179 citations · 2k across the 37 of their papers we have counts for
37 papers · 1 filter
Four-lepton Z-boson decay constraints on the SMEFT
Radja Boughezal, Chien-Yi Chen, Frank Petriello +1
We discuss how four-lepton decays of the Z-boson probe currently unconstrained flat directions in the parameter space of the Standard Model Effective Field Theory (SMEFT). We deriv…
Top quark decay at next-to-leading order in the Standard Model Effective Field Theory
Radja Boughezal, Chien-Yi Chen, Frank Petriello +1
We consider top quark decay in the Standard Model Effective Field Theory (SMEFT). We present a calculation of the total decay width and the -boson helicity fractions at next-to-…
New physics via pion capture and simple nuclear reactions
Chien-Yi Chen, David McKeen, Maxim Pospelov
Light, beyond-the-standard-model particles in the 1-100 MeV mass range can be produced in nuclear and hadronic reactions but would have to decay electromagnetically. We show th…
Exploring Leptophilic Dark Matter with NA64-
Chien-Yi Chen, Jonathan Kozaczuk, Yi-Ming Zhong
We investigate the prospects for detecting light leptophilic dark sectors with a missing-momentum experiment at NA64 running in muon mode. In particular, we consider models in whic…
Power Corrections to the Universal Heavy WIMP-Nucleon Cross Section
Chien-Yi Chen, Richard J. Hill, Mikhail P. Solon +1
WIMP-nucleon scattering is analyzed at order in Heavy WIMP Effective Theory. The power corrections, where is the WIMP mass, distinguish between different und…
CP-Violation in the Two Higgs Doublet Model: from the LHC to EDMs
Chien-Yi Chen, Hao-Lin Li, Michael Ramsey-Musolf
We study the prospective sensitivity to CP-violating Two Higgs Doublet Models from the 14 TeV LHC and future electric dipole moment (EDM) experiments. We concentrate on the search…
US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
Marco Battaglieri, Alberto Belloni, Aaron Chou +248
This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.
Non-resonant Collider Signatures of a Singlet-Driven Electroweak Phase Transition
Chien-Yi Chen, Jonathan Kozaczuk, Ian M. Lewis
We analyze the collider signatures of the real singlet extension of the Standard Model in regions consistent with a strong first-order electroweak phase transition and a singlet-li…
Vector-like Fermions and Higgs Effective Field Theory Revisited
Chien-Yi Chen, S. Dawson, Elisabetta Furlan
Heavy vector-like quarks (VLQs) appear in many models of beyond the Standard Model physics. Direct experimental searches require these new quarks to be heavy, $\gsim$ 800-1000 GeV.…
Muon Beam Experiments to Probe the Dark Sector
Chien-Yi Chen, Maxim Pospelov, Yi-Ming Zhong
A persistence of several anomalies in muon physics, such as the muon anomalous magnetic moment and the muonic hydrogen Lamb shift, hints at new light particles beyond the Standard…
Light dark matter in neutrino beams: production modelling and scattering signatures at MiniBooNE, T2K and SHiP
Patrick deNiverville, Chien-Yi Chen, Maxim Pospelov +1
We analyze the prospects for detection of light sub-GeV dark matter produced in experiments designed to study the properties of neutrinos, such as MiniBooNE, T2K, SHiP, DUNE etc. W…
Lepton flavor violating Z' explanation of the muon anomalous magnetic moment
Wolfgang Altmannshofer, Chien-Yi Chen, P. S. Bhupal Dev +1
We discuss a minimal solution to the long-standing anomaly in a simple extension of the Standard Model with an extra vector boson that has only flavor off-diagonal c…
The Higgs Portal and Cosmology
Ketevi Assamagan, Chien-Yi Chen, John Paul Chou +19
Higgs portal interactions provide a simple mechanism for addressing two open problems in cosmology: dark matter and the baryon asymmetry. In the latter instance, Higgs portal inter…
Diphoton Excess through Dark Mediators
Chien-Yi Chen, Michel Lefebvre, Maxim Pospelov +1
Preliminary ATLAS and CMS results from the first 13 TeV LHC run have encountered an intriguing excess of events in the diphoton channel around the invariant mass of 750 GeV. We inv…
Implications of a Light "Dark Higgs" Solution to the Discrepancy
Chien-Yi Chen, Hooman Davoudiasl, William J. Marciano +1
A light scalar with mass GeV and muonic coupling would explain the 3.5 discrepancy between the Standard Model (SM) muon prediction…
Probing triple-Higgs productions via decay channel at a 100 TeV hadron collider
Chien-Yi Chen, Qi-Shu Yan, Xiaoran Zhao +2
The quartic self-coupling of the Standard Model Higgs boson can only be measured by observing the triple-Higgs production process, but it is challenging for the Large Hadron Collid…
Higgs CP Violation from Vectorlike Quarks
Chien-Yi Chen, S. Dawson, Yue Zhang
We explore CP violating aspects in the Higgs sector of models where new vectorlike quarks carry Yukawa couplings mainly to the third generation quarks of the Standard Model. We poi…
Complementarity of LHC and EDMs for Exploring Higgs CP Violation
Chien-Yi Chen, S. Dawson, Yue Zhang
We analyze the constraints on a CP-violating, flavor conserving, two Higgs doublet model from the measurements of Higgs properties and from the search for heavy Higgs bosons at LHC…
Photon Cascade Decay of the Warped Graviton at LHC14 and a 100 TeV Hadron Collider
Kaustubh Agashe, Chien-Yi Chen, Hooman Davoudiasl +1
In warped 5D models of hierarchy and flavor, the first Kaluza-Klein (KK) state of the graviton is heavy enough to decay into a photon and its first KK mode on-shell: $G…
A Possible Two-component Flux for the High Energy Neutrino Events at IceCube
Chien-Yi Chen, P. S. Bhupal Dev, Amarjit Soni
Understanding the spectral and flavor composition of the astrophysical neutrino flux responsible for the recently observed ultra-high energy events at IceCube is of great importanc…
Heavy Color-Octet Particles at the LHC
Chien-Yi Chen, Ayres Freitas, Tao Han +1
Many new-physics models, especially those with a color-triplet top-quark partner, contain a heavy color-octet state. The "naturalness" argument for a light Higgs boson requires tha…
Exploring Resonant di-Higgs production in the Higgs Singlet Model
Chien-Yi Chen, S. Dawson, I. M. Lewis
We study the enhancement of the di-Higgs production cross section resulting from the resonant decay of a heavy Higgs boson at hadron colliders in a model with a Higgs singlet. This…
Top Partners and Higgs Boson Production
Chien-Yi Chen, S. Dawson, I. M. Lewis
The Higgs boson is produced at the LHC through gluon fusion at roughly the Standard Model rate. New colored fermions, which can contribute to , must have vector-li…
Warped Graviton "Z + Missing Energy" Signal at Hadron Colliders
Chien-Yi Chen, Hooman Davoudiasl, Doojin Kim
We examine the reach at hadron colliders for the lightest warped Kaluza-Klein (KK) graviton G_1 in the Z(->l+l-) Z(->nu nu) channel, l=e,mu, within Randall-Sundrum models of hierar…