97 citations · 1.2k across the 52 of their papers we have counts for
51 papers · 1 filter
A Cosmic Higgs Collider
Bibhushan Shakya
This paper examines frameworks and phenomenology of ultrarelativistic Higgs vacuum bubble collisions in a first-order phase transition associated with the Standard Model Higgs fiel…
Bubble Friction in Symmetry-Restoring Transitions
Andrew J. Long, Bibhushan Shakya, Julia Anabell Ziegler
In standard (symmetry-breaking) first-order phase transitions, the frictional pressure on expanding bubble walls can be dominated by transition radiation -- the emission of a gauge…
Did our Universe Tunnel out of the Wrong Higgs Vacuum?
Bibhushan Shakya
This paper explores various aspects and implications of the initial configuration of the Standard Model (SM) Higgs field at the beginning of our Universe. It is well known that the…
Cosmic Colliders: High Energy Physics with First-Order Phase Transitions
Bibhushan Shakya
Collisions of vacuum bubbles in the early Universe can act as cosmic-scale high-energy colliders with energy reach close to the Planck scale. Such "cosmic colliders" would represen…
Leptogenesis via Bubble Collisions
Martina Cataldi, Bibhushan Shakya
We present a novel realization of leptogenesis from the decays of sterile (right-handed) neutrinos (RHNs) produced from runaway bubble collisions at a first order phase transition.…
Nonthermal Heavy Dark Matter from a First-Order Phase Transition
Gian F. Giudice, Hyun Min Lee, Alex Pomarol +1
We study nonthermal production of heavy dark matter from the dynamics of the background scalar field during a first-order phase transition, predominantly from bubble collisions. In…
Aspects of Particle Production from Bubble Dynamics at a First Order Phase Transition
Bibhushan Shakya
First order phase transitions (FOPTs) constitute an active area of contemporary research as a promising cosmological source of observable gravitational waves. The spacetime dynamic…
On Particle Production from Phase Transition Bubbles
Henda Mansour, Bibhushan Shakya
While first order phase transitions (FOPTs) have been extensively studied as promising cosmological sources of gravitational waves, the phenomenon of particle production from the d…
The Tachyonic Higgs and the Inflationary Universe
Bibhushan Shakya
The Standard Model Higgs becomes tachyonic at high energy scales according to current measurements. This unstable regime of the Higgs potential can be realized in the early Univers…
Sterile Neutrinos from Dark Matter: A Nightmare?
Logan Morrison, Stefano Profumo, Bibhushan Shakya
We provide a comprehensive study of observable spectra from dark matter pair-annihilation or decay into sterile (right-handed) neutrinos. This occurs, for instance, in neutrino por…
TF08 Snowmass Report: BSM Model Building
Patrick J. Fox, Graham D. Kribs, Hitoshi Murayama +53
We summarize the state of Beyond the Standard Model (BSM) model building in particle physics for Snowmass 2021, focusing mainly on several whitepaper contributions to BSM model bui…
Exponential Enhancement of Dark Matter Freezeout Abundance
Bibhushan Shakya
A novel paradigm for thermal dark matter (DM), termed "bouncing dark matter", is presented. In canonical thermal DM scenarios, the DM abundance falls exponentially as the temperatu…
Snowmass 2021 Cross Frontier Report: Dark Matter Complementarity (Extended Version)
Antonio Boveia, Mohamed Berkat, Thomas Y. Chen +24
The fundamental nature of Dark Matter is a central theme of the Snowmass 2021 process, extending across all frontiers. In the last decade, advances in detector technology, analysis…
Snowmass Theory Frontier: Astrophysics and Cosmology
Daniel Green, Joshua T. Ruderman, Benjamin R. Safdi +84
We summarize progress made in theoretical astrophysics and cosmology over the past decade and areas of interest for the coming decade. This Report is prepared as the TF09 "Astrophy…
Bouncing Dark Matter
Lucas Puetter, Joshua T. Ruderman, Ennio Salvioni +1
We present a novel mechanism for thermal dark matter production, characterized by a "bounce": the dark matter equilibrium distribution transitions from the canonical exponentially…
Theories and Experiments for Testable Baryogenesis Mechanisms: A Snowmass White Paper
J. L. Barrow, Leah Broussard, James M. Cline +16
The baryon asymmetry of the Universe is one of the central motivations to expect physics beyond the Standard Model. In this Snowmass white paper, we review the challenges and oppor…
New Ideas in Baryogenesis: A Snowmass White Paper
Gilly Elor, Julia Harz, Seyda Ipek +21
The Standard Model of Particle Physics cannot explain the observed baryon asymmetry of the Universe. This observation is a clear sign of new physics beyond the Standard Model. Ther…
Early-Universe Model Building
Pouya Asadi, Saurabh Bansal, Asher Berlin +37
Theoretical investigations into the evolution of the early universe are an essential part of particle physics that allow us to identify viable extensions to the Standard Model as w…
Snowmass2021 Cosmic Frontier White Paper: Ultraheavy particle dark matter
Daniel Carney, Nirmal Raj, Yang Bai +25
We outline the unique opportunities and challenges in the search for "ultraheavy" dark matter candidates with masses between roughly and the Planck scale $m_{\rm pl}…
Dark Matter Freeze-In with a Heavy Mediator: Beyond the EFT Approach
Evan Frangipane, Stefania Gori, Bibhushan Shakya
We study dark matter freeze-in scenarios where the mass of the mediator particle that couples dark matter to the Standard Model is larger than the reheat temperature, TRH, in the e…
Indirect Detection of Secluded Supersymmetric Dark Matter
Patrick Barnes, Zachary Johnson, Aaron Pierce +1
Weak-scale secluded sector dark matter can reproduce the observed dark matter relic density with thermal freeze-out within that sector. If nature is supersymmetric, three portals t…
Split SIMPs with Decays
Andrey Katz, Ennio Salvioni, Bibhushan Shakya
We discuss a minimal realization of the strongly interacting massive particle (SIMP) framework. The model includes a dark copy of QCD with three colors and three light flavors. A m…
Simple Hidden Sector Dark Matter
Patrick Barnes, Zachary Johnson, Aaron Pierce +1
A hidden sector that kinetically mixes with the Minimal Supersymmetric Standard Model provides simple and well-motivated dark matter candidates that possess many of the properties…
Loop Dominated Signals from Neutrino Portal Dark Matter
Hiren H. Patel, Stefano Profumo, Bibhushan Shakya
We study scenarios where loop processes give the dominant contributions to dark matter decay or annihilation despite the presence of tree level channels. We illustrate this possibi…