Changes between Version 5 and Version 6 of TopBNV

Timestamp:

Jun 14, 2021, 8:26:35 PM (3 years ago)

Author:

gdurieux

Comment:

--

TopBNV

@@ -1 @@
-The model contains baryon-(and lepton)-number-violating (BNV) four-fermion interactions: tbμc, tbue, tτdu. Note all three flavour variations are controlled by the same parameters ({{{aaa}}}, {{{bbb}}}, {{{ccc}}}, {{{ddd}}} and primed analogues). These interactions for instance lead to the t→b̅c̅μ⁺ decay and ub→t̅e⁺ single top production in association with a single lepton.
+= Top-quark baryon number violation =
+
+The model contains baryon-(and lepton)-number-violating (BNV) four-fermion interactions like tbμc, tbue, tτdu. These interactions for instance lead to the t→b̅c̅μ⁺ decay and ub→t̅e⁺ single top production in association with a single lepton.
 
 Following [https://arxiv.org/abs/1107.3805 1107.3805], the implemented mass-eigenstate operators take the form:
 \\[[Image(operators-s-t.png)]]\\
+The corresponding parameters are {{{aaa}}}, {{{bbb}}}, {{{ccc}}}, {{{ddd}}} and their primed analogues.
+Suffixes of the type {{{IxJ}}} encode the generation indices {{{I}}} and {{{J}}} of the fermion in each of the currents.
+An effective scale {{{Lambda}}} is introduced and set by default to 1 TeV.
 Relations between the parameters above and those of the following gauge-eigenstate basis:
 \\[[Image(operators-1-5.png)]]\\
@@ -9 +14 @@
 where the various {{{V}}}'s are the rotations between mass- and gauge eigenstates.
 
-UFO model: [attachment:bnv-ufo.tar.gz]
+To overcome !MadGraph limitations, the model introduces a very heavy fictitious mediator {{{X}}} which effectively generates the required four-fermion interactions. Its mass {{{MX}}} is set by default to 1 PeV and should be kept much higher than the energy scale of the considered process, so that computation do not depend on its exact value.
+
+The BNV decay width of the top quark as well as the {{{u d > t~ ta+}}} matrix element computed by !MadGraph in {{{standalone_cpp}}} mode (for various combinations of {{{aaa3x1}}}, {{{bbb3x1}}}, {{{ccc1x3}}}, {{{ddd1x3}}}, {{{aaaprime3x3}}}, {{{bbbprime3x3}}}, {{{cccprime1x1}}}, {{{dddprime1x1}}} and at various phase-space point) have been validated against analytical computations. 
+
+UFO model: [attachment:bnv_mediator_ufo.tar.gz]
 
 Please refer to: [https://arxiv.org/abs/1107.3805]