我们探讨了“美丽的镜子”模型，该模型旨在解释$A^b_{FB}$的测量值，在$2.9σ$水平上的差异。这种情况引入了矢量状夸克，它们与底部混合，微妙地影响了它与$Z$的耦合。新粒子的光谱由两个底夸克和一个电荷为-4/3的夸克组成，它们都与第三代夸克有电弱相互作用。我们探讨的现象学和发现达到这些新粒子在大型强子对撞机，探索单镜夸克的生产模式，其速率是成比例的相同的混合参数，解决了$A_{FB}^b$异常。我们发现，对于镜像夸克质量，需要$\lesssim 500 GeV, a 14 TeV LHC with 300 {\rm fb}^{-1}$来合理地建立场景并提取相关的混合参数。
英文摘要：
We explore the "Beautiful Mirrors" model, which aims to explain the measured value of $A^b_{FB}$, discrepant at the $2.9σ$ level. This scenario introduces vector-like quarks which mix with the bottom, subtly affecting its coupling to the $Z$. The spectrum of the new particles consists of two bottom-like quarks and a charge -4/3 quark, all of which have electroweak interactions with the third generation. We explore the phenomenology and discovery reach for these new particles at the LHC, exploring single mirror quark production modes whose rates are proportional to the same mixing parameters which resolve the $A_{FB}^b$ anomaly. We find that for mirror quark masses $\lesssim 500 GeV, a 14 TeV LHC with 300 {\rm fb}^{-1}$ is required to reasonably establish the scenario and extract the relevant mixing parameters.
Within a mirror type assignment for the excited composite fermions the neutrino mass term is built up from a Dirac mass, $m_*$, which gives the mass of charged lepton component of the $SU(2)$, right-handed, doublet, and a Majorana mass, $m_L$, for the left-handed component (singlet) of the excited neutrino. The mass matrix is diagonalized leading to two Majorana mass eigenstates. The active neutrino field $ν^*_R$ is thus a superposition of the two mass eigenstates with mixing coefficients which depend on the ratio $m_L/m_*$. We discuss the prospects of discovery of these physical states at the…
Understanding the detailed structure of energy flow within jets, a field known as jet substructure, plays a central role in searches for new physics, and precision studies of QCD. Many applications of jet substructure require an understanding of jets initiated by heavy quarks, whose description has lagged behind remarkable recent progress for massless jets. In this Letter, we initiate a study of correlation functions of energy flow operators on beauty and charm jets to illuminate the effects of the intrinsic mass of the elementary particles of QCD. We present a factorization theorem incorporat…
After a few microseconds of the creation of our Universe through the Big Bang, the primordial matter was believed to be a soup of the fundamental constituents of matter -- quarks and gluons. This is expected to be created in the laboratory by colliding heavy nuclei at ultra-relativistic speeds. A plasma of quarks and gluons, called Quark-Gluon Plasma (QGP) can be created at the energy and luminosity frontiers in the Relativistic Heavy Ion Collider (RHIC), at Brookhaven National Laboratory, New York, USA, and the Large Hadron Collider (LHC) at CERN, Geneva, Switzerland. Heavy quarks, namely the…
The QCD axion provides an elegant solution to the Strong CP Problem. While the minimal realization is vulnerable to the so-called "Axion Quality Problem", we will consider a more robust realization in the presence of a mirror sector related to the Standard Model by a (softly broken) $\mathbb{Z}_2$ symmetry. We point out that the resulting "heavy" axion, while satisfying all theoretical and observational constraints, has a large and uncharted parameter space which allows it to be probed at the LHC as a Long-Lived Particle (LLP). The small defining axionic coupling to gluons results in a challen…
Accidental Peccei-Quinn Symmetry from Chiral Gauge Symmetry and Mirror QCD
The University of Tokyo（东京大学）；Enrico Fermi Institute, Kavli Institute for Cosmological Physics, Leinweber Institute for Theoretical Physics, Department of Physics, The University of Chicago（芝加哥大学费米研究所、卡弗里宇宙物理学研究所、莱因韦伯理论物理研究所、物理系）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo（东京大学先进研究院、汤川秀树数理宇宙物理研究所（WPI））
We extend the Standard Model (SM) with parity symmetry, motivated by the strong CP problem and dark matter. In our model, parity symmetry is conserved at high energy by introducing a mirror sector with the extra gauge symmetry, $ SU(2)_R \times U(1)_R$. The charges of $SU(2)_R \times U(1)_R$ are assigned to the mirror fields in the same way as in the SM, but the chiralities of the mirror fermions are opposite to respect the parity symmetry. The strong CP problem is resolved, since the mirror quarks are also charged under the $SU(3)_c$ in the SM. In the minimal setup, the mirror gauge symmetry …
A new solution to the strong CP problem with distinct experimental signatures (long-lived particles) at the LHC is proposed. It is based on the Yukawa interactions between mirror quarks, Standard Model (SM) quarks and Higgs singlets. (Mirror quarks and leptons which include non-sterile right-handed neutrinos whose Majorana masses are proportional to the electroweak scale, form the basis of the EW-$ν_R$ model.) The aforementioned Yukawa couplings can in general be complex and can contribute to $Arg\, Det M$ ($\barθ = θ_{QCD} + Arg\, Det M$) at tree-level. The model contains a Peccei-Quinn-type …
We present a UV completion of the twin Higgs idea in the framework of holographic composite Higgs. The SM contribution to the Higgs potential is effectively cut off by the SM-singlet mirror partners at the sigma-model scale f, naturally allowing for m_{KK} beyond the LHC reach. The bulk symmetry is SU(7) X SO(8), broken on the IR brane into SU(7) X SO(7) and on the UV brane into (SU(3) X SU(2) X U(1))^{SM} X (SU(3) X SU(2) X U(1))^{mirror} X Z2. The field content on the UV brane is the SM, extended by a sector transforming under the mirror gauge group, with the Z2 exchanging the two sectors. A…
The Twin Higgs scenario stabilizes the Higgs mass through an approximate global symmetry and has remained natural in the face of increasingly stringent LHC bounds on colored top partners. Two basic structural questions in this framework concern the nature of the twin hypercharge gauge symmetry and the origin of the $\mathbb{Z}_2$ symmetry breaking needed to achieve the correct vacuum alignment. Both questions are addressed in a simple extension of the Mirror Twin Higgs model with an exact $\mathbb{Z}_2$ symmetry and a scalar field that spontaneously breaks both twin hypercharge and $\mathbb{Z}…
Supersymmetric Twin Higgs models have a discrete symmetry for which each Standard Model particle and its supersymmetric partner have a corresponding state that transforms under a mirror Standard Model gauge group. This framework is able to accommodate the non-discovery of new particles at the LHC with the naturalness of the electroweak scale. We point out that supersymmetric Twin Higgs models also provide a natural dark matter candidate. We investigate the possibility that a twin bino-like state is the Lightest Supersymmetric Particle and find that its freeze-out abundance can explain the obse…
What does a non-vanishing neutrino mass have to say about the strong CP problem?
提出了一种新的解决方案，强CP问题与不同的实验签名在大型强子对撞机。它是基于镜夸克、标准模型夸克和Higgs单线态之间的Yukawa相互作用。（镜像夸克和轻子，包括非不育的右手中微子，其马约拉纳质量与电弱标度成正比，形成EW- $ν_R$模型的基础。上述Yukawa耦合通常可以是复杂的，并且可以在树水平上贡献于$Arg\, Det M$（$\barθ = θ_{QCD} + Arg\, Det M$）。这篇手稿的关键是，{ \em不管有多大}，汤川耦合中的CP破坏相可能是，$Arg\, Det M$可以保持很小，即$\barθ < 10^{-10}$对于合理的汤川耦合值，事实上，当希格斯单线态（负责跷跷板机制中中微子质量的狄拉克部分）的VEV消失时，$Arg\, Det M$消失。对$\barθ$的贡献很小，{ \em主要是由于}跷跷板机制中两个质量尺度（狄拉克和马约拉纳质量尺度）的比值很小。
