Abstract
Abstract: The top quark can be naturally singled out from other fermions in the Standard Model due to its large mass, of the order of the electroweak scale. We follow this reasoning in models of pseudo Nambu Goldstone Boson composite Higgs, which may derive from an underlying confining dynamics. We consider a new class of flavour models, where the top quark obtains its mass via partial compositeness, while the lighter fermions acquire their masses by a deformation of the dynamics generated at a high flavour scale. One interesting feature of such scenario is that it can avoid all the flavour constraints without the need of flavour symmetries, since the flavour scale can be pushed high enough. We show that both flavour conserving and violating constraints can be satisfied with top partial compositeness without invoking any flavour symmetry for the up-type sector, in the case of the minimal SO(5)/SO(4) coset with top partners in the four-plet and singlet of SO(4). In the down-type sector, some degree of alignment is required if all down-type quarks are elementary. We show that taking the bottom quark partially composite provides a dynamical explanation for the hierarchy causing this alignment. We present explicit realisations of this mechanism which do not require to include additional bottom partner fields. Finally, these conclusions are generalised to scenarios with non-minimal cosets and top partners in larger representations.
| Original language | English |
|---|---|
| Article number | 85 |
| Journal | Journal of High Energy Physics |
| Volume | 2015 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2015 Jun 23 |
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Keywords
- Beyond Standard Model
- Heavy Quark Physics
- Kaon Physics
- Technicolor and Composite Models
ASJC Scopus subject areas
- Nuclear and High Energy Physics
Cite this
Anarchic Yukawas and top partial compositeness : the flavour of a successful marriage. / Cacciapaglia, Giacomo; Cai, Haiying; Flacke, Thomas; Lee, Seung Joon; Parolini, Alberto; Serôdio, Hugo.
In: Journal of High Energy Physics, Vol. 2015, No. 6, 85, 23.06.2015.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Anarchic Yukawas and top partial compositeness
T2 - the flavour of a successful marriage
AU - Cacciapaglia, Giacomo
AU - Cai, Haiying
AU - Flacke, Thomas
AU - Lee, Seung Joon
AU - Parolini, Alberto
AU - Serôdio, Hugo
PY - 2015/6/23
Y1 - 2015/6/23
N2 - Abstract: The top quark can be naturally singled out from other fermions in the Standard Model due to its large mass, of the order of the electroweak scale. We follow this reasoning in models of pseudo Nambu Goldstone Boson composite Higgs, which may derive from an underlying confining dynamics. We consider a new class of flavour models, where the top quark obtains its mass via partial compositeness, while the lighter fermions acquire their masses by a deformation of the dynamics generated at a high flavour scale. One interesting feature of such scenario is that it can avoid all the flavour constraints without the need of flavour symmetries, since the flavour scale can be pushed high enough. We show that both flavour conserving and violating constraints can be satisfied with top partial compositeness without invoking any flavour symmetry for the up-type sector, in the case of the minimal SO(5)/SO(4) coset with top partners in the four-plet and singlet of SO(4). In the down-type sector, some degree of alignment is required if all down-type quarks are elementary. We show that taking the bottom quark partially composite provides a dynamical explanation for the hierarchy causing this alignment. We present explicit realisations of this mechanism which do not require to include additional bottom partner fields. Finally, these conclusions are generalised to scenarios with non-minimal cosets and top partners in larger representations.
AB - Abstract: The top quark can be naturally singled out from other fermions in the Standard Model due to its large mass, of the order of the electroweak scale. We follow this reasoning in models of pseudo Nambu Goldstone Boson composite Higgs, which may derive from an underlying confining dynamics. We consider a new class of flavour models, where the top quark obtains its mass via partial compositeness, while the lighter fermions acquire their masses by a deformation of the dynamics generated at a high flavour scale. One interesting feature of such scenario is that it can avoid all the flavour constraints without the need of flavour symmetries, since the flavour scale can be pushed high enough. We show that both flavour conserving and violating constraints can be satisfied with top partial compositeness without invoking any flavour symmetry for the up-type sector, in the case of the minimal SO(5)/SO(4) coset with top partners in the four-plet and singlet of SO(4). In the down-type sector, some degree of alignment is required if all down-type quarks are elementary. We show that taking the bottom quark partially composite provides a dynamical explanation for the hierarchy causing this alignment. We present explicit realisations of this mechanism which do not require to include additional bottom partner fields. Finally, these conclusions are generalised to scenarios with non-minimal cosets and top partners in larger representations.
KW - Beyond Standard Model
KW - Heavy Quark Physics
KW - Kaon Physics
KW - Technicolor and Composite Models
UR - http://www.scopus.com/inward/record.url?scp=84934980729&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84934980729&partnerID=8YFLogxK
U2 - 10.1007/JHEP06(2015)085
DO - 10.1007/JHEP06(2015)085
M3 - Article
AN - SCOPUS:84934980729
VL - 2015
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
SN - 1126-6708
IS - 6
M1 - 85
ER -