A5081811503- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Noncommutative and Quantum Gravity Theories
- Quantum Chromodynamics and Particle Interactions
- Astrophysics and Cosmic Phenomena
- Computational Physics and Python Applications
- Quantum Mechanics and Applications
- Relativity and Gravitational Theory
- Advanced Thermodynamics and Statistical Mechanics
- Galaxies: Formation, Evolution, Phenomena
- Experimental and Theoretical Physics Studies
- High-Energy Particle Collisions Research
- Quantum, superfluid, helium dynamics
- Quantum Mechanics and Non-Hermitian Physics
- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Atomic and Subatomic Physics Research
- Polynomial and algebraic computation
- Radioactive Decay and Measurement Techniques
- Cold Atom Physics and Bose-Einstein Condensates
- Mathematics and Applications
- Quantum and Classical Electrodynamics
Virginia Tech
2015-2024
Kavli Institute for the Physics and Mathematics of the Universe
2013-2015
The University of Tokyo
2013-2015
Institute of Nuclear and Particle Physics
2010
Amherst College
2003
European Organization for Nuclear Research
1997
Fermi National Accelerator Laboratory
1994-1996
Stanford Synchrotron Radiation Lightsource
1990-1992
Stanford University
1990-1992
SLAC National Accelerator Laboratory
1990-1992
We review the general analysis of contributions electroweak vacuum-polarization diagrams to precision experiments. first representation these by three parameters $S$, $T$, and $U$ discuss assumptions involved in this reduction. then from various models new physics. show that $S$ can be computed a dispersion relation, we use technique estimate technicolor Higgs sector. reliability gauge invariance estimate. Finally, present limits on $T$ imposed current experimental results.
We show that an integral S over the spectral function of spin-1 states Higgs sector is constrained by precision weak-interaction measurements. Current data exclude large technicolor models; asymmetry measurements at CERN ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ collider LEP and SLAC Linear Collider will soon provide more stringent limits on Higgs-boson strong interactions.
This paper is a review of the present status neutrino mass physics, which grew out an APS sponsored study neutrinos in 2004. After discussion knowledge masses and mixing some popular ways to probe new physics implied by recent data, it summarizes what can be learned about interactions as well nature beyond Standard Model from various proposed experiments. The intriguing possibility that may at heart our understanding long standing puzzle cosmology, i.e. origin matter–antimatter asymmetry...
We investigate the effect of minimal length uncertainty relation, motivated by perturbative string theory, on density states in momentum space. The relation is implemented through modified commutation [x_i,p_j]=i hbar[(1 + beta p^2) delta_{ij} beta' p_i p_j]. point out that this which an example UV/IR implies finiteness cosmological constant. While our result does not solve constant problem, it shed new light between outstanding problem and correspondence. also blackbody radiation spectrum...
We determine the energy eigenvalues and eigenfunctions of harmonic oscillator where coordinates momenta are assumed to obey modified commutation relations $[{x}_{i},{p}_{j}]=i\ensuremath{\Elzxh}[(1+\ensuremath{\beta}{p}^{2}){\ensuremath{\delta}}_{\mathrm{ij}}+{\ensuremath{\beta}}^{\ensuremath{'}}{p}_{i}{p}_{j}].$ These motivated by fact that they lead minimal length uncertainty which appear in perturbative string theory. Our solutions illustrate how certain features theory may manifest...
We continue our investigation of the phenomenological implications ``deformed'' commutation relations $[{x}_{i},{p}_{j}]=i\ensuremath{\Elzxh}[(1+\ensuremath{\beta}{p}^{2}){\ensuremath{\delta}}_{\mathrm{ij}}+{\ensuremath{\beta}}^{\ensuremath{'}}{p}_{i}{p}_{j}].$ These are motivated by fact that they lead to minimal length uncertainty relation which appears in perturbative string theory. In this paper, we consider effects deformation on classical orbits particles a central force potential....
We discuss the issue of parity violation in quantum gravity. In particular, we study coupling fermionic degrees freedom presence torsion and physical meaning Immirzi parameter from viewpoint effective field theory. derive low-energy Lagrangian which turns out to involve two parameters: one measuring nonminimal fermions torsion, other being parameter. case contains an axial-vector interaction leading violation. Alternatively, minimal there is no only usual axial-axial interaction. this...
The energy spectrum of the Coulomb potential with minimal length commutation relations $[{X}_{i},{P}_{j}]=i\ensuremath{\hbar}{{\ensuremath{\delta}}_{ij}(1+\ensuremath{\beta}{P}^{2})+{\ensuremath{\beta}}^{\ensuremath{'}}{P}_{i}{P}_{j}}$ is determined both numerically and perturbatively for arbitrary values ${\ensuremath{\beta}}^{\ensuremath{'}}∕\ensuremath{\beta}$ angular momenta $\ensuremath{\ell}$. constraint on scale from precision hydrogen spectroscopy data order a few...
We review our work on the minimal length uncertainty relation as suggested by perturbative string theory. discuss simple phenomenological implications of and then argue that combination principles quantum theory general relativity allow for a dynamical energy-momentum space. implication this problem vacuum energy foundations non-perturbative
We argue that the neutrino oscillation probabilities in matter are best understood by allowing mixing angles and mass-squared differences standard parametrization to ‘run’ with effect parameter a = $ 2\sqrt{2}{G_F}{N_e}E , where N e is electron density E energy. present simple analytical approximations these ‘running’ parameters. show for moderately large value of θ 13, as discovered reactor experiments, running angle 23 CP violating phase δ can be neglected. It simplifies analysis resulting...
The dressed ladder Schwinger-Dyson equation for the fermion self-energy $\ensuremath{\Sigma}({p}^{2})$ with an additional four-fermion coupling term is studied both analytically and numerically. We limit our analysis to asymptotically free theories a large hierarchy between confinement scale ${\ensuremath{\Lambda}}_{c}$ ultraviolet cutoff $\ensuremath{\Lambda}$. dependence of dynamical mass ${\ensuremath{\Sigma}}_{0}\ensuremath{\equiv}\ensuremath{\Sigma}(0)$ condensate...
In previous studies we found that models with flavor-universal suppression of the neutrino-gauge couplings are compatible NuTeV and $Z$-pole data. this paper expand our analysis to obtain constraints on flavor-dependent coupling by including lepton universality data from $W$, $\ensuremath{\tau}$, $\ensuremath{\pi}$ $K$ decays in fits model parameters. We find consistent a variety patterns suppression. particular, scenarios which arises mixing light neutrinos heavy gauge singlet states...
We analyze the position and momentum uncertainties of energy eigenstates harmonic oscillator in context a deformed quantum mechanics, namely, that which commutator between operators is given by $[\stackrel{^}{x},\stackrel{^}{p}]=i\ensuremath{\hbar}(1+\ensuremath{\beta}{\stackrel{^}{p}}^{2})$. This commutation relation leads to minimal length uncertainty $\ensuremath{\Delta}x\ensuremath{\ge}(\ensuremath{\hbar}/2)(1/\ensuremath{\Delta}p+\ensuremath{\beta}\ensuremath{\Delta}p)$, implies...
Motivated by possible scalar-leptoquark explanations of the recently reported $B$-decay anomalies, we investigate whether required leptoquarks can be accommodated within models based on noncommutative geometry (NCG). The considered have gauge structure Pati-Salam models, $SU(4)\times SU(2)_L\times SU(2)_R$, with coupling unification at a single scale. In one find unique scalar leptoquark quantum numbers $(3,1,-\frac{1}{3})_{321}$, originating from complex multiplet $(6,1,1)_{422}$, which...
We update the single-coupling bounds on R-parity violating supersymmetry using most up to date data as of October 2009. In addition listed in 2009 Review Particle Properties, we utilize a new determination weak charge cesium-133, and preliminary tau-decay branching fractions from Babar. Analysis semileptonic D-decay is improved by inclusion experimentally measured form-factors into calculation Standard Model predictions.
We analyze the compatibility of unified left–right symmetric Pati–Salam models motivated by noncommutative geometry and TeV-scale right-handed [Formula: see text] boson suggested recent LHC data. find that unification/matching conditions place conflicting demands on symmetry breaking scales generating required mass coupling is nontrivial.
We use the LEP-SLD data to place constraints on top-color assisted technicolor models. find that, due a large negative shift in ${R}_{b}$ induced by charged top-pion exchange, it is difficult make models compatible with experiment.
MONDian dark matter (MDM) is a new form of quantum that naturally accounts for Milgrom's scaling, usually associated with modified Newtonian dynamics (MOND), and theoretically behaves like cold (CDM) at cluster cosmic scales. In this paper, we provide the first observational test MDM by fitting rotation curves to sample 30 local spiral galaxies (z approximately 0.003). For comparison, also fit galactic using MOND, CDM. We find all three models data well. The predicted MOND are virtually...
We discuss the physical implications of formulating Standard Model (SM) in terms superconnection formalism involving superalgebra su(2/1). In particular, we prediction Higgs mass according to and point out that it is ~170 GeV, clear disagreement with experiment. To remedy this problem, extend su(2/2), which extends SM left-right symmetric model (LRSM) accommodates a ~126 GeV Higgs. Both su(2/1) case LRSM su(2/2) are argued emerge at ~4 TeV from an underlying theory spacetime geometry...
Modified dark matter (MDM) is a phenomenological model of matter, inspired by gravitational thermodynamics. For an accelerating Universe with positive cosmological constant ($\Lambda$), such considerations lead to the emergence critical acceleration parameter related $\Lambda$. Such effective manifestation MDM, and it found in correlations between baryonic galaxy rotation curves. The resulting MDM mass profiles, which are sensitive $\Lambda$, consistent observational data at both galactic...
Recent results from the NuTeV experiment at Fermilab and deviation of Z invisible width, measured CERN LEP SLAC Linear Collider, its standard model (SM) prediction suggest suppression neutrino-Z couplings. Such suppressions occur naturally in models which mix neutrinos with heavy gauge singlet states. We postulate a universal $Z\ensuremath{\nu}\ensuremath{\nu}$ couplings by factor $(1\ensuremath{-}\ensuremath{\varepsilon})$ perform fit to Z-pole observables $\ensuremath{\varepsilon}$ oblique...