Changes between Version 4 and Version 5 of pSPSS

Timestamp:

Oct 11, 2022, 9:38:51 PM (2 years ago)

Author:

Jan Hajer

Comment:

--

pSPSS

@@ -1 @@
-= pSPSS: Phenomenological symmetry protected seesaw =
+= `pSPSS`: Phenomenological symmetry protected seesaw =
 
-The pSPSS describes the interactions of a pseudo-Dirac pair of two Majorana degrees of freedom [[latex($N_1$)]] and [[latex($N_2$)]] generically appearing in low-scale seesaw models.
-In the lepton number conserving (LNC) limit their interactions with the Standard Model are given by
+The motivation and implementation of the `pSPSS` discussed in 
+
+S. Antusch, J. Hajer, and J. Rosskopp. ‘Simulating heavy neutrino-antineutrino oscillations at colliders’ (2022).
+
+== Model description ==
+
+The `pSPSS` describes the interactions of a pseudo-Dirac pair of two Majorana degrees of freedom [[latex($N_1$)]] and [[latex($N_2$)]] generically appearing in low-scale seesaw models protected by a lepton-number like symmetry.
+
+In the lepton number conserving (LNC) limit the interactions of the symmetry protected seesaw (SPSS) with the Standard Model are
 
 [[latex($\mathcal L_\text{SPSS}^L = i \overline N_i \, \not\! \partial N_i -  y_{\alpha1} \widetilde H^\dagger \bar \ell_\alpha N_1^c - \overline N_1 m_M^{} N_2^c + \text{H.c.}$)]]
@@ -11 +18 @@
 [[latex($m_{4/5}^{} = m_M^{} + \frac12 m_M^{} |\theta|^2 \mp \frac12 \Delta m$)]]
 
-The smallness of the lepton number violating interactions ensures unobservable collider effects, except for heavy neutrino-antineutrino oscillations as these are a macroscopic interference effect 
+where [[latex($\theta = m_D / m_M$)]] with [[latex($m_D = y_1 v$)]] and [[latex($v\simeq174 \text{ GeV}$)]].
+The smallness of the lepton number violating interactions ensures unobservable collider effects, with the exception of heavy neutrino-antineutrino oscillations since these are a macroscopic interference effect 
 
-[[latex($P^{\text{LNC}/\text{LNV}}_\text{osc}(\tau) = \frac{1 \pm \cos\left(\Delta m \tau \right) \exp(-\lambda)}2$)]]
+[[latex($P^{\text{LNC}/\text{LNV}}_\text{osc}(\tau) = (1 \pm \cos\left(\Delta m \tau \right) \exp(-\lambda))/2$)]]
 
 where [[latex($\lambda$)]] captures the damping of the oscillations due to decoherence.
 
+== !FeynRules implementation ==
+
+The !FeynRules model file contains as free parameter in addition to the Standard Model parameter
+* Heavy neutrino Yukawa couplings [[latex($y_1$)]] `yvn1`, `yvn2`, `yvn3`
+* Majorana mass [[latex($m_M$)]] `Mmaj`
+* Mass splitting [[latex($\Delta M$)]] `deltaM`
+* Decoherence damping parameter [[latex($\lambda$)]] `damping`
+
 == !MadGraph patch ==
 
-In order to generate events with heavy neutrino-antineutrino oscillations it is necessary to patch the `./bin/internal/common_run_interface.py` file with
+In order to generate events with heavy neutrino-antineutrino oscillations it is necessary to patch the `./bin/internal/common_run_interface.py` file in !MadGraph using
 
 
@@ -38 +54 @@
         if width:
             if id in [8000011, 8000012]:
-                tau0 = random.expovariate(width / cst)|\label{ln:tau0}|
+                tau0 = random.expovariate(width / cst)
                 if 0.5 * (1 + math.cos(mass splitting * tau0 / cst)) >= random.random():
                     write_event = (leptonnumber == 0)
                 else:
                     write_event = (leptonnumber != 0)
-                vtim = tau0 * c|\label{ln:convert_tau0}|
+                vtim = tau0 * c
             else:
                 vtim = c * random.expovariate(width / cst)