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Related papers: Linear Polarimetry with $\gamma \rightarrow e^+e^-…

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Conventional indirect dark matter (DM) searches look for an excess in the electromagnetic emission from the sky that cannot be attributed to known astrophysical sources. Here, we argue that the photon polarisation is an important feature to…

High Energy Physics - Phenomenology · Physics 2021-11-23 Marina Cermeño , Céline Degrande , Luca Mantani

X-ray polarimetry has the potential to make key-contributions to our understanding of galactic compact objects like binary black hole systems and neutron stars, and extragalactic objects like active galactic nuclei, blazars, and Gamma Ray…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Henric Krawczynski

We revisit the measurement of the polarization fraction, $P$, and the measurement of the polarization angle of partially linearly-polarized gamma rays using their conversion to $e^+e^-$ pairs in the field of a nucleus. We show that an…

Instrumentation and Methods for Astrophysics · Physics 2016-12-21 Philippe Gros , Denis Bernard

Recent studies have demonstrated the possibility of accelerating electrons to MeV energies in ambient air using tightly focused laser configurations. In this article, we explore possible strategies to control and optimize the resulting…

Various methods of obtaining longitudinally polarized positrons for future linear colliders are reviewed. Special attention is paid to the schemes using circularly polarized high-energy photons for positron production. Most effectively such…

High Energy Physics - Phenomenology · Physics 2009-11-10 V. Strakhovenko , X. Artru , R. Chehab , M. Chevallier

The physics programme for a coming electron linear collider is dominated by events with final states containing many jets. We develop in this paper the opinion that the best approach is to optimise the independent measurement of the tracks…

High Energy Physics - Experiment · Physics 2009-09-29 J-C. Brient , H. Videau

The proton analyzing power in carbon has been measured for energies of 82 to 217 MeV and proton scattering angles of 5 to 41 degrees. The measurements were carried out using polarized protons from the elastic scattering H(pol. e, pol. p)…

A gas Time Projection Chamber can be used for gamma-ray astronomy with excellent angular-precision and sensitivity to faint sources, and for polarimetry, through the measurement of photon conversion to $e^+e^-$ pairs. We present the…

Using the first station of the Long Wavelength Array (LWA1), we examine polarized pulsar emission between 25 and 88 MHz. Polarized light from pulsars undergoes Faraday rotation as it passes through the magnetized interstellar medium.…

High Energy Astrophysical Phenomena · Physics 2020-07-01 V. Dike , G. B. Taylor , J. Dowell , K. Stovall

We examine the performance of a TPC as a gamma-ray telescope above the pair-creation threshold. The contributions to the photon angular resolution are studied and their dependence on energy is obtained. The effective area per detector unit…

Instrumentation and Methods for Astrophysics · Physics 2014-05-15 Denis Bernard

Sizable hyperpolarisation, i.e. an imbalance of the occupation numbers of nuclear spins in a sample deviating from thermal equilibrium, is needed in various fields of science. For example, hyperpolarised tracers are utilised in magnetic…

An X-ray photoelectric polarimeter based on the Gas Pixel Detector has been proposed to be included in many upcoming space missions to fill the gap of about 30 years from the first (and to date only) positive measurement of polarized X-ray…

The hard X-ray polarimeter POLAR aims to measure the linear polarization of the 50-500 keV photons arriving from the prompt emission of gamma-ray bursts (GRBs). The position in the sky of the detected GRBs is needed to determine their level…

Instrumentation and Methods for Astrophysics · Physics 2010-11-17 E. Suarez-Garcia , D. Haas , W. Hajdas , G. Lamanna , C. Lechanoine-Leluc , R. Marcinkowski , A. Mtchedlishvili , S. Orsi , M. Pohl , N. Produit , D. Rapin , D. Rybka , J. -P. Vialle

The polarization measurement is an important tool to probe the prompt emission mechanism in gamma-ray bursts (GRBs). The synchrotron photons can be scattered by cold electrons in the outflow via Compton scattering processes. The observed…

High Energy Astrophysical Phenomena · Physics 2014-11-19 Zhe Chang , Yunguo Jiang , Hai-Nan Lin

We have developed a bolometric detector that is intrinsically sensitive to linear polarization which is optimized for making measurements of the polarization of the cosmic microwave background radiation. The receiver consists of a pair of…

Astrophysics · Physics 2020-12-22 W. C. Jones , R. S. Bhatia , J. J. Bock , A. E. Lange

The CERN-NA-59 experiment examined a wide range of electromagnetic processes for multi-GeV electrons and photons interacting with oriented single crystals. The various types of crystals and their orientations were used for producing photon…

Imaging polarimetry is an important tool for the study of cosmic magnetic fields. In our Galaxy, polarization levels of a few up to $\sim$10\% are measured in the submillimeter dust emission from molecular clouds and in the synchrotron…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Helmut Wiesemeyer , Talayeh Hezareh , Ernst Kreysa , Axel Weiss , Rolf Güsten , Karl M. Menten , Giorgio Siringo , Frederic Schuller , Attila Kovacs

We discuss contact-interaction searches in the processes e^+e^-\to \mu^+\mu^-, b\bar{b} and c\bar{c} at an e^+e^- Linear Collider with c.m. energy \sqrt{s}=0.5 TeV and with longitudinally polarized beams. The measurement of polarized cross…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. A. Babich , P. Osland , A. A. Pankov , N. Paver

In recent years, Laser Plasma Acceleration (LPA) has become a promising alternative to conventional RF accelerators. However, so far, it has only been theoretically shown that generating polarized LPA beams is possible. The LEAP (Laser…

Blazars are astrophysical sources whose emission is dominated by non-thermal processes, typically interpreted as synchrotron and inverse Compton emission. Although the general picture is rather robust and consistent with observations, many…