A5074155594- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Quantum Chromodynamics and Particle Interactions
- Noncommutative and Quantum Gravity Theories
- High-Energy Particle Collisions Research
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- Pulsars and Gravitational Waves Research
- Advanced NMR Techniques and Applications
- Distributed and Parallel Computing Systems
- Nuclear Physics and Applications
- Relativity and Gravitational Theory
- Cold Atom Physics and Bose-Einstein Condensates
- CCD and CMOS Imaging Sensors
- Theoretical and Computational Physics
- Radioactive Decay and Measurement Techniques
- Quantum Electrodynamics and Casimir Effect
- Biofield Effects and Biophysics
Brookhaven National Laboratory
2016-2025
Brookhaven College
2020
University of Wisconsin–Madison
2005-2008
Institute for Advanced Study
2002-2005
Stanford Synchrotron Radiation Lightsource
1999-2003
SLAC National Accelerator Laboratory
1999-2003
Stanford University
1999-2002
University of Michigan–Ann Arbor
2000
University of California, Santa Cruz
2000
California Institute of Technology
1996-1998
We explore the phenomenology of localized gravity model Randall and Sundrum where a 5-dimensional nonfactorizable geometry generates gauge hierarchy by an exponential function called warp factor. The Kaluza-Klein (KK) tower gravitons in this scenario has different properties from those factorizable models. derive KK graviton interactions with standard fields obtain constraints their direct production at hadron colliders as well virtual exchanges. study spectrum e(+)e(-) annihilation show how...
General consequences of mass mixing between the ordinary Z boson and a relatively light Z_d boson, "dark" Z, arising from U(1)_d gauge symmetry, associated with hidden sector such as dark matter, are examined. New effects beyond kinetic emphasized. Z-Z_d introduces new source low energy parity violation well explored by possible future atomic planned polarized electron scattering experiments. Rare K (B) meson decays into pi (K) l^+ l^- (l = e, mu) nu anti-nu found to already place tight...
The initial data from the Event Horizon Telescope (EHT) on M87$^*$, supermassive black hole at center of M87 galaxy, provide direct observational information its mass, spin, and accretion disk properties. A combination EHT other constraints evidence that M87$^*$ has a mass $\sim 6.5 \times 10^9\,M_\odot$ dimensionless spin parameter $|a^*|\gtrsim 0.5$. These determinations disfavor ultra light bosons $\mu_b\sim 10^{-21}$ eV, within range considered for fuzzy dark matter, invoked to explain...
The phenomenology of the Randall-Sundrum model localized gravity is analyzed in detail for two scenarios where Standard Model (SM) gauge and matter fields are either confined to a TeV scale 3-brane or may propagate slice five dimensional anti-deSitter space. In latter instance, we derive interactions graviton, gauge, fermion Kaluza-Klein (KK) states. resulting phenomenological signatures shown be highly dependent on value 5-dimensional mass differ substantially from case SM lie TeV-brane....
We construct the New Minimal Standard Model that incorporates new discoveries of physics beyond (MSM): Dark Energy, non-baryonic Matter, neutrino masses, as well baryon asymmetry and cosmic inflation, adopting principle minimal particle content most general renormalizable Lagrangian. base model purely on empirical facts rather than aesthetics. need only six degrees freedom MSM. It is free from excessive flavor-changing effects, CP violation, too-rapid proton decay, problems with electroweak...
We study the production and decay of Kaluza-Klein (KK) gravitons at CERN Large Hadron Collider (LHC), in framework a warped extra dimension which standard model (SM) fields propagate. Such scenario can provide solutions to both Planck-weak hierarchy problem flavor puzzle SM. In this scenario, via $q\overline{q}$ annihilation decays conventional photon lepton channels are highly suppressed. However, we show that graviton gluon fusion followed by longitudinal $Z/W$ be significant; vector boson...
We present a novel mechanism for generating both the baryon and dark matter densities of Universe. A new Dirac fermion $X$ carrying conserved number charge couples to standard model quarks as well GeV-scale hidden sector. $CP$-violating decays $X$, produced nonthermally in low-temperature reheating, sequester antibaryon sector, thereby leaving excess visible The antibaryonic states are stable matter. spectacular signature this is baryon-destroying inelastic scattering that can annihilate...
We show that a gravitational interaction between the derivative of Ricci scalar curvature and baryon-number current dynamically breaks $CPT$ in an expanding Universe and, combined with baryon-number-violating interactions, can drive towards equilibrium baryon asymmetry is observationally acceptable.
We study signals at the Large Hadron Collider (LHC) for Kaluza-Klein (KK) excitations of electroweak gauge bosons in framework with standard model (SM) and fermion fields propagating a warped extra dimension. Such addresses both Planck-weak flavor hierarchy problems SM. Unlike often studied ${Z}^{\ensuremath{'}}$ cases, this framework, there are three neutral due to underlying $SU(2{)}_{L}\ifmmode\times\else\texttimes\fi{}SU(2{)}_{R}\ifmmode\times\else\texttimes\fi{}U(1{)}_{X}$ group bulk....
The muon ${g}_{\ensuremath{\mu}}\ensuremath{-}2$ discrepancy between theory and experiment may be explained by a light vector boson ${Z}_{d}$ that couples to the electromagnetic current via kinetic mixing with photon. We illustrate how existing electron ${g}_{e}\ensuremath{-}2$, pion Dalitz decay, other direct production data disfavor explanation if mainly decays into ${e}^{+}{e}^{\ensuremath{-}}$, ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$. Implications of dominant...
Dark sectors, consisting of new, light, weakly-coupled particles that do not interact with the known strong, weak, or electromagnetic forces, are a particularly compelling possibility for new physics. Nature may contain numerous dark each their own beautiful structure, distinct particles, and forces. This review summarizes physics motivation sectors exciting opportunities experimental exploration. It is summary Intensity Frontier subgroup "New, Light, Weakly-coupled Particles" Community...
The similar cosmological energy budgets in visible baryons and dark matter motivate one to consider a common origin for the generation of both. We outline key features scenarios that can accommodate unified framework genesis cosmic matter. In doing so, we provide brief overview some past recent developments discuss main predictions number models.
A recent improved determination of the fine structure constant, $\alpha= 1/137.035999046(27)$, leads to a $\sim 2.4 \sigma$ negative discrepancy between measured electron anomalous magnetic moment and Standard Model prediction. That situation is be compared with muon where positive 3.7 has existed for some time. single scalar solution both anomalies shown possible if two-loop Barr-Zee diagrams dominate one-loop anomaly effect couplings two photons are relatively large. We also briefly...
We propose that the LHC hints for a Higgs diphoton excess and muon $g\ensuremath{-}2\text{ }\text{ }({g}_{\ensuremath{\mu}}\ensuremath{-}2)$ discrepancy between theory experiment may be related by vectorlike ``leptons'' charged under both $U(1{)}_{Y}$ hypercharge ``dark'' $U(1{)}_{d}$. Quantum loops of such leptons can enhance rate also generically lead to $U(1{)}_{Y}\mathrm{\text{\ensuremath{-}}}U(1{)}_{d}$ kinetic mixing. The induced coupling light $U(1{)}_{d}$ gauge boson ${Z}_{d}$...
The muon anomalous magnetic moment exhibits a 3.6σ discrepancy between experiment and theory. One explanation requires the existence of light vector boson, Z(d) (the dark Z), with mass 10-500 MeV that couples weakly to electromagnetic current through kinetic mixing. Support for such solution also comes from astrophysics conjectures regarding utility U(1)(d) gauge symmetry in matter sector. In scenario, we show mixing ordinary Z boson introduces new source "dark" parity violation, which is...
Light sterile neutrinos with a mass of $\sim 1$ eV continue to be interesting due multiple hints from terrestrial experiments. This simple hypothesis suffers strong astrophysical constraints, in particular the early universe as well solar neutrinos. We develop cosmologically viable proposal consistent hints, by sourcing neutrino's ordinary matter via an ultralight scalar $\phi$ which can also dark matter. In this scenario, experimentally implied neutrino is local value and changes throughout...
It has recently been suggested that a scale-invariant "unparticle" sector with nontrivial infrared fixed point may couple to the standard model (SM) via higher-dimensional operators. The weakness of such interactions hides unparticle phenomena at low energies. We demonstrate how cosmology and astrophysics can place significant bounds on strength unparticle-SM interactions. also discuss possibility having non-negligible relic density today.
We investigate new and unusual signals that arise in theories where dark matter is asymmetric carries a net antibaryon number, as may occur when the abundance linked to baryon abundance. Antibaryonic can cause {\it induced nucleon decay} by annihilating visible baryons through inelastic scattering. These processes lead an effective lifetime of 10^{29}-10^{32} years terrestrial decay experiments, if number transfer between sectors arises physics at weak scale. The possibility motivates novel...
A light vector boson, Z_d, associated with a "dark sector" U(1)_d gauge group has been introduced to explain certain astrophysical observations as well low energy laboratory anomalies. In such models, the Higgs boson may decay into X+Z_d, where X=Z, Z_d or \gamma. Here, we provide estimates of those rates functions coupling through either mass-mixing (e.g. via an enlarged mechanism) heavy new fermion loops and examine implied LHC phenomenology. Our studies focus on higher m_{Z_d} case, >...
A light scalar $\ensuremath{\phi}$ with mass $\ensuremath{\lesssim}1\text{ }\text{ }\mathrm{GeV}$ and muonic coupling $\mathcal{O}(1{0}^{\ensuremath{-}3})$ would explain the $3.5\ensuremath{\sigma}$ discrepancy between Standard Model (SM) muon $g\ensuremath{-}2$ prediction experiment. Such a can be associated remnant of Higgs mechanism in ``dark'' sector. We suggest $\ensuremath{\phi}\ensuremath{\rightarrow}{l}^{+}{l}^{\ensuremath{-}}$ bump hunting...