The cosmology/collider connection

新物理学的第一个发现，在基本粒子的标准模型之外，可能来自各种不同类型的实验研究。 这些包括在实验室中通过高能粒子碰撞创造新的粒子，例如大型强子对撞机（LHC），以及对来自宇宙的这种新粒子的天体物理搜索。 该提案旨在综合来自广泛实验的数据，并根据可能的新粒子物理模型对其进行解释，以最大限度地提高我们发现的机会。** 特别是，我们将研究已知存在但尚未确定的宇宙暗物质的可能新效应。 例如，具有非常强的自相互作用的小暗物质成分可能能够揭示超大质量黑洞早期形成的难题，或者超扩散星系的未知起源。 寿命很长的衰变暗物质可以解释南极冰立方天文台测量到的最高能量中微子。 暗物质与粒子和反粒子之间不对称的相互作用可能有助于解释宇宙中物质相对于反物质的优势（称为重子不对称性）。 这种新的相互作用应该在LHC的发现范围内。如果大型强子对撞机在未来几年内没有发现新粒子，我们将被迫依赖于可能的新物理学的不太直接的暗示。 其中之一是希格斯玻色子的势能非常接近稳定的边缘，当外推到非常高的能量时。 这可能对早期宇宙产生深远的影响，我们认为在大爆炸之前，宇宙经历了一个快速的暴胀膨胀时期。 这样的不稳定性已经被证明会导致一个与我们的宇宙非常不同的宇宙，因此希格斯势应该在高能量下保持稳定。 它是否会这样做取决于希格斯玻色子与标准模型之外可能的新粒子（包括暗物质）的相互作用。 我们打算寻找希格斯玻色子不稳定性与粒子物理学标准模型的另外两个问题之间的联系：为什么希格斯质量和宇宙的真空能量远远低于它们应该自然存在的高尺度，即所谓的普朗克尺度，它支配着量子引力。

The first revelation of new physics, outside of the standard model of elementary particles, could come from any of a great range of different kinds of experimental searches. These include creation of new kinds of particles in the laboratory, such as the Large Hadron Collider (LHC), by high-energy particle collisions, as well as astrophysical searches for such new particles coming from the cosmos. This proposal aims to synthesize data coming from a wide range of experiments and interpret it in terms of possible new models of particle physics, to maximize our chances of discovery. ******In particular, we will investigate possible new effects of the dark matter of the universe, known to be present but as yet unidentified. For example a small dark matter component with very strong self-interactions might be able to shed light on the conundrum of early formation of supermassive black holes, or the unknown origin of ultra-diffuse galaxies. Decaying dark matter with a very long lifetime could explain the highest energy neutrinos measured by the IceCube observatory in Antarctica. Dark matter with interactions that do not respect the symmetry between particles and antiparticles could help to explain the preponderance of matter over antimatter (known as the baryon asymmetry) in the universe. Such new interactions should be within the discovery reach of LHC.******If the LHC does not discover new particles in the next few years, we will be forced to rely upon less direct hints of possible new physics. One of these is the peculiar observation that the potential of the Higgs boson is very close to the edge of stability, when extrapolated to very high energies. This can have profound consequences in the early universe, where we believe that a rapid period of inflationary expansion preceded the big bang. Such an instability has been shown to lead to a subsequent universe very unlike our own, hence the Higgs potential should remain stable up to high energies. Whether it does so depends upon the interactions of the Higgs boson with possible new particles beyond the standard model, including dark matter. We propose to search for links between the Higgs boson instability and two other problems of the standard model of particle physics: why the Higgs mass and the vacuum energy of the universe are so far below the high scale where they should naturally be, known as the Planck scale, that governs quantum gravity.**