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The series of conferences "International Meetings on Fundamental Physics," organized by the Spanish HEP community, bring together HEP scientists from various research topics within the field of fundamental physics. These meetings aim to foster collaboration, exchange ideas, and discuss the latest advancements in theoretical and experimental fundamental physics.
The XV CPAN days will bring together the Spanish scientific community integrated into the CPAN Consortium (National Center for Particle, Astroparticle, and Nuclear Physics) for a joint discussion on the current state of the field and its prospects. The conference will feature invited lectures and short scientific presentations on the various research lines covered by CPAN. Additionally, there will be meetings of different networks and parallel discussion sessions for the four areas of CPAN aimed at enhancing cooperation among Spanish research groups and collectively defining priority action lines.
This year's CPAN and IMFP conferences, organized by the IFCA HEP group, will take place at the Magdalena Palace in Santander from October 2nd to October 6th, 2023.
Local Organizing Committee
Alicia Calderón Tazón | IFCA (CSIC-UC) |
Jordi Duarte Campderós | IFCA (CSIC-UC) |
Celso Martínez Rivero | IFCA (CSIC-UC) |
Alberto Ruiz Jimeno (chair) | IFCA (CSIC-UC) |
Iván Vila Álvarez | IFCA (CSIC-UC) |
Rocío Vilar Cortabitarte | IFCA (CSIC-UC) |
Sponsors
Instituto de Física de Cantabria | www.ifca.es |
Consejo Superior de Investigaciones Científicas | www.csic.es |
Universidad de Cantabria | www.unican.es |
Centro Nacional de Física de Partículas, Astropartículas y Nuclear | www.i-cpan.es |
Participación española en Infraestructuras Europeas de Investigación en Física de Partículas, Astropartículas y Nuclear (ERISPAN) | |
Red Temática de Física Nuclear | institucional.us.es/fnuc |
Red MULTIDARK | www.multidark.es |
Red COMCHA | |
Red de Altas Energías | |
Centro de Ciencias Pedro Pascual | www.benasque.org |
Real Sociedad Española de Física (DFTP) | rsef.es |
Fundación Gadea Ciencia | gadeaciencia.org |
Fundación Ramón Areces | www.fundacionareces.es |
Ateneo de Santander | atesant.es |
Ciudad de Santander | turismo.santander.es |
Ministerio de Ciencia e Innovación | www.ciencia.gob.es |
En esta presentación expondremos la instalación de datación por 14C mediante espectrometría de masas con acelerador (AMS) en la Universidad de Salamanca. La instalación, dotada de tecnología puntera, permite una datación por 14C muy precisa y exacta de una amplia gama de tipos de muestras. En esta exposición se describen los detalles técnicos del sistema AMS y las diversas medidas de control de calidad que se aplican para garantizar la integridad de los datos producidos. Además, se informa sobre los resultados iniciales obtenidos en la instalación, en concreto la datación de sedimentos marinos preparados mediante fumigación y de un hueso. La idoneidad del método implementado ha sido comprobada mediante la medición de los estándares y las muestras de edades conocidas analizadas en otros laboratorios de datación internacionales.
Muon tomography is an emerging technology being used as a Non-Destructive Testing (NDT) technique in the context of the industry, civil engineering, border security, volcanology and others. This technology exploits cosmic muons as a natural radiation source and the fact that they attenuate and suffer scattering when crossing matter, in a way that correlates with the geometry and density of the materials. The amount of attenuation and scattering can be used to produce tomographic images of the objects under inspection. These two effects, however, correlate also strongly with the momentum of the muons, which is a magnitude hard to measure with cost-effective detectors. This talk presents a proof-of-concept project to measure muon momentum using Time-Of-Flight measurements of the muons based on the time measurement provided by the Low-Gain Avalanche Detectors (LGADs). A muon tomography telescope with a time resolution of ~ 50 ps is under construction, using the LGAD sensors, fast readout electronics and a precise distributed clock system. In addition, dedicated Machine-Learning algorithms are being developed using the momentum information in order to improve the final resolution of the technique. This work is a joint effort of the CNM, ITAINNOVA, and IFCA.
-INTRODUCTION-
Protontherapy has firmly established itself as a complement to conventional radiotherapy for certain tumor and patient profiles. Its primary benefit lies in its remarkable precision, which enables the preservation of a greater amount of the healthy tissue surrounding the tumor. Moreover, protons cause a larger biological effect than photons. Apart from the particles' deposited energy, the linear energy transfer (LET) is thought to play a major role in determining such effect [1-2].
In previous studies, we used the definitions appearing in [3] to calculate track-averaged LET (LETt) and dose-averaged LET (LETd) on-axis distributions for proton pincel beams. These definitions provide a clear and simple way to calculate LETt and LETd on surfaces. However, this is limited when investigating more complex spatial behaviours.
In this communication, we have calculated LETt and LETd in water using the definitions in [4-5] with the Monte Carlo code PENELOPE [6] and PENH (its extension including protons and neutrons). These definitions are volumetric, which facilitates obtaining results using 3D voxelization.
-MATERIALS & METHODS-
We conduct a comparative analysis of the results obtained through both methods and explain their differences. We also evaluate our new implementation against the Monte Carlo codes FLUKA [7] and TOPAS [8]. Additionally, a comparison with the LETt and LETd analytical models described in [3] has been carried out.
We first use monoenergetic proton pencil beams to calibrate the new implementation. A broader variety of beam types has been used to replicate other Monte Carlo studies present in the literature.
-RESULTS AND CONCLUSIONS-
LETt and LETd on-axis distributions are presented for all three codes. The values obtained for LETt are more stable, offering a higher uniformity between codes and definitions than those of LETd. Both are compatible in the majority of the phantom. The appearing discrepancies are addressed.
-REFERENCES-
[1] Paganetti, "Relative biological effectiveness (RBE) values for proton beam therapy. Variations as a function of biological endpoint, dose, and linear energy transfer". Phys Med Biol. 2014 Nov 21;59(22):R419-72.
[2] Kalholm, F., Grzanka, L., Traneus, E., & Bassler, N. "A systematic review on the usage of averaged LET in radiation biology for particle therapy". In Radiotherapy and Oncology (Vol. 161, pp. 211–221). Elsevier BV, (2021).
[3] Wilkens and Oelfke, "Analytical linear energy transfer calculations for proton therapy". Med Phys. 2003 May;30(5):806-15.
[4] D. A. Granville and G. O. Sawakuchi, "Comparison of linear energy transfer scoring techniques in Monte Carlo simulations of proton beams" 2015 Phys. Med. Biol. 60 N283.
[5] M. A. Cortés-Giraldo and A. Carabe, "A critical study of different Monte Carlo scoring methods of dose average linear-energy-transfer maps calculated in voxelized geometries irradiated with clinical proton beams" 2015 Phys. Med. Biol. 60 2645
[6] F. Salvat, J.M. Fernández-Varea and J. Sempau, "Penelope 2018: a code system for Monte Carlo simulation of electron and photon transport", Nuclear Energy Agency, Barcelona 2018; F. Salvat and J. M. Quesada, Nucl. Ins. Meth. Phys. Res. B 475 (2020) 49.
[7] G. Batistone, "The FLUKA code", Annals of Nuclear Energy 82 (2015) 10.
[8] J. Perl et al, "TOPAS: an innovative proton Monte Carlo platform for research and clinical applications", Med. Phys. 39 (2012) 6818.
(+) Corresponding Author: danipuerta@ugr.es
The IRIS group at IFIC has achieved notable advancements in applying Compton cameras for the verification of hadrontherapy treatments and the assessment of radionuclide therapy (RT).
Two reconfigurable multi-layer systems based on LaBr3 monolithic scintillator crystals coupled to SiPMs have been developed in the group. The first system, MACACO III makes use of the AliVATA readout board, while the second system, FALCON, employs the TOFPET2 ASIC from PETsys electronics. To enhance the efficiency, tests involving an enlarged second detector configuration by combining four crystals per plane has been conducted in both cases.
In the hadrontherapy application, successful tests were conducted with the Proteus C-230 cyclotron available at the Centrum Cyklotronowe Bronowice IFJ PAN (Krakow), demonstrating the prototypes' capability to identify 2 mm proton range shifts. Subsequently, new tests were performed in collaboration with the Quirón Proton Therapy Centre using the S2C2 Proteus One synchrocyclotron—a modern accelerator that imposes more demanding requirements on the system due to its higher average current. Preliminary data analysis indicates the ability to detect range shifts in this challenging environment as well.
In the context of RT, encouraged by the initial successful tests conducted in collaboration with La Fe Hospital (Valencia) involving phantoms filled with FDG and 131I-NaI, as well as thyroid cancer patients, the evaluation of the system has now been extended to include alpha emitters. Simulation studies have indicated the potential for imaging Ac-225, and a measurement campaign is scheduled in partnership with the Léon Bérard Centre (Lyon).
The null results from searches for standard weakly-interacting massive particles (WIMPs) have led to a variety of experiments aiming to test alternative dark matter (DM) hypothesis. In particular, several well-motivated DM production models predict sub-GeV candidates, and this fact has promoted a strong international effort to explore such regime.
In this context, the SuperCDMS SNOLAB experiment is expected to lead the search for DM particles down to 500 MeV in the near future. This threshold can be further lowered by including the Migdal effect, that refers to the predicted atom ionization following a perturbation of the respective nucleus. Several dedicated experiments, such as MIGDAL, are currently aiming to verify such prediction in order to justify its use in DM searches.
In this talk I will first review the SuperCDMS SNOLAB and MIGDAL experiments. After this introduction, I will present the contributions from my group at Universidad Autonoma de Madrid (UAM) to such experiments, that include data analysis, development of experiment infrastructure, and instrumentation. I will finish my presentation with a discussion on the future plans in this field at UAM.
The DAMIC-M experiment is a direct detection experiment searching for dark matter particles using thick, fully depleted silicon charge-coupled devices (CCDs), aiming for a target exposure of 1 kg-year. With the inclusion of skipper readout technology, the experiment is capable of achieving single-electron resolution through multiple non-destructive measurements of individual pixel charges, lowering the detection threshold to the eV-scale. At the end of 2021, the Low Background Chamber (LBC) prototype was installed at the Laboratoire Souterrain de Modane, testing the performance of skipper CCD in a low-background environment. We present the current status of DAMIC-M and first results from the LBC on the search of low-mass dark matter interacting with electrons, including constrains on dark matter daily modulations for this type of interactions.
TREX-DM (TPC for Rare Event eXperiments-Dark Matter) at LSC is an experiment looking for low-mass WIMPs with a TPC equipped with large microbulk Micromegas. An update on the background after the installation of an improved version of the detectors is discussed, as well as the method developed to calibrate in the low-energy range (few and sub keV). Likewise, the latest R&D results using a GEM preamplification stage on top of the Micromegas detector are presented. These are very promising in terms of lowered energy threshold and improved sensitivity of the experiment.
The DarkSide-20k experiment will search for dark matter using double-phase time projection chamber filled with 50 tonnes of liquid argon. The activity of the atmospheric argon in the atmosphere is too large to operate this detector, so a cornerstone for the success of this program is the procurement of low radioactivity argon, which is extracted from underground sources and results in a depletion in Ar-39 by more than three orders of magnitude.
The supply chain begins with the Urania plant in Colorado, which can produce argon at a purity of 99.99% from a CO2 stream sourced from a deep well that reaches the Earth’s mantle, at a rate of about 250 kg/day. The plant has already been fabricated and the site is being prepared for installation. After this initial purification stage, the argon will be transported to Sardinia, Italy, where the Aria plant, based on a 350 m cryogenic distillation column, will further suppress impurities. The Aria plant has already been fully fabricated and is now in the installation phase. A smaller version of 26 m high has been tested over the last three years with very positive results confirming the isotopic cryogenic distillation capabilities. After each of these stages, the activity of the argon will then be tested in DArT, an experiment being commissioned at the Canfranc Underground Laboratory.
The importance of this supply chain and of associated techniques extends well beyond DarkSide-20k. Low-radioactivity argon is also of interest for the LEGEND-1000 experiment, for the ultimate dark-matter search experiment using argon ARGO and is attracting the attention of the DUNE collaboration for its Module of Opportunity.
ANAIS is an experiment aimed at directly detecting dark matter, with the objective to either verify or refute the annual modulation signal observed by DAMA/LIBRA. ANAIS-112, which consist of 112.5 kg of NaI(Tl) scintillators, has been taking data at the Canfranc Underground Laboratory in Spain since August 2017. The results obtained from the first three years of collected data do not indicate any modulation and are inconsistent with the DAMA/LIBRA's results. Furthermore, to effectively test this signal, it's essential to know the scintillation quenching factors (QF), used to convert the measured energies into nuclear recoil energies. Previous QF measurements in NaI(Tl) have shown discrepancies. Therefore, a dedicated neutron calibration strategy is currently being followed to understand the response of the ANAIS-112 detectors to nuclear recoils. This initiative includes two procedures: firstly, the sodium QF was evaluated by inducing nuclear recoils in the ANAIS-112 crystals using 252Cf sources; and secondly, a dedicated measurement was performed using a monoenergetic neutron beam. Such measurement, which is presented in this dissertation, is focused on the analysis of different systematics affecting the QF measurements and analysis. Two different methods used in the previous QF measurements for calibrating the NaI(Tl) response to electron recoils are compared, and the differences in the QF results produced by that systematic are identified.
In this work we study the reach of future Direct Detection Dark Matter experiments within the framework of effective field theory (EFT) to describe the DM-nucleus scattering cross section. To extract as much information as possible, we perform a Bayesian analysis using Machine Learning techniques which allow us to assess the discovery potential of each parameter point in an easy and fast way. Although we use a XENON-like experiment as a benchmark, our analysis can be extended to other detectors since different data representations are tested and compared. We show the results in the Dark Matter mass, coupling-coefficient amplitude and phase space of the EFT operators.
The coalescence of a binary system of neutron stars represents a natural laboratory to study hot and ultra-dense matter. Under these extreme conditions, exotic species like hyperons may be present. In this work, we present a comprehensive study of hyperons in neutron star mergers, focusing on the thermal impact they have on the Equation of State. The presence of the hyperons in a hot dense matter produces a significant drop of the thermal pressure. This effect consequently leaves a trace in the observables that can be measured. In particular, we identify that hyperonic equations of state produce a characteristic increase of the dominant postmerger gravitational-wave frequency by up to ∼ 150 Hz compared to purely nucleonic EoS models. Our findings provide an important analysis tool to finally give an answer to the longstanding question: are hyperons present in ultra dense matter?
Neural Quantum States are at the basis of a new ab-initio method especially designed to tackle the quantum many-body problem. These combine the variational method with neural networks, a flagship tool of modern Machine Learning. Neural Quantum States have been successfully used in spin, electronic and nuclear many-body systems. Neural networks can provide an unbiased approximation of complex wave functions, and so far the growth of network parameters with particle number has been found to be polynomial. One expects the growth to be further mitigated by restricting ansätze to the manifold of states that respect physical symmetries. To this end, starting from the most general way to make a neural network equivariant to a certain symmetry group, we design a many-body neural network ansatz which respects the fermionic particle-exchange symmetry. Previous fermionic ansätze are a specific case of this general approach, which we develop formally, foreseeing the need to develop relevant nuclear symmetries, like spin and isospin, into a Neural Quantum State. I will discuss how this approach will be exploited in future nuclear physics simulations and show some initial results on test systems.
SALSA, SAlamanca Lyso-based Scanning Array, es un sistema de caracterización de cápsulas del espectrómetro AGATA, con el que se busca conseguir una base de datos experimental que relacione las posiciones de interacción de la radiación en el cristal con la forma de los pulsos que éstas generan. Para optimizar el método de caracterización, se ha realizado una simulación en la que se estudian diferentes magnitudes, como las posiciones de interacción o la casuística del proceso de detección. Como perspectiva futura, se están desarrollando una serie de programas para analizar los datos experimentales. Entre las principales etapas del proceso de análisis se encuentran la selección de eventos de interés, la localización de coincidencias, la parametrización de la forma de los pulsos, el estudio de trayectorias y, finalmente, la construcción de la base de datos.
The MOdular Neutron time-of-flight SpectromeTER (MONSTER) was originally conceived within the FAIR-NUSTAR collaboration for the measurement of the energy distribution of $\beta$-delayed neutrons with the TOF technique. $\beta$-delayed neutron emission plays an important role in fields like nuclear technology, structure, and astrophysics. In addition to its original purpose, MONSTER can also be used to obtain the energy distribution of neutrons emitted in other kind of reactions, like $(\alpha,n)$ reactions and other reactions where higher-energy neutrons are emitted.
In order to obtain the neutron energy distribution from the TOF measurement, an innovative methodology based on the iterative Bayesian unfolding method and accurate Monte Carlo simulations has been developed. This methodology has been validated through the analysis of a realistic virtual experiment.
In this meeting, the results obtained from the measurement of the $^{85,86}\textrm{As}$ $\beta$-decays at the IGISOL facility of JYFL-ACCLAB and the $^{27}\textrm{Al}(\alpha,n)^{30}\textrm{P}$ reaction at CNA will be presented. Moreover, the preliminary results of a high-energy (20-40 MeV) characterization of MONSTER will also be presented.
We analyze the $^{28}$Si nucleus using state-of-the-art numerical shell model calculations [1] as well as the generator-coordinate method (GCM) with quadrupole constrained Hartree-Fock-Bogoliubov (HFB) wavefunctions [2]. Experimentally, $^{28}$Si presents shape coexistence between the oblate ground state and an excited prolate structure [3]. Although the standard USDB interaction reproduces well the oblate ground state and the vibrational bands, it fails at establishing a prolate band. A modification of the USDB interaction must be introduced to reproduce the experimental spectrum. Guided by Elliot's SU(3) scheme, we show that this is achieved by slightly lowering the gap between the nearly degenerate $0d_{5/2}$-$1s_{1/2}$ doublet and the $0d_{3/2}$ orbital. Our calculations suggest that the oblate ground state is mostly 0p-0h, whereas the prolate band consists mainly of 4p-4h excitations into the $0d_{3/2}$ orbital.
Additionally, we study whether $^{28}$Si can exhibit a superdeformed structure at higher energies. In order to achieve such deformations, excitations from the sd to the pf shell must be taken into account. We find that most of the deformation contribution comes from the $0f_{7/2}$-$1p_{3/2}$ doublet and that the most favorable states are prolate 2p-2h and 4p-4h excitations into the pf shell. In contrast to previous studies [4], our numerical calculations suggest that this superdeformed state would mix with normal-deformed configurations, and therefore $^{28}$Si would not present a superdeformed band.
Overall, our study combines shell-model and beyond-mean-field HFB techniques to shed light on the rich coexistence of differently deformed states in $^{28}$Si [5,6], challenging the established understanding of its nuclear structure.
[1] Caurier, E. et al. Shell model code ANTOINE. IReS, Strasbourg (1989), 2002.
[2] Bally, B., Sánchez-Fernández, A., & Rodríguez, T. R. Eur Phys J A, 57 (2021), 1.
[3] L. Morris et al., Physical Review C 104.5 (2021), 054323.
[4] Y. Taniguchi et al., Physical Review C 80 (2009), 044316.
[5] Bachelor's thesis: http://hdl.handle.net/2445/188691
[6] D. Frycz, et al., in preparation.
The study of cosmic rays, originating from various sources including the Sun and beyond, remains a field with unanswered questions. To probe these high-energy particles, Extensive Air Showers (EAS) generated by cosmic ray interactions with Earth's atmosphere are analyzed. This paper introduces the miniTRASGO cosmic ray telescope, a portable detector employing Resistive Plate Chambers (RPCs) for data acquisition and analysis, and the new member of the TRASGO family. The telescope measures both muons and electrons, offering potential insights into cosmic ray behavior. Challenges and possibilities of Ultra-High Energy Cosmic Rays (UHECRs) detection are discussed. The telescope's design, RPC structure, and measurement techniques are detailed, including intrinsic efficiency and charge spectra analysis. Future work includes implementing a query system, refining interstrip measurements, exploring higher-order multiplicities, and calculating angular distributions.
Lattice simulations of strong interactions (LQCD) have entered an era where precision plays a crucial role: in order to shed light on possible violations of the Standard Model the aim is to reach percent or sub-percent precision level. To attain such precision, isospin breaking effects must be accounted for in the measurements of numerous hadronic observables, including meson masses and the hadronic correction to muon g-2. These effects do not come only from the difference in mass of the light quarks but also from the difference in their electric charges, for this reason the coupling of LQCD to electrodynamics (QED) has to be investigated.
The RC collaboration has developed a code that incorporates QED through C boundary conditions in space, an approach that preserves locality, translational invariance and gauge invariance at all stages of the calculation. During my talk, I will explain the formalism of C* boundary conditions, present the ensembles generated by our collaboration, and discuss the results obtained from the measurement of observables.
General Relativistic Entropic Acceleration (GREA) gives a general framework in which to study multiple out-of-equilibrium phenomena in the context of general relativity, like the late accelerated expansion of the universe or the formation of galaxies and the large scale structure of the universe. In this talk I describe the consequences of mass accretion onto massive Black Holes. I find that a population of Primordial Super Massive Black Holes (SMBH) whose mass grows significantly due to accretion can act as a source of entropic acceleration and constitute a significant part of the present acceleration of the Universe.
I am going to focus on the production of quarkonia through the fragmentation of a gluon and talk about how to deal with this kind of processes in which the final state is composed of heavy quarks. For this purpose, I will discuss effective field theories such as NRQCD, the TMD factorization into short distance coefficients and long distance matrix elements and give an overview of the calculation of these objects.
For the first time N4LL resummation is used to extract non-perturbative distributions. These are the TMD of quarks in protons and we use TMD factorization. The data that have been included in the fit come from ATLAS, CMS, LHb and other hadron colliders. I will describe the details of the extraction and error analysis. e-Print:2305.07473 [hep-ph]
BabyIAXO is the first implementation of the International AXion Observatory. Currently, works have begun in construction site in Desy, Hamburg, Germany. University of Zaragoza is developing the baseline X-ray detectors, gaseus detectors with Micromegas as readout plane. Two prototipes have been in operation during last year: Iaxo-D0 in Zaragoza with a veto system designed to identify muons and cosmic neutrons, and Iaxo-D1 at Canfranc Undergrund Laboratory, a low background environment useful to chatacterize the intrinsic background (radiopurity) of the detector. Results set the reference level in terms of background for future BabyIAXO detectors.
ANTARES had been searching for cosmic neutrinos from the bottom of the Mediterranean Sea from 2006 until 2022, when KM3NeT, which since 2015 is being built in two sites in the same sea, overtook its sensitivity taking the baton. ANTARES is now preparing the final analyses with its complete data set while at the same time the first results with KM3NeT are coming out. This contribution aims to summarize the latest searches for cosmic neutrinos from the Mediterranean Sea.
KM3NeT/ORCA is a water Cherenkov detector that is currently under con-
struction in the Mediterranean Sea. The main objective of ORCA is the precise
measurement of atmospheric neutrino oscillations but the detector also pro-
vides the possibility to investigate various Beyond Standard Model theories.
Even though the construction is not jet finished, data is already being taken
and a high-purity neutrino sample has been collected with a six Detection Unit
configuration of ORCA during the last two years.
This contribution reviews the results of the latest measurement of the neu-
trino oscillation parameters with ORCA6. Furthermore, the results of vari-
ous Beyond Standard Model searches including invisible neutrino decay, Non-
Standard Interactions and neutrino decoherence are shown.
DUNE (Deep Underground Neutrino Experiment) is a long-baseline neutrino experiment that will measure the neutrino mass ordering and CP-violation by observing neutrino oscillations. It is planned to be made of four far-site LAr-TPCs (Liquid Argon Time Projection Chamber) of ~17kT each, located at SURF (Sanford Underground Research Facility at 1300 km from the neutrino source, 1.5km below earth’s surface) and a near-site complex hosting different detectors to measure the neutrino flux produced at the LBNF (Long Baseline Neutrino Facility) at Fermilab.
DUNE will also be sensitive to processes beyond the standard model (nucleon decays, HNL, dark matter…) and neutrinos of astrophysical origin, most noticeably supernovas and Solar Neutrinos.
Our star produces a continuous flux of neutrinos as a byproduct of fusion reactions. The products of the two most energetic processes (8B and hep chains) will be accessible to DUNE with neutrino energies centered at 10MeV at an expected interaction rate of ~10⁻³ Hz. DUNE’s solar analysis has the potential of characterizing for the first time the contribution of the hep chain to the solar neutrino spectrum as well as constraining the best-fit measurements of Δm²12 of previous solar and reactor experiments.
In this presentation, DUNE’s analysis of solar neutrinos and its reconstruction capabilities in the low energy range (<20MeV) will be presented.
The Deep Underground Neutrino Experiment (DUNE), one of the future long-baseline neutrino experiments, is mainly devoted to investigate unequivocally the 3-neutrino oscillation parameter paradigm. Moreover, it has a broad physics program beyond long-baseline neutrino physics, encompassing Beyond Standard Model physics as well as a variety of non-accelerator searches, such as supernova neutrinos or nucleon decay.
DUNE will consist of the world’s most intense neutrino beam and two neutrino detectors. The Near Detector will be placed at Fermilab. The Far Detector will be located at the Sanford Underground Research Laboratory (SURF), 1300 km away. DUNE’s Far Detector is made of four independent underground modules based on the liquid argon time projection chamber (LArTPC) technology. The photon detection system (PDS) of the Far Detector is responsible for the detection of argon scintillation light, complementing the measurements performed by the TPC. The PDS is the main contribution of the DUNE-Spain’s groups toward the experiment’s construction.
In this talk I will discuss the critical role of the PDS toward DUNE’s physics in the areas of event $t_0$ reconstruction, calorimetry and triggering. I will also present the main R&D developments and ongoing optimizations concerning the PDS system, as well as its validation via the ProtoDUNE demonstrators at CERN.
The NEXT (Neutrino Experiment with a Xenon TPC) project is an international collaboration aimed at finding evidence of neutrinoless double beta decay in Xe-136, using a high-pressure gaseous time projection chamber with electroluminescence and optical read-out. After an initial phase of research and development, the team was able to run a small-scale experiment called NEXT-White, which took place from 2016 to 2021 at the Laboratorio Subterráneo de Canfranc, an underground facility in the Spanish Pyrenees. This detector has proven the outstanding performances of the NEXT technology in terms of energy resolution (<1% FWHM at 2.6 MeV) and event topology reconstruction to identify signal and background events. The current phase of the project involves the construction and operation of a larger experiment, NEXT-100, which will employ 100 kg of xenon. The commissioning of this detector is expected to begin in the fourth quarter of 2023. In this talk we will discuss the most recent results of the experiment and the plans to extend the technology towards the ton-scale for fully exploring the inverse hierarchy of neutrino masses.
The n_TOF Collaboration operates the neutron time-of-flight facility at CERN [1]. The neutron source consists of a lead target irradiated by a 20 GeV/c pulsed proton beam. It comprises two experimental areas, EAR1 [2], located at 185 m from the spallation target, and EAR2 [3], located at 20 m above the target.
During CERN’s second long shutdown (2019-2020), the facility went through a major upgrade, including the installation of a new spallation target. These changes have an impact on the characteristics of the neutron beam, i.e. the neutron flux, the energy resolution and the beam profile. A precise knowledge of the neutron flux is essential for the analysis of the experimental cross sections measured in the facility as well as planning future measurements, therefore the need of it being determined accurately. The energy resolution is the main feature in the characterization of the resonance region of the measured cross-sections. Compared to the previous target, the energy resolution and the characteristics of the flux are significantly improved.
In a commissioning phase in 2021 the changes in the characteristics of EAR2 were investigated. This work presents preliminary results of the neutron flux evaluation in EAR2 compared to extensive Monte Carlo simulations with the FLUKA code, as well as an overview of the improvement of the neutron energy resolution.
[1] Rubbia C. et al., A High Resolution Spallation Driven Facility ATTHE CERN-PS to Measure Neutron Cross Sections in the Interval from 1 eV to 250 MeV: a Relative Performance Assessment, CERN/LHC/98-002-EET, 1998
[2] Guerrero C. et al, Performance of the neutron time-of-flight facility n_TOF at CERN, Eur. Phys. J. A 49, 2013
[3] Colonna N. et al, The Second Beam-Line and Experimental Area at n_TOF: A New Opportunity for Challenging Neutron Measurements at CERN, Nuclear Physics News, 25, 2015
David Rodríguez García on behalf of DESPEC collaboration
Our understanding of the production of the heaviest elements in the Universe is still incomplete. In particular the contribution of the rapid neutron capture (r-) process to the observed abundances of elements with A>180 and the astrophysical site for this process is uncertain. Combining astronomical observations (including gravitational wave detection), nuclear physics laboratory experiments and theoretical modelling we can advance in the solution of the puzzle.
Obtaining nuclear data, particularly in the heavy mass region around A~195 (the 3rd peak), is challenging due to limited experimental data availability. This region is linked to the N=126 shell closure in the production path. Consequently, reliance on theoretical predictions is necessary, especially for vital parameters like T1/2 (half-life) and Pn (neutron emission probability), derived from beta-strength calculations dependent on nuclear structure. However, discrepancies exist in theoretical calculations, particularly near N=126 [Mor14,Cab16], leading to a need for comparison with experimental data. Total Absorption Gamma-ray Spectroscopy (TAGS) proves the most effective method for obtaining beta-strength distributions across the entire energy spectrum [Rub05].
In June 2022, a experiment was performed at the GSI facility, as part of FAIR Phase-0, using the TAGS technique. During the experiment, isotopes of Hg, Au and Pt with N=125-27 were measured. These isotopes were produced by high-energy nuclear reactions with a beam of Pb on Be and selected and identified using the FRagment Separator (FRS) [Win08]. Ion implantations and decays particles were measured with the Advanced Implantation and Decay Array (AIDA) [Hal23], while isometic and β-delayed γ-ray cascades were measured with the Decay Total Absorption Spectrometer (DTAS) [Gua18], both developed within the NUSTAR/DESPEC collaboration.
The analysis of the data is ongoing. Currently, we are working on several fronts. One is the calibration of the FRS detectors in order to improve the identification (A and Z) of the nuclei implanted in AIDA.
We are also analysing DTAS data obtained from the measurement of several radioactive sources and comparing the results with detailed Monte Carlo simulations to benchmark the calculated spectrometer response. And finally we are working on AIDA calibration and noise reduction to be able to construct implant-beta correlations to select the proper gamma decay data. In the talk I will give examples of these.
References
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[Gua18] V. Guadilla et al., Nucl. Instrum. Meth. Phys. Res. Sect. A 910, 79 (2018).
[Hal23] O. Hall et al., Nucl. Instrum. Meth. Phys. Res. Sect. A 1050, 168166 (2023)
[Win08] M. Winkler, et al., Nuclear Instruments and Methods in Physics Research Section B 266 (2008) 4183.
The study of transfer reactions involving weakly bound exotic nuclei is an active field due to the recent advances in radioactive beam facilities. Many of these weakly bound nuclei can be approximately described by a model consisting of an inert core and one or more nucleons. However, for some of these nuclei deformation is especially relevant and should be included in the structure models.
This is the case of $^{11}$Be and $^{17}$C, which can be approximately described as a core and a weakly bound neutron. In order to include the effect of the deformation in these two nuclei, two different models have been used [Phys. Rev. C 108 (2023) 024613]: the semi-microscopic particle-plus-AMD (PAMD) model from [Phys. Rev. C 89 (2014) 014333] and a model based on Nilsson. The models have been tested by applying them to the transfer reactions $^{11}$Be$(p,d)^{10}$Be and $^{16}$C$(d,p)^{17}$C. Good agreement is found for $^{11}$Be$(p,d)^{11}$Be by comparing with the experimental data from [Chinese Phys. Lett. 35 (2018) 082501] and [Nucl. Phys. A 683 (2001) 48]. For $^{16}$C$(d,p)^{17}$C, the transfer to the bound states of $^{17}$C is consistent with the data from [Phys. Lett. B 811 (2020) 135939]. The transfer to the continuum of unbound states of $^{17}$C is also studied, with the additional motivation of proving the N=16 shell gap.
In our calculations, the continuum of $^{11}$Be and $^{17}$C is discretized using the transformed harmonic oscillator basis (THO) [Phys. Rev. C 80 (2009) 054605]. This basis has been successfully applied to the discretization of the continuum of two-body and three-body weakly bound nuclei for the analysis of break up and transfer reactions [Phys. Rev. Lett. 109 (2012) 232502, Phys. Rev. C 94 (2016) 054622].
The need for elemental analysis of helium has recently increased dramatically due to the introduction of several novel applications of He implantation, e.g. in materials of future fusion reactors [1] and in optical waveguides [2, 3]. Proton elastic backscattering spectrometry (p-EBS) is a basic method for depth profiling of helium [4, 5]. Ion beam analysis methods strongly rely on the available cross-section data, and the accuracy of IBA methods cannot exceed that of the available cross-sections. Consequently, precise cross-section curves are required in order to obtain reliable results with IBA. A large number of excitation functions for nuclear reactions relevant to IBA have been measured and are compiled in IBANDL at www.nds.iaea.org/ibandl/. This database reveals a lack of data for the 3He(p,p)3He cross section. Only one serie of data appears at one angle (159.2°) in a limited range of energies (1520-2860 keV).
In this work we have measured the elastic scattering cross section using novel solid Si-3He targets developed by the NanoMatMicro group from the Institute of Materials Science. [7]. With these data we have propose completed the resonance of the elastic cross section in a range of energy from 800 to 4500 keV at different angles (159, 165 and 150°) and we have compared with the scarce data in the literature.
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[7] Asunción Fernández, Dirk Hufschmidt, Julien L. Colaux, Jose Javier Valiente-Dobón, Vanda Godinho, Maria C. Jiménez de Haro, David Feria, Andrés Gadea, Stéphane Lucas, Low gas consumption fabrication of 3He solid targets for nuclear reactions, Materials & Design, 186 (2020) 108337 (1-10)
Rapid neutron capture nucleosynthesis (the r-process) produces nearly half of the nuclei heavier than iron in explosive stellar scenarios.
The solar system r-process residual abundances show two peaks located at $A\sim 130$ and $A\sim 195$. Between these peaks lies the Rare-Earth Peak (REP), a distinct but small peak at mass number $A\sim 160$ that arises from the freeze-out during the final stages of neutron exposure. According to theoretical models and sensitivity studies, half-lives $(T_{1/2})$ and $\beta$-delayed neutron emission probabilities $(P_{xn})$ of neutron-rich nuclei, in the mass region $A\sim 160$ for 55$\le$Z$\le$64 are critical for the formation of the REP [1,2]. The BRIKEN collaboration [3] conducted an extensive measurement program of $\beta$-decay properties of nuclei involved in the r-process at the Radioactive Isotope Beam Factory (RIBF) located in the RIKEN Nishina Center, Japan. The BRIKEN-REP experiment has measured $T_{1/2}$ and $P_{1n}$ of nuclei from Ba to Eu (A $\sim$ 160), belonging to the region that is the most influential to the REP formation [4,5]. In this contribution, we will present the experimental results of new $T_{1/2}$ and $P_{1n}$ branchings within the Ba to Nd region. Furthermore, we will discuss how these new experimental data trends match with the trends from recent nuclear model calculations used for r-process simulations of the REP.
[1] M. R. Mumpower et al , Phys. Rev. C 85, 045801 (2012).
[2] A. Arcones and G. Martinez Pinedo , Phys. Rev. C 83, 045809 (2011).
[3] J.L. Tain et. al , Acta physica polonica B 49(03), 417 $-$ 428 (2018).
[4] G. G. Kiss, et al., The Astrophysical Journal 936 2, 107 (2022).
[5] A. Tarifeño-Saldivia et al , RIKEN Accel. Prog. Rep. 54, 27. (2021).
Nucleosynthesis in explosive hydrogen burning at high temperatures (T$\ > 10^8$ K) is characterized mainly by the rapid proton capture rp-process. One of the possible sites for the rp-process are Type I X-ray bursts (XRBs). Several N=Z nuclei, such as ${}^{64}$Ge, act as waiting points in the nuclear flow. The beta decays of these waiting points are needed in theoretical modeling for astrophysical calculations of XRBs light curves. Several such theoretical calculations have shown that, in the conditions of XBRs, continuum electron capture and decay rates from excited states play an important role, in particular for nuclear species at and around the waiting-point nuclei.
Within the framework of the IS570 experiment we have measured the beta decay of ${}^{64-66}$Ge and their daughters ${}^{64-66}$Ga with the Total Absorption Spectrometer (TAS) at ISOLDE, with the main goal of determining the B(GT) distribution for these decays.
For every Ge analysis we performed an analysis on its isobar Ga daughter, because they did appears as a contaminant on the Ge measurements. The preliminary results of N=64 for ${}^{64}$Ga show that the largest difference between the existing data and our new measurement is the noticeable emergence of feeding at around 6080 keV, relatively close to the Q-value of 7171 keV, while for ${}^{64}$Ge revealed a considerably large amount of beta intensity above the last known level at 817 keV up to the Q-value of 4517 keV. For the N=66 case the ${}^{66}$Ga decay shows a difference in feeding distribution but a overall good agreement with ENSDF data.
In this contribution we will present our results on the beta decay of ${}^{64-66}$Ga and will discuss their relevance in the context of isospin mixing of the ground state and our results on the beta decay of ${}^{64}$Ge as for the B(GT) of this new results and its relevance in rp-process calculations.
Neutrons are produced continuously as a secondary radiation from cosmic-rays interactions in the upper atmosphere of our planet. The characterization of such secondary neutrons is connected with different fields such as environmental radioactivity [1], single event upsets (SEUs) in microelectronics [2], the physics of cosmic-rays and space weather [3].
In this work, the High Efficiency Neutron Spectrometry Array (HENSA++) is presented [4]. HENSA++ is intended for high efficiency measurements of cosmic-ray neutrons and the neutron background in underground facilities [5]. The operation of HENSA++ is based on the principle of the Bonner Spheres Spectrometer (BSS) [6]. The use of large 3He tubes has enabled to improve the detection efficiency between 5 up to 10 times over the standard BSS [6]. The current version of HENSA++ is composed by an array of fifteen He-3 tubes, each one embedded in different materials including high density polyethylene neutron moderators, cadmium neutron shieldings and lead neutron converters. This setup allows for spectral sensitivity from thermal up to GeV’s neutrons. For cosmic-ray neutrons, the high detection efficiency of HENSA++ provides near real-time measurements of the neutron spectrum on a time scale of tens of minutes up to few hours, thus enabling possible applications in space weather as a neutron monitor with spectral sensitivity. Moreover, in 2020, the older version of HENSA++, HENSA, has been used to map the cosmic-ray neutron background along the Spanish territory in quiet solar conditions during the beginning of the solar cycle #25. In the present work, the status of the design methodology for HENSA++ and the challenges for the reconstruction of wide energy range spectra (thermal up to 1 GeV) from BSS measurements are discussed. Preliminary results from the 2020 cosmic-ray neutrons measurement campaign with HENSA and some test measurements with HENSA++ are also presented.
Bibliography:
[1] European Radiation Dosimetry Group (2004). Report 140: Cosmic Radiation Exposure of Aircraft Crew.
[2] J. F. Ziegler, et al. (1996). IBM Journal of Research and Development, 40(1).
[3] J. A. Simpson (2000). Space Science Reviews, 93, p. 11–32.
[4] https://www.hensaproject.org/
[5] D. Jordán et al., Astroparticle Physics 42 (2013) 1.
[6] D.J. Thomas and A.V. Alevra (2002). NIMA, 476, p. 12–20.
[7] https://fciencias.ugr.es/34-noticias/3528-hensa-realiza-medidas-en-granada-para-la-caracterizacion-de-los-neutrones-producidos-por-rayos-cosmicos-durante-el-minimo-de-actividad-solar
Neutron capture cross-section measurements are fundamental in the study of astrophysical phenomena, such as the slow neutron capture (s-) process of nucleosynthesis operating in red-giant and massive stars. One of the best suited methods to measure neutron capture (n,γ) cross sections over the full stellar range of interest is the time-of-flight (TOF) technique.
TOF neutron capture measurements on key s-process branching isotopes are very challenging due to the limited mass (~mg) available and the high experimental background arising from the sample activity. Overcoming the current experimental limitations requires the combination of facilities with high instantaneous flux, such as the CERN n_TOF facility, with detection systems with an enhanced detection sensitivity and high counting rate capabilities.
This contribution will present a brief summary about recent improvements at the n_TOF facility and new detection systems for (n,γ) measurements, such as i-TED, an innovative device which exploits the Compton imaging technique to reduce the dominant neutron scattering background. The discussion will be illustrated with results of the first measurement of the s-process branching-point reaction 79Se(n,γ).
Last, an overview will be given on the brand new high-flux n_TOF-NEAR activation station, and the future perspectives for new measurements of astrophysical interest involving unstable targets will be discussed.
El cáncer es la segunda causa de muerte en el mundo, con unos 9,6 millones de fallecimientos [1]. Se trata de un amplio grupo de enfermedades complejas que afectan a casi todos los órganos o tejidos del cuerpo y presentan múltiples rasgos característicos. Las técnicas de imagen son el método por excelencia para analizar el estado e incluso la relación entre varios rasgos distintivos tumorales. Sin embargo, hasta hace poco dichos parámetros distintivos se analizaban mediante técnicas de imagen separadas, lo que dificultaba la correlación multiparamétrica y respondía a diferentes estados fisiológicos del paciente. Para superar esta dificultad, nuestro grupo ha desarrollado una tecnología de imagen preclínica in vivo no invasiva denominada PETRUS (Positron Emission Tomography Registered UltraSonography). PETRUS fusiona imágenes de tomografía por emisión de positrones (PET) para estudiar la desregulación del metabolismo energético de la glucosa típica de los tejidos en proliferación [2], y la ultrasonografía ultrarrápida (UUS), una técnica emergente que proporciona información sobre la arquitectura y la dinámica vasculares, con una resolución espacial y temporal muy alta (~100 um y ~0. 1 mseg, respectivamente) [3-6]. Este equipo ofrece perspectivas únicas en el campo de la oncología, ya que proporciona un marco excelente para estudiar la compleja interacción entre metabolismo y vascularización in vivo, de forma longitudinal, adquirida simultáneamente y completamente corregistrada. En este trabajo presentaremos la caracterización física del sistema, los métodos de registro de imágenes desarrollados, así como como algunos de los resultados y aplicaciones obtenidos hasta el momento con PETRUS que ponen de manifiesto su potencial como futura herramienta para la planificación y monitorización de tratamientos en oncología.
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Perez-Liva M et al., (2018), PMB. [5] Facchin, Pérez-Liva et al., (2020), Theranostics. [6] Pérez-Liva et al., (2020), Mol.Imag and Biol.
High energy physics, radio astronomy, astroparticle physics, all are expected to significantly advance the state of the art of modelling and simulation. The EU-funded interTwin project will co-design and implement the prototype of an interdisciplinary digital twin engine. This open-source platform will provide generic and tailored software components for modelling and simulation to integrate application-specific digital twins. The goal is to develop a common approach that is applicable across the whole spectrum of scientific disciplines to facilitate developments and collaboration. As a result, a consolidation of software technologies supporting research will emerge. In this presentation the developments of the project interTwin will be presented with a focus on HEP simulations from an experimental (detector simulations) and theoretical (Lattice QCD simulations).
In this talk, I will analyse the effect of the resonant production of low-mass vector mediators from neutrino-antineutrino coalescence in the core of proto-neutron stars on the supernova neutrino flux duration. First, I will argue that, in the regime where neutrino-antineutrino interactions via the new vector mediator dominate over the Standard Model neutrino-nucleon scattering, a redistribution of the neutrino energies might take place, making low-energy neutrinos more trapped. Since this only affects 10% of the neutrino population, it cannot be observed in the SN 1987A data, but it could be analysed with future supernova detection data. I will then focus on small gauge couplings, where the decay length of the new gauge boson is larger than the neutrino-nucleon mean free path, but still smaller than the size of proto-neutron star. I will show for the first time that, in this regime, the resonant production of a long-lived vector mediator and its subsequent decay into neutrinos can significantly reduce the duration of the neutrino burst. By using this argument, we rule out new areas of the parameter space of the well-motivated U(1)Lμ-Lτ model. In particular, we extend cooling bounds to higher couplings, probing values of the coupling to 6x10-8.
In this seminar, I will explore the potential for uncovering new neutrino physics through the use of dark matter direct detection experiments and its complementarity with spallation source experiments. In particular, I will analyse the Sterile Baryonic Neutrino Model, an extension of the SM in which we add a sterile massive neutrino. I will show how the sterile neutrino can be generated through the inelastic scattering of an active neutrino with the target material of the experiments in both direct detection and spallation source experiments, giving rise to a characteristic spectrum. This might allow for a reconstruction of the neutrino mass (in the event of a positive detection), which is limited by the experiment energy threshold and resolution. Direct detection experiments, being sensitive to the solar tau neutrino flux, add extra complementary information that allows to improve the determination of the sterile neutrino couplings and its mass.
We investigate how the resonant conversion at a temperature $\overline{T}=25$-$65$ keV of a fraction of the CMB photons into an axion-like majoron affects BBN. The scenario, that assumes the presence of a primordial magnetic field and the subsequent decay of the majorons into neutrinos at $T\approx 1$ eV, has been proposed to solve the $H_0$ tension. We find two main effects. First, since we lose photons to majorons at $\overline{T}$, the baryon to photon ratio is smaller at the beginning of BBN ($T>\overline{T}$) than during decoupling and structure formation ($T\ll \overline{T}$). This relaxes the $2\sigma$ mismatch between the observed deuterium abundance and the one predicted by the standard $\Lambda$CDM model. Second, since the conversion implies a sudden drop in the temperature of the CMB during the final phase of BBN, it interrupts the synthesis of lithium and beryllium and reduces their final abundance, possibly alleviating the lithium problem
The process of Coherent Elastic Neutrino-Nucleus Scattering (CEvNS), first observed in 2017 by the COHERENT collaboration, has provided a powerful tool to study physics beyond the Standard Model within the neutrino sector. In this talk, we present the current bounds on non-standard interactions and electromagnetic properties of neutrinos obtained from CEvNS measurements. Our analysis includes the latest data from the two measurements provided by the COHERENT collaboration using cesium iodide and liquid argon detectors.
Continuous gravitational waves are long-duration gravitational-wave signals
that still remain to be detected. These signals are expected to be produced
by rapidly-spinning non-axisymmetric neutron stars,
and would provide valuable information on the physics of such compact objects;
additionally, they would allow us to probe the galactic population of
EM-dark neutron stars, whose properties may be different from the observed pulsar.
Other sources include the evaporation of boson clouds around spinning black holes
dark matter matter halos, or binary systems of light primordial black holes.
In this talk, I give a brief overview of the continuous gravitational-wave search
results produced by the LIGO-Virgo-KAGRA collaboration using data from their third
observing run O3, and discuss prospects from the now ongoing fourth observing run O4.
Additionally, I will discuss ongoing developments in blind searches, such as the results
of the latest Kaggle competition for CW signals.
The production of neutrons through α-induced reactions play an important role in fields such as nuclear astrophysics, underground laboratories, fission and fusion reactors and non-destructive assays for non-proliferation and spent fuel management applications. However, most of the currently available experimental data was measured decades ago, is incomplete and/or present large discrepancies not compatible with the declared uncertainties. New measurements addressing the actual needs are, therefore, required [1]. To that end the Measurement of Alpha Neutron Yields and spectra (MANY) collaboration was formed.
MANY is a coordinated effort aiming to carry out measurements of (α,n) production yields, reaction cross-sections and neutron energy spectra. The project relies on the use of the α-beams produced by the accelerators at CMAM (Madrid) [2] and CNA (Sevilla) [3]. The measurements are carried out using different types of detection systems, including the miniBELEN neutron counter [4], the MONSTER spectrometer [5] and an array of fast LaBr3(Ce) scintillation detectors of the FATIMA type [6] with angular resolution capabilities, complemented with high purity germanium detectors for gamma spectrometry.
In this work we report the comissioning experiment carried out in the period 2021 - 2023 at CMAM using natural aluminium targets. In particular we present the results from the measurement of the 27Al(α,n)30P thick target production yields using the miniBELEN detector. The determination of the differential cross-sections will also be discussed.
References
[1] S S Westerdale et al. Tech. report INDC(NDS)-0836 (2022)
[2] A Redondo-Cubero et al. Eur Phys J Plus 136 (2021) 175
[3] J Gómez-Camacho et al. Eur Phys J Plus 136 (2021) 273
[4] N Mont-Geli et al. EPJ Web of Conferences 284 (2020)
[5] A R Garcia et al. Journal of Instrumentation 7 (2012) C05012
[6] V Vedia et al. Nucl Instrum Methods Phys Res A 857 (2017) 98
Underground laboratories are key facilities for the study of rare phenomena. The attenuation of cosmic rays and secondary by-products like gamma rays, electrons and muons by several orders of magnitude provide a low background environment that is suitable for experiments dealing with dark matter, neutrinoless double beta decay, measurement of cross sections of astrophysical reactions, etc. However, there is still a background composed of neutrons from spontaneous fission and $\alpha$-n reactions produced in the rocks surrounding the laboratories that needs to be characterized and even monitored.
In the last years, CLYC detectors are gaining interest due to their good discrimination properties between gamma rays an neutron particles, and could potentially be used in underground facilities. In this work, we have used two CLYC detectors to measure thermal neutron flux. CLYC detectors present an intrinsic alpha activity that overlaps with the region of interest for thermal neutrons. Thus, detectors had to be thoroughly characterized for their use in low background conditions, and a dedicated pulse shape analysis was developed to obtain the neutron flux.
The thermal neutron flux was also measured using He-3 detectors. In this case, the spectra also show contributions from other signals apart from neutrons: gamma rays, microdischarges and intrinsic alpha activity from the cathode. A pulse analysis was also developed to obtain a clean neutron spectrum and the thermal neutron flux.
The neutron flux was compared with the one obtained with the CLYC detectors, finding a good agreement between both measurements. The flux was also monitored for several months to observe the possible changes in the thermal neutron background, finding no remarkable changes within the statistical fluctuations.
The study of the slow neutron capture process is fundamental for understanding the creation of isotopes heavier than $^{56}$Fe in stars and, by extension, the relative abundances of the different elements.
One of the most prominent methods to constrain the stellar models for the s-process is measuring the neutron capture cross-section (n,$\gamma$) in the neutron energy range of astrophysical interest (1 - 100 keV) in neutron time-of-flight experiments.
However, for some isotopes, these are experimentally limited by the overwhelming $\gamma$-ray background radiation induced by the neutrons scattered from the target and interacting with the surroundings.
i-TED, a total-energy detector with imaging capabilities based on the Compton camera design, was proposed to tackle this limitation by suppressing background
events based on their spatial origin, different from the sample under study.
After several years of development, the multi i-TED array, composed of four modules, was mounted and successfully used for the first $^{79}$Se(n,$\gamma$) cross-section measurement at CERN n_TOF. Recently, we have implemented several hardware and software upgrades to optimize its performance further.
This contribution will present a brief summary of the recent upgrades and first characterization of the final multi i-TED detector setup.
The results of the first systematic study of the background suppression capabilities based on selections in the Compton imaging domain will be presented, comparing the performance of several methodologies.
An outlook into future simulation work and the applicability of ML methods for the optimization of event selection will also be included.
Neutron emitted from ($\alpha$,n) reactions play an important role in several fields such as nuclear technology, nuclear astrophysics or underground (low background) physics. However, the current knowledge of the neutron yields and neutron energy spectra from ($\alpha$,n) reactions is neither complete nor accurate; which has triggered a renewed interest in studying such reactions. In this context, several Spanish research groups has established the MANY Collaboration that aims at measuring ($\alpha$,n) reactions by means of activation, neutron counting and time-of-flight at the CNA HISPANOS (Seville) and CMAM facilities (Madrid).
The preliminary results of the recent experiment carried out at CNA HISPANOS for the study of the $^{27}$Al($\alpha$,n) reaction by means of activation (using LaBr$_3$ detectors) and by time-of-flight (using a pulsed beam and a liquid scintillator module from the MONSTER array) will be presented. Then, the prospects for upgrades and future measurements will be discussed.
The WASA-FRS HypHI Experiment focuses on the study of light hypernuclei by means of heavy-ion induced reactions. It is part of the WASA-FRS experimental campaign, and so is the eta-prime experiment [1]. The distinctive combination of the high-resolution spectrometer FRS [2] and the high-acceptance detector system WASA [3] is used. The experiment was successfully conducted at GSI-FAIR in Germany in March 2022 as a component of the FAIR Phase-0 Physics Program, within the Super-FRS Experiment Collaboration. Currently, the data from the experiment is under analysis.
In this experiment, the production of the hypernuclei is achieved by bombarding a diamond target with a ⁶Li beam at 1.96A GeV. In this collision, Λ hyperon can merge with the nuclear fragment, forming a hypernucleus. The production of hypernuclei in the spectator rapidity region, with a similar velocity of the incident beam, allows for the in-flight study of the hypernuclei behind the target material. The hypernuclear events are identified by detecting both the residual nuclei and the π − particles emitted from the mesonic weak decay of the hypernuclei.
The second half of the FRagment Separator FRS serves as a high-resolution spectrometer for measuring the decay fragments. Additionally, the Wide Angle Shower Apparatus (WASA), placed in the mid-focal plane of the FRS, is employed for tracking the decay π⁻ particle. The WASA system consists of a superconducting magnet and a group of detectors, including a drift chamber of several layers of strawtubes and plastic scintillator barrel and walls. The hypernucleus is subsequently reconstructed, and its properties, such as invariant mass and lifetime, are analysed.
The primary objectives of this experiment are twofold: to shed light on the hypertriton puzzle [4] and to investigate the existence of the previously proposed nnΛ bound state [5]. Firstly, the significantly shorter hypertriton lifetime reported by three independent state-of-the-art experiments, namely ALICE [6], STAR [7], and HypHI [8], compared to the predictions of theoretical models remains poorly understood. Therefore, obtaining new accurate results for the invariant mass and lifetime of H3Λ (and H4Λ) is crucial to reach a definitive conclusion. Secondly, the observed enhancement in the invariant mass distributions of the d + π⁻ and t + π⁻ final states, as reported by the HypHI Collaboration [5], cannot be accounted for by existing theoretical calculations, which indicate the absence of a neutral nnΛ bound state. Consequently, the WASA-FRS HypHI Experiment aims to produce more precise and statistically significant experimental results that can provide clarification on the potential existence of nnΛ.
My contribution to the conference will provide an overview of the WASA-FRS HypHI Experiment, including its objectives and methodology. Details of the experiment approach that combines for the first time a cylindrical detection system with a fragment separator will be presented. I will also explain the opportunities that such experimental setup provide. Finally, I will discuss the current state of the experiment analysis and show the first preliminary results of track and event reconstruction.
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Electricity generation from nuclear plants has consistently increased since the establishment of the first facility in 1954. This growth cashort-lived andn be attributed mainly to its significant advantage in reducing greenhouse gas emissions through uranium fission. However, nuclear energy comes with significant drawbacks, notably the production and management of radioactive waste. The latter, varying in levels of radioactivity and longevity, necessitate disposal in specialized facilities for thousands of years. This underscores the importance of refining the classification process to minimize disposal needs, achieved by segregating very low level waste (VLLW), low level waste (LLW) and intermediate level waste (ILW) from high level waste (HLW).
To such aim we have explored the applicability of a high resolution $\gamma$-ray imaging spectrometer, called i-TED, which was initially developed for nuclear astrophysics experiments at CERN n_TOF [1]. Essentially, i-TED is a modular Compton camera with a very broad Field of View (FoV) and large efficiency, a high image- and energy-resolution, while still portable and scalable.
In this work, we present the first results obtained after applying i-TED to measure radioactive residues of low- and medium-activity at the disposal center of El Cabril (Cordoba, Spain). Five radioactive drums were arranged in a specific configuration, with i-TED positioned in front of them at eight different locations for data collection. Additionally, an RGB commercial camera was attached to i-TED to capture the surrounding environment. This integration allows us to create an image of the observed scene, incorporating the radioactivity data provided by i-TED through the application of computer vision techniques, such as fiducial marker detection and segmentation. In summary, a comprehensive spatial assessment of radioactivity within a scene can be achieved using i-TED, whose main advantages are related to its portability, scalability, a wide field of view (FoV) and high detection efficiency.
[1] Domingo-Pardo, C.: i-TED: A novel concept for high-sensitivity (n,γ) cross-section measurements. Nuclear Instruments and Methods in Physics Research A 825, 78–86 (2016)
In this study, the sextic oscillator adapted to the Bohr Hamiltonian was employed to describe even isotopes of platinum (Pt) and osmium (Os) within specific mass number ranges. The primary objective was to investigate the transition of these isotopes from a "γ-unstable" state to a "spherical vibrator" state. The model utilized a potential that was independent of the γ shape variable, allowing for closed analytical solutions for physical properties like energy eigenvalues and B(E2) values. The study aligned experimental energy levels with theoretical predictions and considered electric quadrupole transition data for this purpose. Special focus was placed on transitions between specific excited nuclear states, particularly those that indicate changes in shape phases between spherical and deformed potential minima. The study determined the parameters of the Hamiltonian through a weighted least square fit procedure and analyzed trends in ground-state and excited state bands. Additionally, the study plotted trajectories in a two-dimensional phase space, finding that most nuclei exhibited a deformed potential minimum, except for the heaviest Pt isotope (198Pt), which transitioned to a spherical shape phase. While data for other isotopes (200Pt and 194Os) was less complete, there were indications that they also approached or fell within the domain of a spherical potential minimum.
The shape of nuclei is determined by a fine balance between the stabilizing effect of closed shells and the pairing and quadrupole force that tends to make them deformed. As other well known cases, located in the A = 100 mass region, as Yb, Zr or Nb for example, Sr isotopes [1] are good candidates to study the existence of this nuclear deformation, while Ru and Mo [2] isotopes are interesting to study the dissapearance of this phenomenon. In particular, in the Sr case, particle-hole excitations are favoured because of the presence of the proton subshell closure Z = 40, resulting in low-lying intruder bands.
This study will clarify the presence of low-lying intruder states in the even-even isotopes considered together with the way it connects with the onset of deformations. In order to reach this aim, the study of the nuclear structure of neutron rich even-even isotopes of Sr, Ru and Mo using the description of excitation energies, B(E2) transition rates, nuclear radii and two neutron separation energies within the framework of the Interacting Boson Model with configuration mixing is developed.
For the whole chain of isotopes analysed, good agreement between theoretical and experimental values of excitation energies, transition rates, separation energies, radii and isotope shift has been obtained. Furthermore, the wave functions, together with the obtention of mean field energy surfaces and the value of nuclear deformation have been analysed. Finally, an analysis of the existence of quantum phase transitions for Sr, Mo and Ru isotopes is included.
[1] E. Maya-Barbecho and J.E. García-Ramos, “Shape coexistence in Sr isotopes”, Physical
Review C 105, 034341-16p (2022).
[2] E. Maya-Barbecho, S. Baid, J.M. Arias and J.E. García-Ramos, “At the borderline of shape coexistence: Mo and Ru”, to be published.
In recent articles, the discussion on the treatment of Power Corrections in the three-jet limit, along with its influence on precision $\alpha_s$ determinations from fits to event shape experimental data, has attracted a lot of attention. On the basis of a factorization formula for the $e^+e-$ thrust distribution, derived within soft-collinear effective theory, we discuss the treatment of Power Corrections in the tail region of the spectrum and the problems connected to it. In addition, we review past studies on the strong coupling determination from event shapes carried out by some of us, and provide updated results produced with a new numerical code which incorporates recent theoretical developments. Furthermore, we show the mild effect caused by the tau-dependent power correction recently advocated for in the literature.
Fragmentation Functions (FF) are universal non-perturbative objects that model hadronization in some general kind of processes. They are mainly extracted from experimental data, hence constraining the parameters of the corresponding fits is crucial for achieving reliable results. As expected, the production of lighter hadrons is favoured w.r.t. heavy ones, thus we would like to exploit the precise knowledge of pion FFs to constraint the shape of kaon (or heavier) FFs. In this talk, we show how imposing specific cuts on photon-hadron production leads to relations among u-started FFs. For doing so, we rely on the reconstruction of momentum fractions in terms of experimentally-accessible quantities, exploiting machine-learning techniques. Also, we consistently introduce NLO QCD + LO QED corrections. Our results point towards an efficient strategy which might help to reduce heavy-hadron FFs uncertainties.
Quantum tomography has become an indispensable tool in order to compute the density matrix $\rho$ of quantum systems in Physics. Recently, it has further gained importance as a basic step to test entanglement and violation of Bell inequalities in High-Energy Particle Physics. In this talk, I present the theoretical framework for reconstructing the helicity quantum initial state of a general scattering process. In particular, I perform an expansion of $\rho$ over the irreducible tensor operators $\{T^L_M\}$ and compute the corresponding coefficients uniquely by averaging, under properly chosen Wigner D-matrices weights, the angular distribution data of the final particles. Besides, I provide the explicit angular dependence of both the normalised differential cross section and the generalised production matrix $\Gamma$. Finally, I re-derive all our previous results from a quantum-information perspective using the Weyl-Wigner-Moyal formalism and obtain in addition simple analytical expressions for the Wigner $P$ and $Q$ symbols.
Participarán:
Cesar Domingo Pardo
Igor García Irastorza
Santiago Folgueras Gómez
Carla Marín