Hidden gauged U ( 1 ) model: Unifying scotogenic neutrino and flavor dark matter
Not Available
Yu, Jiang-Hao↗
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Residue theorem and summing over Kaluza-Klein excitations
Applying the equations of motion together with corresponding boundary conditions of bulk profiles at infrared and ultraviolet branes, we verify some lemmas on the eigenvalues of Kaluza-Klein modes in extension of the standard model with a warped extra dimension and the custodial symmetry SU(3){sub c}xSU(2){sub L}xSU(2){sub R}xU(1){sub X}xP{sub LR}. Using the lemmas and performing properly analytic extensions of bulk profiles, we present the sufficient condition for a convergent series of Kaluza-Klein excitations and sum over the series through the residue theorem. The method can also be applied to sum over the infinite series of Kaluza-Klein excitations in a universal extra dimension. Furthermore, we analyze the possible connection between the propagators in five-dimensional full theory and the product of bulk profiles with corresponding propagators of exciting Kaluza-Klein modes in four-dimensional effective theory, and recover some relations presented in the literature for warped and universal extra dimensions, respectively. As an example, we present the correction from new physics to the branching ratio of B{yields}X{sub s{gamma}} to the order O({mu}{sub EW}{sup 2}/{Lambda}{sub KK}{sup 2}) in extension of the standard model with a warped extra dimension and the custodial symmetry, where {Lambda}{sub KK} denotes the energy scale of low-lying Kaluza-Klein excitations and {mu}{sub EW} denotes the electroweak energy scale.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Particle spectroscopy of supersymmetric SO(10) with nonuniversal gaugino masses
Not Available
Okada, Nobuchika↗
Low mass neutralino dark matter in minimal supergravity and more general models in the light of LHC data
The b{tau}jEeT signal at the ongoing LHC experiments is simulated with Pythia in the minimal supergravity (mSUGRA) and other models of supersymmetry (SUSY) breaking. Special attention is given to the compatibility of this signature with the low mass neutralino dark matter (LMNDM) scenario consistent with the Wilkinson Microwave Anisotropy Probe data. In the mSUGRA model the above signal as well as the LMNDM scenario are strongly disfavored due to the constraints from the ongoing SUSY searches at the LHC. This tension, however, originates from the model dependent correlations among the parameters in the strong and electroweak sectors of mSUGRA. That there is no serious conflict between the LMNDM scenario and the LHC data is demonstrated by constructing generic phenomenological models such that the strong sector is unconstrained or mildly constrained by the existing LHC data and parameters in the electroweak sector, unrelated to the strong sector, yield dark matter relic density consistent with the Wilkinson Microwave Anisotropy Probe data. The proposed models, fairly insensitive to the conventional SUSY searches in the jets+Ee{sub T} and other channels, yield observable signal in the suggested channel for L > or approx. 1 fb{sup -1} of data. They are also consistent with the LMNDM scenario and can be tested by the direct dark matter search experiments in the near future. Some of these models can be realized by nonuniversal scalar and gaugino masses at the grand unified theory scale.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Ultrahigh jet multiplicity signal of stringy no-scale F − S U ( 5 ) at the s = 7 TeV LHC
Not Available
Li, Tianjun↗
6 GeV Parity Violating Deep Inelastic Scattering at Jefferson Laboratory
The 6 GeV Parity Violating Deep Inelastic Scattering (PVDIS) experiment has measured a 10{sup -4} level asymmetry through polarized electron scattering off a liquid deuterium target with a beam energy of 6 GeV. This experiment has a goal of measuring a combination of the product of the weak neutral couplings of the electron and the quark with a factor of six improvement in precision over world data. Precise data for the couplings are essential to search for physics beyond the Standard Model. The experiment took place in Hall A at Thomas Jefferson National Accelerator Facility (Jefferson Laboratory) and data collection was completed in the end of 2009. A highly specialized counting data acquisition system with an inherent particle identification was developed and utilized. We have taken data at two Q{sup 2} points in order to possibly address the hadronic correction due to higher twist effects. An overview of the experiment will be presented.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
SWIFT OBSERVATIONS OF THE 2006 OUTBURST OF THE RECURRENT NOVA RS OPHIUCHI. III. X-RAY SPECTRAL MODELING
Following the Swift X-ray observations of the 2006 outburst of the recurrent nova RS Ophiuchi, we developed hydrodynamical models of mass ejection from which the forward shock velocities were used to estimate the ejecta mass and velocity. In order to further constrain our model parameters, we present synthetic X-ray spectra from our hydrodynamical calculations, which we compare to the Swift data. An extensive set of simulations was carried out to find a model that best fits the spectra up to 100 days after outburst. We find a good fit at high energies but require additional absorption to match the low energy emission. We estimate the ejecta mass to be in the range (2-5) x 10{sup -7} M{sub sun} and the ejection velocity to be greater than 6000 km s{sup -1} (and probably closer to 10, 000 km s{sup -1}). We also find that estimates of shock velocity derived from gas temperatures via standard model fits to the X-ray spectra are much lower than those of the true shock velocities.
79 ASTRONOMY AND ASTROPHYSICS↗
Gauged L{sub {mu}}-L{sub {tau}} symmetry at the electroweak scale
The extension of the standard model by a spontaneously broken abelian gauge group based on the L{sub {mu}}-L{sub {tau}} lepton number can resolve the long-standing discrepancy between experimental and theoretical values for the magnetic moment of the muon. It furthermore naturally generates {mu}-{tau} symmetric lepton mixing, introduces neutrino nonstandard interactions, and the associated gauge boson Z' serves as a mediator to the right-handed neutrino sector. A detailed fit to electroweak data is performed to identify the allowed values for the mass of Z' and its mixing with the standard model Z. An economical new scalar sector is constructed that spontaneously breaks L{sub {mu}}-L{sub {tau}} and leads to experimental consequences such as lepton flavor violation and collider signatures. Furthermore we discuss the nonabelian extension to an SU(2){sup '}, particularly the neutrino sector.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Minimal hidden sector models for CoGeNT/DAMA events
Motivated by recent attempts to reconcile hints of direct dark matter detection by the CoGeNT and DAMA experiments, we construct simple particle physics models that can accommodate the constraints. We point out challenges for building reasonable models and identify the most promising scenarios for getting isospin violation and inelasticity, as indicated by some phenomenological studies. If inelastic scattering is demanded, we need two new light gauge bosons, one of which kinetically mixes with the standard model hypercharge and has mass <2 GeV, and another which couples to baryon number and has mass 6.8{+-}(0.1/0.2) GeV. Their interference gives the desired amount of isospin violation. The dark matter is nearly Dirac, but with small Majorana masses induced by spontaneous symmetry breaking, so that the gauge boson couplings become exactly off-diagonal in the mass basis, and the small mass splitting needed for inelasticity is simultaneously produced. If only elastic scattering is demanded, then an alternative model, with interference between the kinetically mixed gauge boson and a hidden sector scalar Higgs, is adequate to give the required isospin violation. In both cases, the light kinetically mixed gauge boson is in the range of interest for currently running fixed target experiments.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Proton stability and light Z' inspired by string derived models
Proton stability is one of the most perplexing puzzles in particle physics. While the renormalizable standard model forbids proton decay mediating operators due to accidental global symmetries, many of its extensions introduce such dimension four, five and six operators. Furthermore, it is, in general, expected that quantum gravity only respects local gauge, or discreet, symmetries. String theory provides the arena to study particle physics in a consistent framework of perturbative quantum gravity. An appealing proposition, in this context, is that the dangerous operators are suppressed by an Abelian gauge symmetry, which is broken near the TeV scale. A viable U(1) symmetry should also be anomaly free, be family universal, and allow the generation of fermion masses via the Higgs mechanism. We discuss such U(1) symmetries that arise in quasirealistic free fermionic heterotic-string derived models. Ensuring that the U(1) symmetry is anomaly free at the low scale requires that the standard model spectrum is augmented by additional states that are compatible with the charge assignments in the string models. We construct such string-inspired models and discuss some of their phenomenological implications.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Parity-Violating PVDIS with SoLID
We are planning an experiment at JLab to measure parity-violation in deep inelastic scattering to high precision over a broad kinematic range. The goal of the experiment is to test the Standard Model, search for charge symmetry violation at the quark level, and to search for higher twist effects due to quark-quark interactions. We will also be able to measure the d/u ratio for the nucleon and search for nuclear effects in deep inelastic scattering.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
MEG Experiment - New Result and Prospects
The MEG Experiment searches for a lepton flavour violating muon decay, {mu}{sup +} {yields} e{sup +}{gamma}, with a branching ratio sensitivity of 10{sup -13} in order to explore the parameter region predicted by many theoretical models beyond the Standard Model. The first physics run has been performed in 2008, and the second phase of data taking was carried out in 2009 after some detector upgrades. We have performed a likelihood analysis with a sensitivity of 6.1 x10{sup -12}, which is approximately twice better than the current upper limit set by the previous experiment, and set an upper limit on the branching ratio B({mu}{sup +}{yields}e{sup +}{gamma})<1.5x10{sup -11}(90%C.L.).
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Constraint on R-parity violating MSSM at the one-loop level from CP-odd N-N interaction
Minimal supersymmetric standard model with R-parity violation (RPVMSSM) contributes to the P-, CP-odd four-quark interaction. The P-, CP-odd four-quark interaction is constrained by the new {sup 199}Hg EDM experimental data. It is then possible to constrain R-parity violating (RPV) couplings from the {sup 199}Hg EDM data. In this talk, we analyze the RPV contribution to the P-, CP-odd four-quark interaction at the one-loop level to give constraints on RPV parameters.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Astrophysical limits on light NMSSM neutralinos
It was recently shown that light LSP neutralinos could be found in the framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). These candidates would escape known particle physics constraints even though they are relatively light. We now investigate the astrophysical limits which can be set on these particles. We show, in particular, that the Fermi observation of dwarf spheroidal galaxies enable to constrain the parameter space associated with these candidates. Combined with the XENON100 experimental limits, our results illustrate the complementarity between direct and indirect searches for dark matter. Yet, our findings also suggest that probing light neutralinos in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) scenario will be very difficult because the sensitivity of both dark matter direct and indirect detection experiments would have to be improved by at least six orders of magnitude compared to present values in order to explore the entire parameter space. Finally, we show that the parameter space compatible with the CoGeNT signal (albeit disfavored by the XENON100 limit) is not excluded by gamma nor radio observations.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
New Limit on Time-Reversal Violation in Beta Decay
We report the results of an improved determination of the triple correlation DP{center_dot}(p{sub e}xp{sub v}) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the standard model. Our result is D=[-0.96{+-}1.89(stat){+-}1.01(sys)]x10{sup -4}. The corresponding phase between g{sub A} and g{sub V} is {phi}{sub AV}=180.013 deg. {+-}0.028 deg. (68% confidence level). This result represents the most sensitive measurement of D in nuclear {beta} decay.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Gauged baryon and lepton number in MSSM{sub 4} brane worlds
A recent D-brane model designed to accommodate a phenomenologically acceptable fourth generation of chiral fermions was noted to produce an unexpected additional unbroken nonanomalous U(1) gauge group at the string scale. We show that the corresponding charges acting on minimal supersymmetric standard model fields count baryon and lepton numbers. If broken spontaneously at lower scales, these U(1){sub B} and U(1){sub L} symmetries provide potential avenues for preserving baryogenesis while nonetheless explaining the suppression of proton decay (without the need for R parity), as well as the smallness of right-handed neutrino Majorana masses compared to the string scale.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Lightest supersymmetric particle stability and new Higgs signals at the LHC
Not Available
Fileviez Pérez, Pavel↗
Neutrino Phenomenology of gauged L{sub {mu}}--L{sub {tau}}: MINOS and beyond
If a Z'gauge boson from a gauged L{sub {mu}}--L{sub {tau}} symmetry is very light, it is associated with a long-range leptonic force. In this case the particles in the Sun create via mixing of the Z'with the Standard Model Z a flavor-dependent potential for muon neutrinos in terrestrial long-baseline experiments. The potential changes sign for anti-neutrinos and hence can lead to apparent differences in neutrino and anti-neutrino oscillations without introducing CP or CPT violation. This could for instance explain the recently found discrepancy in the MINOS experiment. We obtain the associated parameters of gauged L{sub {mu}}--L{sub {tau}} required to explain this anomaly. The consequences for future long-baseline experiments are also discussed, and we compare the scenario to standard NSIs. When used to explain MINOS, both approaches have severe difficulties with existing limits.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗