45th SLAC Summer Institute

Session

Poster social

16 Aug 2017, 18:00

ROB Patio (SLAC)

69. 2-FAST: Fast and Accurate Computation of Projected Two-point Functions

Henry Grasshorn Gebhardt (Penn State)

We present the 2-FAST (2-point function from Fast and Accurate Spherical bessel Transformation) algorithm for a fast and accurate computation of integrals involving one or two spherical Bessel functions. These types of integrals occur when projecting the galaxy power spectrum $P(k)$ onto the configuration space, $\xi_\ell^\nu(r)$, or spherical harmonic space, $C_\ell(\chi,\chi')$. With the...

39. Characterizing dark matter in LHC dilepton spectra

Rodolfo Capdevilla (University of Notre Dame)

Spectral features in LHC dileptonic events may signal radiative corrections from dark matter and mediators. It is shown using simplified models how these features may reveal the fundamental properties of the dark sector, such as the self-conjugation, spin and mass of DM, and the quantum numbers of the mediator. Distributions of both the invariant mass mll and the Collins-Soper scattering angle...

65. Cosmological Constraints and Detection Prospects for Sub-MeV Dark Matter

Benjamin Lehmann (UC Santa Cruz)

Sub-MeV dark matter remains relatively unconstrained by direct detection, and several well-motivated candidates in this mass range have aroused great interest. Electron recoil experiments have been proposed as a technique to detect such a light particle, but little is known about the extent of cosmological restrictions on a light species coupled to electrons. We perform a systematic study of...

68. Dark Matter Relics and Scalar Tensor Theories

Esteban Jimenez (Texas A&M University)

The expansion rate of the universe had a strong influence on the origin of the dark matter abundance during the early stages of the universe's evolution, mainly prior to big-bang nucleosynthesis. Any departure of the expansion rate of the universe from the standard cosmological model during that time can modify the dark matter abundance. In this poster, I will show the role played by a scalar...

62. Dielectric Haloscopes: A New Way to Detect Axion Dark Matter

Alexander Millar (Max Planck Institute for Phyiscs)

We propose a new strategy to search for dark matter axions in the mass range of 40--400 $\mu$eV by introducing dielectric haloscopes, which consist of dielectric disks placed in a magnetic field. The changing dielectric media cause discontinuities in the axion-induced electric field, leading to the generation of propagating electromagnetic waves to satisfy the continuity requirements at the...

67. Early Dark Energy & the Hubble Tension

Tanvi Karwal (Johns Hopkins University)

We explore a scenario with a new exotic energy density that behaves like a cosmological constant at early times and then decays quickly at some critical redshift $z_c$. This work was motivated by tensions between the value of the Hubble constant $H_0$ determined from the CMB and that measured in the local universe. By increasing the expansion rate at early times, the very precisely determined...

66. Elastically Decoupling Dark Matter

Yu-Dai Tsai (Cornell University)

We present a novel dark matter candidate, an Elastically Decoupling Relic (ELDER), which is a cold thermal relic whose present abundance is determined by the cross-section of its elastic scattering on Standard Model particles. The dark matter candidate is predicted to have a mass ranging from a few to a few hundred MeV, and an elastic scattering cross-section with electrons, photons and/or...

48. Estimate CIB Contamination in $\kappa-y$ Cross-Correlation

Mr Ziang Yan (UBC)

This study is basically a noise analysis in an existing result. We reconstructed a $y$ map using NILC method to null CMB and galactic dust signal. We then constructed a CIB-subtracted $y$ map. We estimated the fraction of CIB contamination in the $\kappa-y$ cross-correlation in the reconstructed $y$ map by comparing the cross correlation signal in the two $y$ maps. The result suggest that The...

47. Exploring circular polarization in the CMB due to conventional sources of cosmic birefringence

Paulo Montero-Camacho (The Ohio State University, CCAPP)

Circular polarization of the CMB is currently assumed to be zero in the standard cosmological model. Here we explore the actual level of circular polarization in the CMB by looking at conventional sources of cosmic birefringence. The sources studied include the following: photon-photon scattering, spin polarized hydrogen atoms, static non-linear polarizability of hydrogen and plasma delay. The...

46. FAST-PT: An Extremely Efficient Algorithm For Cosmological Perturbation Theory

Xiao Fang (The Ohio State University)

Cosmological perturbation theory is a powerful tool to model observations of large-scale structure in the weakly non-linear regime. However, even at next-to-leading order, it results in computationally expensive mode-coupling integrals. In this poster presentation, I will focus on the physics of our extremely efficient algorithm, FAST-PT. I will show how the algorithm can be applied to...

49. Going underground to look at the Sun: recent results on solar neutrinos by Borexino

Silvia Caprioli (INFN - National Institute for Nuclear Physics)

Since they barely interact with matter, neutrinos are ideal messengers to investigate the inner processes of astrophysical objects. Solar neutrinos are produced in the Sun as a consequence of the nuclear reaction which take place in its core. Therefore, a detailed study of solar neutrinos is bound to provide
unique direct information on stellar interior, as well as validity of existing...

64. Heavy Photon Search

Sebouh Paul, Miriam Deborah Joy Diamond (University of Toronto (CA))

Compelling motivations, including promising classes of dark matter models compatible with various observed astrophysical anomalies, motivate the existence of a massive gauge boson carrier of a $U'(1)$ gauge symmetry beyond the Standard Model. This hypothesized ``heavy photon" (abbreviated $A'$) would interact feebly with the SM, through kinetic mixing with the SM photon. Our experiment seeks...

44. Imprints on the CMB angular power spectrum from relativistic species that decouple late

Mr Gongjun Choi (Stony Brook University)

The phase shift in the acoustic peaks in the angular power spectrum of CMB temperature and polarization anisotropy plays an important role as a probe of the nature of contribution to Neff. It can determine whether the extra species are free-streaming particles, like neutrinos, or tightly-coupled, like the photons, during eras probed by the CMB. On the other hand, some extensions of the...

38. Primordial gravitational waves produced in bouncing models

Arthur Constantino Scardua (Brazilian Center for Physical Research)

The primordial background of gravitational waves is investigated for a Universe with a bounce, i.e.,a Universe that has a contraction before its expansion. The bounce is caused by quantum effects. It is shown the spectrum is scale dependent,which is different from the standard inflation models. The model investigated is evolved with three non-interacting fluids, with sound velocities equal to...

45. Search for the lepton flavour violating decay Bs,d → e+μ− at the LHCb experiment

Mr Guido Andreassi (EPFL)

Rare leptonic $b \rightarrow s\ell\ell’$ processes are sensitive indirect probes for new effects beyond the Standard Model (SM). Recent deviations from the SM observed in LHCb suggest lepton flavour universality violation effects that could imply the existence of lepton flavour violation processes at an accessible energy scale. In particular it is interesting to search for $b \rightarrow...

61. Uncertainties in the Calculation of Dark Matter Observables

Paul Bergeron (University of Utah)

The LHC's null results for searches beyond the the Standard Model have ruled out the simplest and most constrained version of supersymmetry (SUSY). Many more formulation of SUSY remain viable and to be tested by experiments, but these require detailed computations to be carried out. Numerous publicly available software packages have been developed for such calculations, and comparisons of...