161 research outputs found
Unification for Yukawas and its implications
The supersymmetric finite threshold effects are studied in the presence of
non minimal soft terms that can correct the problematic mass ratios of the
light generations in the minimal SU(5) GUT. We show that with large soft
A-terms, one can achieve simple unification for lighter generations without
additional Higgs multiplet, while having sfermions lighter than 1 TeV. The
presence of such large A-terms will distort the sfermion mass spectrum upon
running from GUT scale down to the electroweak scale making it distinct from
the universal SUSY breaking scenarios, especially in the first two generations.
The implications of these splittings are studied in K and D meson oscillations
and in rare processes D^+ -> pi^+ nu anti-nu and K^+ -> pi^+ nu anti-nu, and in
the latter case the effect is found to be important.Comment: 4 pages, based on a talk given at SUSY 09, 5-10 Jun 200
Scalar leptoquarks and Higgs pair production at the LHC
The presence of colored particles can affect both the single and the pair
Higgs productions substantially. For scalar particles, this happens if their
portal couplings to the Standard Model Higgs are large and their masses are not
too high. In the present work these processes are studied in the case of
several leptoquarks which may appear in many beyond Standard Model theories. It
is found that the constraints on the portal couplings from the single Higgs
production and the decays to various channels measured by the LHC experiments
still allow increased Higgs pair production rate. For the masses in the range
from 180 GeV to 300 GeV, depending on the strength of such portal couplings,
the Higgs pair production may reach an order to several hundred in magnitude
larger rate than the Standard Model case for the 8 TeV run. Therefore, combined
with the on going searches for leptoquarks by both the CMS and ATLAS, this is
one of the possible scenarios to be probed directly by the current data. The
current study demonstrates that if colored scalars modify scalar potentials
through portal couplings, which has been studied for variety of motivations
such as playing a potentially important role in electroweak phase transition,
composite models or radiative neutrino masses, this fact may appear as the
modified Higgs pair production.Comment: 19 pages, 4 figures, references added and typos correcte
China`'s Breakout from Encirclement: Belt and Road Initiative
China is a country with unique geographic position surrounded by twenty nations big and small (including Taiwan) around its periphery. China`s greatest security concern has always been a strategic encirclement – its neighbors aligning with one another or with strong powers such as the United States to isolate China. How does this sense of encirclement influence China’s strategic behavior? China`s central geographic position between Russia and the United States makes it hard for Beijing to maneuver its foreign policy in the region. Thus, China`s current leader came up with the idea of implementing a project, a modern version of the ancient Silk Road, whose specific function is to link countries of the world by the different types of infrastructure. Emerging as a feature of China`s so-called peaceful development, the Belt and Road Initiative (BRI) is a manifestation of its aspiration for connecting itself to the countries of the great Afro-Eurasian landmass by railroads, highways, shipping routes and communication networks. This article portrays the BRI as Chinese strategy of a breakout from encirclement. It argues that China is employing the BRI to pursue its strategic interests of enhancing its influence in its peripheral areas and extending its strategic reach further beyond its traditional periphery by gaining control over strategically important lands and ports
LIGHT LEPTOQUARKS AND HIGGS PAIR PRODUCTION
The data collected by the LHC experiments at 7 and 8 TeV with ~5 and 20fb-1 respectively is refining the details of the Higgs like resonances found last year [1,2]. Many decay channels have been searched for and the individual channels so far have given us a consistent picture with what one expects from the SM Higgs. On the other hand, the self interaction of the Higgs, which is probed by the Higgs pair production [3-7], is too feeble in the SM to be detected with these early data set. Even at 14 TeV run, the luminosity required for probing this process is very high [7-17]. This fact, namely the smallness of the corresponding Higgs pair production cross-section, makes it sensitive to a presence of a new physics [18-31]. In particular, relatively light colored particles are known to affect the cross-section substantially [18-22]. As a mater of fact there are many models with various motivations including models of GUT remnants [32-39], composite models [40-48] or a radiative neutrino mass models [49-51] which may give such contributions. Among these the scalars are interesting as they may play crucial role in the spontaneous symmetry breaking through additional terms with large portal couplings in the scalar potential. In the present work we study the phenomenological consequences of the Standard Model extension by two or more colored scalar particles. As a case study we take several leptoquarks (LQ) since there is an active experimental program by both ATLAS and CMS [52-57] and the lower bounds on their masses have now reached impressive levels some as high as a TeV value. On the other hand simultaneous presence of several LQs, may open up additional channels and therefore weakens these bounds. Specific models where the LQs are introduced to explain a certain phenomenon usually requires more than one LQs as in the model we study here. I examine a possibility of the existence of LQs with masses as light as ~180 GeV and study their effect for the single and di Higgs productions. As we will see the Higgs pair production is substantially altered in the low mass range below 300 GeV without too much change in the Higss diphoton decay channel if portal couplings are large. These couplings are required to have opposite signs by the latest Higgs data or small in magnitude. The model I consider has two LQs, an SU(2) doublet ω and a singlet χ. As we will see their simultaneous presence still allows them to have relatively light masses and escape the current bounds. In particular, the current bounds do not include LQs decaying to τt the masses below 200 GeV. Such a scenario, for example, has appeared in a model considered by Babu and Julio [49], where the light neutrino masses are induced by two-loop effects from LQs. If their masses are only of order few hundred GeV, as it is required in this case, the scenario can be probed or even excluded with the data from the LHC. Therefore this is one of the easiest model which can be tested and is the subject of the current study. Although I consider a particular model, it should be stressed that other models with colored particles can affect the pair productions in a similar manner.In Section II, I briefly list the current experimental status on the Higgs production and decay rates. Then I introduce the model I examined in the paper. Section III contains main part of this work where the numerical results for the single and pair Higgs productions are presented. The conclusion is given in Section IV
A Note on Anti-Berge Equilibrium for Bimatrix Game
Game theory plays an important role in applied mathematics, economics and decision theory. There are many works devoted to game theory. Most of them deals with a Nash equilibrium. A global search algorithm for finding a Nash equilibrium was proposed in [13]. Also, the extraproximal and extragradient algorithms for the Nash equilibrium have been discussed in [3]. Berge equilibrium is a model of cooperation in social dilemmas, including the Prisoner’s Dilemma games [15].
The Berge equilibrium concept was introduced by the French mathematician Claude Berge [5] for coalition games. The first research works of Berge equilibrium were conducted by Vaisman and Zhukovskiy [18; 19]. A method for constructing a Berge equilibrium which is Pareto-maximal with respect to all other Berge equilibriums has been examined in Zhukovskiy [10]. Also, the equilibrium was studied in [16] from a view point of differential games. Abalo and Kostreva [1; 2] proved the existence theorems for pure-strategy Berge equilibrium in strategic-form games of differential games. Nessah [11] and Larbani, Tazdait [12] provided with a new existence theorem. Applications of Berge equilibrium in social science have been discussed in [6; 17]. Also, the work [7] deals with an application of Berge equilibrium in economics. Connection of Nash and Berge equilibriums has been shown in [17]. Most recently, the Berge equilibrium was examined in Enkhbat and Batbileg [14] for Bimatrix game with its nonconvex optimization reduction. In this paper, inspired by Nash and Berge equilibriums, we introduce a new notion of equilibrium so-called Anti-Berge equilibrium. The main goal of this paper is to examine Anti-Berge equilibrium for bimatrix game.
The work is organized as follows. Section 2 is devoted to the existence of Anti-Berge equilibrium in a bimatrix game for mixed strategies. In Section 3, an optimization formulation of Anti-Berge equilibrium has been formulated
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