اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدLarge Hadron Collider constraints on a light baryon number violating sbottom coupling to a top and a light quark
119
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We investigate a model of R-parity violating (RPV) supersymmetry in which the right-handed sbottom is the lightest supersymmetric particle, and a baryon number violating coupling involving a top is the only non-negligible RPV coupling. This model evades proton decay and flavour constraints. We consider in turn each of the couplings lambda_{313} and lambda_{323} as the only non-negligible RPV coupling, and we recast two recent Large Hadron Collider (LHC) measurements and searches (CMS top transverse momentum p_T(t) spectrum and ATLAS multiple jet resonance search) in the form of constraints on the mass-coupling parameter planes. We delineate a large region in the parameter space of the mass of the sbottom (m_{b_R}) and the lambda_{313} coupling that is ruled out by the measurements, as well as a smaller region in the parameter space of m_{b_R} and lambda_{323}. A certain region of the m_{b_R}-lambda_{313} parameter space was previously found to successfully explain the anomalously large ttbar forward backward asymmetry measured by Tevatron experiments. The entire region is excluded at the 95% CL by CMS measurements of the top p_T spectrum. We also present p_T(ttbar) distributions of the forward-backward asymmetry for this model.
قيم البحث
اقرأ أيضاً
In this talk, I review the T-odd correlations induced by CP violating anomalous top-quark couplings at both production and decay level in the process gg --> t t_bar --> (b mu+ nu_mu) (b_bar mu-nu_mu_bar). In addition I will also focus on experimental
sensitivities corresponding to the anomalous couplings at the LHC.
We investigate the bounds on light pseudoscalars that arise from a variety of collider searches. Special attention is thereby devoted to the mass regions $[3, 5] , {rm GeV}$ and $[9,11] , {rm GeV}$, in which a meaningful theoretical description has t
o include estimates of non-perturbative effects such as the mixing of the pseudoscalar with QCD bound states. A compendium of formulas that allows to deal with the relevant corrections is provided. It should prove useful for the interpretation of future LHC searches for light CP-odd spin-0 states.
A radion in a scenario with a warped extra dimension can be lighter than the Higgs boson, even if the Kaluza-Klein excitation modes of the graviton turn out to be in the multi-TeV region. The discovery of such a light radion would be gateway to new p
hysics. We show how the two-photon mode of decay can enable us to probe a radion in the mass range 60 - 110 GeV. We take into account the diphoton background, including fragmentation effects, and include cuts designed to suppress the background to the maximum possible extent. Our conclusion is that, with an integrated luminosity of 3000 $rm fb^{-1}$ or less, the next run of the Large Hadron Collider should be able to detect a radion in this mass range, with a significance of 5 standard deviations or more.
We analyze several signals at HERA and the Tevatron of a light $U(1)_B$ gauge boson ($gamma_B$) coupling to baryon number. We show that the study of the production of $b bar{b}$ pairs at the (upgraded) Tevatron can exclude $gamma_B$ with masses ($m_B
$) in the range $40 lesssim m_B lesssim 300$ GeV for $gamma_B$ couplings ($alpha_B$) greater than $2 times 10^{-2}$ ($3 times 10^{-3}$). We also show that the HERA experiments cannot improve the present bounds on $gamma_B$. Moreover, we demonstrate that the production at HERA and the Tevatron of di--jet events with large rapidity gaps between the jets cannot be explained by the existence of a light $gamma_B$.
Nonstandard CP violation in the Higgs sector can play an essential role in electroweak baryogenesis. We calculate the full two-loop matching conditions of the standard model, with Higgs Yukawa couplings to light quarks modified to include arbitrary C
P-violating phases, onto an effective Lagrangian comprising CP-odd electric and chromoelectric light-quark (up, down, and strange) dipole operators. We find large isospin-breaking contributions of the electroweak diagrams. Using these results, we obtain significant constraints on the phases of the light-quark Yukawas from experimental bounds on the neutron and mercury electric dipole moments.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
