Muon capture isotope production (MuCIP) using negative ordinary muon capture reactions (OMC) is used to efficiently produce various kinds of nuclear isotopes for both fundamental and applied science studies. The large capture probability of muon into a nucleus, together with the high intensity muon beam, make it possible to produce nuclear isotopes in the order of 10^{9-10} per second depending on the muon beam intensity. Radioactive isotopes (RIs) produced by MuCIP are complementary to those produced by photon and neutron capture reactions and are used for various science and technology applications. MuCIP on ^{Nat}Mo by using the RCNP MuSIC \muon beam is presented to demonstrate the feasibility of MuCIP. Nuclear isotopes produced by MuCIP are evaluated by using a pre-equilibrium (PEQ) and equilibrium (EQ) proton neutron emission model. Radioactive $^{99}$Mo isotopes and the metastable ^{99m}Tc isotopes, which are used extensively in medical science, are produced by MuCIP on ^{Nat}Mo and ^{100}Mo.
Radioactive isotopes produced through cosmic muon spallation are a background for rare-event detection in $ν$ detectors, double-$β$-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of $^{11}$C. Data from the Kamioka liquid-scintillator antineutrino detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillators, …
While cosmic ray muons themselves are relatively easy to veto in underground detectors, their interactions with nuclei create more insidious backgrounds via: (i) the decays of long-lived isotopes produced by muon-induced spallation reactions inside the detector, (ii) spallation reactions initiated by fast muon-induced neutrons entering from outside the detector, and (iii) nuclear recoils initiated by fast muon-induced neutrons entering from outside the detector. These backgrounds, which are difficult to veto or shield against, are very important for solar, reactor, dark matter, and other under…
The isotope $ {}^{99} \rm{Mo} $, the generator of $ {}^{99m} \rm{Tc} $ used for diagnostic imaging, is supplied by extracting from fission fragments of highly enriched uranium in reactors. However, a reactor-free production method of $ {}^{99} \rm{Mo} $ is searched over the world from the point of view of nuclear proliferation. Recently, $ {}^{99} \rm{Mo} $ production through a muon capture reaction was proposed and it was found that about $ 50 \, \% $ of $ {}^{100} \rm{Mo} $ turned into $ {}^{99} \rm{Mo} $ through $ {}^{100} \rm{Mo} \left( μ^-, n \right) $ reaction [arXiv:1908.08166]. However…
Absolute intensity measurement of pulsed muon beams using in-beam activation
CMMS, TRIUMF（TRIUMF）；Department of Physics, Graduate School of Science, The University of Tokyo（东京大学理学研究科物理学系）；Nishina Center, RIKEN（理化学研究所仁科加速器科学研究中心）；ISIS Neutron and Muon Facility, STFC Rutherford Appleton Laboratory（STFC卢瑟福阿普尔顿实验室ISIS中子与μ子设施）；High Energy Accelerator Research Organization (KEK)（高能加速器研究机构(KEK)）；Department of Advanced Energy Science and Engineering, Kyushu University（九州大学先进能源工学部）；Research Center for Nuclear Physics, The University of Osaka（大阪大学核物理研究中心）
Charge radii of Cl isotopes from x-ray spectroscopy of muonic atoms
Max-Planck-Institut für Kernphysik（马克斯·普朗克核物理研究所）；KU Leuven, Instituut voor Kern- en Stralingsfysica（荷语鲁汶大学核与辐射物理学研究所）；Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering（霍里亚·胡卢贝伊国家物理与核工程研发研究所）；Université Libre de Bruxelles, Institut d’Astronomie et d’Astrophysique（布鲁塞尔自由大学天文与天体物理研究所）；Brussels Laboratory of the Universe-BLU-ULB（布鲁塞尔宇宙实验室）；PSI Center for Neutron and Muon Sciences（保罗谢勒研究所中子与μ子科学中心）；ETH Zürich, Institute for Particle Physics and Astrophysics（苏黎世联邦理工学院粒子物理与天体物理研究所）；The Helen Diller Quantum Center, Department of Physics, Technion-Israel Institute of Technology（以色列理工学院海伦·迪勒量子中心物理学系）；Institut für Kernphysik, Johannes Gutenberg-Universität Mainz（美因茨约翰内斯·古腾堡大学核物理研究所）；PRISMA ++ Cluster of Excellence, Johannes Gutenberg-Universität Mainz（美因茨约翰内斯·古腾堡大学PRISMA++卓越集群）；Institute of Physics, Slovak Academy of Sciences（斯洛伐克科学院物理研究所）；Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France（卡斯特尔-布罗塞尔实验室）
The negative-muon capture reaction (MCR) on the enriched $^{100}Mo$ isotope was studied for the first time to investigate neutrino nuclear response for neutrino-less double beta decays and supernova neutrino nuclear interactions. MCR on $^{100}Mo$ proceeds mainly as $^{100}Mo(mu,xn)^{100-x}Nb$ with $x$ being the number of neutrons emitted from MCR. The Nb isotope mass distribution was obtained by measuring delayed gamma-rays from radioactive $^{100-x}Nb$. By using the neutron emission model after MCR, the neutrino response (the strength distribution) for MCR was derived. Giant resonance (GR)-l…
A simultaneous analysis is made of the measured rates of ordinary muon capture (OMC) and radiative muon capture (RMC) in liquid hydrogen, using theoretical estimates for the relevant atomic capture rates that have been obtained in chiral perturbation theory with the use of the most recent values of the coupling constants. We reexamine the basic formulas for relating the atomic OMC and RMC rates to the liquid-hydrogen OMC and RMC rates, respectively. Although the analysis is significantly influenced by ambiguity in the molecular state population, we can demonstrate that, while the OMC data can …
When muons travel through matter, their energy losses lead to nuclear breakup ("spallation") processes. The delayed decays of unstable daughter nuclei produced by cosmic-ray muons are important backgrounds for low-energy astrophysical neutrino experiments, e.g., those seeking to detect solar neutrino or Diffuse Supernova Neutrino Background (DSNB) signals. Even though Super-Kamiokande has strong general cuts to reduce these spallation-induced backgrounds, the remaining rate before additional cuts for specific signals is much larger than the signal rates for kinetic energies of about 6 -- 18 Me…
We calculate ordinary and radiative muon capture on the proton in an effective field theory of pions, nucleons and delta isobars, working to third and second order in the small scale expansion respectively. Preceding calculations in chiral effective field theories only employed pion and nucleon degrees of freedom and were not able to reproduce the photon spectrum in the pioneering experiment of radiative muon capture on the proton from TRIUMF. For the past few years it has been speculated that the discrepancy between theory and experiment might be due to Delta(1232) related effects, which are …
Precise measurement of $γ$-rays following ordinary (non-radiative) capture of negative muons by natural Se, Kr, Cd and Sm, as well as isotopically enriched $^{48}$Ti, $^{76}$Se, $^{82}$Kr, $^{106}$Cd and $^{150}$Sm targets was performed by means of HPGe detectors. Energy and time distributions were investigated and total life time of negative muon in different isotopes was deduced. Detailed analysis of $γ$-lines intensity allows to extract relative yield of several daughter nuclei and partial rates of ($μ$,$ν$) capture to numerous excited levels of the $^{48}$Sc, $^{76}$As, $^{82}$Br, $^{106}$…
Using the Double Chooz detector, designed to measure the neutrino mixing angle $θ_{13}$, the products of $μ^-$ capture on $^{12}$C, $^{13}$C, $^{14}$N and $^{16}$O have been measured. Over a period of 489.5 days, $2.3\times10^6$ stopping cosmic $μ^-$ have been collected, of which $1.8\times10^5$ captured on carbon, nitrogen, or oxygen nuclei in the inner detector scintillator or acrylic vessels. The resulting isotopes were tagged using prompt neutron emission (when applicable), the subsequent beta decays, and, in some cases, $β$-delayed neutrons. The most precise measurement of the rate of $^{…
Underground argon (UAr) with lower cosmogenic activities of $^{39}Ar$ and $^{42}Ar$ has been planned as a detector in detecting scintillation light and charge collection using time projection chambers for dark matter searches and as a veto detector in suppressing backgrounds for neutrinoless double beta decay (0$νββ$) experiments. Long-lived radioactive isotopes, $^{39}Ar$ and $^{42}Ar$, can also be produced on the surface when UAr is pumped out from a deep well. Understanding the production of long-lived isotopes in Ar is important for utilizing UAr for dark matter and 0$νββ$ experiments in t…
In-situ production of long-lived isotopes by cosmic muon interactions may generate a non-negligible background for deep underground rare event searches. Previous Monte Carlo studies for the GERDA experiment at LNGS identified the delayed decays of $^{77}$Ge and its metastable state $^{77m}$Ge as dominant cosmogenic background in the search for neutrinoless double beta decay of $^{76}$Ge. This might limit the sensitivity of next generation experiments aiming for increased $^{76}$Ge mass at background-free conditions and thereby define a minimum depth requirement. A re-evaluation of the $^{77(m)…
\item[Background] The nuclear responses for antineutrinos associated with double beta decays (DBDs) and astro-antineutrino interactions are studied by measuring ordinary muon capture (OMC) rates. \item[Purpose]The experimental studies of absolute OMC rates and their mass number dependence for $^{100}$Mo and the natural Mo are currently of interest in astro-antineutrinos and DBDs. \item[Method]The OMC rates were obtained experimentally by measuring the time spectrum of the trapped muon's decay into electrons to obtain the half-lives of the trapped muons. \item[Results]The OMC rate for the enric…
The results of investigation of Xe-127 radioactive isotope production in the xenon sample enriched in Xe-124, Xe-126, Xe-128 are presented. The isotope is supposed to be the source of the background events in the low-background experiment on search for 2K-capture of Xe-124. In this work we consider two channels of Xe-127 production: the neutron knock-out from Xe-128 nucleus by cosmogenic muons and the neutron capture by Xe-126 nucleus. For the first channel the upper limit of the cross section of Xe-127 production was found to be sigma >= 0.007 barn at 95\% C.L. For the second channel the valu…
Measurement of the branching ratio of $\mathrm{^{16}N}$, $\mathrm{^{15}C}$, $\mathrm{^{12}B}$, and $\mathrm{^{13}B}$ isotopes through the nuclear muon capture reaction in the Super-Kamiokande detector
Dokkyo Medical University（独协医科大学）；The University of Tokyo（东京大学）；RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS)（理化学研究所跨学科理论与数学科学中心(iTHEMS)）；Saitama University（埼玉大学）；Nishina Center, RIKEN（理化学研究所仁科中心）
We report the measured production rates of unstable isotopes $^9$Li and $^8$He produced by cosmic muon spallation on $^{12}$C using two identical detectors of the RENO experiment. Their beta-decays accompanied by a neutron make a significant contribution to backgrounds of reactor antineutrino events in precise determination of the smallest neutrino mixing angle. The mean muon energy of its near (far) detector with an overburden of 120 (450) m.w.e. is estimated as 33.1 +- 2.3 (73.6 +- 4.4) GeV. Based on roughly 3100 days of data, the cosmogenic production rate of $^9$Li ($^8$He) isotope is meas…
Determination of the Muon Lifetime in $^{76}$Se with the MONUMENT experiment
University of Zurich（苏黎世大学）；University of Alabama（阿拉巴马大学）；Joint Institute for Nuclear Research（俄罗斯联合核子研究所）；IRFU, CEA, Université Paris-Saclay（法国原子能和替代能源署法国研究和技术中心萨克雷大学 IRFU）；Technical University of Munich（慕尼黑工业大学）；KU Leuven, Institute for Nuclear and Radiation Physics（荷语鲁汶大学核与辐射物理研究所）；Research Center on Nuclear Physics, Osaka University（大阪大学核物理研究中心）；Universiti Teknologi Malaysia（马来西亚理工大学）；Paul Scherrer Institut（保罗谢尔研究所）；Max-Planck-Institut für Kernphysik（马克斯·普朗克核物理研究所）
Accurate Charge Radius Measurement of $^{14}$C Confronts Ab Initio Theory
Technische Universität Darmstadt（达姆施塔特工业大学）；Helmholtz Research Academy Hesse for FAIR, GSI Darmstadt（黑森亥姆霍兹FAIR研究院）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；National Center for Computational Sciences, Oak Ridge National Laboratory（橡树岭国家实验室计算科学中心）；Physics Division, Oak Ridge National Laboratory（橡树岭国家实验室物理部）；Physics Division, Argonne National Laboratory（阿贡国家实验室物理部）；Computational Science Division, Argonne National Laboratory（阿贡国家实验室计算科学部）；INFN-TIFPA Trento Institute of Fundamental Physics and Applications（意大利国家核物理研究所特伦托基础物理与应用研究所）；Instituto de Física Corpuscular (IFIC), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Valencia（西班牙高等科学研究理事会与巴伦西亚大学粒子物理研究所）；Dept. of Physics and Astronomy, Iowa State University（爱荷华州立大学物理与天文学系）
Low values of the fusion cross sections and very short half-lives of nuclei with Z$>$120 put obstacles in synthesis of new elements. Different nuclear reactions (fusion of stable and radioactive nuclei, multi-nucleon transfers and neutron capture), which could be used for the production of new isotopes of superheavy (SH) elements, are discussed in the paper. The gap of unknown SH nuclei, located between the isotopes which were produced earlier in the cold and hot fusion reactions, can be filled in fusion reactions of $^{48}$Ca with available lighter isotopes of Pu, Am, and Cm. Cross sections f…
