Search Publications
Astrophysical constraints on decaying dark gravitons
Obied, Georges; Law-Smith, Jamie A. P.; Prabhu, Anirudh +1 more
In the dark dimension scenario, which predicts an extra dimension of micron scale, dark gravitons (KK modes) are a natural dark matter candidate. In this paper, we study observable features of this model. In particular, their decay to standard matter fields can distort the CMB and impact other astrophysical signals. Using this we place bounds on t…
Spinning primordial black holes from first order phase transition
Banerjee, Indra Kumar; Dey, Ujjal Kumar
We conduct a novel study to obtain the initial spin of the primordial black holes created during a first-order phase transition due to delayed false vacuum decay. Remaining within the parameter space consistent with observational bounds, we express the abundance and the initial spin of the primordial black holes as functions of the phase transitio…
Light thermal dark matter beyond p-wave annihilation in minimal Higgs portal model
Wu, Lei; Chen, Yu-Tong; Matsumoto, Shigeki +2 more
This study explores a minimal renormalizable dark matter (DM) model, incorporating a sub-GeV Majorana DM and a singlet scalar particle ϕ. Using scalar and pseudo-scalar interactions (couplings cs and cp), we investigate implications for DM detection, considering s-wave, p-wave, and combined (s+p wave) contributions in DM anni…
Freezing-in cannibal dark sectors
Hryczuk, Andrzej; Cervantes, Esau
Self-Interacting Dark Matter models can successfully explain dark matter (DM) production through interactions confined within the dark sector. However, they often lack measurable experimental signals due to their secluded nature. Including a feeble interaction with the visible sector through a Higgs portal leads not only to potential detection ave…
Updated constraints and future prospects on majoron dark matter
Akita, Kensuke; Niibo, Michiru
Majorons are (pseudo-)Nambu-Goldstone bosons associated with lepton number symmetry breaking due to the Majorana mass term of neutrinos introduced in the seesaw mechanism. They are good dark matter candidates since their lifetime is suppressed by the lepton number breaking scale. We update constraints and discuss future prospects on majoron dark m…
Phenomenology of CP-even ALP
Sakurai, Kodai; Yin, Wen
Axion or axion-like particle (ALP) has been usually considered as a CP-odd Nambu-Goldstone boson (NGB) from the spontaneous breakdown of a global U(1) symmetry. In this paper, we point out that the NGB behaves as a CP-even particle coupled to the SM particles in a large class of simple (or perhaps the simplest) renormalizable models. We provide a …
Crosspolar performance of an elliptical corrugated-horn antenna
Silk, Joseph; Wu, Yi-Peng; Pinetti, Elena +1 more
The ultra-slow-roll (USR) inflation represents a class of single-field models with sharp deceleration of the rolling dynamics on small scales, leading to a significantly enhanced power spectrum of the curvature perturbations and primordial black hole (PBH) formation. Such a sharp transition of the inflationary background can trigger the coherent m…
Neutrino lines from majoron dark matter
Garcia-Cely, Camilo; Heeck, Julian
Models with spontaneously broken global lepton number can lead to a pseudo-Goldstone boson as a long-lived dark matter candidate. Here we revisit the case of singlet majoron dark matter and discuss multiple constraints. For masses above MeV, this model could lead to a detectable flux of monochromatic mass-eigenstate neutrinos, which have flavor ra…
Pico-charged intermediate particles rescue dark matter interpretation of 511 keV signal
Farzan, Y.; Rajaee, M.
Various alleged indirect dark matter search signals, such as the 511 keV line from galaxy center or the PAMELA/AMS02 signal, are often challenged by the absence of corresponding signal from dwarf galaxies and/or by the absence of an impact on CMB through delayed recombination. We propose a novel scenario that can avoid these bounds based on the de…
Natural emergence of neutrino masses and dark matter from R-symmetry
Chakraborty, Sabyasachi; Chakrabortty, Joydeep
We propose a supersymmetric extension of the Standard Model (SM) with a continuous global U(1) R symmetry. The R-charges of the SM fields are identified with that of their lepton numbers. As a result, both bilinear and trilinear ` R-parity violating' (RPV) terms could be present at the superpotential. However, R-symmetry is not an exac…