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2017:groups:np:efttherror [2017/06/21 16:48]
francesco.riva
2017:groups:np:efttherror [2017/08/15 13:45] (current)
francesco.riva
Line 2: Line 2:
 [Estimation of the theoretical uncertainties in EFT] [Estimation of the theoretical uncertainties in EFT]
  
-** interested people:** Olivier Mattelaer, Ken Mimasu, Kentarou Mawatari, Shankha Banerjee, Biplob Bhattacherjee,​ Francesco Riva, Benjamin Fuks, Ramona Groeber, Julia Harz, Jorge de Blas, Kristin Lohwasser, Alexandra Carvalho... ADD YOUR NAME HERE+** interested people:** Olivier Mattelaer, Ken Mimasu, Kentarou Mawatari, Shankha Banerjee, Biplob Bhattacherjee,​ Francesco Riva, Benjamin Fuks, Ramona Groeber, Julia Harz, Jorge de Blas, Kristin Lohwasser, Alexandra Carvalho, Adam Falkowski... ADD YOUR NAME HERE
  
  
-A question that often arises is wheter dimension-8 effects compromise present analysis testing dimension-6 ones. Normally this requires a discussion about the expected size of dimension-8 operators under given assumptions (see for instance "On the Validity of the Effective Field Theory Approach to SM Precision Tests" https://​arxiv.org/​pdf/​1604.06444.pdf) 
  
-Here we want to compute a class of dimesnion-8 effects that arises after a change of basis, in such a way that their coefficient is uniquely related to the coefficients of dimension-6 operators.+A question that often arises is whether dimension-8 effects compromise present analysis testing dimension-6 ones. Normally this requires a discussion about the expected size of dimension-8 operators under given assumptions (see for instance "On the Validity of the Effective Field Theory Approach to SM Precision Tests" https://​arxiv.org/​pdf/​1604.06444.pdf) 
 + 
 +Here we want to compute a class of dimension-8 effects that arises after a change of basis, in such a way that their coefficient is uniquely related to the coefficients of dimension-6 operators.
 The goal of this analysis will be to understand under what conditions we can trust the dimension-6 analysis in the rotated basis. The goal of this analysis will be to understand under what conditions we can trust the dimension-6 analysis in the rotated basis.
  
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 Now, it will be interesting to understand when this dim-8 contribution is important, and in particular if it is important when the square of the dimension-6 becomes bigger than the linear (interference) term. Now, it will be interesting to understand when this dim-8 contribution is important, and in particular if it is important when the square of the dimension-6 becomes bigger than the linear (interference) term.
 It seems that the dimension-8 is always suppressed by the m/energy, but this needs to be checked. It seems that the dimension-8 is always suppressed by the m/energy, but this needs to be checked.
 +
  
 In practice this project involves the following steps: In practice this project involves the following steps:
  
 1) perform field redefinition to find the coefficient of O_8 as a function of the coefficient of O_1 1) perform field redefinition to find the coefficient of O_8 as a function of the coefficient of O_1
 +-> **Francesco**
  
 2) comupte contribution to \psi\psi -> V_L V_L from O_1, O_2 and O_8 2) comupte contribution to \psi\psi -> V_L V_L from O_1, O_2 and O_8
 +Use Re-Weighting method to avoid statistical error in the various generation
 +-> Model and param_card created by Ken + **Ramona** -> Run by **Olivier**
  
 3) Impose that the quadratic piece be bigger than the linear piece, and test in these conditions how big the dimension-8 contribution becomes 3) Impose that the quadratic piece be bigger than the linear piece, and test in these conditions how big the dimension-8 contribution becomes
 +-> **Olivier**
  
 4) Understand wheter this behavior is the same in other processes 4) Understand wheter this behavior is the same in other processes
 +-> **Shankha**:​ O_W, O_B and O_WB and O_phi_1 (this one is strongly constrained by custodial symmetry, that's what I remember) (Eq. 2 in Ref. https://​arxiv.org/​pdf/​1211.4580.pdf) which modify the ZWW/ gamma WW couplings as given in Eqs. 27 and 28.
 +-> **Ken** and **Ramona** for generating the model, **Biplob** and **Shankha** for the generation/​comparaison
 +
 +
 +Another possibly interesting question would be the EFT effect included in the definition of the dependent electroweak parameters. This is assumed to be super small, but we may want to verify it quantitatively. After all, this is also part of the dim8 effects that we are after. I honestly think it is small, but i have never seen anything where this was tested.
 +
 +Todo:
 +
 +1) generate the model with and without those contributions
 +-> **Benj**
 +
 + * {{:​2017:​groups:​np:​hel.dim6.fullytruncated.tgz|Here}} is a model fully truncated at the dim 6 level.
  
 +2) generate p p > W W (same process as above) and compare the various results.
 +Use Re-Weighting method to avoid statistical error in the various generation
 +-> **Ken** and **Olivier**
  
  
2017/groups/np/efttherror.1498056495.txt.gz · Last modified: 2017/06/21 16:48 by francesco.riva