Higgs mass corrections in the SUSY B−L model with inverse seesaw

Abstract

In the context of the Supersymmetric (SUSY) B − L (Baryon minus Lepton number) model with an inverse seesaw mechanism, we calculate the one-loop radiative corrections due to right-handed (s)neutrinos to the mass of the lightest Higgs boson when the latter is Standard Model (SM)-like. We show that such effects can be as large as O(100) GeV, thereby giving an absolute upper limit on such a mass around 200 GeV. The importance of this result from a phenomenological point of view is twofold. On the one hand, this enhancement greatly reconciles theory and experiment, by alleviating the so-called 'little hierarchy problem' of the minimal SUSY realisation, whereby the current experimental limit on the SM-like Higgs mass is very near its absolute upper limit predicted theoretically, of 130 GeV. On the other hand, a SM-like Higgs boson with mass below 200 GeV is still well within the reach of the Large Hadron Collider (LHC), so that the SUSY realisation discussed here is just as testable as the minimal version. PACS numbers:The Higgs boson is the last missing particle in the SM. Higgs boson discovery at the LHC is, therefore, crucial for its validity as a low energy approximation of a new physics scenario valid to high energy scales. A possibility for the latter emerges in SUSY theories, wherein the Higgs mechanism is retained for mass generation and multiple Higgs bosons appear in order to cancel anomalies. In addition, the stabilization of the Higgs mass against loop corrections (gauge hierarchy problem) is possibly the strongest motivation for a SUSY theory of nature. Hence, Higgs boson discovery at the LHC is also crucial for SUSY as a whole. A consequence of a SUSY Higgs sector is the existence of a stringent upper bound on the mass of the lightest SUSY Higgs boson, h, when the latter is SM-like. In the Minimal Supersymmetric Standard Model (MSSM), this value is m h < ∼ 130 GeV. Therefore, non-observing at the LHC a SM-like Higgs boson lighter than 130 GeV would rule out the MSSM.In detail, in the MSSM, the mass of the lightest Higgs state can be approximated, at the one-loop level, as [1]where g is the SU (2) gauge coupling. mt 1,2 are the two stop physical masses. The ratio of the Electro-Weak (EW) Vacuum Expectation Values (VEVs) is given by tan β = v 2 /v 1 . Note that the factor 3 in the above topstop correction is due to color. If one assumes that the stop masses are of order TeV, then the one-loop effect leads to a correction of order O(100) GeV, which implies that m MSSM h < ∼ (90 GeV) 2 + (100 GeV) 2 ≃ 135 GeV. (2) It is worth mentioning that the two-loop corrections reduce this upper bound by a few GeVs, to the aforementioned 130 GeV or so value [2].Experimental evidence now exists for physics beyond the SM, in the form of neutrino oscillations, which imply neutrino masses [3]. In turn, the latter imply new physics beyond not only the SM, but also the MSSM. Right-handed neutrino superfields are usually introduced in order to implement the seesaw mechanism, which provides an elegant solution for the smallnes...

Light stops and fine-tuning in MSSM

“…This situation can be drastically different if MSSM is extended with new particles and/or new symmetries [22][23][24][25][26][27] which contribute to the Higgs boson mass as significantly as the stop. In this context, the minimal supersymmetric models may not cover the full picture of physics.…”

Double Higgs peak in the minimal SUSYB−Lmodel

“…Thus, the righthanded neutrino masses are naturally of order TeV and the Dirac neutrino masses must be less than 10 −4 GeV (i.e., they are of order the electron mass) [11][12][13][14], as data appear to demand. Furthermore, a similar BLSSM setup, based on an inverse seesaw mechanism, relieves the so-called small hierarchy problem of the MSSM, wherein the discovered Higgs boson mass of 125 GeV is dangerously close to its predicted absolute upper limit (130 GeV or so), by providing (s)neutrino mass corrections which can up-lift this value to 170 GeV or so [15,16] (see also [17]). Finally, the BLSSM could also contribute, with respect to the MSSM, additional loop corrections to the h → γγ rate [18], should this channel be confirmed to be enhanced by future CERN data.…”

Asymptotic Models for Studying Kinetics of Formation of Compact Objects with Strong Internal Bonds

“…It could not be ruled out that the above new particle is a product of disintegration of another heavier particle. It is also important to mark approximate accordance of obtained evaluation for fund m to the value of the upper limit of the Higgs mass identified in [81] as 170 GeV. These factors argue in favor of validity of relation (32) in terms of fundamental processes in microcosm.…”