ترغب بنشر مسار تعليمي؟ اضغط هنا

A Flavorful Composite Higgs Model : Connecting the B anomalies with the hierarchy problem

57   0   0.0 ( 0 )
 نشر من قبل Yi Chung
 تاريخ النشر 2021
  مجال البحث
والبحث باللغة English
 تأليف Yi Chung




اسأل ChatGPT حول البحث

We present a model which connects the neutral current B anomalies with composite Higgs models. The model is based on the minimal fundamental composite Higgs model with $SU(4)/Sp(4)$ coset. The strong dynamics spontaneously break the symmetry and introduce five Nambu-Goldstone bosons. Four of them become the Standard Model Higgs doublet and the last one, corresponding to the broken local $U(1)$ symmetry, is eaten by the gauge boson. This leads to an additional TeV-scale $Z$ boson, which can explain the recent B anomalies. The experimental constraints and allowed parameter space are discussed in detail.



قيم البحث

اقرأ أيضاً

We analyze the flavor structure of composite vector bosons arising in a model of vectorlike technicolor, often called hypercolor (HC), with eight flavors that form a one-family content of HC fermions. Dynamics of the composite vector bosons, referred to as HC rho in this paper, are formulated together with HC pions by the hidden local symmetry (HLS), in a way analogous to QCD vector mesons. Then coupling properties to the standard model (SM) fermions, which respect the HLS gauge symmetry, are described in a way that couplings of the HC rhos to the left-handed SM quarks and leptons are given by a well-defined setup as taking the flavor mixing structures into account. Under the present scenario, we discuss significant bounds on the model from electroweak precision tests, flavor physics, and collider physics. We also try to address B anomalies in processes such as B -> K(*) mu+ mu- and B -> D(*) tau nu, recently reported by LHCb, Belle, (ATLAS, and CMS in part.) Then we find that the present model can account for the anomaly in B -> K(*) mu+ mu- consistently with the other constraints while it predicts no significant deviations in B -> D(*) tau nu from the SM, which can be examined in the future Belle II experiment. The former is archived with the form C9 = -C10 of the Wilson coefficients for effective operators of b -> s mu+ mu-, which has been favored by the recent experimental data. We also investigate current and future experimental limits at the Large Hadron Collider (LHC) and see that possible collider signals come from dijet and ditau, or dimuon resonant searches for the present scenario with TeV mass range. To conclude, the present b -> s mu+ mu- anomaly is likely to imply discovery of new vector bosons in the ditau or dimuon channel in the context of the HC rho model. Our model can be considered as a UV completion of conventional U(1) model.
We propose a new framework to generate the Standard Model (SM) quark flavor hierarchies in the context of two Higgs doublet models (2HDM). The `flavorful 2HDM couples the SM-like Higgs doublet exclusively to the third quark generation, while the firs t two generations couple exclusively to an additional source of electroweak symmetry breaking, potentially generating striking collider signatures. We synthesize the flavorful 2HDM with the `flavor-locking mechanism, that dynamically generates large quark mass hierarchies through a flavor-blind portal to distinct flavon and hierarchon sectors: Dynamical alignment of the flavons allows a unique hierarchon to control the respective quark masses. We further develop the theoretical construction of this mechanism, and show that in the context of a flavorful 2HDM-type setup, it can automatically achieve realistic flavor structures: The CKM matrix is automatically hierarchical with $|V_{cb}|$ and $|V_{ub}|$ generically of the observed size. Exotic contributions to meson oscillation observables may also be generated, that may accommodate current data mildly better than the SM itself.
We analyse Starobinsky inflation in the presence of the Brout Englert Higgs (BEH) boson with a non-minimal coupling to the Ricci scalar, $R$. The latter induces a coupling of the massive scaleron associated with the $R^2$ term to the BEH boson and th is leads to a radiative correction to the BEH mass that must be fine tuned to keep the scalar light. For the case of $R^2$ driven inflation this requires a high level of fine tuning of order 1 part in $10^{8}$; for the case of Higgs inflation it is very much greater. We consider a scale invariant extension of the $R^2$/Higgs model and find that for $R^2$ driven inflation but not for Higgs inflation the required fine tuning is significantly reduced to one part in $10^{3-4}$. We consider the vacuum stability of the fine tuned model and its reheating and dilaton abundance after inflation. We also discuss possible gravitational wave signals associated with the model and the constraint on the mass of scalar or fermion dark matter candidates if they are produced by the gravitational couplings of the scalaron.
131 - Puneet Batra , Z. Chacko 2008
Twin Higgs models are economical extensions of the Standard Model that stabilize the electroweak scale. In these theories the Higgs field is a pseudo Nambu-Goldstone boson that is protected against radiative corrections up to scales of order 5 TeV by a discrete parity symmetry. We construct, for the first time, a class of composite twin Higgs models based on confining QCD-like dynamics. These theories naturally incoporate a custodial isospin symmetry and predict a rich spectrum of particles with masses of order a TeV that will be accessible at the LHC.
Most of the analysis of composite Higgs have focussed on the Minimal Composite Higgs Model, based on the coset SO(5)$times$U(1)$_X$/SO(4)$times$U(1)$_X$. We consider a model based on the coset of simple groups SO(7)/SO(6), with SO(4)$times$U(1)$_X$ e mbedded into SO(6). This extension of the minimal model leads to a new complex pNGB that has hypercharge and is a singlet of SU(2)$_L$, with properties mostly determined by the pattern of symmetry breaking and a mass of order TeV. Composite electroweak unification also leads to new bosonic and fermion resonances with exotic charges, not present in the minimal model. The lightest of these resonances is stable, and in some cases could provide candidates for dark matter. A new rich phenomenology is expected at LHC.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا