Accurate masses and radii of normal stars: modern results and applications

This paper presents and discusses a critical compilation of accurate, fundamental determinations of stellar masses and radii. We have identified 95 detached binary systems containing 190 stars (94 eclipsing systems, and alpha Centauri) that satisfy our criterion that the mass and radius of both stars be known to 3% or better. To these we add interstellar reddening, effective temperature, metal abundance, rotational velocity and apsidal motion determinations when available, and we compute a number of other physical parameters, notably luminosity and distance. We discuss the use of this information for testing models of stellar evolution. The amount and quality of the data also allow us to analyse the tidal evolution of the systems in considerable depth, testing prescriptions of rotational synchronisation and orbital circularisation in greater detail than possible before. The new data also enable us to derive empirical calibrations of M and R for single (post-) main-sequence stars above 0.6 M(Sun). Simple, polynomial functions of T(eff), log g and [Fe/H] yield M and R with errors of 6% and 3%, respectively. Excellent agreement is found with independent determinations for host stars of transiting extrasolar planets, and good agreement with determinations of M and R from stellar models as constrained by trigonometric parallaxes and spectroscopic values of T(eff) and [Fe/H]. Finally, we list a set of 23 interferometric binaries with masses known to better than 3%, but without fundamental radius determinations (except alpha Aur). We discuss the prospects for improving these and other stellar parameters in the near future.Comment: 56 pages including figures and tables. To appear in The Astronomy and Astrophysics Review. Ascii versions of the tables will appear in the online version of the articl

Demonstration of the event identification capabilities of the NEXT-White detector

In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a 228Th calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 ± 1.5 stat± 0.3 sys% for a background acceptance of 20.6 ± 0.4 stat± 0.3 sys% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies. [Figure not available: see fulltext.

Energy calibration of the NEXT-White detector with 1% resolution near Q ββ of 136Xe

Excellent energy resolution is one of the primary advantages of electroluminescent high-pressure xenon TPCs. These detectors are promising tools in searching for rare physics events, such as neutrinoless double-beta decay (ββ0ν), which require precise energy measurements. Using the NEXT-White detector, developed by the NEXT (Neutrino Experiment with a Xenon TPC) collaboration, we show for the first time that an energy resolution of 1% FWHM can be achieved at 2.6 MeV, establishing the present technology as the one with the best energy resolution of all xenon detectors for ββ0ν searches. [Figure not available: see fulltext.

Radiogenic backgrounds in the NEXT double beta decay experiment

Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterráneo de Canfranc with xenon depleted in 136Xe are analyzed to derive a total background rate of (0.84±0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of 60Co, 40K, 214Bi and 208Tl to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25±0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5σ after 1 year of data taking. The background measurement in a Qββ±100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75±0.12) events. [Figure not available: see fulltext.]

Prospective associations between a priori dietary patterns adherence and kidney function in an elderly Mediterranean population at high cardiovascular risk.

PURPOSE: To assess the association between three different a priori dietary patterns adherence (17-item energy reduced-Mediterranean Diet (MedDiet), Trichopoulou-MedDiet and Dietary Approach to Stop Hypertension (DASH)), as well as the Protein Diet Score and kidney function decline after one year of follow-up in elderly individuals with overweight/obesity and metabolic syndrome (MetS). METHODS: We prospectively analyzed 5675 participants (55-75 years) from the PREDIMED-Plus study. At baseline and at one year, we evaluated the creatinine-based estimated glomerular filtration rate (eGFR) and food-frequency questionnaires-derived dietary scores. Associations between four categories (decrease/maintenance and tertiles of increase) of each dietary pattern and changes in eGFR (ml/min/1.73m2) or ≥ 10% eGFR decline were assessed by fitting multivariable linear or logistic regression models, as appropriate. RESULTS: Participants in the highest tertile of increase in 17-item erMedDiet Score showed higher upward changes in eGFR (β: 1.87 ml/min/1.73m2; 95% CI: 1.00-2.73) and had lower odds of ≥ 10% eGFR decline (OR: 0.62; 95% CI: 0.47-0.82) compared to individuals in the decrease/maintenance category, while Trichopoulou-MedDiet and DASH Scores were not associated with any renal outcomes. Those in the highest tertile of increase in Protein Diet Score had greater downward changes in eGFR (β: - 0.87 ml/min/1.73m2; 95% CI: - 1.73 to - 0.01) and 32% higher odds of eGFR decline (OR: 1.32; 95% CI: 1.00-1.75). CONCLUSIONS: Among elderly individuals with overweight/obesity and MetS, only higher upward change in the 17-item erMedDiet score adherence was associated with better kidney function after one year. However, increasing Protein Diet Score appeared to have an adverse impact on kidney health. TRIAL REGISTRATION NUMBER: ISRCTN89898870 (Data of registration: 2014)

Sortilin Participates in Light-dependent Photoreceptor Degeneration in Vivo

Both proNGF and the neurotrophin receptor p75 (p75NTR) are known to regulate photoreceptor cell death caused by exposure of albino mice to intense illumination. ProNGF-induced apoptosis requires the participation of sortilin as a necessary p75NTR co-receptor, suggesting that sortilin may participate in the photoreceptor degeneration triggered by intense lighting. We report here that light-exposed albino mice showed sortilin, p75NTR, and proNGF expression in the outer nuclear layer, the retinal layer where photoreceptor cell bodies are located. In addition, cone progenitor-derived 661W cells subjected to intense illumination expressed sortilin and p75NTR and released proNGF into the culture medium. Pharmacological blockade of sortilin with either neurotensin or the “pro” domain of proNGF (pro-peptide) favored the survival of 661W cells subjected to intense light. In vivo, the pro-peptide attenuated retinal cell death in light-exposed albino mice. We propose that an auto/paracrine proapoptotic mechanism based on the interaction of proNGF with the receptor complex p75NTR/sortilin participates in intense light-dependent photoreceptor cell death. We therefore propose sortilin as a putative target for intervention in hereditary retinal dystrophies

Electroluminescence TPCs at the thermal diffusion limit

[EN] The NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the 136Xe isotope using a high-purity xenon TPC. Efficient discrimination of the events through pattern recognition of the topology of primary ionisation tracks is a major requirement for the experiment. However, it is limited by the diffusion of electrons. It is known that the addition of a small fraction of a molecular gas to xenon reduces electron diffusion. On the other hand, the electroluminescence (EL) yield drops and the achievable energy resolution may be compromised. We have studied the effect of adding several molecular gases to xenon (CO2, CH4 and CF4) on the EL yield and energy resolution obtained in a small prototype of driftless gas proportional scintillation counter. We have compared our results on the scintillation characteristics (EL yield and energy resolution) with a microscopic simulation, obtaining the diffusion coefficients in those conditions as well. Accordingly, electron diffusion may be reduced from about 10 mm/ sqrt(¿) for pure xenon down to 2.5 mm/sqrt(m) using additive concentrations of about 0.05%, 0.2% and 0.02% for CO2, CH4 and CF4, respectively. Our results show that CF4 admixtures present the highest EL yield in those conditions, but very poor energy resolution as a result of huge fluctuations observed in the EL formation. CH4 presents the best energy resolution despite the EL yield being the lowest. The results obtained with xenon admixtures are extrapolated to the operational conditions of the NEXT-100 TPC. CO2 and CH4 show potential as molecular additives in a large xenon TPC. While CO2 has some operational constraints, making it difficult to be used in a large TPC, CH4 shows the best performance and stability as molecular additive to be used in the NEXT-100 TPC, with an extrapolated energy resolution of 0.4% at 2.45 MeV for concentrations below 0.4%, which is only slightly worse than the one obtained for pure xenon. We demonstrate the possibility to have an electroluminescence TPC operating very close to the thermal diffusion limit without jeopardizing the TPC performance, if CO2 or CH4 are chosen as additives.The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Marie Sklodowska-Curie Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economia y Competitividad of Spain under grants FIS2014-53371-C04, the Severo Ochoa Program SEV-2014-0398 and the Maria de Maetzu Program MDM-2016-0692; the GVA of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014, under project UID/FIS/04559/2013 to fund the activities of LIBPhys, and under grants PD/BD/105921/2014, SFRH/BPD/109180/2015 and SFRH/BPD/76842/2011; the U.S. Department of Energy under contracts number DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), DE-AC02-06CH11357 (Argonne National Laboratory), DE-FG02-13ER42020 (Texas A&M) and DE-SC0017721 (University of Texas at Arlington); and the University of Texas at Arlington. DGD acknowledges Ramon y Cajal program (Spain) under contract number RYC-2015-18820. We also warmly acknowledge the Laboratori Nazionali del Gran Sasso (LNGS) and the Dark Side collaboration for their help with TPB coating of various parts of the NEXT-White TPC. Finally, we are grateful to the Laboratorio Subterraneo de Canfranc for hosting and supporting the NEXT experiment.Henriques, CAO.; Monteiro, CMB.; Gonzalez-Diaz, D.; Azevedo, CDR.; Freitas, EDC.; Mano, RDP.; Jorge, MR.... (2019). Electroluminescence TPCs at the thermal diffusion limit. Journal of High Energy Physics (Online). 1:1-20. https://doi.org/10.1007/JHEP01(2019)027S1201NEXT collaboration, J. Martín-Albo et al., Sensitivity of NEXT-100 to neutrinoless double beta decay, JHEP 05 (2016) 159 [ arXiv:1511.09246 ] [ INSPIRE ].T. Brunner et al., An RF-only ion-funnel for extraction from high-pressure gases, Intern. J. Mass Spectrom. 379 (2015) 110 [ INSPIRE ].PANDAX-III collaboration, J. Galan, Microbulk MicrOMEGAs for the search of 0νββ of 136 Xe in the PandaX-III experiment, 2016 JINST 11 P04024 [ arXiv:1512.09034 ] [ INSPIRE ].D. Yu. Akimov, A.A. Burenkov, V.F. Kuzichev, V.L. Morgunov and V.N. Solovev, Low background experiments with high pressure gas scintillation proportional detector, physics/9704021 [ INSPIRE ].Yu. M. Gavrilyuk et al., A technique for searching for the 2K capture in 124 Xe with a copper proportional counter, Phys. Atom. Nucl. 78 (2015) 1563 [ INSPIRE ].D.R. Nygren, Columnar recombination: a tool for nuclear recoil directional sensitivity in a xenon-based direct detection WIMP search, J. Phys. Conf. Ser. 460 (2013) 012006 [ INSPIRE ].XENON collaboration, E. Aprile et al., First Dark Matter Search Results from the XENON1T Experiment, Phys. Rev. Lett. 119 (2017) 181301 [ arXiv:1705.06655 ] [ INSPIRE ].XENON100 collaboration, E. Aprile et al., Dark Matter Results from 225 Live Days of XENON100 Data, Phys. Rev. Lett. 109 (2012) 181301 [ arXiv:1207.5988 ] [ INSPIRE ].LUX collaboration, D.S. Akerib et al., Results from a search for dark matter in the complete LUX exposure, Phys. Rev. Lett. 118 (2017) 021303 [ arXiv:1608.07648 ] [ INSPIRE ].PandaX-II collaboration, X. Cui et al., Dark Matter Results From 54-Ton-Day Exposure of PandaX-II Experiment, Phys. Rev. Lett. 119 (2017) 181302 [ arXiv:1708.06917 ] [ INSPIRE ].EXO collaboration, J.B. Albert et al., Search for Neutrinoless Double-Beta Decay with the Upgraded EXO-200 Detector, Phys. Rev. Lett. 120 (2018) 072701 [ arXiv:1707.08707 ] [ INSPIRE ].KamLAND-Zen collaboration, A. Gando et al., Search for Majorana Neutrinos near the Inverted Mass Hierarchy Region with KamLAND-Zen, Phys. Rev. Lett. 117 (2016) 082503 [ arXiv:1605.02889 ] [ INSPIRE ].XMASS collaboration, K. Abe et al., Search for two-neutrino double electron capture on 124 Xe with the XMASS-I detector, Phys. Lett. B 759 (2016) 64 [ arXiv:1510.00754 ] [ INSPIRE ].XENON collaboration, E. Aprile et al., Search for two-neutrino double electron capture of 124 Xe with XENON100, Phys. Rev. C 95 (2017) 024605 [ arXiv:1609.03354 ] [ INSPIRE ].R. Lüscher et al., Search for ββ decay in 136 Xe: new results from the Gotthard experiment, Phys. Lett. B 434 (1998) 407 [ INSPIRE ].NEXT collaboration, P. Ferrario et al., First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment, JHEP 01 (2016) 104 [ arXiv:1507.05902 ] [ INSPIRE ].NEXT collaboration, D. Lorca et al., Characterisation of NEXT-DEMO using xenon K α X-rays, 2014 JINST 9 P10007 [ arXiv:1407.3966 ] [ INSPIRE ].NEXT collaboration, D. González-Díaz et al., Accurate γ and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atm, Nucl. Instrum. Meth. A 804 (2015) 8 [ arXiv:1504.03678 ] [ INSPIRE ].C.M.B. Monteiro et al., Secondary Scintillation Yield in Pure Xenon, 2007 JINST 2 P05001 [ physics/0702142 ] [ INSPIRE ].C.M.B. Monteiro, J.A.M. Lopes, J.F. C.A. Veloso and J.M.F. dos Santos, Secondary scintillation yield in pure argon, Phys. Lett. B 668 (2008) 167 [ INSPIRE ].E.D.C. Freitas et al., Secondary scintillation yield in high-pressure xenon gas for neutrinoless double beta decay (0νββ) search, Phys. Lett. B 684 (2010) 205 [ INSPIRE ].C.M.B. Monteiro et al., Secondary scintillation yield from gaseous micropattern electron multipliers in direct dark matter detection, Phys. Lett. B 677 (2009) 133 [ INSPIRE ].C.M.B. Monteiro, L.M.P. Fernandes, J.F. C.A. Veloso, C.A.B. Oliveira and J.M.F. dos Santos, Secondary scintillation yield from GEM and THGEM gaseous electron multipliers for direct dark matter search, Phys. Lett. B 714 (2012) 18 [ INSPIRE ].C. Balan et al., MicrOMEGAs operation in high pressure xenon: Charge and scintillation readout, 2011 JINST 6 P02006 [ arXiv:1009.2960 ] [ INSPIRE ].J.M.F. dos Santos et al., Development of portable gas proportional scintillation counters for x-ray spectrometry, X-Ray Spectrom. 30 (2001) 373.NEXT collaboration, J. Renner et al., Background rejection in NEXT using deep neural networks, 2017 JINST 12 T01004 [ arXiv:1609.06202 ] [ INSPIRE ].T. Himi et al., Emission spectra from Ar-Xe, Ar-Kr, Ar-N2, Ar-CH4, Ar-CO2 and Xe-N2 gas proportional scintillation counters, Nucl. Instrum. Meth. 205 (1983) 591.C.D.R. Azevedo et al., An homeopathic cure to pure Xenon large diffusion, 2016 JINST 11 C02007 [ arXiv:1511.07189 ] [ INSPIRE ].NEXT collaboration, C.A.O. Henriques et al., Secondary scintillation yield of xenon with sub-percent levels of CO 2 additive for rare-event detection, Phys. Lett. B 773 (2017) 663 [ arXiv:1704.01623 ] [ INSPIRE ].P.C.P.S. Simões, J.M.F. dos Santos and C.A.N. Conde, Driftless gas proportional scintillation counter pulse analysis using digital processing techniques, X Ray Spectrom. 30 (2001) 342.P.C.P.S. Simões et al., A new method for pulse analysis of driftless-gas proportional scintillation counters, Nucl. Instrum. Meth. A 505 (2003) 247.C.D.R. Azevedo et al., Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives, Nucl. Instrum. Meth. A 877 (2018) 157 [ arXiv:1705.09481 ] [ INSPIRE ].L.M.P. Fernandes et al., Primary and secondary scintillation measurements in a xenon Gas Proportional Scintillation Counter, 2010 JINST 5 P09006 [Erratum ibid. 5 (2010) A12001] [ arXiv:1009.2719 ] [ INSPIRE ].C.M.B. Monteiro et al., An argon gas proportional scintillation counter with UV avalanche photodiode scintillation readout, IEEE Trans. Nucl. Sci. 48 (2001) 1081.J.A.M. Lopes et al., A xenon gas proportional scintillation counter with a UV-sensitive large-area avalanche photodiode, IEEE Trans. Nucl. Sci. 48 (2001) 312.D.F. Anderson et al., A large area gas scintillation proportional counter, Nucl. Instrum. Meth. 163 (1979) 125.Z. Kowalski et al., Fano factor implications from gas scintillation proportional counter measurements, Nucl. Instrum. Meth. A 279 (1989) 567.S.J.C. do Carmo et al., Experimental study of the ω-values and Fano factors of gaseous xenon and Ar-Xe mixtures for X-rays, IEEE Trans. Nucl. Sci. 55 (2008) 2637.http://magboltz.web.cern.ch/magboltz/ (accessed 14.11.2016).T.H.V.T. Dias et al., Full-energy absorption of x-ray energies near the Xe L- and K-photoionization thresholds in xenon gas detectors: Simulation and experimental results, J. Appl. Phys. 82 (1997) 2742.D. Nygren, High-pressure xenon gas electroluminescent TPC for 0νββ-decay search, Nucl. Instrum. Meth. A 603 (2009) 337 [ INSPIRE ].NEXT collaboration, V. Álvarez et al., The NEXT-100 experiment for neutrinoless double beta decay searches (Conceptual Design Report), arXiv:1106.3630 [ INSPIRE ].NEXT collaboration, V. Álvarez et al., Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array, 2013 JINST 8 P09011 [ arXiv:1306.0471 ] [ INSPIRE ]