Real time solar neutrino spectroscopy with Borexino phase 2

使用 Borexino Phase 2 进行实时太阳中微子光谱分析

• 批准号: 284839683
• 负责人: Professor Dr. Lothar Oberauer
• 金额: --
• 依托单位: Institut für Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/284839683?language=en
• 关键词: Real; time; solar; neutrino; spectroscopy

For decades the study of missing solar neutrinos was one of the biggest problems in particle astrophysics. Meanwhile this problem is considered to be solved as neutrino oscillations in matter describe all observations well,including the ones from Borexino. Borexino is the worldwide cleanest - in terms of radio purity- scintillation detector and also has a very low threshold, which allowed a first real time measurement of even pp-neutrinos from the fundamental fusion process. This grant application is linked to phase 2 of Borexino, a phase with even lower background due to a performed purification campaign. To improve measurements further two new calibration sources will be built in this grant to extend the calibrated region to higher energies. From the analysis point of few two topics will be dealt with in this grant. Of high priority is the first ever measurement of CNO-neutrinos, which would experimentally prove the existence of this cycle. Within this context the solar abundance problem will be explored. Recent 3-D modeling of photosphere lines lead to a lower abundance of heavier elements like C,N and O by 20-40%. However, this causes some larger discrepancy between solar models and helioseismological observations. The only way to probe the abundancies in the interior of the Sun are CNO-neutrinos. This will also shed some light on fundamental assumptions in stellar astrophysics, namely the homogeneous distribution of elements. In the same analysis an improved measurement of the pep-neutrinos is possible. The major background for these searches is 11C produced by myon interactions in the scintillator. Within this grant a new method based on a likelihood analysis will be developed to remove these events with a higher efficiency than the current one. Another research question tackled in this grant is the low energy behavior of the 8B spectrum. The lowest data point of all real time solar experiments shows the opposite behavior one would expect from oscillations. Thus, for a long time other non-standard interaction (NSI) scenarios are discussed. The improved phase 2 data will be analyzed in this direction and will distinguish between the different solutions or at least strongly constrain the parameters.

几十年来，对丢失的太阳中微子的研究是粒子天体物理学中最大的问题之一。与此同时，这个问题被认为是解决了中微子振荡的物质很好地描述了所有的观测，包括Borexino。Borexino是世界上最干净的-在无线电纯度方面-闪烁探测器，也有一个非常低的阈值，这使得第一个真实的时间测量甚至pp中微子从基本聚变过程。该资助申请与Borexino的第2阶段有关，该阶段由于进行了纯化活动而具有更低的背景。为了进一步改善测量，将在该资助中建立两个新的校准源，以将校准区域扩展到更高的能量。从分析的角度来看，有两个主题将在本补助金中处理。最重要的是首次测量hoc中微子，这将在实验上证明这种循环的存在。在这方面的太阳丰度问题将进行探讨。最近的光球线三维模型导致较重元素如C，N和O的丰度降低了20- 40%。然而，这导致太阳模型和日震观测之间存在较大的差异。探测太阳内部丰度的唯一方法是hoc中微子。这也将有助于阐明恒星天体物理学的基本假设，即元素的均匀分布。在同样的分析中，一种改进的pep中微子的测量是可能的。这些搜索的主要背景是在闪烁体中的myon相互作用产生的11 C。在该补助金内，将开发一种基于可能性分析的新方法，以比目前更高的效率删除这些事件。在这项资助中解决的另一个研究问题是8B光谱的低能行为。所有真实的太阳实验的最低数据点显示了人们从振荡中预期的相反行为。因此，很长一段时间以来，其他非标准交互（NSI）的场景进行了讨论。改进的第2阶段数据将在这个方向上进行分析，并将区分不同的解决方案或至少强烈约束参数。

项目成果

Sensitivity to neutrinos from the solar CNO cycle in Borexino

• DOI: 10.1140/epjc/s10052-020-08534-2
• 发表时间: 2020-05
• 期刊: The European Physical Journal C
• 作者: M. Agostini;K. Altenmüller;S. Appel;V. Atroshchenko;Z. Bagdasarian;Z. Bagdasarian;D. Basilico;G. Bellini;J. Benziger;R. Biondi;D. Bravo;B. Caccianiga;F. Calaprice;A. Caminata;P. Cavalcante;A. Chepurnov;D. D’Angelo;S. Davini;A. Derbin;A. D. Giacinto;V. D. Marcello;X. Ding;A. D. Ludovico;L. Noto;I. Drachnev;A. Formozov;D. Franco;C. Galbiati;C. Ghiano;M. Giammarchi;A. Goretti;A. Göttel;A. Göttel;M. Gromov;M. Gromov;D. Guffanti;A. Ianni;A. Ianni;A. Jany;D. Jeschke;V. Kobychev;G. Korga;S. Kumaran;S. Kumaran;M. Laubenstein;E. Litvinovich;E. Litvinovich;P. Lombardi;I. Lomskaya;L. Ludhova;L. Ludhova;G. Lukyanchenko;L. Lukyanchenko;I. Machulin;I. Machulin;J. Martyn;E. Meroni;M. Meyer;L. Miramonti;M. Misiaszek;V. Muratova;B. Neumair;M. Nieslony;R. Nugmanov;R. Nugmanov;L. Oberauer;V. Orekhov;F. Ortica;M. Pallavicini;L. Papp;Ö. Penek;Ö. Penek;L. Pietrofaccia;N. Pilipenko;A. Pocar;G. Raikov;M. Ranalli;G. Ranucci;A. Razeto;A. Re;M. Redchuk;M. Redchuk;A. Romani;N. Rossi;S. Schönert;D. Semenov;G. Settanta;M. Skorokhvatov;M. Skorokhvatov;O. Smirnov;A. Sotnikov;Y. Suvorov;R. Tartaglia;G. Testera;J. Thurn;E. Unzhakov;F. Villante;A. Vishneva;R. Vogelaar;F. Feilitzsch;M. Wójcik;M. Wurm;S. Zavatarelli;K. Zuber;G. Zuzel

Experimental evidence of neutrinos produced in the CNO fusion cycle in the Sun

• DOI: 10.1038/s41586-020-2934-0
• 发表时间: 2020-06
• 期刊: Nature
• 影响因子: 64.8
• 作者: M. K. S. V. Z. D. G. J. R. D. B. F. A. P. A. D. S. A. Agostini Altenmüller Appel Atroshchenko Bagdasaria-M.-K.-S.-V.-Z.-D.-G.-J.-R.-D.-B.-F.-A.-P.-A.-D.-S.;M. Agostini;K. Altenmüller;S. Appel;V. Atroshchenko;Z. Bagdasarian;D. Basilico;G. Bellini;J. Benziger;R. Biondi;D. Bravo;B. Caccianiga;F. Calaprice;A. Caminata;P. Cavalcante;A. Chepurnov;D. D’Angelo;S. Davini;A. Derbin;A. Di Giacinto;V. Di Marcello;X. Ding;A. Di Ludovico;L. Di noto;I. Drachnev;A. Formozov;D. Franco;C. Galbiati;C. Ghiano;M. Giammarchi;A. Goretti;A. Göttel;M. Gromov;D. Guffanti;A. Ianni;A. Ianni;A. Jany;D. Jeschke;V. Kobychev;G. Korga;S. Kumaran;M. Laubenstein;E. Litvinovich;P. Lombardi;I. Lomskaya;L. Ludhova;G. Lukyanchenko;L. Lukyanchenko;I. Machulin;J. Martyn;E. Meroni;M. Meyer;L. Miramonti;M. Misiaszek;V. Muratova;B. Neumair;M. Nieslony;R. Nugmanov;L. Oberauer;V. Orekhov;F. Ortica;M. Pallavicini;L. Papp;L. Pelicci;Ö. Penek;L. Pietrofaccia;N. Pilipenko;A. Pocar;G. Raikov;M. Ranalli;G. Ranucci;A. Razeto;A. Re;M. Redchuk;A. Romani;N. Rossi;S. Schönert;D. Semenov;G. Settanta;M. Skorokhvatov;A. Singhal;O. Smirnov;A. Sotnikov;Y. Suvorov;R. Tartaglia;G. Testera;J. Thurn;E. Unzhakov;F. Villante;A. Vishneva;R. Vogelaar;F. von Feilitzsch;M. Wójcik;M. Wurm;S. Zavatarelli;K. Zuber;G. Zuzel