Dark matter-baryon interactions can cool the baryonic fluid, which has been shown to modify the cosmological 21-cm global signal. We show that in a two-component dark sector with an interacting millicharged component, dark matter-baryon scattering can produce a 21-cm power spectrum signal with acoustic oscillations. The signal can be up to three orders of magnitude larger than expected in $Λ$CDM cosmology, given realistic astrophysical models. This model provides a new-physics target for near-future experiments such as HERA or NenuFAR, which can potentially discover or strongly constrain the dark matter explanation of the putative EDGES anomaly.
The standard model of fundamental interactions is remarkably successful, but it leaves an unfinished agenda. Several major questions seem ripe for exploration in the near future. I anticipate that the coming decade will be a Golden Age of discovery in fundamental physics.
At the LHC, dileptonic events may turn up new physics interacting with quarks and leptons. The poster child for this scenario is a resonant $Z'$, much anticipated in $\ell^+ \ell^-$ invariant mass spectra. However, angular spectra of dileptons may play an equal or stronger role in discovering a non-resonant species. This paper avails of their LHC measurements to corner the couplings and masses of leptoquarks (LQs), that can mediate $q \bar{q} \rightarrow \ell^+ \ell^-$ in the $t$-channel and dramatically alter Standard Model angular spectra. Also derived are constraints from alterations to $m_…
CP violation in neutral $B$ meson oscillations is an experimental observable that could be directly related to the baryon asymmetry of the Universe through the $B$-Mesogenesis mechanism. As this phenomenon is highly suppressed in the Standard Model, it could also be a sensitive probe for many new physics scenarios that modify neutral meson mixing. Motivated by these facts, and the timely $B$ physics program at the LHC and Belle II, we analyze how large CP violation in the mixing of neutral $B_d$ and $B_s$ meson systems could be. We answer this question, in light of current experimental data, w…
We present an illustrative discussion of the physics potential of $μ^-$- $e^+$ conversion. We point out that this process, although much less frequently studied than the related but much more popular processes of $μ^-$- $e^-$ conversion and neutrinoless double beta decay, in fact is a promising alternative possibility to detect both lepton flavour and number violation. However, for this goal to be reached, a combined effort of experiments and theory, both in nuclear and particle physics, is necessary to advance. The aim of this paper is to be an "appetiser" to trigger such an initiative.
Cosmological data provide a powerful tool in the search for physics beyond the Standard Model (SM). An interesting target are light relics, new degrees of freedom which decoupled from the SM while relativistic. Nearly massless relics contribute to the radiation energy budget, and are commonly parametrized as variations in the effective number $N_{\rm eff}$ of neutrino species. Additionally, relics with masses greater than $10^{-4}$ eV become non-relativistic before today, and thus behave as matter instead of radiation. This leaves an imprint in the clustering of the large-scale structure of th…
We investigate the ability of the upcoming Hyper-Kamiokande (Hyper-K) neutrino experiment to detect new physics phenomena beyond the standard, three-massive-neutrinos paradigm; namely the existence of a fourth, sterile neutrino or weaker-than-weak, non-standard neutrino interactions. With both beam-based neutrinos from the Japan Proton Accelerator Research Complex (J-PARC) and atmospheric neutrinos, Hyper-K is capable of exploring new ranges of parameter space in these new-physics scenarios. We find that Hyper-K has comparable capability to the upcoming Deep Underground Neutrino Experiment (DU…
Physics issues at the upcoming and planned colliders are discussed. We critically review the the different arguments that suggest that New Physics is bound to materialise at the TeV scale and why we should keep an open minded approach. The complementarity of the LHC and a moderate energy e+ e- collider is stressed together with the need for higher energy machines.
We discuss the sensitivity of the CP violating measurements at the upcoming B factories to the presence of physics beyond the Standard Model. We review the three manifestations of CP violation possible in the B meson system. We give examples of decay modes for each of these which are sensitive to new physics, are experimentally feasible, and theoretically clean. Finally, we present techniques to extract Standard Model parameters in the presence of new physics.
In the context of upcoming new physics searches at the LHC, we investigate the impact of multidimensional differential rates in typical LHC analyses. We discuss the properties of shape information, and argue that multidimensional rates bring limited information in the scope of a discovery, but can have a large impact on model discrimination. We also point out subtleties about systematic uncertainties cancellations and the Cauchy-Schwarz bound on interference terms.
Observational constraints on gamma rays produced by the annihilation of weakly interacting massive particles around primordial black holes (PBHs) imply that these two classes of Dark Matter candidates cannot coexist. We show here that the successful detection of one or more PBHs by radio searches (with the Square Kilometer Array) and gravitational waves searches (with LIGO/Virgo and the upcoming Einstein Telescope) would set extraordinarily stringent constraints on virtually all weak-scale extensions of the Standard Model with stable relics, including those predicting a WIMP abundance much sma…
These lectures, presented at TASI 2016: Anticipating the Next Discoveries in Particle Physics, provide an introduction to some key methods and tools of indirect dark matter searches. Topics covered include estimation of dark matter signals, thermal freezeout and related scenarios, potential effects of dark matter annihilation on the early universe, modeling photon signals from annihilation or decay, and a brief and qualitative introduction to diffusive propagation of cosmic rays. The second half of the notes gives a status report (circa summer 2016) on selected experimental searches, the resul…
We discuss the B-physics signature of a supersymmetric U(2) flavor model in which the third generation scalars are relatively light (electroweak scale masses). We impose current experimental constraints on such a framework and obtain expectations for various B-physics processes. Here we present CP violation in (b->s gamma) and (b->phi K), and, Bs-Bsbar mixing. We show that if realized in nature, such a framework can be discovered in current and upcoming experiments.
The cosmological collider provides a model-independent probe of particle physics during inflation. We extend the study of cosmological collider physics to much smaller scales through gravitational wave (GW) probes. With a Chern-Simons interaction, a massive vector field can obtain a chemical potential and its particle production can cause significant non-Gaussian GW signals. We calculate the mass and spin dependences of the induced GW 3-point correlation function in the squeezed limit, and estimate its amplitude. Such signals may be detectable in the current and upcoming GW interferometer expe…
Astrometric weak gravitational lensing is a powerful probe of the distribution of matter on sub-Galactic scales, which harbor important information about the fundamental nature of dark matter. We propose a novel method that utilizes angular power spectra to search for the correlated pattern of apparent motions of celestial objects induced from time-dependent lensing by a population of Galactic subhalos. Application of this method to upcoming astrometric datasets will allow for the direct measurement of the properties of Galactic substructure, with implications for the underlying particle physi…
New physics beyond the electroweak scale may increase weak interaction cross sections beyond the Standard Model predictions. Such cross sections can be expected within theories that solve the hierarchy problem of known interactions with a unification scale in the TeV range. We derive constraints on these cross sections from the flux of neutrinos expected from cosmic ray interactions with the microwave background and the non-observation of horizontal air showers. We also discuss how this limit can be improved by upcoming cosmic ray and neutrino experiments, and how the energy dependence of the …
We review how the muon anomalous magnetic moment ($g-2$) and the quest for lepton flavor violation are intimately correlated. Indeed the decay $μ\to e γ$ is induced by the same amplitude for different choices of in- and outgoing leptons. In this work, we try to address some intriguing questions such as: Which hierarchy in the charged lepton sector one should have in order to reconcile possible signals coming simultaneously from $g-2$ and lepton flavor violation? What can we learn if the $g-2$ anomaly is confirmed by the upcoming flagship experiments at FERMILAB and J-PARC, and no signal is see…
The confirmation of excess in $R_{D^*}$ at the LHCb is an indication of lepton flavor non-universality. Various different new physics operators and their coupling strengths, which provide a good fit to $R_D$, $R_{D^*}$ and $q^2$ spectra, were identfied previously. In this work, we try to find angular observables in $\bar{B} \to D^* τ\barν$ which enable us to distinguish between these new physics operators. We find that the $D^*$ polarization fraction $f_L(q^2)$ is a good discriminant of scalar and tensor new physics operators. The change in $\langle f_L(q^2) \rangle$, induced by scalar and ten…
Axion-like particles (ALPs) are ubiquitous in models of new physics explaining some of the most pressing puzzles of the Standard Model. However, until relatively recently, little attention has been paid to its interplay with flavour. In this work, we study in detail the phenomenology of ALPs that exclusively interact with up-type quarks at the tree-level, which arise in some well-motivated ultra-violet completions such as QCD-like dark sectors or Froggatt-Nielsen type models of flavour. Our study is performed in the low-energy effective theory to highlight the key features of these scenarios i…
We examine the prospects of probing nonstandard interactions (NSI) of neutrinos in the e-tau sector with upcoming long-baseline nu_mu -> nu_e oscillation experiments. First conjectured decades ago, neutrino NSI remain of great interest, especially in light of the recent 8B solar neutrino measurements by SNO, Super-Kamiokande, and Borexino. We observe that the recent discovery of large theta_13 implies that long-baseline experiments have considerable NSI sensitivity, thanks to the interference of the standard and new physics conversion amplitudes. In particular, in some parts of NSI parameter s…
We study dark matter physics in the Minimal Supersymmetric Standard Model with non-universal gaugino masses at the unification scale. In this scenario, the specific ratio of wino and gluino masses realizes the electro-weak scale naturally and achieves 125 GeV Higgs boson mass. Then, relatively light higgsino is predicted and the lightest neutral particle, that is dominantly given by the neutral component of higgsino, is a good dark matter candidate. The direct detection of the dark matter is sensitive to not only a higgsino mass but also gaugino masses significantly. The upcoming XENON1T exper…
