Higgs boson production and decay: Effects from light third generation and vectorlike matter

Abstract

We study the implications of light third generation sparticles on the production cross section and decay widths of a light CP-even Higgs boson. For simplicity, we consider scenarios in which only one of the sfermions from the third generation is light. For each case, we attempt to explain the apparently large enhancement in the Higgs production and decay in the diphoton channel with small deviations in the ZZ channel. In the MSSM framework we find that only a light stau can explain these observations while keeping the lightest CP-even Higgs boson mass in the interval 123 GeV m h 127 GeV. For the light stop scenario, the observations related to the diphoton and ZZ channel can be accommodated but, in order to satisfy the Higgs mass bound, one needs to go beyond the MSSM. In particular, we invoke vector like particles with masses around a TeV. These new particles preserve gauge coupling unification and provide additional contributions to the Higgs mass. With these new contributions a 126 GeV Higgs mass is easily achieved. We also find that with only a light sbottom quark, the above mentioned excess is hard to accommodate.

h → γγ in U(1) R -lepton number model with a right-handed neutrino

“…On the other hand, CMS collaboration reported a best-fit signal strength in their main analysis [4] where, µ γγ = 1.14 +0. 26 −0. 23 .…”

Dark two Higgs doublet model

“…(For some vectorlike fermion extension examples, see Refs. [4][5][6][7][8][9][10][11][12][13][14][15].) Certainly, detailed analyses of these extensions are worthwhile and might provide guidance to experimenters searching for physics beyond the SM.…”

Light staus and enhanced Higgs diphoton rate with non-universal gaugino masses and SO(10) Yukawa unification

“…The coefficients in front of D are fixed by charges under the broken U(1). It has been shown that for D > 0, m 10 > m 16 and universal other soft terms proper REWSB is consistent with top-bottom-tau Yukawa unification [48]. The crucial role in top-bottom-tau Yukawa unification is played by the sign of µ because it controls the sign of the dominant finite SUSY threshold corrections to the bottom mass [40,41,74]:…”

“…refs. [15][16][17][18][19][20][21][22][23][24][25][26][27]. In this paper we focus on the possibility that such new states are supersymmetric and study enhanced h → γγ rate in the MSSM.…”