====== $^{\rm BSM}_{\rm\ \ BBN}$ ======

==== Group ====
  * Ermal (parameter)
  * Jianping (analysis)
  * Alex B. (code)

==== Task ====
We will explore the impact of non-standard model physics on BBN:
  * Varying $\Lambda_{QCD}$
  * Neutron magnetic moment
  * Variations in gravitational constant

==== Results ====
For our results, please refer to our {{::bsmbbn-presentation.pdf|final presentation}}

==== Logbook ====
=== Monday, June 9 ===
  * decided on project topic
  * started familiarizing with BBN code and researching required inputs

=== Tuesday, June 10 ===
  * wrote wrapper script enabling us to vary some of the constants like neutron and proton mass, gravitational constant, Hubble parameter etc.
  * ran calculations of BBN dependence on grav. constant; H0 seems to be unused by the code, so varying it does not lead anywhere.
  * varying $\Lambda_{QCD}$ and the neutron magnetic moment both incluence the deuteron formation rate $p(n,\gamma)d$. Hence we rewrote this rate with parameters in the ''bigbang.f90'' code and [[group2_code|wrote a wrapper script]] which reads in a table with sets of parameters and calculates the BBN composition
  * started figuring out how the proton-neutron mass splitting and the deuteron properties depend on our input parameters
  * fixed several bugs in the code, continued familiarizing ourselves with Fortran and the BBN code

=== Wednesday, June 11 ===
  * produced plots of BBN abundance as function of grav. constant
  * tried to calculate and fit the $p(n,\gamma)d$ rate to use as input; partially succeeded

=== Thursday, June 12 ===
  * produced data and plots for BBN abundance as function of $\Lambda_{QCD}$ and $\mu_n$
  * also looked at the individual effects of $\Lambda_{QCD}$ on the actual inputs to the BBN calculation (neutron-proton mass splitting, neutron life time, deuteron energy, $p(n,\gamma)d$ rate) and identified the life time effect as the main effect driving the change in the <sup>4</sup>He abundance.
  * created {{::bsmbbn-presentation.pdf|final presentation}}