ترغب بنشر مسار تعليمي؟ اضغط هنا

One-loop effects of MSSM particles in e^-e^+ to Zh and e^-e^+ to ubar u h at the ILC

107   0   0.0 ( 0 )
 نشر من قبل Yusaku Kouda
 تاريخ النشر 2018
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

The 1-loop effects of the MSSM at the ILC are investigated through numerical analysis. We studied the higgs production processes $e^-e^+rightarrow Zh$ and $e^-e^+rightarrow ubar{ u}h$ at the ILC. It is found that the magnitude of the MSSM contribution through the 1-loop effects is sizable enough to be detected. In the study, three sets of the MSSM parameters are proposed, which are consistent with the observed higgs mass, the muon $g$-$2$, the dark matter abundance and the decay branching ratios of $B$ mesons. In the $e^-e^+rightarrow Zh$ process, the 1-loop effects of the MSSM are visible and the distinction of the parameter sets is partially possible. For the study of $e^-e^+rightarrow ubar{ u}h$, we used the equivalent $it W$-boson approximation in the evaluation of the 1-loop cross section. While the 1-loop effect of the MSSM is visible, the distinction of the parameter sets might not be possible in this process under the value of realistic luminosity at the ILC.



قيم البحث

اقرأ أيضاً

The paper describes high-precision theoretical predictions obtained for the cross sections of the process $e^+e^- to ZH$ for future electron-positron colliders. The calculations performed using the SANC platform taking into account the full contribut ion of one-loop electroweak radiative corrections, as well as longitudinal polarization of the initial beams. Numerical results are given for the energy range $E_{cm}=250$ GeV - $1000$ GeV with various polarization degrees.
117 - G.J. Gounaris , F.M. Renard 2014
We study the process $e^-e^+to ZH$ where $H$ represents the standard model (SM) Higgs particle $H_{SM}$, or the MSSM ones $h^0$ and $H^0$. In each case, we compute the one-loop effects and establish very simple expressions, called supersimple (sim), for the helicity conserving (dominant) and the helicity violating (suppressed) amplitudes. Such expressions, are then used to construct various cross sections and asymmetries, involving polarized or unpolarized beams and Z-polarization measurements. We examine the adequacy of such expressions to distinguish SM or MSSM effects, from other types of BSM (beyond the standard model) contributions.
This paper presents a full simulation study of the measurement of the production cross section ($sigma_{mathrm{ZH}}$) of the Higgsstrahlung process $mathrm{e^{+}e^{-}rightarrow ZH}$ and the Higgs boson mass ($M_{mathrm{H}}$) at the International Line ar Collider (ILC), using events in which a Higgs boson recoils against a Z boson decaying into a pair of muons or electrons. The analysis is carried out for three center-of-mass energies $sqrt{s}$ = 250, 350, and 500 GeV, and two beam polarizations $mathrm{e_{L}^{-}e_{R}^{+}}$ and $mathrm{e_{R}^{-}e_{L}^{+}}$, for which the polarizations of $mathrm{e^{-}}$ and $mathrm{e^{+}}$ are $left(Pmathrm{e^{-}},Pmathrm{e^{+}}right)$ =($-$80%, +30%) and (+80%, $-$30%), respectively. Assuming an integrated luminosity of 250 $mathrm{fb^{-1}}$ for each beam polarization at $sqrt{s}$ = 250 GeV, where the best lepton momentum resolution is obtainable, $sigma_{mathrm{ZH}}$ and $M_{mathrm{H}}$ can be determined with a precision of 2.5% and 37 MeV for $mathrm{e_{L}^{-}e_{R}^{+}}$ and 2.9% and 41 MeV for $mathrm{e_{R}^{-}e_{L}^{+}}$, respectively. Regarding a 20 year ILC physics program, the expected precisions for the $mathrm{HZZ}$ coupling and $M_{mathrm{H}}$ are estimated to be 0.4% and 14 MeV, respectively. The event selection is designed to optimize the precisions of $sigma_{mathrm{ZH}}$ and $M_{mathrm{H}}$ while minimizing the bias on the measured $sigma_{mathrm{ZH}}$ due to discrepancy in signal efficiencies among Higgs decay modes. For the first time, model independence has been demonstrated to a sub-percent level for the $sigma_{mathrm{ZH}}$ measurement at each of the three center-of-mass energies. The results presented show the impact of center-of-mass energy and beam polarization on the evaluated precisons and serve as a benchmark for the planning of the ILC run scenario.
By using the GRACE-Loop system, we calculate the full $mathcal{O}(alpha)$ electroweak radiative corrections to the process $e^+e^- rightarrow e^+e^- gamma$, which is important for future investigations at the International Linear Collider (ILC). With the GRACE-Loop system, the calculations are checked numerically by three consistency tests: ultraviolet finiteness, infrared finiteness, and gauge-parameter independence. The results show good numerical stability when quadruple precision is used. In the phenomenological results, we find that the electroweak corrections to the total cross section range from $sim -4%$ to $sim -21%$ when $sqrt{s}$ varies from $250$ GeV to $1$ TeV. The corrections also significantly affect the differential cross sections, which are a function of the invariant masses and angles and the final-particle energies. Such corrections will play an important role for the high-precision program at the ILC.
The processes of neutrino production of electron-positron pairs, $ u bar u to e^- e^+$ and $ u to u e^- e^+$, in a magnetic field of arbitrary strength, where electrons and positrons can be created in the states corresponding to excited Landau level s, are analysed. The results can be applied for calculating the efficiency of the electron-positron plasma production by neutrinos in the conditions of the Kerr black hole accretion disc considered by experts as the most possible source of a short cosmological gamma burst.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا