Nuclear Experiment·nucl-ex
10 papers—3 primary·7 cross-listed·reconstructed*
E. B. Norman🇺🇸 · T. E. Chupp🇺🇸 · K. T. Lesko🇺🇸 · G. L. Woodruff · P. J. Grant
Thick-target neutron yields from the 19F(alpha,n) reaction are reported for E(alpha) = 3.5 - 10.0 MeV.
Ramni Gupta🇮🇳 · Rohni Sharma🇮🇳
Event-by-event fluctuations in the spatial patterns in charged particles generated in Pb--Pb collisions at the center-of-mass energy = 2.76 TeV are studied within A MultiPhase Transport (AMPT) model. The spatial patterns of the particles generated in the () space for are studied using the methodology of intermittency and erraticity analysis. We find negative intermittency for charged particles generated in a range of windows. This result contrasts sharply from what is expected for a quark-gluon plasma undergoing hadronization by a second-order phase transition. Appropriate scaling behavior is examined, resulting in definitive scaling exponent . Event-by-event fluctuations in the spatial patterns quantified by an index, named erraticity index are determined for different bins GeV/c, for AMPT model. This is the first time that the intermittency and erraticity indices are determined for any model at such high energies. The results presented here can be used for comparison with the fluctuation properties of the experimental data and hence can help the development of a wider scope of understanding of validity of the particle production process by AMPT at these energies on the one hand, and of the true nature of the real data on the other.
R. Han🇨🇳 · R. Wada🇨🇳 · Z. Chen🇨🇳 · Y. Nie🇨🇳 · X. Liu · S. Zhang · P. Ren · B. Jia🇨🇳 · G. Tian🇨🇳 · F. Luo🇨🇳 · W. Lin🇨🇳 · J. Liu and 9 other authors
Benchmarking of evaluated nuclear data libraries was performed for MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by MeV neutrons and leakage neutron energy spectra were measured at 60 and 120. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.
J. Amaré🇪🇸 · S. Cebrián🇪🇸 · C. Cuesta🇪🇸 · E. García🇪🇸 · C. Ginestra🇪🇸 · M. Martínez🇪🇸 · M.A. Oliván🇪🇸 · Y. Ortigoza🇪🇸 · A. Ortiz de Solórzano🇪🇸 · C. Pobes🇪🇸 · J. Puimedón🇪🇸 · M.L. Sarsa🇪🇸 · J.A. Villar🇪🇸 · P. Villar🇪🇸
The production of long-lived radioactive isotopes in materials due to the exposure to cosmic rays on Earth surface can be an hazard for experiments demanding ultra-low background conditions, typically performed deep underground. Production rates of cosmogenic isotopes in all the materials present in the experimental set-up, as well as the corresponding cosmic rays exposure history, must be both well known in order to assess the relevance of this effect in the achievable sensitivity of a given experiment. Although NaI(Tl) scintillators are being used in experiments aiming at the direct detection of dark matter since the first nineties of the last century, very few data about cosmogenic isotopes production rates have been published up to date. In this work we present data from two 12.5 kg NaI(Tl) detectors, developed in the frame of the ANAIS project, which were installed inside a convenient shielding at the Canfranc Underground Laboratory just after finishing surface exposure to cosmic rays. The very fast start of data taking allowed to identify and quantify isotopes with half-lives of the order of tens of days. Initial activities underground have been measured and then production rates at sea level have been estimated following the history of detectors; values of about a few tens of nuclei per kg and day for Te isotopes and 22Na and of a few hundreds for I isotopes have been found. These are the first direct estimates of production rates of cosmogenic nuclides in NaI crystals. A comparison of the so deduced rates with calculations using typical cosmic neutron flux at sea level and a carefully selected description of excitation functions will be also presented together with an estimate of the corresponding contribution to the background at low and high energies, which can be relevant for experiments aiming at rare events searches.
We review the current status and future prospect for probing the transverse momentum dependent (TMD) parton distributions using the Drell-Yan process. We focus on the Boer-Mulders and Sivers functions, which are expected to undergo a sign-change from semi-inclusive deep-inelastic scattering (SIDIS) to Drell-Yan process. The constraints of existing Drell-Yan and SIDIS experiments on the signs of these functions are discussed. Future Drell-Yan measurements for the TMDs are also presented.
Akinobu Doté🇯🇵 · Takashi Inoue🇯🇵 · Takayuki Myo🇯🇵
Kaonic nuclei (nuclear system with anti-kaons) have been an interesting subject in hadron and strange nuclear physics, because the strong attraction between anti-kaon and nucleon might bring exotic properties to that system. In this article, we investigate as a prototype of kaonic nuclei. Here, is a three-body resonant state in the - coupled channels. (=, ) To treat resonant states in a coupled-channel system properly, we propose newly a coupled-channel complex scaling method combined with the Feshbach projection (ccCSM+Feshbach method). In this method, the Feshbach projection is realized with help of so-called the extended closure relation held in the complex scaling method, and a complicated coupled-channel problem is reduced to a simple single-channel problem which one can treat easily. First, we confirm that the ccCSM+Feshbach method completely reproduces results of a full coupled-channel calculation in case of two-body - system. We then proceed to study of three-body - system, and successfully find solutions of the resonance by imposing self-consistency for the complex energy. Obtained binding energy of is well converged around 27 MeV, with an energy-dependent (-) potential based on the chiral SU(3) theory, independently of ansatz for the self-consistency. This binding energy is small as ones reported in earlier studies based on chiral models. The decay width of strongly depends on the ansatz. We calculate also the correlation density of and pairs by using the obtained complex-scaled wave function of the resonance. Effect of the repulsive core of potential and survival of resonance are confirmed.
Denis Lacroix🇫🇷 · Karim Bennaceur🇫🇷
To solve difficulties related to the use of nuclear density functional theory applied in its beyond mean-field version, we introduce a semi-contact 3-body effective interaction. We show that this interaction is a good candidate to replace the widely used density dependent effective interaction. The resulting new functionals are able to describe symmetric, neutron, polarized and neutron polarized nuclear matter as well as the effective mass properties simultaneously.
D. Lorca (for the NEXT Collaboration)🇪🇸
The NEXT-100 detector will search for the neutrinoless double beta decay of Xe using an electroluminescent high-pressure xenon gas TPC filled with 100 kg of enriched Xe. An observation of this hypothetical process would establish a Majorana nature for the neutrino and prove the violation of lepton number. A scaled-down prototype, NEXT-DEMO, has been built to demonstrate the feasibility of the technology. NEXT-DEMO includes an energy plane made of PMTs and a tracking plane made of SiPMs. X-ray energy depositions, produced by the de-excitation of xenon atoms after their interaction with gamma rays, have been used to characterize the detector response. With this method, the released energy by gammas coming from Na source has been corrected, achieving an energy resolution of 5.691% FWHM and 1.62% FWHM at the 29.7 keV and 511 keV peaks respectively, which extrapolate to 0.62% FWHM and 0.73% FWHM at Q value of Xenon.
Jiunn-Wei Chen🇹🇼 · Hsin-Chang Chi🇹🇼 · Keh-Ning Huang🇹🇼 · Hau-Bin Li🇹🇼 · C.-P. Liu🇹🇼 · Lakhwinder Singh🇹🇼 · Henry T. Wong🇹🇼 · Chih-Liang Wu🇹🇼 · Chih-Pan Wu🇹🇼
The electromagnetic properties of neutrinos, which are either trivial or negligible in the context of the Standard Model, can probe new physics and have significant implications in astrophysics and cosmology. The current best direct limits on the neutrino millicharges and magnetic moments are both derived from data taken with germanium detectors with low thresholds at keV levels. In this paper, we discuss in detail a robust, ab initio method: the multiconfiguration relativistic random phase approximation, that enables us to reliably understand the germanium detector response at the sub-keV level, where atomic many-body physics matters. Using existing data with sub-keV thresholds, limits on reactor antineutrino's millicharge, magnetic moment, and charge radius squared are derived. The projected sensitivities for next generation experiments are also given and discussed.
We study the survival probability of moving relativistic unstable particles with definite momentum . The amplitude of the survival probability of these particles is calculated using its integral representation. We found decay curves of such particles for the quantum mechanical models considered. These model studies show that late time deviations of the survival probability of these particles from the exponential form of the decay law, that is the transition times region between exponential and non-expo\-nen\-tial form of the survival probability, should occur much earlier than it follows from the classical standard approach resolving itself into replacing time by (where is the relativistic Lorentz factor) in the formula for the survival probability and that the survival probabilities should tend to zero as much slower than one would expect using classical time dilation relation. Here we show also that for some physically admissible models of unstable states the computed decay curves of the moving particles have fluctuating form at relatively short times including times of order of the lifetime.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.