A5061581174- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Distributed and Parallel Computing Systems
- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
- Scientific Research and Discoveries
- Galaxies: Formation, Evolution, Phenomena
- International Science and Diplomacy
- Relativity and Gravitational Theory
- Superconducting Materials and Applications
- Astronomy and Astrophysical Research
- Radioactive Decay and Measurement Techniques
- Space Science and Extraterrestrial Life
- Advanced X-ray Imaging Techniques
- Stellar, planetary, and galactic studies
- Graphite, nuclear technology, radiation studies
- Research Data Management Practices
University of California System
2010-2025
University of California, Irvine
2015-2024
Irvine University
2022
The Ohio State University
2022
University of Amsterdam
2018
Indian Institute of Science Bangalore
2017
Istituto Nazionale di Fisica Nucleare, Sezione di Pavia
2017
UCLA Health
2014
Argonne National Laboratory
2000-2012
Northwestern University
2008-2012
We show that colliders can impose strong constraints on models of dark matter, in particular when the matter is light. analyze where a fermion or scalar interacting with quarks and/or gluons through an effective theory containing higher dimensional operators which represent heavier states have been integrated out field theory. determine bounds from existing Tevatron searches for monojets as well expected LHC reaches discovery. find provide information complementary some cases even superior...
We study the discovery potential of Tevatron for a ${Z}^{\ensuremath{'}}$ gauge boson. introduce parametrization signal which provides convenient bridge between collider searches and specific models. The cross section $p\overline{p}\ensuremath{\rightarrow}{Z}^{\ensuremath{'}}X\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}X$ depends primarily on mass decay branching fraction into leptons times average square coupling to up down quarks. If quark lepton...
This document proposes a collection of simplified models relevant to the design new-physics searches at LHC and characterization their results. Both ATLAS CMS have already presented some results in terms models, we encourage them continue expand this effort, which supplements both signature-based benchmark model interpretations. A is defined by an effective Lagrangian describing interactions small number new particles. Simplified can equally well be described masses cross-sections. These...
We explore model-independent collider constraints on light Majorana dark matter particles. find that colliders provide a complementary probe of WIMPs to direct detection, and give the strongest current DM Collider experiments can access interactions not probed by detection searches, outperform about an order magnitude for certain operators in large part parameter space. For which are suppresssed at low momentum transfer, searches have already placed such limiting their use as explanation DAMA.
In the light of LHC, we revisit implications a fourth generation chiral matter. We identify specific ensemble particle masses and mixings that are in agreement with all current experimental bounds as well minimize contributions to electroweak precision observables. Higgs between 115-315 (115-750) GeV allowed by data at 68% 95% CL. Within this parameter space, there dramatic effects on phenomenology: production rates enhanced, weak-boson-fusion channels suppressed, angular distributions...
This document a outlines set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these have when applied searches at LHC, provide number useful expressions reference. The list includes both s-channel t-channel scenarios. For s-channel, spin-0 spin-1 mediations are discussed, also realizations where Higgs particle provides portal between visible sectors. guiding principles underpinning proposed...
We derive limits on the interactions of dark matter with quarks from ATLAS null searches for jets + missing energy based ~1 fb^-1 integrated luminosity, using a model-insensitive effective theory framework. find that new LHC significantly extend previously derived CDF data at Tevatron. Translated into parameter space direct searches, these are particularly ~GeV mass WIMPs. Our indicate tension isospin violating models satisfying minimal flavor violation which attempt to reconcile purported...
There is strong evidence in favor of the idea that dark matter self interacting, with cross section-to-mass ratio $\sigma / m \sim 1\,\mathrm{cm^2/g} 1\,\mathrm{barn/GeV}$. We show viable models this large section are straightforwardly realized non-Abelian hidden sectors. In simplest such models, sector a pure gauge theory, and composed glueballs mass around $100\,\mathrm{MeV}$. Alternatively, may be supersymmetric theory $\sim 10\,\mathrm{TeV}$ gluino thermal relic. case, largely...
Recently a 6.8$\sigma$ anomaly has been reported in the opening angle and invariant mass distributions of $e^+ e^-$ pairs produced $^8\text{Be}$ nuclear transitions. The data are explained by 17 MeV vector gauge boson $X$ that is decay an excited state to ground state, $^8\text{Be}^* \to {}^8\text{Be} \, X$, then decays through $X e^+ e^-$. mediates fifth force with characteristic range 12 fm milli-charged couplings up down quarks electrons, proton coupling suppressed relative neutrons....
The 6.8$\sigma$ anomaly in excited 8Be nuclear decays via internal pair creation is fit well by a new particle interpretation. In previous analysis, we showed that 17 MeV protophobic gauge boson provides physics explanation of the consistent with all existing constraints. Here begin review and characteristics observed anomaly. To develop its interpretation, provide an effective operator analysis for to particles variety spins parities show these considerations exclude simple models scalar...
In this work we present PRyMordial: A package dedicated to efficient computations of observables in the Early Universe with focus on cosmological era Big Bang Nucleosynthesis (BBN). The code offers fast and precise evaluation BBN light-element abundances together effective number relativistic degrees freedom, including non-instantaneous decoupling effects. PRyMordial is suitable for state-of-the-art analyses Standard Model as well general investigations into New Physics active during BBN....
Production of single top quarks at a high energy hadron collider is studied as means to identify physics beyond the standard model related electroweak symmetry breaking. The sensitivity s-channel ${W}^{*}$ mode, t-channel W-gluon fusion and ${\mathrm{tW}}^{\ensuremath{-}}$ mode various possible forms new assessed, it found that three modes are sensitive different physics, indicating they provide complimentary information about properties quark. Polarization observables also considered,...
Assuming that dark matter is a weakly interacting massive particle (WIMP) species X produced in the early Universe as cold thermal relic, we study collider signal of pp or $ p\bar{p} \rightarrow \bar{X}X + jets and its distinguishability from standard-model background processes associated with missing energy. We assume WIMP sole related to within reach LHC — "maverick" it couples quarks through higher dimensional contact interaction. simulate final-state X\bar{X} dominant (SM) find...
The standard model (SM) with a light Higgs boson provides very good description of the precision electroweak observable data coming from CERN LEP, SLD and Fermilab Tevatron experiments. Most observables, notable exception forward-backward asymmetry bottom quark, point towards mass far below its current experimental bound. disagreement, within SM, between values for weak mixing angle as obtained measurement leptonic hadronic asymmetries at lepton colliders, may be taken to indicate new...
We present simplified models for the galactic center $\ensuremath{\gamma}$-ray excess where Dirac dark matter annihilates into pairs or triplets of on-shell bosonic mediators to standard model. These annihilation modes allow mass be heavier than those conventional effective theories excess. Because rate is set by matter--mediator coupling, model coupling can made parametrically small ``hide'' sector suppressing direct detection and collider signals. explore viability these as a thermal relic...
We consider the recent measurement of top quark forward-backward asymmetry at Fermilab Tevatron, which shows a discrepancy slightly more than 2$\sigma$ compared to SM prediction. find that $t$-channel exchange color sextet or triplet scalar particle can explain measurement, while leaving cross section for $t \bar{t}$ production within measured uncertainties. Such particles have good discovery prospects by study kinematic structure \bar{t}$+jets LHC.
As part of the Snowmass process, Cosmic Frontier WIMP Direct Detection subgroup (CF1) has drawn on input from and broader Particle Physics community to produce this document. The charge CF1 was (a) summarize current status projected sensitivity direct detection experiments worldwide, (b) motivate dark matter searches over a broad parameter space by examining spectrum models, (c) establish consensus type experimental program required explore that space, (d) identify common infrastructure...
Scalar gluons—or sgluons—are color octet scalars without electroweak charges. They occur in supersymmetric models of Dirac gauginos as the scalar partners gluino and carry Standard-Model-type R charge. This allows them to interact with ordinary matter be produced at LHC, singly well pairs. Sgluons dominantly decay into gluons, top pairs a quark plus light quark. A pair sgluons decaying like-sign tops would provide striking signature LHC. In our discussion this channel we especially focus on...
Searches for dark matter at colliders typically involve signatures with energetic initial-state radiation without visible recoil particles. mono-jet or mono-photon have yielded powerful constraints on interactions Standard Model We extend this to the mono-Z signature and reinterpret an ATLAS analysis of events a Z boson missing transverse momentum derive interaction mass scale nucleon cross sections in context effective field theories describing which interacts via heavy mediator particles...