56216722
Could two NMSSM Higgs bosons be present near 125 GeV
We examine next-to-minimal supersymmetric model scenarios with partial parameter unification at the grand unification scale in which both ${h}_{1}$ and ${h}_{2}$ lie in the 123\char21{}128 GeV mass range. Very substantially enhanced $\ensuremath{\gamma}\ensuremath{\gamma}$ and other rates are possible. Broadened mass peaks are natural.
119296553
Extending two-Higgs-doublet models by a singlet scalar field — The case for dark matter
A bstractWe extend the two-Higgs doublet models of Type I and Type II by adding a real gauge-singlet scalar S dark matter candidate (2HDMS models). We impose theoretical constraints deriving from perturbativity, stability, unitarity and correct electroweak symmetry breaking and require that the lightest CP-even Higgs, h, fit the LHC data for the ∼ 125.5 GeV state at the 68% C.L. after including existing constraints from LEP and B physics and LHC limits on the heavier Higgs bosons. We find that these models are easily consistent with the LUX and SuperCDMS limits on dark-matter-Nucleon scattering and the observed Ωh2 for S masses above about 55 GeV. At lower mS, the situation is more delicate. For points with mS in the 6-25 GeV range corresponding to the CDMS II and CRESST-II positive signal ranges, the dark-matter-Nucleon cross sections predicted by the Type I and Type II models more or less automatically fall within the 95%–99% C.L. signal region boundaries. Were it not for the LUX and SuperCDMS limits, which exclude all (almost all) such points in the case of Type I (Type II), this would be a success for the 2HDMS models. In fact, in the case of Type II there are a few points with 5.5 GeV ≲ mS ≲ 6.2 GeV that survive the LUX and SuperCDMS limits and fall within the CDMS II 99% C.L. signal region. Possibilities for dark matter to be isospin-violating in this 2HDMS context are also examined.
45741338
Diagnosing degenerate Higgs bosons at 125 GeV.
We develop diagnostic tools that would provide incontrovertible evidence for the presence of more than one Higgs boson near 125 GeV in the LHC data.
53533731
String bits and the spin vertex
Abstract We initiate a novel formalism for computing correlation functions of trace operators in the planar N = 4 SYM theory. The central object in our formalism is the spin vertex which is the weak coupling analogy of the string vertex in string field theory. We construct the spin vertex explicitly for all sectors at the leading order using a set of bosonic and fermionic oscillators. We prove that the vertex has trivial monodromy, or put in other words, it is a Yangian invariant. Since the monodromy of the vertex is the product of the monodromies of the three states, the Yangian invariance of the vertex implies an infinite exact symmetry for the three-point function. We conjecture that this infinite symmetry can be lifted to any loop order.
118672738
From spin vertex to string vertex
A bstractIn the recent publication [1] the spin vertex was introduced as a new approach for computing three-point functions in N=4$$ \mathcal{N}=4 $$ SYM. In this note we consider the BMN limit of the spin vertex for scalar excitations and show that it reproduces the string vertex in the light-cone string field theory which describes the string interactions in the pp-wave background at the leading order of λ′ expansion. This is achieved by introducing a polynomial representation for the spin vertex. We derive the Neumann coefficients from the spin vertex at weak coupling and show they match with the Neumann coefficients from the string field theory.
16931224
Loop induced W+- H-+ associated production via photon-photon collisions in the THDM and the MSSM
We study the loop induced production of charged Higgs boson associated with W-boson via photon-photon collisions at linear colliders (LC). The investigation is carried out under the two-Higgs-doublet model(THDM) and the minimal supersymmetric model (MSSM) using full on-mass-shell renormalization scheme. The numerical analysis of their production rates is presented with some typical parameter sets. The results show that the total cross sections in frame of the MSSM at linear colliders(LC) can reach 0.1 femto barn quantitatively. The contributions from supersymmetric sector can lead to an order of magnitude enhancement of the cross section in some parameter space. We conclude that the associated WH production rate in photon-photon collision mode is comparable to that in ee collision mode. PACS number(s): 12.60.Jv, 12.60.Fr, 12.15.Lk, 13.85.-t The project supported by National Natural Science Foundation of China
122386462
RF undulator for compact X-ray SASE source of variable wavelength
A room-temperature RF undulator, fed by Ka-band radiation and intended to produce ∼1 nm wavelength radiation using moderate energy electrons, is considered. The necessary electron bunches with energy 0.2-1 GeV could be produced by petawatt laser pulses injected into plasma bubbles.
117382818
The Study of Rare $B_c\rightarrow D^{(*)}_{s,d}l\bar{l}$ Decays
In this paper, we study rare decays $B_c\rightarrow D^{(*)}_{s,d}l\bar{l}$ within the Standard Model. The penguin, box, annihilation, color-favored cascade and color-suppressed cascade contributions are included. Based on our calculation, the annihilation and color-favored cascade diagrams play important roles in the differential branching fractions, forward-backward asymmetries, longitudinal polarizations of the final vector mesons and leptonic longitudinal polarization asymmetries. More importantly, color-favored cascade decays largely enhance the resonance cascade contributions. To avoid the resonance cascade contribution pollution, new cutting regions are put forward.