====== Flavour puzzle ======


<tabbox Intuitive> 

The flavor puzzle is the question why do the particles in the [[models:standard_model|standard model of particle physics]] have the values they have, and why do the mixing angles in the PMNS and CKM matrix have the values they have.
  
<tabbox Concrete> 
  * [[https://arxiv.org/pdf/hep-ph/9210250.pdf|The Fermion Mass Problem]] by K.S. Babu
  * [[https://eldorado.tu-dortmund.de/bitstream/2003/35777/1/Dissertation_Schumacher.pdf|A Model-Building Approach to the Origin of Flavor]] by E. Schuhmacher
  * [[https://arxiv.org/abs/1503.04071|Pieces of the Flavour Puzzle by Ferruccio Feruglio]]
<tabbox Abstract> 

<tabbox Research>

<blockquote>The Yukawa couplings express the flavour problem, i.e. our inability to compute quark and lepton masses and mixing angles. [...]

no significant progress has ever been made in computing quark and lepton masses and mixing angles or understanding the dynamical origin of their pattern. [...]  Given our failure in cracking the flavour problem, it is unlikely that its solution is simple and that it manifests itself in simple ways. Only crazy results in flavour physics have a chance to be true.


<cite>https://arxiv.org/pdf/1710.07663.pdf#page23</cite>

</blockquote>


-->Flavor Democracy#

See [[models:speculative_models:democracy]]
<--

--> "all fermions are created equal"#

See [[http://www.sciencedirect.com/science/article/pii/0370269383905841|On the proposition that all fermions are created equal]] by Howard Georgi, Ann Nelson, Aneesh Manohar

 
<--

--> Flavor Symmetries#

For a great introduction, see this [[https://www.nikhef.nl/pub/theory/phd-theses/reinier_adelhart.pdf|thesis]]. 


<--
  
<tabbox Why is it interesting?> 
<blockquote>"In a recent interview published in CERN COURIER, Steven Weinberg was asked what single open question he would like to see answered in his lifetime, and Weinberg replied that it is only the mystery of the observed pattern of quark and lepton masses[1]. " <cite>https://arxiv.org/pdf/1712.08052.pdf</cite></blockquote>





</tabbox>