Conveners
Parallel Session IV：Neutrino, Astroparticle Physics and Cosmology
- Zong-Kuan GUO (ITP-CAS)
- Liangjian Wen (高能所)
- Zhe Wang (Tsinghua University)
- Min Min Zha (高能所)
Parallel Session IV：Neutrino, Astroparticle Physics and Cosmology
- Zhe Wang (Tsinghua University)
- Zong-Kuan GUO (ITP-CAS)
- Liangjian Wen (高能所)
- Min Min Zha (高能所)
Parallel Session IV：Neutrino, Astroparticle Physics and Cosmology
- Zong-Kuan GUO (ITP-CAS)
- Liangjian Wen (高能所)
- Min Min Zha (高能所)
- Zhe Wang (Tsinghua University)
Parallel Session IV：Neutrino, Astroparticle Physics and Cosmology
- Zong-Kuan GUO (ITP-CAS)
- Min Min Zha (高能所)
- Liangjian Wen (高能所)
- Zhe Wang (Tsinghua University)
Parallel Session IV：Neutrino, Astroparticle Physics and Cosmology
- Zong-Kuan GUO (ITP-CAS)
- Min Min Zha (高能所)
- Liangjian Wen (高能所)
- Zhe Wang (Tsinghua University)
Parallel Session IV：Neutrino, Astroparticle Physics and Cosmology
- Min Min Zha (高能所)
- Zhe Wang (Tsinghua University)
- Zong-Kuan GUO (ITP-CAS)
- Liangjian Wen (高能所)
Parallel Session IV：Neutrino, Astroparticle Physics and Cosmology
- Liangjian Wen (高能所)
- Min Min Zha (高能所)
- Zhe Wang (Tsinghua University)
- Zong-Kuan GUO (ITP-CAS)
Parallel Session IV：Neutrino, Astroparticle Physics and Cosmology
- Min Min Zha (高能所)
- Zong-Kuan GUO (ITP-CAS)
- Liangjian Wen (高能所)
- Zhe Wang (Tsinghua University)
Dr
SongZhan Chen
(IHEP,CAS, Beijing)
16/08/2021, 14:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The results of LHAASO-KM2A will be presented
世聪 胡
(高能所)
16/08/2021, 14:15
4. 中微子物理、粒子天体物理与宇宙学
Oral report
Large High Altitude Air Shower Array (LHAASO) is a large hybrid EAS experiment located in Haizi Moutain, Daocheng, Sichuan province. Water Cherenkov Detector Array (WCDA) is one of sub-arrays aiming at VHE gamma ray astronomy. LHAASO-WCDA has finished 2 pools installation and data-taking in the year of 2020. Based on these data a lot of works and implementation have been proceed, such as the...
Hengying Zhang
(Shandong University)
16/08/2021, 14:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The number of muons observed at the ground from air showers is sensitive to the mass composition of cosmic rays. The KM2A sub-array of the Large High Altitude Air Shower Observatory (LHAASO) can measure the size and muon content of an air shower simultaneously with high precision for cosmic rays with energies in the knee region. In this paper, the performance of the KM2A is validated in that...
Liping Wang
(SDU)
16/08/2021, 14:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The longitude development of the muonic component in the extensive air shower can help to determine mass composition of cosmic rays. By using the timing information of muons, the production positions of muons can be reconstructed. $X_{max}^{\mu}$ which is the position with muon production reaching maximum is sensitive to the mass composition of cosmic rays. In this paper, the reconstruction...
Dr
Quanbu Gou
(Institute of High Energy Physics, CAS)
16/08/2021, 15:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
LHAASO-KM2A is a sub-array of the Large High Altitude Air Shower Observatory (LHAASO)
with an area of 1.3 km^2. It consists of 5195 electromagnetic detectors (EDs, 1 m^2 each) and 1171 muon detectors (MDs, 36 m^2 each). Horizontal Air Showers (HAS) are a fundamental tool to detect penetrating particles like neutrinos and to study hadronic interactions. HAS detected at ground are mainly...
Dr
Shoushan Zhang
(Institute of High Energy Physics)
16/08/2021, 15:15
4. 中微子物理、粒子天体物理与宇宙学
Oral report
2021年5月17日，LHAASO在nature期刊发表了十二个百TeV以上的伽马射线源，开创了超高能伽马射线（PeVotran）观测的新窗口，解开超高能宇宙线起源这一世纪之谜出现了曙光。然而，LHAASO的角分辨约为0.3度，不足以对源的进行精细观测，需要更高角分辨（0.06度）的成像大气切伦科夫望远镜阵列，对这些源进行精细观测，从而确定超高能伽马射线源的本质并解开超高能宇宙线起源的世纪之谜。欧洲的科学家在2004年提出CTA计划，其计划涵盖高能和低能伽马源定点跟踪观测。LHAASO实验和CTA计划自然而然形成了国际分工，由LHAASO全天区扫描，发现伽马源，然后由CTA对源进行跟踪精细观测，例如对源的morphology进行研究。LHAASO将于今年8月份全阵列投入运行，而欧洲CTA计划却滞后严重，特别是超高能望远镜的建设严重滞后。从CTA官网公布的建设计划看，预计在未来6年内，...
Mr
Xin Wang
(1. Xinjiang Astronomical Observatories, CAS)
16/08/2021, 15:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
On the one hand, observations show that there are proton spectral ''breaks'' with energy $E_{br}$ at 1-10MeV in some large solar energetic particle (SEP) events. Such as in the 2006 Dec 13 SEP event, which would be associated with the converging interaction between the coronal mass ejection (CME)-diven shock and the Earth's bow shock. On the other hand, the ground-level enhancement (GLE)...
Dr
堃 方
(中国科学院高能物理研究所)
16/08/2021, 15:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
宇宙线正电子的高能超出部分最有可能的来源是脉冲星和暗物质。对于脉冲星的解释，近期的一些观测进展促使我们对该模型重新进行分析。首先，AMS-02最新的正电子能谱测量以较高的显著性表明了高能截断的存在。我们认为，这个结果意味着高能正电子很有可能主要由个别的脉冲星贡献。另外，HAWC、LHAASO等实验表明脉冲星附近可能普遍存在着尺度为数十pc的宇宙线慢扩散区，该区域中的扩散系数要显著小于一般星际介质中的数值。在这个双区扩散模型下，脉冲星在地球处产生的正电子流量相比先前的单区模型会有显著的改变。我们遍历了目前观测到的所有脉冲星，发现除了先前认为的重要候选者Geminga之外，PSR B1055-52是一个非常有可能的高能正电子来源。该脉冲星有可能是观测到的脉冲星中距离我们最近的，并且特点和Geminga十分类似。我们发现，该脉冲星甚至有可能对HESS实验探测到的20TeV左右的正负电子流量做出解释。
Mr
祖豪 李
(高能所粒子天体)
16/08/2021, 16:10
4. 中微子物理、粒子天体物理与宇宙学
Oral report
AMS合作组基于190万正电子事例数精确测量得到0.5GeV-1TeV宇宙线正电子流强谱结果。测量结果表明：1. 正电子流强谱在25.2GeV以上开始有明显相对于单一幂率谱的超出；2. 在284GeV以上能区流强谱迅速下降；3. 在整个能区正电子流强谱可以很好地用宇宙线传播模型加一个高能区域的正电子源进行描述； 4. 正电子流强谱在高能区域迅速下降的截止能量为810GeV，置信度大于4倍sigma。这表明高能区域的正电子主要来自暗物质湮灭或者新的天体源。
Dr
志成 唐
(高能所)
16/08/2021, 16:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
报告展示AMS测量得到的原初宇宙线带电基本粒子在1GV至2000GV刚度绝对值区域内的流强谱结果及流强谱比率。在60GV至500GV的刚度绝对值区域内，反质子、质子和正电子流强谱有近乎一致的随刚度变化趋势，而与电子流强谱的随刚度变化趋势不同。在60GV之下，反质子与质子比率，反质子与正电子比率以及质子与正电子比率均已达到最大值。特别值得一提的是更新了原初宇宙线带电基本粒子流强谱在500GV以上能区的结果。
Dr
诚 张
(高能所)
16/08/2021, 16:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
报告展示AMS测量得到的原初宇宙线氖镁硅原子核流强谱在2.15GV至3TV刚度能区的精确结果。流强谱分析基于AMS收集的180万氖原子核事例、220万镁原子核事例以及160万硅原子核事例。从流强谱结果可以看到：氖和镁原子核流强谱在3.65GV以上能区有一致的随刚度变化趋势；在86.5GV以上能区氖、镁和硅三者均有一致的随刚度变化趋势； 在200GV以上能区三者流强谱一致上升，不服从单一幂律谱。尤其出乎意料的是，86.5GV以上能区氖、镁和硅原子核流强谱的一致性随刚度变化趋势与同样是初级宇宙线的氦、碳和氧原子核的随刚度变化趋势并不相同。这说明氖镁硅和氦碳氧属于两种不同类型的初级宇宙线。
扈嘉钰
16/08/2021, 17:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
报告展示AMS测量得到的宇宙线氟原子核流强谱在2.15 GV至2.9 TV刚度能区的精确结果，基于收集到的29万氟原子核事例。从流强谱结果可以看到：氟原子核流强谱在200GV以上能区不服从单一幂律谱；重核次级-初级宇宙线比率（F/Si）的随刚度变化趋势与轻核的次级-初级宇宙线比率（B/O或B/C）不同，具体而言10GV以上能区（F/Si）/（B/O）可以用单一幂指数分布描述（幂率为0.052±0.007）。这说明氟到硅的重核宇宙线与氦到氧的轻核宇宙线有不同的宇宙线传播机制，且有两种不同类型的次级宇宙线：氦碳氧和氟。
Dr
兆民 王
(山东高等技术研究院)
16/08/2021, 17:15
4. 中微子物理、粒子天体物理与宇宙学
Oral report
宇宙线铁原子核主要在天体源内产生并加速，对铁原子核流强在GV至TV磁刚度（动量/电荷）区间内的精确测量有助于加深对宇宙线起源与加速机制的理解。基于国际空间站上阿尔法磁谱仪（AMS）实验收集的62万初级宇宙线铁原子核建立的2.65GV至3.0TV能谱显示出新的能谱特征。AMS铁能谱在200GV处偏离单一幂律谱。出乎意料之外，在80.5GV以上，铁原子核流强与初级宇宙线氦、碳、氧原子核具有相同的磁刚度依赖特性，铁、氧流强比为常量0.155+/-0.006。这一结果显示宇宙线铁与电荷数较小的初级宇宙线氦、碳、氧原子核属于同一类别，而不同于另一类电荷数较大的初级宇宙线氖、镁、硅原子核。
尧 陈
(S)
16/08/2021, 17:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
阿尔法磁谱仪（AMS）实验位于国际空间站，是目前唯一在外太空运行的大型磁谱仪实验，自2011年5月运作以来，已采集了超过1700亿宇宙线事例。通常认为，宇宙线锂和铍原子核的主要起源是初级宇宙线在传播中的碎裂过程。因此宇宙线锂铍能谱的精确测量结果是宇宙线传播与起源研究的必要实验数据，而二者在宇宙线中的同位素组分将为宇宙线研究提供新的视角。其中铍原子核的同位素比值，10Be/9Be，可作为研究宇宙线在银河系中居留时间的放射性时钟。基于AMS运行8.5年以来的宇宙线数据， 本次报告将介绍宇宙线锂原子核同位素（6Li和7Li）以及铍原子核同位素（7Be、9Be和10Be）的能谱以及同位素比值的测量结果。
Dr
Zetong Sun
(IHEP)
16/08/2021, 17:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
报告展示AMS测量得到的正负电子流强谱在2011年5月20日至2019年10月29日期间以月为单位的随时间变化结果。给出了超过半个太阳周期范围内的不同时间尺度下与太阳活动有关的流强谱随时间变化情况，并探讨了不同电荷粒子随时间变化的区别。
Mr
朝义 渠
(山东高等技术研究院)
16/08/2021, 18:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
AMS-02 探测器是多物理目标、广能量探测范围、高统计量、大接收度的外太空磁谱仪。因其拥有独特的永久磁铁结构，使得 AMS-02 能够区分宇宙射线粒子电荷正负，即AMS-02是外太空中能够直接测量反物质的探测器。
宇宙射线粒子进入 AMS-02 探测器，在磁场中发生偏转，其运动轨迹通过径迹探测器获得。为了快速重建宇宙射线轨迹，报告人创新性构建了Cellular...
伟伟 许
(Shandong University)
17/08/2021, 08:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
阿尔法磁谱仪（AMS）实验基于在国际空间站所收集的2800万个电子事例，测量了在0.5GeV－1.4 TeV能量范围内宇宙线电子流强。实验结果显示，电子和正电子流强无论在强度还是在能量依赖关系上都有明显的区别。电子流强在41.2 GeV出开始明显超出其在低能区间的变化趋势，但是该超出与正电子起始于25.2 GeV处的超出有着本质的区别。正电子在810 GeV处存在指数型截止能量，而电子能谱以超过5倍显著性排除了能量低于1.9 TeV的截止能量。AMS电子能谱在整个能量区间可以描述为两个幂律谱的叠加。AMS结果表明高能电子和正电子存在不同的起源。
Dr
Tong Su
(Shandong Institute of Advanced Technology)
17/08/2021, 08:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
本报告将介绍阿尔法磁谱仪（AMS）实验关于每天的宇宙线电子流强的新结果。通过测量和分析宇宙线电子自2011年5月20日至2019年10月29日的流强变化，揭示出电子流强具有不同时间尺度的周期性特征，并与太阳自转等周期性太阳活动存在一定的关联。本报告还将详细对比AMS实验测量的质子（Z=+1）和电子（Z=-1）的流强变化，研究太阳活动对于不同电荷符号的宇宙线粒子产生的不同调制现象。
Dr
Zhi-Long Han
(济南大学)
17/08/2021, 09:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
Within the framework of canonical type-I seesaw, a feebly interacting massive particle (FIMP) $\chi$ is introduced as a dark matter candidate. The leptogenesis mechanism and dark matter relic density share a common origin via decays of Majorana neutrinos $N$. Provided an additional species $\varphi$ whose energy density red-shifts as $\rho_{\varphi}\propto a^{-(4+n)}$, the Hubble expansion...
Yu Gao
(IHEP)
17/08/2021, 09:15
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The precision cosmic microwave background (CMB) measurement and the anticipated observation of neutral hydrogen 21cm line tell us a lot about the CMB propagation during the dark and reionization epochs of the Universe. The CMB can be a powerful indirect test of energy deposition from beyond the Standard Model physics: Dark matter annihilation and decays, or the radiation from primordial black...
Fa Peng Huang
(Sun Yat-Sen (Zhongshan) University)
17/08/2021, 09:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
We study new approaches to explore light dark matter by radio telescope (SKA,Fast) based on the resonant conversion effects.
Dr
Peng-Fei Yin
(IHEP)
17/08/2021, 09:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
Axion as one of the promising dark matter candidates can be detected through narrow radio lines emitted from the magnetic white dwarf stars. Due to the existence of the strong magnetic field, the axion may be resonantly converted into the radio photon, when it passes through a narrow region in the corona of the magnetic white dwarf, where the plasma frequency is equal to the axion mass. We...
Mr
传阳(Chuan-Yang) 邢(Xing)
(北京大学(Peking University))
17/08/2021, 10:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
We present a novel paradigm of dark matter freeze-out in the early universe, named "catalyzed freeze-out", in which the freeze-out of dark matter is controlled by catalyzed reactions. We discuss in detail the regime that the depletion of dark matter proceeds via $2\chi \to 2A'$ and $3A' \to 2\chi$ processes, in which $\chi$ and $A'$ denote dark matter and the catalyst respectively.
Dr
Yun-Long Zhang
(National Astronomical Observatories, Chinese Academy of Sciences(NAOC))
17/08/2021, 10:40
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The axion objects such as axion mini-clusters and axion clouds around spinning black holes induce parametric resonances of electromagnetic waves through the axion-photon interaction. In particular, it has been known that the resonances from the axion with the mass around mueV may explain the observed fast radio bursts (FRBs). Here we argue that similar bursts of high frequency gravitational...
Dr
Ligong（立功） Bian（边）
(Chongqing University(重庆大学))
17/08/2021, 11:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
我在报告中将与大家讨论电弱相变与新物理的关系，以及我们组在电弱相变产生引力波和原初磁场方面的研究进展。
Prof.
Bo-Qiang Ma
(Peking University)
17/08/2021, 11:20
4. 中微子物理、粒子天体物理与宇宙学
Oral report
Cosmic photons from astrophysical sources are ideal for investigating the Lorentz symmetry violation (LV). A series of studies on high energy gamma-ray burst (GRB) photons suggest a light speed variation with linear energy dependence at the Lorentz violation scale of $3.6*10^{17}$ GeV, with subluminal propagation of high energy photons in cosmological space. I show that a string theory model...
Prof.
Shuang-Yong Zhou
(USTC)
17/08/2021, 11:40
4. 中微子物理、粒子天体物理与宇宙学
Oral report
Lorentz invariance, locality, unitarity and analyticity are some of the most fundamental properties of S-matrix/quantum field theory. I will explain why these fundamental principles can impose positivity bounds on the Wilson coefficients of the EFT, and how to obtain the strongest bounds in the forward limit and beyond. These positivity bounds are then used to constrain the parameter space of...
Mr
Xin WANG
(中科院高能物理研究所)
17/08/2021, 14:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The finite modular symmetry provides us with an attractive and novel way to understand
lepton flavor mixing, and has recently attracted a lot of attention. In a class of neutrino mass models with modular flavor symmetries, it has been observed that CP symmetry is preserved at the stabilizer of the modulus parameter $\tau = {\rm i}$, whereas significant CP violation emerges within the...
Dr
忻怿 张
(中国科学院高能物理研究所)
17/08/2021, 14:15
4. 中微子物理、粒子天体物理与宇宙学
Oral report
In this work, we present a systematic investigation on simple inverse seesaw models for neutrino masses and flavor mixing based on the modular $S^{}_4$ symmetry. Two right-handed neutrinos and three extra fermion singlets are introduced to account for light neutrino masses through the inverse seesaw mechanism and to provide a keV-mass sterile neutrino as the candidate for warm dark matter in...
振华 赵
(辽宁师范大学)
17/08/2021, 14:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
中微子振荡现象表明中微子具有非零的质量并发生了混合。如何理解中微子的微小质量以及混合模式是粒子物理理论研究的一个重要问题。跷跷板机制是最为广泛接受的产生中微子质量的方法，其不仅能够自然地解释中微子质量的微小，而且为宇宙的正-反物质不对称提供了一个非常具有吸引力的解释—轻子生成机制。
然而，一般性的、包含三个右手中微子的跷跷板模型由于参数太多，无论对中微子质量还是轻子生成的解释都只是定性的，缺乏定量预言的能力。为了提高跷跷板模型的预言能力，文献中有两种典型的减少其参数的做法：一是把右手中微子的数量减少至两个（称为最小跷跷板模型）；二是利用味道对称性（如mu-tau对称性）限制其味结构。
本报告将介绍跷跷板模型简化结构（最小跷跷板模型及味道对称性）及相关的轻子生成的一些研究现状。
Prof.
Xun Xue
(East China Normal University)
17/08/2021, 14:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
We investigate the scattering of neutrino by torsion field and find the different scattering responses between the Dirac type and Majorana type. The difference may be an possible way to determine the fermion type of neutrino by the propagation of neutrino in the universe. We also investigate the propagation of spin 1/2 particle in the torsion field.
Dr
Peihong Gu
(Southeast University)
17/08/2021, 15:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
We propose an efficient mechanism to realize an invisible axion from a low scale Peccei-Quinn symmetry breaking. Our basic model only contains a gauge boson, an up-type vector-like quark, two Higgs doublets and two Higgs singlets besides the standard model fermions and gauge bosons. The physical Peccei-Quinn global symmetry is a result of two independent global symmetries connected by the new...
Mr
Zhang Di
(IHEP, CAS)
17/08/2021, 15:15
4. 中微子物理、粒子天体物理与宇宙学
We propose a leptoquark model with two scalar leptoquarks $S_1 ( {\bar{3}},1,\frac{1}{3} )$ and ${\widetilde R_2}(3,2,\frac{1}{6})$ to give a combined explanation of neutrino masses, lepton flavor mixing and the anomaly of muon $g-2$, satisfying the constraints from the radiative decays of charged leptons. The neutrino masses are generated via one-loop corrections resulting from a mixing...
郁槟榕
(高能所)
17/08/2021, 15:40
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The flavor invariants, which are invariant under the unitary transformation in the flavor space, turn out to be a powerful tool in studying the CP violation in a model-independent way. In this talk, I will discuss the application of the flavor invariants in constructing the sufficient and necessary conditions of CP conservation in the leptonic sector with Majorana neutrinos. Furthermore, the...
Jie ZHAO Jie
(高能所)
17/08/2021, 15:55
4. 中微子物理、粒子天体物理与宇宙学
Oral report
In this talk we describe in detail the feasibility of detecting $^8$B solar neutrino at JUNO with three reaction channels (neutrino-electron elastic scattering, neutrino-$^{13}$C charged current, and neutral current interactions). A reduced 2 MeV threshold on the recoil electron energy is achievable with optimized background reduction strategies. The advantage of JUNO for charge and neutral...
Yi-Lei Tang
(中山大学)
17/08/2021, 16:10
We calculate the thermal processes of a a sterile neutrino with the mass around the electroweak scale 50 GeV ≤ mN ≤ 200 GeV, within this range we developed the method to calculate the 1<->2 process with thermal corrections around the electroweak crossover. Preliminary calculations of leptogenesis have also been performed.
Mr
Lin Zhao
(Department of Engineering Physics, Tsinghua University)
17/08/2021, 16:25
4. 中微子物理、粒子天体物理与宇宙学
Oral report
Solar-, geo-, and supernova neutrino experiments are subject to the background from cosmic-ray muons and muon-induced neutrons. China Jinping Underground Laboratory (CJPL), with its unique advantage of 2400 m rock coverage and far away from nuclear power plants, is ideal for neutrino search. Using a 1-ton prototype detector of the Jinping Neutrino Experiment, we detected 343 high-energy...
Wentai Luo
(University of Chinese Academy of Sciences)
17/08/2021, 16:40
4. 中微子物理、粒子天体物理与宇宙学
Oral report
We proposed to build a Cherenkov scintillation detector with kilo-ton fiducial mass in China Jinping Underground Laboratory. We have made significant progress in developing the water-based liquid scintillator (WbLS) technique and optimizing the detector geometry. WbLS emits Cherenkov and scintillation photons for each charged particle. With the feature of the delayed scintillation light and...
宇逸 王
(清华大学)
17/08/2021, 16:55
4. 中微子物理、粒子天体物理与宇宙学
Oral report
Liquid scintillator detectors are used in many neutrino experiments, in which ionizing radiation deposits energy, scintillates, and is finally detected by PMTs. $\gamma$ from natural radioactivity has strong penetrative power, and causes Compton effects including background. We conjecture that efficiency of PID could be increased, if the particle tracks could be reconstructed, and...
Weiran Xu
(Massachusetts Institute of Technology)
18/08/2021, 08:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The discovery of neutrino oscillation proves that neutrinos must have non-zero mass. While the differences of squared neutrino mass eigenvalues have been probed by neutrino oscillation experiments, the absolute neutrino mass scale still remains one of the most important open questions in particle and astroparticle physics. By exploiting the single $\beta$ decay of molecular tritium, the...
Dr
丽桃 杨
(Tsinghua University)
18/08/2021, 08:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
CDEX合作组自2009年以来在世界岩石覆盖最深的锦屏地下实验室使用点电极高纯锗锗探测器开展暗物质直接探测。最近，基于CDEX-1和CDEX-10实验发表了多项国际先进水平的物理结果，包括暗物质年度调制效应分析[1]、基于Migdal效应的亚GeV轻暗物质搜索[2]、暗光子探测[3]、太阳轴子和类轴子探测[4]、有效场论框架下的WIMP探测[5]等。目前正在开展50公斤级高纯锗阵列暗物质实验（CDEX-50dm）的准备和关键技术预研，如锗晶体生长、高纯锗探测器自主研制、地下实验室低本底电解铜、低噪声低阈值前端电子学等。本报告将讨论CDEX暗物质实验的现状以及未来展望。
1. L. T. Yang et al., (CDEX Collaboration) Light WIMPs Search by Annual Modulation Analysis with a...
秋红 王
(复旦大学)
18/08/2021, 09:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
We report the dark matter search results obtained using the full 132 ton$\cdot$day exposure of the PandaX-II experiment, including all data from March 2016 to August 2018. No significant excess of events is identified above the expected background. Upper limits are set on the spin-independent dark matter-nucleon interactions. The lowest 90$\%$ confidence level exclusion on the...
Hao Ma
(Tsinghua University)
18/08/2021, 09:15
4. 中微子物理、粒子天体物理与宇宙学
Oral report
无中微子双贝塔衰变测量实验是当前粒子物理与核物理研究领域的重要科学前沿，对中微子性质研究具有重大意义。采用高纯锗探测器开展$^{76}$Ge无中微子双贝塔衰变测量实验具有低本底、高效率、最高能量分辨率的优势。CDEX-300ν实验计划在锦屏地下实验室（CJPL）建立300公斤级高纯锗探测器阵列（$^{76}$Ge同位素丰度达到86%），结合液氩反符合探测器开展无中微子双贝塔衰变研究。本报告将重点介绍CDEX-300ν实验的概念设计和未来计划，以及探测器、电子学、低本底等关键技术的研发进展。
Jijun Yang
(SJTU)
18/08/2021, 09:30
4. 中微子物理、粒子天体物理与宇宙学
Oral report
传统的暗物质模型WIMP(大质量弱相互作用粒子)成功的解释了宇宙大尺度结构的形成，但它在解释观测星系中暗物质分布方面困难重重。近年来，研究人员假设暗物质之间存在相互作用，并且预言了这种相互作用是通过一个小质量的传播子来传递的，也就是所谓的自相互作用暗物质模型。研究表明自相互作用暗物质模型可以很好地解决传统冷暗物质理论与星系观测间的矛盾。如果该轻质量传播子和标准模型粒子比如光子发生耦合，那么在暗物质直接探测实验上就可以产生可观测的信号，通过探测这类信号，就可以证实自相互作用暗物质的存在。另外，标准大爆炸核合成理论可以对轻传播子的寿命做出限制，进而可以对自相互作用暗物质模型预言的轻传播子质量做出限制。本报告将结合PandaX-II暗物质直接探测实验全部曝光量的数据，汇报一下在PandaX-II暗物质探测实验上搜寻轻质量传播子和标准模型粒子碰撞产生的信号的最新进展，以及来自暗物质直接探测实...
Mr
仲智 刘
(清华大学)
18/08/2021, 09:45
4. 中微子物理、粒子天体物理与宇宙学
Oral report
近年来理论学家提出的Migdal效应认为， WIMPs粒子与靶核发生反应的是非弹性散射，有一定概率在发生核反冲的电离或激发出电子且电子能量会大于核反冲能量。通过探测反冲电子与反冲核的总能量，可以在实验硬件阈值不变的情况下，获得对更轻质量暗物质的灵敏度限制。
基于Migdal效应，利用CDEX-1和CDEX-10实验数据开展了亚GeV区域的轻暗物质搜索。暗物质直接探测的质量下限降低一个数量级至50MeV，大大扩展了实验所能约束的暗物质质量空间并给出了新的灵敏限制。本报告将总结CDEX-1B实验和CDEX-10实验亚GeV轻暗物质探测的物理分析结果，并讨论地球屏蔽效应的影响。
祥仪 崔
(上海交通大学)
18/08/2021, 10:00
4. 中微子物理、粒子天体物理与宇宙学
Oral report
The PandaX-II experiment, located in the China Jinping Underground Laboratory(CJPL), operated with the dual phase xenon time projection chambers. Scintillation and ionization signals generated by the scatting between the incoming particle and xenon atoms are used for the dark matter(DM)-nucleus interactions study. Also, the DM-nucleus interactions will allow the cosmic rays, like protons or...
涛 李
(Sun Yat-Sen (Zhongshan) University)
18/08/2021, 10:15
4. 中微子物理、粒子天体物理与宇宙学
Oral report
1) 无中微子双贝塔衰变的物理意义和气体时间投影室探测器的介绍；
2) 针对不同能量分辨率和读出平面精度的本底和信号的模拟；
3) 径迹重建方法KFB的介绍，包括数据预处理、卡尔曼建模和滤波方法、拓扑特征提取；
4) 事件鉴别效率和对实验灵敏度的分析。
Lingyin Luo
(school of physics Peking Uniersity)
18/08/2021, 10:40
4. 中微子物理、粒子天体物理与宇宙学
Oral report
$^{136}Xe$双beta衰变背景介绍
PandaX实验寻找(NL)DBD-ES
PandaX-III(NL)DBD-ES蒙特卡洛模拟
PandaX-III(NL)DBD-ES粒子径迹拓扑特征分析
PandaX-4T(NL)DBD_ES蒙特卡洛模拟
结论与展望
泽 佘
(Tsinghua University)
18/08/2021, 10:55
4. 中微子物理、粒子天体物理与宇宙学
Oral report
暗光子是一种可能的暗物质候选粒子，也可能是一种新的标准模型粒子与暗物质粒子相互作用的媒介子，对暗光子的理论和实验研究，有助于发现超越粒子物理标准模型的新物理，扩展人类对宇宙起源和演化的认识，在当前暗物质直接探测领域内受到广泛的关注。基于中国暗物质实验组CDEX-10实验的两个极低阈值极低本底的高纯锗探测器，本文采用了最小化卡方值的统计方法计算了CDEX-10实验分别对太阳暗光子和暗光子暗物质的动能混合参数κ的限制结果．基于C10-B1探测器（分析阈值为160 eV）的205.4公斤天的测量数据，给出了轻质量的太阳暗光子动能混合参数在90%置信度下的上限值，并在10到300电子伏特区间上得到了国际上最好的直接探测实验结果；利用C10-B1的205.4公斤天和C10-C1的244.2公斤天的数据对暗光子暗物质的动能混合参数κ进行了联合分析，给出了其在0.1~4.0...
Mr
Chen Cheng
(Sun Yat-sen University)
18/08/2021, 11:10
4. 中微子物理、粒子天体物理与宇宙学
Oral report
We report constraints on light dark matter through its interactions with shell electrons in the PandaX-II liquid xenon detector with a total 46.9 tonnes·day exposure. To effectively search for these very low energy electron recoils, ionization-only signals are selected from the data. 1821 candidates are identified within an ionization signal range between 50 and 75 photoelectrons,...
Ms
Xuyang Ning
(sjtu)
18/08/2021, 11:25
4. 中微子物理、粒子天体物理与宇宙学
Oral report
PandaX is a direct detection of DM experiment with a dual phase Xenon TPC. Constraintson the simplest EFT dark matter-nucleus spin-independent (SI) interaction with full exposuredata had been delivered recently. There are other DM models like EFT magnetic or electricdipole moment interactions and boosted scenario which produce quite different signal spectrafrom the simplest EFT SI model. They...
ZHANG Yiyu
18/08/2021, 11:40
4. 中微子物理、粒子天体物理与宇宙学
Oral report
Neutrino electromagnetic properties are import windows in neutrino physics to go beyond the Standard Model. The coherent elastic neutrino-nucleus scattering process is a powerful probe of the neutrino electromagnetic properties, which was first observed in 2017 at the COHERENT experiment by the cesium-iodide (CsI) detector and later in 2020 at the argon (Ar) detector.
In this talk, we present...
