fix: Correct the pTperHelixRadius calculation in SeedFinderConfig (#2132

)

To synchronize with acts-project/traccc#403

The right equation is rho [mm] / pT [MeV] = 0.0033356 / B[kT] <=>  pT[MeV] / rho[mm] = 299.796 * B[kT], so the factor of 300 is wrong

Reference: https://en.wikipedia.org/wiki/Rigidity_(electromagnetism)

Core/include/Acts/Seeding/SeedFinderConfig.hpp

@@ -263,6 +263,8 @@ struct SeedFinderOptions {
 
   template <typename Config>
   SeedFinderOptions calculateDerivedQuantities(const Config& config) const {
+    using namespace Acts::UnitLiterals;
+
     if (!isInInternalUnits) {
       throw std::runtime_error(
           "Derived quantities in SeedFinderOptions can only be calculated from "
@@ -272,7 +274,7 @@ struct SeedFinderOptions {
     // helix radius in homogeneous magnetic field. Units are Kilotesla, MeV and
     // millimeter
     // TODO: change using ACTS units
-    options.pTPerHelixRadius = 300. * options.bFieldInZ;
+    options.pTPerHelixRadius = 1_T * 1e6 * options.bFieldInZ;
     options.minHelixDiameter2 =
         std::pow(config.minPt * 2 / options.pTPerHelixRadius, 2);
     options.pT2perRadius =

Examples/Python/tests/root_file_hashes.txt

@@ -49,8 +49,8 @@ test_digitization_example_input[smeared]__particles.root: 8549ba6e20338004ab8ba2
 test_digitization_example_input[smeared]__measurements.root: 97d695ea55114aa3cb6c967c43e820472ceb8129afbb4f1f22bf1b3eca55ced9
 test_digitization_example_input[geometric]__particles.root: 8549ba6e20338004ab8ba299fc65e1ee5071985b46df8f77f887cb6fef56a8ec
 test_digitization_example_input[geometric]__measurements.root: 9e7ab4e553966728306c0aa70496b95e440165d40ea89483fc5f7295988debe6
-test_ckf_tracks_example[generic-full_seeding]__trackstates_ckf.root: c85f29c499769b7c50e45167e3280d3ca753096609b766f67bf56af7adb38293
-test_ckf_tracks_example[generic-full_seeding]__tracksummary_ckf.root: d9542be93badd8f1dafb6728e1d418444880776bbe0d0fc52b494606a110cc99
+test_ckf_tracks_example[generic-full_seeding]__trackstates_ckf.root: b9fbda5adfa24d128ec94c464575cbd788599a9c02e6aa54090d03c753d839cb
+test_ckf_tracks_example[generic-full_seeding]__tracksummary_ckf.root: 3c7251078c7a062e90d9e93ff80498289c25bb4fdb3b6ede00c92fc3c4e63d34
 test_ckf_tracks_example[generic-full_seeding]__performance_seeding_trees.root: 0e0676ffafdb27112fbda50d1cf627859fa745760f98073261dcf6db3f2f991e
 test_ckf_tracks_example[generic-truth_estimated]__trackstates_ckf.root: 3575fdef14664866447ecf84b682305228181ec19365d834c661a9b40ed5ac75
 test_ckf_tracks_example[generic-truth_estimated]__tracksummary_ckf.root: 2c71b3d55b146f8fd4ac9cb9086abbe5236a281d07c7616e6da36effff8d19b6