87966 - ASTROPARTICLE PHYSICS

Learning outcomes

At the end of the course, the student will have knowledge of the experimental and phenomenological aspects of the origin, nature and propagation of charged cosmic rays and neutrinos and a basic knowledge of the nature of Dark Matter, Gravitational Waves and Cosmic Microwave Background and the related experimental detection techniques. In particular, the student will be able to understand the connection between astrophysics and particle physics.

Course contents

1. An Overview of Multimessenger Astrophysics. What "Multimessenger" astrophysics is. The role of particle detectors in astroparticle physics. Complementarity between astrophysics with traditional electromagnetic radiation and astrophysics using new probes (charged cosmic rays, gamma-rays, neutrinos and gravitational waves). Outlook of the course

2. Charged Cosmic Rays in Our Galaxy. Brief history on the detection of Cosmic Rays (CR). Flux of CR on Earth: primary and secondary particles. Energy density of CR in our Galaxy. A Toy Telescope for primary CRs. Differential and integral Fluxes. Energy Spectrum of primary CRs. The physical properties of the galaxy. Low-energy CRs from the Sun. Number and energy density of CRs. Energy considerations on CR sources.

3. Direct Cosmic Ray Detection. Generalities on direct measurements. Measuring charge, momentum and energy of incoming CRs. Experiments on balloon and satellites. The AMS-02 experiment on the International Space Station. Abundances of elements in the Solar System and in CRs. Energy spectrum of CR Protons and Nuclei. Antimatter in our Galaxy. The electron and positron component of CRs.

4. Indirect Cosmic Ray Detection. The Structure of the Atmosphere. The Electromagnetic (EM) cascade: Heitler’s model of EM showers. Showers initiated by protons and nuclei. The Monte Carlo simulations of showers. Detectors of Extensive Air Showers (EAS) at the energy of the knee: a toy model and some real EAS experiments. The CR flux measured with EAS arrays. Mass composition of CRs around the knee .

5. Diffusion of Cosmic Rays in the Galaxy. The Overabundance of Li, Be, and B in CRs; why Li, Be, B are rare on Earth; Production of Li, Be, and B during propagation. Dating of CRs with radioactive nuclei. The Leaky Box Model. Energy dependence of the escape time. Energy Spectrum of CRs at the sources.

6. Galactic Accelerators and Acceleration Mechanisms. Second- and First-Order Fermi Acceleration Mechanisms . Magnetic Mirrors . The power-law energy spectrum from the Fermi model. Diffusive shock acceleration in strong shock waves. Supernova Remnants (SNRs) and the Standard Model of CRs acceleration. Maximum energy attainable in the SNR model. The spectral index of the energy spectrum. White Dwarfs, Neutron Stars and Pulsars. Stellar mass Black Holes. Possible Galactic sources of CRs above the knee: a simplified model.

7. The Extragalactic Sources and UHECRs. The Large-Scale Structure of the Universe. Hubble’s Law and the Cosmic Microwave Background Radiation (CMBR). Anisotropy of UHECRs: The extragalactic magnetic fields. The quest for extragalactic sources of UHECRs. Propagation of UHECRs. Fluorescent Light and Fluorescence Detectors. UHECR measurements with a single technique. Large hybrid observatories of UHECRs and their results on flux, arrival directions and composition.

8. The Sky Seen in gamma-rays. The Spectral Energy Distribution (SED) and multiwavelength observations. Astrophysical gamma-rays: The leptonic and the hadronic production models. Galactic sources and gamma-rays: a simple estimate. The Compton Gamma-Ray Observatory (CGRO) Legacy. Fermi-LAT and other experiments for gamma-ray astronomy. Diffuse gamma-rays in the Galactic plane. The Fermi-LAT catalogs. Gamma Ray Bursts (GRBs). Classification of GRBs.

9. The TeV Sky and Multiwavelength Astrophysics. The Imaging Cherenkov Technique (IACTs). EAS Arrays for gamma-astronomy. TeV Astronomy: the catalog. The CRAB Pulsar and Nebula. The problem of the identification of Galactic CR sources. The SED of some peculiar SNRs. Active Galaxies. The extragalactic gamma-ray sky.

10. High-Energy Neutrino Astrophysics. The CR, gamma-ray and neutrino connection. Neutrino detection principle. Background in large volume neutrino detectors. Neutrino detectors and neutrino telescopes. Reconstruction of neutrino-induced tracks and showers. Why km3-scale telescopes? Running and planned neutrino detectors. Results from neutrino telescopes. The first evidences of cosmic neutrinos

11. Atmospheric Muons and Neutrinos. Underground Muons. Early experiments for atmospheric neutrinos. Oscillations of atmospheric neutrinos. Measurement of atmospheric muon neutrino oscillations in underground experiments .

12. Low-Energy Neutrino Physics. Stellar Evolution of solar mass stars. The Standard Solar Model and neutrinos. Solar Neutrino Detection: Homestake, Gallex/GNO, Sage, Super-Kamiokande, SNO, Borexino. Deficit of solar neutrino as due to neutrino oscillations. Formation of heavy elements in massive stars. Stellae Novae. Core-Collapse Supernovae (Type II). Neutrino signal from a core-collapse SN. The SN1987A . Stellar Nucleosynthesis and the origin of trans-Fe elements

13. Basics on the Observations of Gravitational Waves (GWs). From Einstein Equation to GWs: a long story short. Energy Carried by a GW. The Two-Body System. Ground-based Laser Interferometers . GW150914: ger physical information from observed quantities (strain, frequency, frequency variation). Astrophysics of Stellar Black Holes after GW150914. GW170817, GRB170817A and AT 2017gfo: One Event. The Kilonova: Electromagnetic Follow-up of GW170817. Perspectives for observational cosmology after GW170817

14. Microcosm and Macrocosm. The Standard Model of the Microcosm: The Big Bang. The Standard Model of particle physics and beyond. Gravitational evidence of dark matter. Interactions of WIMPs with Ordinary Matter. Direct detection of dark matter: event rates. Direct searches for WIMPs. Indirect Searches for WIMPs. What’s Next?

 

Readings/Bibliography

This series of lectures originated the book (see below) published on 2014 by Springer. The content of the lectures for this academic year strictly follows the second edition of the book (Summer 2018), immediately available for students as PDF.

 

Maurizio Spurio: PROBES OF MULTIMESSENGER ASTROPHYSICS : Charged cosmic rays, neutrinos, γ-rays and gravitational waves

[ https://www.springer.com/la/book/9783319968537 ]-

Springer DOI: 10.1007/978-3-319-96854-4

Students not from the "Nuclear and Subnuclear Physics" curriculum MUST necessarily have pre-requisites of introductory knowledge of particle physics, particle detection and particle detectors. The introductory chapters of the book

Braibant, S., Giacomelli, G., Spurio, M. (2012): Particles and Fundamental Interactions [https://www.springer.com/la/book/9789400724631]

are recommended:

Teaching methods

Lectures on blackboard and with PC.

Assessment methods

Oral

Links to further information

https://www.springer.com/la/book/9783319968537

Office hours

See the website of Maurizio Spurio