheating. Next, these equations are solved exactly by means of a new numerical code. Moreover, new analytical techniques, allowing us to interpret and approximate these solutions, are developed. As an illustration of a physical prediction that could be affected by the micro-physics of reheating, the amplitude of non-adiabatic perturbations in double inflation is considered. It is found that ignoring the fine-structure of reheating, as usually done in the standard approach, can lead to differences as big as ∼ 50%, while our semi-analytic estimates can reduce this error to ∼ 10%. We conclude that, in multi-field inflation, tracking the perturbations through the details of the reheating process is important and, to achieve good precision, requires the use of numerical calculations.

Glass implanted 210 Po as a method of defining long-term retrospective exposure to radon: First experiments in Israel

In most epidemiological studies, contemporary radon measurements are used as a proxy for radon concentrations during the latency period even though extreme changes in radon levels may have occurred. Airborne radon decay products are deposited and implanted through alpha recoil into exposed glass surfaces, providing a measure of time-integrated retrospective radon concentration in the environment in which the glass has been located.