اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدElectroweak symmetry breaking by a neutral sector: Dynamical relaxation of the little hierarchy problem
63
0
0.0
(
0
)
تأليف
Bumseok Kyae
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We propose a new dynamical relaxation mechanism of the little hierarchy problem, based on a singlet extension of the minimal supersymmetric standard model (MSSM). In this scenario, the small soft mass parameter of an MSSM singlet is responsible for the electroweak symmetry breaking and the non-zero Higgs vacuum expectation value, whereas the effect of the large soft mass parameter of the Higgs boson, -m_{h_u}^2 is dynamically compensated by a flat direction of the MSSM singlets. The small singlets soft mass and the Z boson mass can be protected, even if the stop mass is heavier than 10 or 20 TeV, since the gravity-mediated supersymmetry breaking effects and the relevant Yukawa couplings are relatively small. A focus point of the singlets soft mass parameter can emerge around the stop mass scale, and so various fine-tuning measures can reduce well below 100. Due to the relatively large gauge-mediated effects, the MSSM superpartners are much heavier than the experimental bounds, and the unwanted flavor changing processes are adequately suppressed.
قيم البحث
اقرأ أيضاً
We review the connection between $m_t$ and the $Zbbar b$ vertex in ETC models and discuss the resulting experimental constraint on models with weak-singlet ETC bosons. We mention several recent efforts to bring ETC models into agreement with this con
straint, and explore the most promising one (non-commuting ETC) in detail.
We point out that in theories where the gravitino mass, $M_{3/2}$, is in the range (10-50)TeV, with soft-breaking scalar masses and trilinear couplings of the same order, there exists a robust region of parameter space where the conditions for electr
oweak symmetry breaking (EWSB) are satisfied without large imposed cancellations. Compactified string/M-theory with stabilized moduli that satisfy cosmological constraints generically require a gravitino mass greater than about 30 TeV and provide the natural explanation for this phenomenon. We find that even though scalar masses and trilinear couplings (and the soft-breaking $B$ parameter) are of order (10-50)TeV, the Higgs vev takes its expected value and the $mu$ parameter is naturally of order a TeV. The mechanism provides a natural solution to the cosmological moduli and gravitino problems with EWSB.
We show that all the parameters which destabilize the weak scale can be taken around the weak scale in the MSSM without conflicting with the SM Higgs mass bound set by LEP experiment. The essential point is that if the lightest CP-even Higgs h in the
MSSM has only a small coupling to Z boson, g_{ZZh}, LEP cannot generate the Higgs sufficiently. In the scenario, the SM Higgs mass bound constrains the mass of the heaviest CP-even Higgs H which has the SM like g_{ZZH} coupling. However, it is easier to make the heaviest Higgs heavy by the effect of off-diagonal elements of the mass matrix of the CP-even Higgs because the larger eigenvalue of 2 times 2 matrix becomes larger by introducing off-diagonal elements. Thus, the smaller stop masses can be consistent with the LEP constraints. Moreover, the two excesses observed at LEP Higgs search can naturally be explained as the signals of the MSSM Higgs h and H in this scenario. One of the most interesting results in the scenario is that all the Higgs in the MSSM have the weak scale masses. For example, the charged Higgs mass should be around 130 GeV. This looks inconsistent with the lower bound obtained by the b --> s gamma process as m_{H^pm}>350GeV. However, we show that the amplitude induced by the charged Higgs can naturally be compensated by that of the chargino if we take the mass parameters by which the little hierarchy problem can be solved. The point is that the both amplitudes have the same order of magnitudes when all the fields in the both loops have the same order of masses.
We explore the use of the Inverse Amplitude Method for unitarization of scattering amplitudes to derive the existence and properties of possible new heavy states associated with perturbative extensions of the electroweak breaking sector of the Standa
rd Model starting from the low energy effective theory. We use a toy effective theory generated by integrating out a heavy singlet scalar and compare the pole mass and width of the unitarized amplitudes with those of the original model. Our results show that the Inverse Amplitude Method reproduces correctly the singlet mass up to factors of O(1-3), but its width is overestimated.
We review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. We emphasize the direct observation of the new interactions through high-energy scatterin
g of vector bosons. We also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models. [Working group summary report from the Snowmass `96 summer study, to appear in the proceedings.]
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
