相关论文: Light Stop and the $b\rightarrow s\gamma$ Process
The EDGES Collaboration has recently reported the detection of a stronger-than-expected absorption feature in the global 21-cm spectrum, centered at a frequency corresponding to a redshift of z ~ 17. This observation has been interpreted as…
The possibility of creating baryon asymmetry at the electroweak phase transition in the minimal supersymmetric standard model is considered for the case when right-handed squarks are much lighter than left-handed ones. It is shown that the…
We investigate the implications of the Higgs rate measurements from Run 1 of the LHC for the mass of the light scalar top partner (stop) in the Minimal Supersymmetric Standard Model (MSSM). We focus on light stop masses, and we decouple the…
In order to reproduce the measured mass of the Higgs boson mh = 125GeV in the minimal supersymmetric standard model, one usually has to rely on heavy stops, increasing the fine tuning of the electroweak scale. By introducing a new gauge…
Recent re-evaluations of the Standard Model (SM) contribution to ${\mathcal Br(b\to s\gamma)$ hint at a positive correction from new physics. Since a charged Higgs boson exchange always gives a positive contribution to this branching ratio,…
We discuss the phenomenology of a light U(1) gauge boson, $\gamma_B$, that couples only to baryon number. We assume that the new U(1) gauge symmetry is spontaneously broken and that the $\gamma_B$ mass is smaller than $m_Z$. Nevertheless,…
We study the finite-temperature effective potential of the Minimal Supersymmetric Standard Model, in the limit of only one light Higgs boson. Because of the large top Yukawa coupling, there can be significant differences with respect to the…
We propose using the lightest CP-even Higgs boson in the minimal supersymmetric standard model (MSSM) to probe the stop sector. Unlike measuring stop masses in production/decay processes which requires knowledge of masses and mixing angles…
It has been proposed that the observed diphoton excess at 750 GeV could be explained within the constrained minimal supersymmetric standard model via resonantly produced stop bound states. We reanalyze this scenario critically and extend…
The discovery of a Higgs boson with a mass of 126 GeV at the LHC when combined with the non-observation of new physics both in direct and indirect searches imposes strong constraints on supersymmetric models and in particular on the top…
We perform an analysis of the behaviour of the electroweak phase transition in the Minimal Supersymmetric Standard Model, in the presence of light stops. We show that, in previously unexplored regions of parameter space, the order parameter…
We obtain an improved upper bound on the lightest neutral CP-even Higgs boson mass from a low energy renormalisation-group analysis of the Higgs sector of the next-to-minimal supersymmetric standard model. We find $m_h< 145$ GeV for…
We perform a detailed study of the constraints from $b\to s\gamma$ on a large class of supergravity models, including generic four-parameter supergravity models, the minimal $SU(5)$ supergravity model, and $SU(5)\times U(1)$ supergravity.…
The process gamma gamma \to mu tau b bbar is studied in the minimal supersymmetric standard model within a large tan_beta scenario imposing on the parameter space present direct and indirect constraints from B physics and rare LFV…
The recent results of the CLEO Collaboration on both inclusive and exclusive radiative $B$ decays are combined with those of the UA2 Collaboration on $W\gamma$ production to highly constrain the anomalous trilinear gauge couplings of the…
We study the mass, the mixing and the coupling with $Z$ boson of the lightest Higgs boson in the next-to-minimal supersymmetric standard model. The vacuum structure of the Higgs potential is analyzed and the new false vacua are discussed.…
The experimental measurement of $B(b \to s\gamma)$ imposes important constraints on the charged Higgs boson mass in the MSSM. We show that by adding bilinear R--Parity violation (BRpV) in the tau sector, these bounds are relaxed. The bound…
We examine various direct and indirect experimental constraints on the nearly minimal supersymmetric standard model (nMSSM) and obtain the following observations: (i) Current experiments stringently constrain the parameter space, setting a…
Isospin asymmetry in b -> s gamma transitions provides severe constraints on new physics parameters, due to the small values of the experimental measurements. We exploit here this new observable to study different supersymmetric models. For…
New limits on the Higgs mass from LEP and new calculations on the radiative (penguin) decay of the b->s gamma branching ratio restrict the parameter space of the Constrained Minimal Supersymmetric Standard Model (CMSSM). We find that for…