.. _sphx_glr_api_gallery_particle_detector_signatures:

Detector signatures
----------------------

Curved cloud-chamber tracks and branching cascade showers -- the
signatures that identified the positron, the muon, and cosmic-ray
showers, from :mod:`physicskit.particle.collider`.


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  <div id='sg-tag-list' class='sphx-glr-tag-list'></div>


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    <div class="sphx-glr-thumbnails">

.. thumbnail-parent-div-open

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    <div class="sphx-glr-thumbcontainer" tooltip="A charged particle in a magnetic field traces a circular arc of radius r=p_T/(qB). Anderson (1932) used exactly this geometry to identify the positron from a single cloud-chamber photograph: a track curving the &quot;wrong&quot; way for an electron or proton moving in the direction its ionization required. Four years later, Anderson and Neddermeyer (and independently Street and Stevenson) found tracks implying a mass between the electron&#x27;s and the proton&#x27;s -- the muon, identified from the same curvature-plus-ionization method. This example builds both tracks with charged_track_points and animate_detector_event, and shows how the arc radius alone fixes momentum, while momentum together with an independent speed estimate is what actually fixes mass.">

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  .. image:: /api/gallery/particle/detector_signatures/images/thumb/sphx_glr_plot_01_cloud_chamber_tracks_thumb.gif
    :alt:

  :doc:`/api/gallery/particle/detector_signatures/plot_01_cloud_chamber_tracks`

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      <div class="sphx-glr-thumbnail-title">Cloud-chamber tracks: the positron and the muon</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Bhabha, Heitler, Carlson, and Oppenheimer (1937) explained the cosmic-ray &quot;transition curve&quot; -- the number of shower particles first growing, then shrinking, with depth -- as a branching cascade: a single high-energy electron, positron, or photon alternately radiates a photon or materializes one into an electron-positron pair, each product repeating the process until individual energies fall low enough for ordinary ionization losses to take over. This example builds exactly this kind of branching cascade with simple_shower, checks that its total four-momentum is conserved from the single primary particle down to every final-state leaf, and shows the exponential growth in particle count with generation that gives the transition curve its characteristic rise.">

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  .. image:: /api/gallery/particle/detector_signatures/images/thumb/sphx_glr_plot_02_cascade_showers_thumb.gif
    :alt:

  :doc:`/api/gallery/particle/detector_signatures/plot_02_cascade_showers`

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      <div class="sphx-glr-thumbnail-title">Bhabha and Heitler's cascade theory of cosmic-ray showers</div>
    </div>


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    </div>


.. toctree::
   :hidden:

   /api/gallery/particle/detector_signatures/plot_01_cloud_chamber_tracks
   /api/gallery/particle/detector_signatures/plot_02_cascade_showers