Add massive neutrino support and improve CSV/CLI output

- Add neutrino mass parameter to SpectrumConfig and CLI interface
- Update PhaseSpace component to handle neutrino mass effects properly
- Update CSV headers to show basic endpoint and all transition types
- Add --csv-verbosity option to CLI with 'full' and 'concise' options
- Fix comparison plots to properly show linear scale variations
- Add comprehensive tests for neutrino mass functionality

beta_spectrum/spectrum.py

@@ -2,7 +2,7 @@
 from __future__ import annotations
 
 import logging
-from typing import TYPE_CHECKING, Dict, List, Optional, Tuple
+from typing import Dict, List, Optional, Tuple
 from dataclasses import dataclass
 
 import numpy as np
@@ -15,7 +15,6 @@ from beta_spectrum.components.screening import ScreeningCorrection
 from beta_spectrum.components.exchange import ExchangeCorrection
 from beta_spectrum.components.radiative import RadiativeCorrection
 from beta_spectrum.utils import T_to_W
-from beta_spectrum.constants import ME_MEV
 
 
 @dataclass
@@ -71,6 +70,7 @@ class SpectrumConfig:
     endpoint_MeV: float
     transition_type: str = "A"  # should be [A, F1, F1U, F2, F2U, F3, F3U, F4]
     e_step_MeV: float = 0.001
+    neutrino_mass_MeV: float = 0.0
 
     # Toggle components and corrections
     use_phase_space: bool = True
@@ -251,7 +251,12 @@ class BetaSpectrum:
 
         if config.use_phase_space:
             components.append(
-                PhaseSpace(W0=W0, transition_type=config.transition_type, logger=logger)
+                PhaseSpace(
+                    W0=W0,
+                    transition_type=config.transition_type,
+                    m_nu=config.neutrino_mass_MeV,
+                    logger=logger,
+                )
             )
 
         if config.use_fermi:
@@ -331,6 +336,7 @@ class BetaSpectrum:
                 endpoint_MeV=branch.endpoint_MeV,
                 transition_type=branch.transition_type,
                 e_step_MeV=config.e_step_MeV,
+                neutrino_mass_MeV=config.neutrino_mass_MeV,
                 # Branch-dependent components
                 use_phase_space=config.use_phase_space,
                 use_radiative=config.use_radiative,
@@ -451,7 +457,3 @@ class BetaSpectrum:
             branch_spectrum = branch_spec(W)
             result.append(self.branches[i].intensity * np.maximum(0.0, branch_spectrum))
         return result
-
-
-
-