scholarly journals Charged scalar production at the compact linear collider for the $$S_3 \otimes \mathbb {Z}_2$$ model

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
G. De Conto ◽  
A. C. B. Machado ◽  
J. Montaño ◽  
P. Chimenti

AbstractWe present a model with $$S_3 \otimes \mathbb {Z}_2$$ S 3 ⊗ Z 2 model plus a sterile neutrino and its phenomenological expectations for the production of charged scalars at the compact linear collider. At tree level, our model predicts a total cross section in between 0.1 and $$10^{-5}$$ 10 - 5 pb for the $$e^- e^+ \rightarrow H^+ H^-$$ e - e + → H + H - process, considering all possible mass values for the charged scalar in the CLIC experiment. We also show that this prediction holds regardless of the masses of the other exotic particles and their couplings. We also show that an indirect detection from its effects in the $$e \overline{e} \rightarrow e \overline{e}$$ e e ¯ → e e ¯ + missing energy process is possible under specific conditions, or a direct detection under other circumstances. However, one cannot use this process to study the sterile neutrinos present in this model, given that they have a small influence in the total cross-section for the direct detection of the exotic scalar to be possible.

2021 ◽  
Author(s):  
He-Yi Li ◽  
Ren-You Zhang ◽  
Wen-Gan Ma ◽  
Yi Jiang ◽  
Xiao-Zhou Li

Abstract We present the full NLO electroweak radiative corrections to $e^+e^-\gamma$ production in $\gamma\gamma$ collision, which is an ideal channel for calibrating the beam luminosity of Photon Linear Collider. We analyse the dependence of the total cross section on the beam colliding energy, and investigate the kinematic distributions of final particles at various initial photon beam polarizations at EW NLO accuracy. The numerical results show that the EW relative corrections to the total cross section are non-negligible and become more and more significant as the increase of the beam colliding energy, even can exceed $-10\%$ in $\text{J} = 2$ $\gamma\gamma$ collision at $\sqrt{\hat{s}}=1~ \text{TeV}$. Such EW corrections are very important and should be taken into consideration in precision theoretical and experimental studies at high-energy $\gamma\gamma$ colliders.


2012 ◽  
Vol 27 (07) ◽  
pp. 1250024
Author(s):  
DAPENG YANG ◽  
BINGFANG YANG ◽  
BIN XU

In the framework of the Left–Right Twin Higgs model, we studied the bottom-quark pair production via e+e- collision at the International Linear Collider. We calculated the bottom-quark pair production cross-section at tree level and the relevant differential distributions. The relative correction of the production cross-section is significant and the result will be a sensitive probe of the Left–Right Twin Higgs model.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Yuta Hamada ◽  
Hikaru Kawai ◽  
Kin-ya Oda ◽  
Kei Yagyu

Abstract We investigate a model with two real scalar fields that minimally generates exponentially different scales in an analog of the Coleman-Weinberg mechanism. The classical scale invariance — the absence of dimensionful parameters in the tree-level action, required in such a scale generation — can naturally be understood as a special case of the multicritical-point principle. This two-scalar model can couple to the Standard Model Higgs field to realize a maximum multicriticality (with all the dimensionful parameters being tuned to critical values) for field values around the electroweak scale, providing a generalization of the classical scale invariance to a wider class of criticality. As a bonus, one of the two scalars can be identified as Higgs-portal dark matter. We find that this model can be consistent with the constraints from dark matter relic abundance, its direct detection experiments, and the latest LHC data, while keeping the perturbativity up to the reduced Planck scale. We then present successful benchmark points satisfying all these constraints: the mass of dark matter is a few TeV, and its scattering cross section with nuclei is of the order of 10−9 pb, reachable in near future experiments. The mass of extra Higgs boson H is smaller than or of the order of 100 GeV, and the cross section of e+e− → ZH can be of fb level for collision energy 250 GeV, targetted at future lepton colliders.


1992 ◽  
Vol 07 (14) ◽  
pp. 1209-1218 ◽  
Author(s):  
TETSURO KOBAYASHI ◽  
TADASHI KON ◽  
KEIICHIRO NAKAMURA ◽  
TAKESHI SUZUKI

We investigate the production of the light scalar top quark [Formula: see text] via boson-gluon fusion at ep collider HERA, based on the minimal supersymmetric standard model. The cross-section is obtained by both an exact tree level calculation and the Weizsäcker-Williams approximation. It is shown that the total cross-section is larger than 0.1pb if [Formula: see text] and does not depend on the mixing angle θt of scalar top quarks. This enables us to search a possible region of parameters for existence of light scalar top at HERA in a wider parameter space [Formula: see text] than LEP.


2013 ◽  
Vol 28 (01) ◽  
pp. 1350004 ◽  
Author(s):  
PRASANTA KUMAR DAS ◽  
ABHISHODH PRAKASH

We study the 126 GeV Higgs boson pair production through e+e- collision in the noncommutative extension of the standard model using the Seiberg–Witten map of this to the first order of the noncommutative parameter Θμν. The process is forbidden in the standard model at the tree level. We study the time-averaged cross-section of the pair production at TeV scale linear collider and investigate the sensitivity of the cross-section on the orientation angle η and the noncommutative scale Λ. We found that Λ lies in the range 0.5 TeV–1.0 TeV, which can be reached by the upcoming linear collider.


2000 ◽  
Vol 15 (40) ◽  
pp. 2387-2400
Author(s):  
FANG-XIAO DONG ◽  
XIAN-JIAN ZHOU

The analytic helicity amplitudes of Z→3γ, γγ→Zγ and γZ→γγ via W-loop and charged scalar-loop are presented. There is some difference between our results and those in Ref. 13 for Z→3γ via W-loop and fermion-loop, which has different physical meanings. We have calculated the unpolarized and polarized cross-sections for γγ→γZ process. We find that the total cross-section of γγ→γZ is larger than that of γγ→γγ at 500 GeV of γγ c.m.s. energy. In principle this process provides a test of the non-Abelian nature of the standard model.


2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Salvatore Bottaro ◽  
Dario Buttazzo ◽  
Marco Costa ◽  
Roberto Franceschini ◽  
Paolo Panci ◽  
...  

AbstractWe study scenarios where Dark Matter is a weakly interacting particle (WIMP) embedded in an ElectroWeak multiplet. In particular, we consider real SU(2) representations with zero hypercharge, that automatically avoid direct detection constraints from tree-level Z-exchange. We compute for the first time all the calculable thermal masses for scalar and fermionic WIMPs, including Sommerfeld enhancement and bound states formation at leading order in gauge boson exchange and emission. WIMP masses of few hundred TeV are shown to be compatible both with s-wave unitarity of the annihilation cross-section, and perturbativity. We also provide theory uncertainties on the masses for all multiplets, which are shown to be significant for large SU(2) multiplets. We then outline a strategy to probe these scenarios at future experiments. Electroweak 3-plets and 5-plets have masses up to about 16 TeV and can efficiently be probed at a high energy muon collider. We study various experimental signatures, such as single and double gauge boson emission with missing energy, and disappearing tracks, and determine the collider energy and luminosity required to probe the thermal Dark Matter masses. Larger multiplets are out of reach of any realistic future collider, but can be tested in future $$\gamma $$ γ -ray telescopes and possibly in large-exposure liquid Xenon experiments.


2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Masashi Aiko ◽  
Shinya Kanemura ◽  
Kentarou Mawatari

AbstractWe present the cross section for $$e^{+}e^{-}\rightarrow hZ$$ e + e - → h Z with arbitrary sets of electron and Z boson polarizations at the full next-to-leading order in various extended Higgs models, such as the Higgs singlet model (HSM), the inert doublet model (IDM) and the two Higgs doublet model (2HDM). We systematically perform complete one-loop calculations to the helicity amplitudes in the on-shell renormalization scheme, and present the full analytic results as well as numerical evaluations. The deviation $$\Delta R^{hZ}$$ Δ R hZ in the total cross section from its standard model (SM) prediction is comprehensively analyzed, and the differences among these models are discussed in details. We find that new physics effects appearing in the renormalized hZZ vertex almost govern the behavior of $$\Delta R^{hZ}$$ Δ R hZ , and it takes a negative value in most cases. The possible size of $$\Delta R^{hZ}$$ Δ R hZ reaches several percent under the theoretical and experimental bounds. We also analyze the deviation $$\Delta R^{hZ}_{XY}$$ Δ R XY hZ in the total cross section times decay branching ratios of the discovered Higgs boson by utilizing the program. It is found that the four types of 2HDMs can be discriminated by analyzing the correlation between $$\Delta R^{hZ}_{\tau \tau }$$ Δ R τ τ hZ and $$\Delta R^{hZ}_{bb}$$ Δ R bb hZ and those between $$\Delta R^{hZ}_{\tau \tau }$$ Δ R τ τ hZ and $$\Delta R^{hZ}_{cc}$$ Δ R cc hZ . Furthermore, the HSM and the IDM can be discriminated from the 2HDMs by measuring $$\Delta R^{hZ}_{WW}$$ Δ R WW hZ . These signatures can be tested by precision measurements at future Higgs factories such as the International Linear Collider.


Author(s):  
Charles W. Allen

With respect to structural consequences within a material, energetic electrons, above a threshold value of energy characteristic of a particular material, produce vacancy-interstial pairs (Frenkel pairs) by displacement of individual atoms, as illustrated for several materials in Table 1. Ion projectiles produce cascades of Frenkel pairs. Such displacement cascades result from high energy primary knock-on atoms which produce many secondary defects. These defects rearrange to form a variety of defect complexes on the time scale of tens of picoseconds following the primary displacement. A convenient measure of the extent of irradiation damage, both for electrons and ions, is the number of displacements per atom (dpa). 1 dpa means, on average, each atom in the irradiated region of material has been displaced once from its original lattice position. Displacement rate (dpa/s) is proportional to particle flux (cm-2s-1), the proportionality factor being the “displacement cross-section” σD (cm2). The cross-section σD depends mainly on the masses of target and projectile and on the kinetic energy of the projectile particle.


Sign in / Sign up

Export Citation Format

Share Document