5th International Solar Neutrino Conference

11 Jun 2018, 08:00 → 15 Jun 2018, 18:00 Europe/Berlin

Dülfer Saal (TU Dresden)

5th International Solar Neutrino Conference

The 5th International Solar Neutrino Conference will take place in Dresden from June 11-14 2018. The scientific program will focus on solar neutrino physics with particular emphasis on running and future solar neutrino experiments, detection techniques, solar models, helioseismology, phenomenological aspects, neutrino oscillations and nuclear physics related to solar models. The year 2018 also marks the 50th anniversary of the first Homestake results. The conference lasting four days is going to feature both invited talks and a poster session. 

PhD students and young researchers are invited to contribute a poster with their recent research results. Talks are given by invited renowned experts of their field.

Credit: NASA

Associated to the international solar neutrino conference, a special programme for Alumni Germany is organized. Alumni Germany are international scientists who have spent at least three months in Germany, studying or working on research as doctoral candidates, post-doctoral researchers or at a more advanced career stage.

In addition to the scientific program, the TU Dresden is offering a frame program on the 14^th (afternoon) and 15^th of June.

The workshops and excursions within the frame program aim to introduce TU Dresden and the Alliance DRESDEN-concept, to support networking and to inspire exchange of collaboration ideas. Conference participants are very welcome to join for free.

Participants having this status can apply for financial support for their whole journey and stay. Further information can be found on the side menu.

The conference is supported by the DAAD (German Academic Exchange Service).

The conference poster can be found here.

 

 

Monday, 11 June

Registration

Welcome and Introduction

Convener: Prof. Kai Zuber (TU Dresden)

slides 2018-06-11_101_Welcome_kzuber.pdf

50th anniversary of the first Homestake results

slides 2018-06-11_102_Homestake_klande.pdf

1 The Homestake Solar Neutrino Detection Experiment

It is now a half century since Raymond Davis first announced his startling results – the observed flux of electron neutrinos from the Sun was much smaller than predicted by model. Of course, the most impressive early result of this experiment was that neutrinos emitted by the Sun were detected and that this signal was visible above the background. Over three decades this initial “discovery” observation evolved into a fairly precise, 5% statistical uncertainty, measurement. This observation had three impressive results, (1) it was the first detection of neutrinos from a non-terrestrial source, (2) it experimentally demonstrated that the Sun was powered by hydrogen fusion into helium, and (3) it provided the first indication that the electron neutrinos emitted by the Sun converted into other neutrino species during their flight from Sun to Earth. This talk will review some of the steps and obstacles involved in carrying out this thirty year observation and the resulting conclusions.

Speaker: Prof. Kenneth Lande (University of Pennsylvania)

Slides 2018-06-11_102_Homestake_klande.pdf

10:30 Coffee Break

Solar Models and Experiments

Convener: Mr Aldo Serenelli (Institute of Space Sciences (ICE/CSIC-IEEC))

2 THE SOLAR CHEMICAL COMPOSITION: PAST and PRESENT

We shall briefly recall what we knew 50 years ago concerning the solar chemical composition. Solar abundances at that time were sometimes called “cosmic abundances” as they were thought to apply to all astronomical objects! We shall then discuss the present solar chemical composition derived from the photospheric spectrum thanks to the use of 3D photospheric models, with non-LTE, using all the indicators, atoms and molecules. These new results will be compared with older results and we will show why the new abundances of the most abundant elements (O, C, …) are lower than the old values. The present solar abundances will also be compared with other sources of data like spectroscopic measurements of the corona, observations of solar particles from the two solar wind regimes, solar energetic particles as well as meteorites. Some of the data from these outer solar sources are especially important to derive the solar abundance of Neon! We shall finally very briefly mention the impact of the new solar chemical composition on the solar models (details will be given in other talks) i.e. what was first called “the solar abundance problem”, then modified to “the solar modelling problem”. And finally why not again modified to “the solar opacity problem”! Who knows?

Speaker: Dr Nicolas Grevesse (Centre Spatial de Liege)

Slides 2018-06-11_201_solar-composition_ngrevesse.pdf

3 Helioseismology and solar neutrinos

Analysis of solar neutrinos and studies of the solar interior by means of helioseismology, based on observed solar oscillations, have had a close interplay over many decades. Early calculations of solar oscillations were motivated by a proposed mixing mechanism to reduce (temporarily) the flux of electron neutrinos from the solar core. Early observations of solar oscillations showed that the observed frequencies were inconsistent with proposed non-standard models with a reduced neutrino flux, pointing towards a non-astrophysical solution to the observed neutrino deficit. With increasingly tight helioseismic constraints on solar structure this strongly supported the search for a solution involving neutrino-flavour changes, triumphantly realized with the SNO observations. Given the increasingly tightly constrained neutrino properties, from independent measurements, the observed neutrino fluxes can now (finally) contribute to our knowledge about conditions in the solar core, in a manner that complements helioseismic investigations.

Speaker: Prof. Jørgen Christensen-Dalsgaard (Stellar Astrophysics Centre, Aarhus University)

Slides jcd

4 Monte Carlo simulation in solar neutrino experiments

Monte Carlo simulations have continuously increased their importance in solar neutrino physics. Nowadays they play a crucial role in the interpretation of acquired data. Consequently the understanding and a proper modelling of the detector response is a key point for a successful experiment. Recent Borexino updates show in a clear way how precision measurements can benefit from a reliable detector simulation. After a brief introduction to the similarities and the peculiarities of the Monte Carlo codes of several recent solar neutrino experiments, this talk will highlight the important aspects to take into account using the Borexino experiment as a test case. Particular emphasis will be given to a novel efficient method for simulating external background events surviving passive shielding. This technique allows to reliably predict the effect in the final spectrum of the contaminants present in the construction materials and can be very useful for the next generation of liquid scintillator experiments.

Speaker: Dr Alessio Caminata (INFN Genova)

Slides SolarNeutrinoConference.pdf

13:00 Lunch Break

Nuclear Astrophysics

Convener: Prof. Jørgen Christensen-Dalsgaard (Stellar Astrophysics Centre, Aarhus University)

5 3He(3He,2p)4He and 3He(alpha,gamma)7Be

TBA

Speaker: Prof. Gianluca Imbriani (Physics Department, University of Naples Federico II and INFN section of Naples)

Slides 2018-Dresda-imbriani.pptx

6 Study of 2H(p,gamma)3He cross section over a wide energy range

Nuclear reactions involving few-nucleon systems are relevant both in stellar environments and during Big Bang Nucleosynthesis (BBN) when, soon after the Big Bang, light elements were produced. This phenomenon can be described by a theoretical model (BBN theory) that requires as input the cross section of the nuclear reactions involved in the formation of the light elements, as well as cosmological and standard physics input, and produce as output the prediction for the light nuclei abundances. From the comparison of such prediction with astronomical observational data an indirect test of both cosmological and fundamental physics models comes out. In the case of deuterium, the abundance derived by recent observations is characterized by a much smaller uncertainty than that predicted by BBN theory and a small tension between the two values exists. The uncertainty on the BBN prediction is dominated by that on the 2H(p,gamma)3He cross section poorly known in the BBN energy range. In this talk, I will report on two recent measurements of such cross section done at the LUNA 400 kV accelerator in the underground Gran Sasso Laboratory and at the 3MV Tandetron accelerator in HZDR, respectively. The two measurements were performed using different experimental setups and cover, as a whole, the energy range 50-800 keV.

Speaker: Prof. Alessandra Guglielmetti (Università degli Studi di Milano and INFN Milano)

Slides guglielmetti_Dresden_2018.pptx

7 Investigation of the 3He(α,γ)7Be reaction using the Asymptotic Normalization Coefficient technique

The 3He(α,γ)7Be reaction plays an important role in several astrophysical scenarios including stellar hydrogen burning and Big Bang nucleosynthesis [1]. Contrary to its importance – and despite the large number of experimental and theoretical works devoted to this reaction (e.g. [2,3,4] and further references therein) – the knowledge on the reaction cross section at the relevant energies is still limited and further experimental efforts are needed [5,6]. The precise knowledge on the external capture contribution to the 3He(α,γ)7Be reaction cross section is of crucial for the theoretical description reaction mechanism. Therefore, the aim of the present work is to measure this direct contribution using the Asymptotic Normalization Coefficient technique [7] and through this to improve our knowledge on the reaction rate at the temperatures of the solar core. To extract the 3He(α,γ)7Be reaction cross section, the angular distribution of deuterons emitted in the 6Li(3He,d)7Be α-transfer reaction was measured with high precision at several energies. The experimental details and the preliminary results are planned to be presented. [1] C. Iliadis, Nuclear Physics of Stars (New York: Wiley) (2007). [2] D. Bemmerer et al., Phys. Rev. Lett. 97 (2006) 122502. [3] A. Di Leva et al., Phys. Rev. Lett. 102 (2009) 232502. [4] T. Neff, Phys. Rev. Lett. 106 (2011) 042502. [5] E. G. Adelberger et al., Rev. Mod. Phys. 83 (2011) 195. [6] R. J. deBoer et al., Phys. Rev. C 90 (2014) 035804. [7] H. M. Xu el al., Phys. Rev. Lett. 73 (1994) 2027.

Speaker: Gabor Kiss (MTA Atomki)

Slides 2018-06-11_303_helium-reaction_gkiss.pptx

8 New direct measurement of the 6Li(p,gamma)7Be cross section at LUNA

The $^{6}$Li(p,$\gamma$)$^{7}$Be reaction is involved in many astrophysical scenario, ranging from Big Bang Nucleosynthesis to pre-main sequence stellar evolution and solar neutrino. At astrophysical energies, proton capture on $^{6}$Li proceeds through the $^{6}$Li(p,$\alpha$)$^{3}$He and the $^{6}$Li(p,$\gamma$)$^{7}$Be reactions. The $^{6}$Li(p,$\alpha$)$^{3}$He cross section is well known from the literature, but the measured angular distribution can only be explained introducing positive parity excited states of $^{7}$Be in addition to the known negative parity levels. Although the existence of positive parity excited states in $^{7}$Be has never been confirmed experimentally, a recent measurement of the $^{6}$Li(p,$\gamma$)$^{7}$Be cross section revealed a resonance-like structure at center of mass energy of 195 keV. The observed S-factor could be reproduced introducing a new $^{7}$Be excited state with E $\approx$ 5800 keV and J$^{\pi}$ = (1/2$^{+}$, 3/2$^{+}$). The existence of such excited state might also affect the cross section of the $^{3}$He($^{4}$He,$\gamma$)$^{7}$Be reaction and, consequently, the estimated flux of $^{7}$Be solar neutrino. A new measurement of the $^{6}$Li(p,$\gamma$)$^{7}$Be cross section at proton energies between 50 and 400 keV has been performed at the Laboratory for Underground Nuclear Astrophysics. The poster provides a description of the experimental setup and shows preliminary results of the data analysis.

Speaker: Dr Rosanna Depalo (INFN - Sezione di Padova)

Slides Depalo_ISNC.pdf

Poster Session

Poster Session with snacks and drinks

9 Solar neutrino based redetermination of the 7Be(p,gamma)8B S-factor

Among the solar fusion reactions, the rate of the $^7$Be($p,\gamma$)$^8$B reaction is one of the most difficult to determine. In a number of previous experiments, its astrophysical $S$-factor has been measured at $E$ = 0.1-2.5 MeV center-of-mass energy. However, no experimental data are available below 0.1 MeV. Thus, an extrapolation to solar energies is necessary, resulting in significant uncertainty for the extrapolated $S$-factor. On the other hand, the flux of solar neutrinos has been recently measured with high precision, which provides an opportunity to turn the problem of the $S$-factor determination around: Using the measured $^7$Be and $^8$B neutrino fluxes, and the Standard Solar Model, the $^7$Be($p,\gamma$)$^8$B astrophysical $S$-factor is determined here at the solar Gamow peak.

Speaker: Dr Marcell Peter Takacs (Physikalisch-Technische Bundesanstalt)

10 CASPAR – Nuclear Astrophysics Underground at SURF

Fifty years after the first publication of results of the Homestake experiment to detect solar neutrinos, the Sanford Underground Research Facility (SURF) hosts various facil- ities for astrophysics experiments deep underground in the Homestake mine. The Ross Campus, located at a depth of 4850 ft (4300 m.w.e.), is home to the Compact Accelerator System for Performing Astrophysical Research (CASPAR), which has recently taken up regular operation. The single-ended accelerator at CASPAR with a terminal voltage of up to 1 MV allows to study proton- and alpha-induced reactions for nuclear astrophysics at higher energies than those previously available in underground experiments. After an initial phase of (p,γ) reaction studies for commissioning and characterization of the machine, the next set of measurements at CASPAR will be dedicated to the study of (α,n) reactions, such as the neutron sources for the astrophysical s-process. In this poster we will present an overview of CASPAR’s commissioning, current status and scientific program.

Speaker: Mr Axel Böltzig (Universitiy of Notre Dame)

11 The Internal and External Ion Sources for the Felsenkeller Underground Accelerator

In order to determine the cross sections of astrophysical reactions at relevant energies pioneering work has been done at LUNA using a 0.4 MV accelerator. The new Felsenkeller laboratory, Germany, will house a 5 MV Pelletron accelerator with stable and intense ion beams in a low background environment to extend on this framework. For this purpose two ion sources are going to be part of the shallow-underground accelerator facility: First an external 134 MC-SNICS cesium sputter source providing carbon beams in tandem mode, secondly an internal radio frequency source for hydrogen and helium beams in single-ended mode. In order to determine the characteristics of these ion sources, overground tests were undertaken at HZDR. This poster will report on long time measurements of the ion current for both ion sources and the beam emittance for the external one.

Speaker: Mr Marcel Grieger (Helmholtz-Zentrum Dresden-Rossendorf)

12 Background studies with actively vetoed germanium gamma-ray detector in Felsenkeller tunnels VIII and IX

A new underground accelerator facility is being built in tunnels VIII and IX of the Dresden Felsenkeller. Previous $\gamma$-ray background measurements in another part of the tunnel system showed suitable conditions for in-beam nuclear astrophysics experiments [1,2] using germanium detectors with active veto against the cosmic-ray muons. These stable ion beam experiments are of high importance to understand the reactions of the stellar burning phases, and in particular the solar fusion reactions. The new laboratory is now ready to host measurements mapping the background conditions. This work reports on the measured background in actively vetoed $\gamma$-ray detector at the place of the target station in the laboratory used for the upcoming experiments. [1] T. Szücs et al., Eur. Phys. Jour. A 48 (2012) 8. [2] T. Szücs et al., Eur. Phys. Jour. A 51 (2015) 33.

Speaker: Dr Tamás Szücs (Helmholtz-Zentrum Dresden-Rossendorf)

13 LOREX - Geochemical Detection of the pp-Neutrino flux with 205Tl

LOREX (LORandite EXperiment) [1] is based on determining the solar (pp) neutrino flux for the period of 4.31(2) My from the reaction 205Tl + ve →205Pb + e-, the lowest threshold (52 keV) for neutrino capture. For this purpose, one employs the naturally occurring lorandite (TlAsS2) minerals. The goals of LOREX [2] are (i) to determine the probability for capturing Solar neutrinos on 205Tl leading to the first excited state in 205Pb, (ii) to collect sufficient amount, around several kilograms, of lorandite and to determine background contributions producing 205Pb, (iii) to chemically extract Pb from lorandite, and (iv) finally to determine the ratio of 205Pb/205Tl. (i) The weak interaction matrix element for the transition of interest will be determined through the bound-state beta decay of fully-ionized 205Tl81+ ions [3]. The measurements will be conducted at the experimental storage ring ESR at GSI and are planned for 2018. The experiment is supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 682841 “ASTRUm”); (ii) The collection of lorandite is ongoing at the Allchar mine in FYR Macedonia. The background 205Pb atoms are predominantly produced via fast-muon-induced reactions, which depend critically on the paleo-depth of lorandite including the eroded layer over 4.3 My. The paleo-depth is obtained by using cosmogenic nuclides. (iii) Identification of the 205Pb nuclei in the lead sample extracted from the lorandite mineral requires 10-10 to 10-11 overall detection sensitivity for 205Pb/Pb and a comparable suppression of the 205Tl isobar. Therefore, a chemical extraction of Pb from lorandite is foreseen. (iv) The determination of the 205Pb/205Tl ratio will be done with the storage-ring mass spectrometry, which is sensitive to single ions. Pilot experiments are planned at RIKEN-RIBF ion-beam factory in Japan as well as at the GSI accelerator facility. In this contribution we will present the present status of the LOREX project and outline the future steps to finally achieving the major objective of the project, namely the determination of the solar pp-neutrino flux integrated over the last 4.31(2) My. References [1] M.K. Pevićević et al., Nucl. Instr. and Meth. A 271, 287 (1988). [2] M.K. Pevićević et al., Nucl. Instr. and Meth. A 621, 278 (2010). [3] Yu. A. Litvinov and F. Bosch, Rep. Prog. Phys. 74, 016301 (2011).

Speaker: Mr Ragandeep Singh Sidhu (GSI Darmstadt)

14 New direct measurement of the 6Li(p,gamma)7Be cross section at LUNA

The $^{6}$Li(p,$\gamma$)$^{7}$Be reaction is involved in many astrophysical scenario, ranging from Big Bang Nucleosynthesis to pre-main sequence stellar evolution and solar neutrino. At astrophysical energies, proton capture on $^{6}$Li proceeds through the $^{6}$Li(p,$\alpha$)$^{3}$He and the $^{6}$Li(p,$\gamma$)$^{7}$Be reactions. The $^{6}$Li(p,$\alpha$)$^{3}$He cross section is well known from the literature, but the measured angular distribution can only be explained introducing positive parity excited states of $^{7}$Be in addition to the known negative parity levels. Although the existence of positive parity excited states in $^{7}$Be has never been confirmed experimentally, a recent measurement of the $^{6}$Li(p,$\gamma$)$^{7}$Be cross section revealed a resonance-like structure at center of mass energy of 195 keV. The observed S-factor could be reproduced introducing a new $^{7}$Be excited state with E $\approx$ 5800 keV and J$^{\pi}$ = (1/2$^{+}$, 3/2$^{+}$). The existence of such excited state might also affect the cross section of the $^{3}$He($^{4}$He,$\gamma$)$^{7}$Be reaction and, consequently, the estimated flux of $^{7}$Be solar neutrino. A new measurement of the $^{6}$Li(p,$\gamma$)$^{7}$Be cross section at proton energies between 50 and 400 keV has been performed at the Laboratory for Underground Nuclear Astrophysics. The poster provides a description of the experimental setup and shows preliminary results of the data analysis.

Speaker: Dr Rosanna Depalo (INFN - Sezione di Padova)

15 Ambient Neutron Background in the Shallow-Underground Laboratory Felsenkeller

One important component of the ambient background in underground laboratories are neutrons, which may cover a wide energy range from thermal up to 100 MeV and may affect γ-ray spectra for example by capture and inelastic scattering processes. Underground with more than a few meters rock overburden, cosmic-ray neutrons are removed, and the remaining flux is due to neutron production by cosmic-ray muons and by (α,n) reactions caused by natural radioactivity in the rock. There are only a few measurements of the spectral neutron flux underground available in the literature, a fact which hampers comparisons between laboratories and negatively affects the planning of future experiments. In an effort to overcome this problem, a setup consisting of moderated and one unmoderated 3 He neutron counters that has already been used at a depth of 850 m in the Canfranc underground laboratory, Spain [1], was utilized to study the neutron flux in the 47 m deep Felsenkeller underground laboratory, Germany. At Felsenkeller, one more counter with a lead liner was added in order to address also the high-energy flux up to several hundreds of MeV. The contribution will describe the Monte Carlo modeling of the neutron detectors, its validation with calibrated neutron sources, the spectral deconvolution of the neutron flux, and the final neutron flux data. Potential normalization issues in previous measurements will be discussed. The experimental neutron flux data at Felsenkeller are matched by a Monte Carlo simulation starting from the measured muon flux (for the muon-induced neutrons) and the known ambient radioactivity of the rock and construction materials (for the (α,n) neutrons). The present data have influenced the planning of the new laboratory hosting the 5 MV Pelletron ion accelerator in Felsenkeller. [1] D. Jordan et al., Astropart. Phys. 42, 1 (2013).

Speaker: Mr Thomas Hensel (Helmholtz-Zentrum Dresden-Rossendorf)

16 Measurement of the 3He(α,γ)7Be gamma-ray angular distribution

The $^3$He($\alpha,\gamma$)$^7$Be reaction affects the nucleosynthesis of $^7$Li as well as the predicted solar $^7$Be and $^8$B neutrino fluxes. It is being studied over a wide energy range at the Rossendorf 3$\,$MV Tandetron accelerator, with a focus on the measurement of the $\gamma$-ray angular distribution at E$\,\approx\,$1$\,$MeV. There are multiple and overlapping precise experimental data sets at E$\,$=$\,$0.7$\,$-$\,$1.3$\,$MeV. Any extrapolation of this precise data down to a unique data set from an experiment of the LUNA collaboration at E$\,$=$\,$0.09$\,$MeV$\,$-$\,$0.13$\,$MeV has to deal with the fact that at E$\,$=$\,$1$\,$MeV, the capture is possible both from s-wave incident particles and from d-wave incident particles, whereas at 0.1$\,$MeV and lower the d-wave component plays no role due to the angular momentum barrier. A measurement of the angular distribution of the emitted $\gamma$-rays at E$\,$=$\,$1$\,$MeV may constrain the relative contributions of s-wave and d-wave components at high energies and thus enable a better comparison between the high-energy and the low-energy data points. Data from a first run for the angular distribution of the emitted prompt $\gamma$-rays in the $^3$He($\alpha,\gamma$)$^7$Be reaction was done using a setup of four HPGe detectors at various angles and shall be presented here.

Speaker: Mr Steffen Turkat (IKTP, TU Dresden)

17 Germanium-detector based study of the 2H(p,γ)3He cross section at LUNA

Recent, precise measurements of the primordial 2 H abundance [1] have opened the possibility to precisely determine of the primordial baryon-to-photon ratio, independent from the cosmic microwave background. For their interpretation, the 2 H abundance data require equally precise nuclear data, in particular on the 2H(p,γ)3He reaction. Deep underground in the Gran Sasso laboratory, Italy, the LUNA collaboration is undertaking a dedicated effort to measure the 2H(p,γ)3He cross section directly in the Big Bang energy window of interest. The campaign is divided in two phases based on a BGO and a high-purity germanium (HPGe) detector, respectively. The present poster will report on the second, HPGe-based phase of the experiment. Due to the Doppler shift of the emitted γ-rays, in addition to the absolute yield also in- formation on the γ -ray angular distribution, thus reducing the systematic uncertainty. The characterization and calibration of the setup and detectors, background conditions, and potential sources of uncertainty will be discussed. References [1] R. J. Cooke, M. Pettini, R. A. Jorgenson, M. T. Murphy, and C. C. Steidel, Astrophys. J. 781, 31 (2014).

Speaker: Mr Klaus Stöckel (HZDR)

18 Muon flux measurement in the shallow-underground laboratory Felsenkeller

Muons, which are produced by cosmic rays in the atmosphere, are highly penetrating and are only mitigated by the roughly $50\,$m of rock above the shallow underground laboratory Felsenkeller in Dresden, Germany, which will be used for the study of reactions happening in the sun. In order to determine the precise flux and angular distribution amount of muons reaching the tunnels of Felsenkeller, a portable muon detector developed and built by the REGARD group [1] was employed. Data have been taken at four positions in Felsenkeller tunnels VIII and IX, where the new $5\,$MV accelerator will be hosted, and in addition for reference at three positions in Felsenkeller tunnel IV. At each position, seven different orientations of the detector were used to compile a map of the upper hemisphere. The measured muon flux data are compared with a GEANT4 simulation using the known shape and density of the local rock cover. **References** [1] D. Varga, G. Kiss, G. Hamar, and G. Bencedi, Nucl. Inst. Meth. A 698, 11 (2013).

Speaker: Felix Ludwig (Helmholtz-Zentrum Dresden-Rossendorf)

19 Filling the gap: the solar neutrino flux at keV energies

In the last few decades we have entered a new era in neutrino observations, from cosmic neutrino background detection proposals to high energy neutrinos astronomy. As theorists, we have to provide the expected flux at different energies. In this poster, I will present a previous overlooked contribution to the "grand unified neutrino spectrum" at Earth: the Solar neutrino thermal flux at keV energies. Besides being a signal, such a flux would also be the background for a futuristic keV sterile neutrino direct detection experiment. I will review the processes contributing to this spectrum, with particular emphasis on thermal effects due to the presence of a plasma.

Speaker: Mr Edoardo Vitagliano (Max Planck Institute for Physics)

20 Study of the 2H(p,γ)3He cross section at E_p = 400-800 keV

The amount of deuterium produced in Big Bang Nucleosynthesis depends sensitively on cosmological parameters such as the baryon energy density and the effective number of neutrino species. The recently improved precision of astronomical measurements of the primordial deuterium abundance [1] calls also for more precise nuclear data. Currently, the precision of the Big Bang abundance prediction of ²H is limited to the uncertainty of ²H destruction in the ²H(p,γ)³He reaction. The same nuclear reaction also affects Big Bang production of ⁷Li and plays a role in solar physics. The present contribution reports on an experimental study of the ²H(p,γ)³He cross section at energies of E_p = 400-800 keV, recently performed at the HZDR 3 MV Tandetron accelerator in Dresden, Germany. [1] R. J. Cooke, M. Pettini, R. A. Jorgenson, M. T. Murphy, and C. C. Steidel, Astrophys. J. 781, 31 (2014).

Speaker: Mr Sebastian Hammer (HZDR Dresden-Rossendorf)

21 Introduction to COMET Phase-I Experiment

COMET is an experiment to search for neutrino-less μ− - e− conversion in a field of aluminum nucleus, which is a charged Lepton Flavor Violation process. In COMET Phase-I, a single event sensitivity (SES) is expected to be 3 × 10^−15 which is a factor of 100 times better than the current world’s limit. This poster will explain the physics motivation the principle of the COMET experiment.

Speaker: Mr Sam Wong Ting

Tuesday, 12 June

From Radiochemical to Real-time Detection of Solar Neutrinos: GALLEX, Borexino and SNO+

Convener: Prof. Kenneth Lande (University of Pennsylvania)

22 GALLEX/GNO: Context and recollections

The pioneering Homestake Chlorine Solar Neutrino Experiment of Ray Davis detected only at a level of about 1/3 of what was roughly expected from the Standard Solar Model for B8-neutrinos. This established the "Solar Neutrino Problem" (SNP). The deficit could have been caused either: - by deviations due to an incomplete or false description of the solar interior by the standard solar model (SSM) and/or by inaccurate input parameters: - astrophysical solution of the SNP – or: - by non-standard neutrino properties: - particle physics solution of the SNP - (like, e.g. non-zero neutrino mass at the root of neutrino flavor oscillations). If a significant deficit would be observed for pp-neutrinos, one could rule out the astrophysical solution since their flux at origin is directly fixed to the well-known solar luminosity. pp-neutrinos are by far the most abundant solar neutrinos, yet their energy is very low (<420 keV). This demands a detection reaction with very low threshold. The only practical option was Ga71(v, e-)Ge71. The GALLEX experiment, a big technological challenge, was the solution. Here I will recall in the historical context the GALLEX/GNO discovery of solar pp-neutrinos in 1992 and the first assurance of non-zero neutrino mass (most probably related to neutrino flavor oscillations). GALLEX/GNO collected observational solar neutrino data at the Laboratori Nazionali del Gran Sasso (LNGS) from 5/1991 through 4/2003. I will summarize the milestones of the project and connect them with some personal recollections.

Speaker: Prof. Till Kirsten (Max-Planck-Institut für Kernphysik)

Slides Kirsten_Dresden__latest_issue.pdf Kirsten_Dresden__latest_issue.pptx

23 Solar neutrino spectroscopy in Borexino

In more than 10 years of operation, Borexino has performed a precision measurement of the solar neutrino spectrum, resolving almost of all spectral components originating from the proton-proton fusion chain. The presentation will review the results recently released for the second data taking phase 2012-16 during which the detector excelled by its unprecedentedly low background levels and enhanced time stability. I will discuss not only absolute measurements of the neutrino fluxes and corresponding neutrino oscillation probabitilies but also the annual modulation analysis of the Be-7 neutrino signal as well as new experimental limits on the neutrino magnetic moment.

Speaker: Prof. Michael Wurm (JGU Mainz)

Slides wurm_borexino_solarnu_jun18.pdf

24 The SNO+ experiment

SNO+ is a large liquid scintillator based experiment located in the SNOLAB underground laboratory in Sudbury, Canada. The SNO+ experiment uses the 12 m diameter acrylic vessel as well as the PMT array of the SNO detector, with several upgrades necessary to fill with liquid scintillator. The main physics goal of SNO+ is the search for the neutrinoless double-beta (0n2b) decay with 130Te. During the initial double-beta phase, the liquid scintillator will be loaded with 0.5% natural tellurium, corresponding to 1330 kg of 130Te. SNO+ sensitivity to the effective Majorana neutrino mass will begin to explore the parameter space in the inverted hierarchy region. Higher Te loading are being developed and a SNO+ Phase II would extend sensitivity to the entire inverted hierarchy region. Designed as a general purpose neutrino experiment, the low background levels and the low thresholds will allow to additionally measure the reactor neutrino oscillations, geo-neutrinos in a geologically-interesting location, watch for supernova neutrinos, and measure the low energy solar neutrinos, like low energy 8B, pep and CNO. This talk will focus on the current status of the SNO+ experiment, its sensitivity, and in particular the solar and supernova neutrino measurements. This work is supported by FCT.

Speaker: Dr Valentina Lozza (LIP Lisboa)

Slides LozzaV_seminar_DD18_V4.pdf

10:30 Coffee Break

CNO Cycle: Theoretical Aspects and Experimental Perspectives: Solar abundance problem, nuclear reactions, experimental perpectives at Borexino and Jinping

Convener: Prof. Yoichiro Suzuki (Kavli Institute for the Physics and Mathematics of the Universe)

25 Quantitative analysis of the solar abundance problem

I will perform a quantitative analysis of the solar abundance problem. I will discuss the properties of the Sun that can be constrained by solar neutrino fluxes and helioseismic observables. I will consider, in particular, the helioseismic and neutrino constraints on the opacity profile of the Sun and the degeneracy between effects produced by chemical composition and opacity modifications. I will then comment on the importance of neutrinos produced within the CN-NO cycle (CNO and ecCNO neutrinos) and on the perspectives for their detection.

Speaker: Prof. Francesco Villante (Università dell'Aquila and INFN-LNGS)

Slides 2018-06-12_201_solar-abundance_fvillante.pdf

26 Experimental Study of thermonuclear reaction for the CNO cycle

The CNO cycle is not the main responsible for the production of energy in the Sun, but it is much more relevant for the production of the Solar neutrinos. Among the all different cycles of the CNO there are several reactions that have an important role and have to be studied deeply, especially the reactions that works as bridge between different cycles (for example 15N(p,gamma)16O, 17O(p,gamma)18F, and 17O(p,alpha)14N) and of course the bottleneck of the CN cycle: the 14N(p,gamma)15O reaction. This is one of the main nuclear ingredients to calculate the neutrinos production from the Sun. It has been studied by many direct experiments during years, but still, to solve the so called solar composition problem, new data are requested. In particular, the uncertainties on its S-factor have to be lowered from the 8%, quoted by the recent database (Adelberger et al. 2011) to what requested by Solar models (5%). The previous experiments performed on this reaction together with measurements planned in the future will be presented in this contribution. For the reactions involved in the other CNO-cycles the studies performed at LUNA will be presented with comparison with other facilities.

Speaker: Dr Antonio Caciolli (University of Padova)

Slides Caciolli-CNO-Dresden-2018.pdf

27 Perspectives for CNO neutrino detection in Borexino

Borexino measured with unprecedented accuracy the fluxes of solar neutrinos emitted at all the steps of the pp fusion chain. Still missing is the measurement of the flux of neutrinos produced in the CNO cycle. A positive measurement of the CNO neutrino flux is of fundamental importance for understanding the evolution of stars and addressing the unresolved controversy on the solar abundances. The measurement of the CNO neutrino flux in Borexino is challenging because of the low intensity of this component (CNO cycle accounts for about 1% of the energy emitted by Sun), the lack of prominent spectral features and the presence of background sources. The main background component is $^{210}$Bi decay in the liquid scintillator of Borexino that creates events with an energy distribution very close to the one of CNO neutrino interactions. The talk will discuss the efforts to constrain the rate of $^{210}$Bi and the projected sensitivity for the discovery of a CNO signal.

Speaker: Mr Daniele Guffanti (Gran Sasso Science Institute & INFN LNGS)

Slides 5ISNC-CNOprospects_Guffanti.pdf

28 The Prospect of Solar Neutrino Study of the Jinping Neutrino Experiment

Solar neutrino experiments triggered almost all modern neutrino oscillation experiments and neutrino astrophysics research. The solar neutrino oscillation assumption is still missing two experimental evidence, i.e. the transition of matter dominated oscillation from high energy to vacuum oscillation at low energy, and a clear day-night difference due to the Earth matter effect. The standard solar model is also not experimentally complete since the neutrinos from carbon-nitrogen-oxygen fission cycle is not observed yet. The high-low metallicity problem presents a new challenge to the solar evolution model. Jinping underground laboratory has an overburden of 2400 meter of rock and is an ideal site for low background solar neutrino experimental research. In this talk, the Jinping laboratory, the proposed Jinping neutrino experiment, and the physics prospect will be discussed. The recent progress on detector R&D will also be presented.

Speaker: Dr Zhe Wang (Tsinghua University)

Slides JinpingNeutrino-ZheWang.pdf

13:00 Lunch Break

Solar Flare Neutrinos and Neutrino Measurements

Convener: Prof. Vladimir Gavrin (INR RAS)

29 Magnetic moment of the neutrino

A short review of theory and phenomenology of neutrino electromagnetic properties is given. The general structure of the Dirac and Majorana neutrinos electromagnetic interactions is discussed. Constraints on neutrino magnetic moments from the terrestrial laboratory experiments and astrophysical observations are reviewed. Special credit is done to bounds obtained by the reactor (MUNU, TEXONO and GEMMA) and solar Super-Kamiokande and the Borexino, and the recent COHERENT experiments. The best world experimental bounds on neutrino magnetic moments are confronted with predictions of theories beyond the Standard Model. The history and present status of neutrino spin and spin flavor oscillations induced by the neutrino magnetic moment interaction with a magnetic field is reviewed. The importance of neutrino spin oscillations for neutrino phenomenology in astrophysics is underlined. We also discuss a new effect of neutrino magnetic moment interaction with the transversal magnetic field on neutrino flavor oscillations. The prospects in studies of neutrino magnetic moments with future large-volume liquid-scintillator detectors experiments are discussed.

Speaker: Prof. Alexander Studentikin (Moscow State University and JINR-Dubna)

Slides 2018-06-12_301_nu-magnetic-moment_astudentikin.pdf

30 Nuclei as Neutrino Detectors

Neutrinos make reactions with nuclei by means of neutral current (NC) as well as charged current (CC). In nuclear physics, the reactions caused by the NC are called "inelastic scattering (IE scattering)." On the other hand, those caused by the CC are named "charge-exchange reaction (CE reaction)." Since leptons have small mass and cannot bring in (or carry out) large angular momentum, the so-called "allowed transitions" are caused by the operators with \Delta L =0 nature. They are the Fermi and Gamow-Teller transitions caused by the operators \tau [isospin operator: isovector (IV) current] and \sigma \tau [spin-isospin operator: axial-IV current], respectively. The NC-type neutrino-induced reactions are caused by the axial-IV current, while CC-type reactions can be caused by the axial-IV current and also by the IV current. We examine the properties of nuclear excitations caused by these currents for the p-shell (mass number A= 5-16) and also sd-shell nuclei (A= 17-40) with the z-component of isospin T_{z} = 0, \pm 1/2, and also \pm 1. We seek the possible use of some of these nuclei as neutrino detectors. The high energy-resolution (3He,t) reaction at the intermediate incident enrgy of 140 MeV/nucleon played an important role in the study of Fermi and Gamow-Teller transitions.

Speaker: Prof. Yoshitaka FUJITA (Research Center for Nuclear Physics, Osaka Univeristy)

Slides 2018-06-12_302_nu-detector_yfujita.ppt

31 Solar Neutrino Flares detection in HyperKamiokande in Japan and Corea.

The project and building of a twin Megaton neutrino detector as HyperKamiokande both in Japan and possibly, in South Corea will provide in near future the most advanced (in few MeV up to several GeVs energy windows) telescope of galactic and nearby (Andromeda, LMC..) Supernova (SN) thermal neutrino events by their SN neutrino burst. These rare SN must be located within one or a few Mpc. The underground HK may also better trace the atmospheric neutrinos signals testing their precise flavor mixing and their matter-anti matter component (or eventual asymmetry). In this flavor test the same elusive tau neutrino appearence (by atmospheric muon neutrino oscillation at several GeV) may be also be finally well probed. In addition to astrophysical and (atmospheric and fundamental) physics, the HK may also discover the first multiwave detection of X-gamma photons and their correlated tens MeV (up to GeV) neutrino signals during largest solar flare. Such a physics may combine the solar flare plasma physics with its inner proton proton scattering and with consequent pion and Kaon production . This expected discover, after SN1987A and Solar neutrino astronomy, will open a third independent solar Neutrino windows. Foreseen solar neutrino spectra, signature and rate in HK for each flavor will be shown in details. References: 1) D.Fargion, "Detecting Solar Neutrino Flares and Flavors"; JHEP 0406,045, (2004). 2) D. Fargion, "Anti-Neutrino Imprint in Solar Neutrino Flare", Phys.Scripta T127:22-24,(2006). 3) D. Fargion, P. Di Giacomo, Detecting Solar Neutrino Flare in Megaton and km3detectors;Nucl:P hys:P roc:Suppl:188 : 142 - 145; (2009)

Speaker: Dr Daniele Fargion (Physics Depart., ROME UNIVERSITY 1 and INFN)

Slides 2018-06-12_303_nu-flares_dfargion.pptx xflares.mpeg

16:00 Coffee Break

Solar Neutrinos as background and nuclear astrophysics

Convener: Prof. Alessandra Guglielmetti (Università degli Studi di Milano and INFN Milano Italy)

32 Solar neutrino responses for Ga-71 and double-beta-decay isotopes

Solar neutrino nuclear responses (square of nuclear matrix elements NMEs) for Ga-71 and double-beta-decay (DBD) isotopes are discussed. Recently we measured the neutrino responses (Gamow Teller GT NMEs) by using high energy-resolution charge exchange reactions at RCNP Osaka. The Ga-71 responses, together with high-precision Ga-71 experiment, provide an opportunity to study CNO neutrino contributions. The measured responses for low-lying states in Ga-71 are consistent with those used for the evaluation of the Ga-71 neutrino capture rates, suggesting that the origin of the Ga-anomaly is not the nuclear capture rate, but something else like oscillation to a possible sterile neutrino or others. Solar neutrino responses for DBD isotopes of current interest show that low-energy solar neutrinos are measured by using some DBD detectors, while solar neutrino charged current interactions with DBD detectors are potential backgrounds in future DBD experiments.

Speaker: Prof. Hiroyasu Ejiri (RCNP Osaka University)

Slides 2018-06-12_401_solar-nu-double-beta_hejiri.pdf 2018-06-12_401_solar-nu-double-beta_hejiri.pptx

33 Gas-jet targets for nuclear astrophysics

Nuclear astrophysics experiments, including future studies of solar fusion reactions, will benefit from the development of next generation gas-target setups. In the present contribution, supersonic gas-jet targets for nuclear physics are reviewed. The advantages of a localized, dense and pure target are discussed in detail by taking the example of the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) windowless gas-jet target. JENSA provides an unprecedentedly high number density of ~10^{19} atoms/cm^2 and enables the direct measurement of various hydrogen and helium-induced astrophysical reactions. Finally, perspectives of future gas targets are presented.

Speaker: Dr Konrad Schmidt (NSCL/MSU)

Slides 2018-06-12_402_gas-targets_kschmidt.pdf

34 Measurement of the 7Be(p,gamma)8B cross section with the recoil separator ERNA

7Be(p,gamma)8B still represents one of the major uncertainties on the predicted high energy component of solar neutrino flux and it has also a direct impact on the 7Li abundance after the Big Bang Nucleosynthesis. Previous experiments producing data with useful precision were performed in direct kinematics, using an intense proton beam on a radioactive 7Be target. The complicated target stoichiometry and the deterioration under beam bombardment might possibly be the origin of the discrepancies observed between the results of different measurements. Inverse kinematics, i.e. a 7Be ion beam and a hydrogen target, would shed light on systematic effects. Unfortunately, efforts attempted so far were limited by the low 7Be beam intensity. We present here the results of a new experiment, exploiting a high intensity 7Be beam in combination with a windowless gas target and the recoil mass separator ERNA (European Recoil mass separator for Nuclear Astrophysics) at CIRCE (Center for Isotopic Research on Cultural and Environmental heritage), Caserta, Italy. Aim of the experiment is the direct measurement of the total reaction cross section by means of the detection of the 8B recoils. The final results and their astrophysical impact will be illustrated.

Speaker: Dr Raffaele Buompane (Università degli Studi della Campania "Luigi Vanvitelli", Dipartimento di Matematica e Fisica and INFN sezione di Napoli.)

Slides Buompane_ISN_2018.pdf

Wednesday, 13 June

SNO, Super-Kamiokande and JUNO

Convener: Prof. Till Kirsten (Max-Planck-Institut für Kernphysik)

35 SNO: The neutrino's day in the sun

The flux of neutrinos from the sun's core depends on the rate at which the sun produces energy, a testable prediction as Ray Davis realized in the early 1960s. How that test turned out is one of the most dramatic stories in modern physics. With the hindsight of our current understanding, it is interesting to look back at the experimental and theoretical steps that led to the disclosure of new properties of nature. The Sudbury Neutrino Observatory (SNO) project was specifically designed to determine whether the `solar neutrino problem' lay in the astrophysics of stars or the properties of neutrinos. We will recall the basic ideas that led to SNO, how it was built, and what was learned.

Speaker: Prof. Hamish Robertson (University of Washington)

Slides 2018-06-13_101_SNO_hrobertson.pdf 2018-06-13_101_SNO_hrobertson.pptx

36 Super-Kamiokande

Super-Kamiokande, 50,000 ton Imaging Water Cherenkov detector, can detect neutrinos with vary wide range of energy from 3.5 MeV to above a few hundreds of GeV. Study of solar neutrinos is one of the major subjects of the experiment. Super-K started to take data on 1st of April in 1996 and has been operated continuously for more than 20 years. Super-K has shown the evidence of the neutrino oscillation in the study of the atmospheric neutrinos in 1998. It took us longer time to solve the problem of the solar neutrinos. In 2001, together with the charged current data from SNO experiment, it was shown that the solar neutrinos are also oscillated. In this presentation, I will discuss the brief history of Super-Kamiokande including also its pre-history. I will also explain the basic Characteristics of the experiment as well as the current situation and future of the solar neutrino study in Super-K.

Speaker: Prof. Yoichiro Suzuki (Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo)

Slides 2018-06-13_102_SuperK_ysuzuki.pptx

37 Solar neutrinos with the JUNO experiment

The JUNO liquid scintillator-based experiment, construction of which in ongoing in Jiangmen (China), will start operations in 2020 and will detect antineutrinos from nearby reactors; but also solar neutrinos via elastic scattering on electrons. Its physics goals are broad; its primary aim to measure the neutrino mass ordering demands to collect large statistics (from which descends JUNO’s 20 kt sensitive mass) and achieve an unprecedented energy resolution (3%/√E). Thanks to these characteristics, JUNO is in a very good position to improve on the solar neutrino studies of previous experiments of similar technology. It will collect a large sample of neutrinos from 7Be and 8B. In particular, for 7Be the target energy resolution will provide a powerful tool to isolate the electron energy end point from backgrounds like 210Bi and 85Kr. At the same time, challenges will have to be faced mainly related to the reduction and estimation of the backgrounds. While a thorough LS purification campaign is being planned, the desired level of purification is less aggressive than e.g. Borexino. Also, cosmogenic backgrounds such as cosmic ray muons traversing the relatively thin layer of ground above JUNO (700 m) and crossing the detector will need to be vetoed with dedicated techniques for the extraction of 8B. Finally, the limitation from the current benchmark energy threshold of 500 keV will need to be considered for the solar physics potential. We will review JUNO's preliminary analysis strategy and challenges in the solar neutrino sector; and provide the current estimates of its potential to discriminate solar models and neutrino-in-matter effects, assuming two benchmark scenarios of scintillator radio-purity.

Speaker: Giuseppe Salamanna (University and INFN Roma Tre)

Slides Dresden_Salamanna.pdf

10:30 Coffee Break

MSW effect and new experiments

Convener: Prof. Hamish Robertson (University of Washington)

38 MSW effect, solar neutrinos and the possibility to search for new physics

The MSW effect - the adiabatic flavor conversion of neutrinos in matter driven by density change is realized for solar neutrinos propagating inside the Sun. The features and status of the ``LMA MSW solution'' are described. Recent results on oscillations of the solar neutrinos inside the Earth are presented. New physics beyond the standard three neutrino paradigm includes non-standard neutrino interactions, mixing with sterile neutrinos, non-unitarity of mixing and non-universality, violation of the fundamental symmetries, dynamical nature of neutrino mass. Searches of new physics effects in solar neutrinos, the present bounds and perspectives will be discussed.

Speaker: Prof. Alexei Smirnov (Max-Planck-Institut fur Kernphysik)

Slides 2018-06-13_201_MSW-effect_asmirnov.pdf

39 Coherent Elastic Neutrino-Nucleus Scattering

This talk will discuss neutral-current coherent elastic neutrino-nucleus scattering (CEvNS) experiments using low-threshold detectors and different neutrino sources. I will explore the potential physics reach of these measurements with emphasis on possibilities for future solar neutrino detection.

Speaker: Kate Scholberg (Duke University)

Slides dresden18.pdf

40 The Prospects of Solar Neutrino Detection in a Liquid Xenon Experiment

As liquid xenon dark matter detectors advance, they become increasingly more sensitive to neutrino sources. In particular, they will obtain sensitivity to solar neutrinos through both elastic electron scattering and coherent elastic nuclear scattering. While these solar neutrinos constitute the ultimate background in the search for dark matter, they will also afford us an opportunity to study the Sun. In this presentation, we will explore the physics reach of a tonne-scale liquid xenon experiment, the expected sources of background, and the ongoing R&D efforts for DARWIN.

Speaker: Shayne Reichard (University of Zurich)

Slides 5thISNC.pdf

Introduction to the Felsenkeller laboratory

41 Introduction to the Felsenkeller

In preparation of the upcoming tour, a short overview and introduction to the Felsenkeller laboratory is given.

Speaker: Dr Daniel Bemmerer (Helmholtz-Zentrum Dresden-Rossendorf)

Slides Bemmerer_Felsenkeller.pdf

13:00 Lunch Break

Visit of Felsenkeller

15:45 Free Time

Guided tour through the city center of Dresden

Social Dinner

Thursday, 14 June

SAGE, THEIA and Intertwinements in the determinations of PP and CNO neutrinos

Convener: Prof. Alexei Smirnov (Max-Planck-Institut fur Kernphysik)

42 The History, Present and Future of SAGE (Soviet-American Gallium Experiment)

The SAGE experiment is a radiochemical gallium solar neutrino experiment which was created to solve solar neutrino problem arisen from Chlorine Davis experiment. The SAGE experiment together with the West European gallium experiment GALLEX contributed to the solution of the solar neutrino problem and simultaneously gave rise to a new problem which known as the gallium anomaly. To shed light on the solution of this new problem the new experiment BEST with 3MCi 51Cr source now is preparing based on Gallium-Germanium neutrino telescope (GGNT) of the SAGE experiment.

Speaker: Prof. Vladimir Gavrin (INR RAS)

Slides VNGavrin_Drezden.pptx

43 Intertwinements in the determinations of PP and CNO neutrinos

The great experimental progresses in the determination of solar neutrinos poses us new challenges. We show 1) that a precise determination of the PEP neutrinos is a prerequisite to extract the CNO neutrino signal; conversely, we argue 1) that the empirical determination of PP neutrinos requires to know the CNO neutrinos sufficiently well. For these current and urgent issues, the luminosity constraint plays a key role: we examine it critically, assess its importance and illustrate that it causes the intertwinements in the determinations of PP and CNO neutrinos.

Speaker: Dr Francesco Vissani (Gran Sasso & INFN, Aquila)

Slides vissani.pdf

44 Solar neutrino sensitivity with THEIA

A first measurement of neutrinos from the CNO fusion cycle in the Sun would allow a resolution to the current solar metallicity problem. Detection of these low-energy neutrinos requires a low-threshold detector, while discrimination from radioactive backgrounds in the region of interest is significantly enhanced via directional sensitivity. This combination can be achieved in a water-based liquid scintillator target, which offers enhanced energy resolution beyond a standard water Cherenkov detector. We present the sensitivity of such a detector to CNO neutrinos under various detector and background scenarios, and draw conclusions about the requirements for such a detector to successfully measure the CNO neutrino flux. A detector designed to measure CNO neutrinos could also achieve a few-percent measurement of pep neutrinos.

Speaker: Prof. Gabriel Orebi Gann (UC Berkeley / LBNL)

Slides 2018-06-14_THEIA_Dresden.pdf

10:30 Coffee break

Novel methods and techniques

Convener: Prof. Michael Wurm (JGU Mainz)

45 3D Topological Reconstruction in Liquid Scintillator Detectors

The precise reconstruction of charged particle tracks in unsegmented liquid scintillator (LSc) neutrino detectors, e.g., from muons, is an important prerequisite for the efficient rejection of cosmogenic background events or the analysis of multi-GeV neutrino interactions. Topological information on such events, i.e., the reconstructed 3D density distribution of isotropically emitted scintillation photons, opens up new ways to accomplish these tasks. Especially future multi-kiloton LSc detectors will profit from improved (muon) track reconstruction possibilities, both regarding their low- and high-energy neutrino physics programs. Furthermore, the method presented here can also give valuable information on events traditionally thought as point-like (MeV). This offers the potential for particle discrimination at energies relevant for solar- or reactor-neutrino programs. Cherenkov-light presents a challenge, but also an opportunity in this context.

Speaker: Björn Wonsak (UniHH Opera)

Slides Slides_Reco_Dresden2018_final.pdf

46 Event classification based on spectral analysis of scintillation waveforms

Liquid scintillators are a very common tool for neutrino physics at MeV energies, due to their good light yield and timing. However, in large detectors their capability to perform efficient pulse shape discrimination for background rejection is often limited. In this talk I present a novel approach for event classification, which was developed in the context of the Double Chooz reactor antineutrino experiment. This method uses the Fourier power spectra of the scintillation pulse shapes to obtain event-wise information. A classifier variable built from spectral information was able to achieve an unprecedented performance, even though the detector was not explicitly optimized for pulse shape analysis. Example applications of this technique include the identification of the interaction volume and an efficient rejection of instrumental light noise. A certain sensitivity to the particle type was also demonstrated with stopping muons, ortho-positronium formation, alpha particles as well as electrons and positrons. In combination with other techniques this method is expected to increase sensitivity and to provide a versatile and efficient background rejection in the future, especially if detector optimization is taken into account at the design level.

Speaker: Dr Stefan Wagner (APC)

Slides SSD_SolarNeutrinoConference_StefanWagner.pdf

47 Stars within 10 PC from the Sun and their neutrino flux at Earth

This work explores the opportunity of whether neutrinos produced by stars from the solar neighborhood might be detectable in the near future by means of their theoretical predicted fluxes at Earth. The prospects to be the strongest stellar neutrino sources, the main stars in the $\alpha$-Centauri system, Sirius A, Arcturus, Procyon A, Vega, Fomalhaut and Altair, were taken from the Gliese catalog (Gliese & Jahreiß, 1991) and their data were used to create numerical models, that, while reproducing their radius, luminosity and effective temperature within the known error bars, allow to estimate their neutrino luminosity. The shapes on what would be their spectra, compared to the solar neutrino spectrum, are also shown. The possibility for a potential detection, in view of the current and next generation neutrino telescopes is discussed. In the same way as the study of planets has been extended to exoplanets and helioseismology towards asteroseismology, this would be another new, unique extension of solar system studies out into the Milky Way.

Speaker: Dr santiago Arceo (Instituto Tecnológico de Colima)

Slides 2018-06-14_204_nu-flux-stars_sarceo.pdf

13:00 Lunch break

Solar Temperature Measurements and Neutrino Detection

Convener: Dr Zhe Wang (Tsinghua University)

48 Using neutrino lines for solar temperature measurements

TBA

Speaker: Prof. Carlos Pena-Garay (CSIC)

Slides 2018-06-14_301_solar-temperature_cpenagaray.pdf

49 Jinping, and the solar neutrinos

The expected transition from matter effect to vacuum oscillation in solar energy spectrum, or the solar spectral `upturn' towards low energy region, has not been observed yet, leaving space for non-standard neutrino interactions as well as light sterile neutrinos. Jinping neutrino experiment is a proposed 2 kiloton fiducial mass slow liquid scintillator detector located in China Jinping Underground Laboratory. The deep overburden of 6,720 w.m.e. and extremely low muon rate at $(2.0\pm0.4)\times10^{-10}/(\text{cm}^2\cdot\text{s})$ at Jinping enables background-free detection from the spallation product $^{11}$C, which overlap with the crucial transition region of 1-3 MeV. The energy response of scintillation light is not linear at low energy, requiring strict nonlinearity correction for neutrino energy reconstruction. A fast detector response model is thus presented, which fits a minimal set of physically-motivated parameters that capture the essential processes of detector response and naturally account for changes in scintillator characteristics over time, helping to avoid associated biases or systematic uncertainties.

Speaker: Ms Linyan WAN (Tsinghua University)

Slides SolarNu@JP.pdf

50 Limits on neutrino magnetic moments from the spectral analysis of the Borexino Phase-II data

In this study a contribution to the neutrino-electron scattering caused by the non-zero neutrino magnetic moment has been searched for in the Borexino Phase-II solar neutrino data. No significant deviations from the expected shape are found, and as a result, a new limit on the effective magnetic moment of solar neutrinos is obtained, namely, $\mu_\nu<2.8\cdot10^{-11}\mu_{B}$ (90% C. L.). This result has been used to constrain the magnetic moments of flavor eigenstates, and the ones of mass eigenstates for Dirac neutrinos and the transition moments of Majorana neutrinos. Comparison with the results of other experimental studies is given.

Speaker: Mrs Alina Vishneva (JINR)

Slides Bx_munu_Dresden.pdf

51 Filling the gap: the solar neutrino flux at keV energies

In the last few decades we have entered a new era in neutrino observations, from cosmic neutrino background detection proposals to high energy neutrinos astronomy. As theorists, we have to provide the expected flux at different energies. In this poster, I will present a previous overlooked contribution to the "grand unified neutrino spectrum" at Earth: the Solar neutrino thermal flux at keV energies. Besides being a signal, such a flux would also be the background for a futuristic keV sterile neutrino direct detection experiment. I will review the processes contributing to this spectrum, with particular emphasis on thermal effects due to the presence of a plasma.

Speaker: Mr Edoardo Vitagliano (Max Planck Institute for Physics)

Slides DRESDAtalk.pdf

52 Solar neutrino spectroscopy with thermal detectors

In the field of low background physics, cryogenic detectors demonstrated in the last years to be a promising technology, not fully explored yet, for the investigation of rare events. They feature excellent energy resolution over a wide energy range and, lately, scalability to large masses have been demonstrated, as well as the discrimination of the particle interactions. This technology has been widely employed for the investigation of rare process thanks to their flexibility, since many different isotopes can be chosen as absorbing detector. In particular, by choosing a proper target isotope, thermal detectors can be used to detect solar neutrinos trough weak charged-current reactions, detecting the de-excitation products of the radioactive daughter nucleus. As an example, a thermal detector including Bromine, based on the charged current reaction on the Br-81 isotope, could be used to perform a precise study of the shape of the Be-7 line, allowing for a measurement of the central temperature of the Sun. A similar measurement could be performed by a thermal detector containing Molybdenum, detecting the charged current reaction on Mo-100 by the subsequent decay to Ru-100. Thanks to their excellent energy resolution and to their granularity these detectors are ideal perform a precise spectroscopic measurement of the low energy neutrino fluxes from the Sun, solving important questions both in solar physics and neutrino physics. In this contribution, the potentialities and the challenges of the application of thermal detectors to investigate solar neutrinos are discussed.

Speaker: Dr Lucia Canonica (Max-Planck-Institut für Physik)

Slides Canonica_solarNu.pdf

Closing and Summary

Conveners: Dr Daniel Bemmerer (Helmholtz-Zentrum Dresden-Rossendorf), Prof. Kai Zuber (TU Dresden), Dr Mikko Meyer (TU Dresden)

Introduction to the International Alumni Project and Reimbursement of Travel Costs

Convener: Ms Maria Richter-Babekoff (International Office School of Science and Center for Teacher Education and Educational Research, Technische Universität Dresden)

Friday, 15 June

Workshop for international Alumni and Friends of TU Dresden

Framework Programme

Convener: Mrs Maria Richter-Babekoff