分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-07-08
摘要： We explicitly show that split-universal extra dimension (split-UED), a recently suggested extension of universal extra dimension (UED) model, can nicely explain recent anomalies in cosmic-ray positrons and electrons observed by PAMELA and ATIC/PPB-BETS. Kaluza-Klein (KK)dark matters mainly annihilate into leptons because the hadronic branching fraction is highly suppressed by large KK quark masses and the antiproton flux agrees very well with the observation where no excess is found. The flux of cosmic gamma-rays from pion decay is also highly suppressed and hardly detected in low energy region (E-gamma less than or similar to 20GeV). Collider signatures of colored KK particles at the LHC, especially q(1)q(1) production, are studied in detail. Due to the large split in masses of KK quarks and other particles, hard p(T) jets and missing E-T are generated, which make it possible to suppress the standard model background and discover the signals.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-07-05
摘要： We consider the spin determination of new colored particles in the missing energy plus jets channel at the early stage of the discovery. We use a three site moose model to describe the low energy Lagrangian of all same spin partner (LHT or UED like) models and check the gauge invariance of the amplitude. For the benchmark production and decay channel pp -> (UU(R))-U-(R) -> uuB(H)B(H), in contrast to those in supersymmetric models, there are spin correlations which affect the polar and azimuthal angle distributions of the quarks from the heavy partner U(R) decay. We show such effects would be visible in the E-Tmiss/M-eff distribution and the reconstructed azimuthal angle correlation using MAOS reconstruction.
点击量
待评议
点击量
下载量
评论
