Axial couplings in heavy-hadron chiral perturbation theory at the next-to-leading order
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Detmold, William↗
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Timelike Compton Scattering
Generalized Parton Distributions (GPDs) have become a key concept in our studies of hadron structure in QCD. The measurement of suitable experimental observables and the extraction of GPDs from these data is one of the high priority 12 GeV programs at Jefferson Lab. Deeply Virtual Compton Scattering (DVCS) is generally thought of as the most promising channel for probing GPDs in the valence quark region. However, the inverse process, Timelike Compton Scattering (TCS) can provide an important complementary measurement, in particular of the real part of the Compton amplitude and power corrections at intermediate values of Q{sup 2}. The first studies of TCS using real tagged and quasi-real untagged photons were performed in Hall B at Jefferson Lab.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Measurement of the t-Channel Single Top Quark Production Cross Section in pp Collisions at {radical}(s)=7 TeV
Electroweak production of the top quark is measured for the first time in pp collisions at {radical}(s)=7 TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb{sup -1}. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data. The second approach uses a multivariate analysis technique to probe the compatibility with signal topology expected from electroweak top-quark production. The combined measurement of the cross section is 83.6{+-}29.8(stat+syst){+-}3.3(lumi) pb, consistent with the standard model expectation.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
QCD Resummation for Single Spin Asymmetries
We study the transverse momentum dependent factorization for single spin asymmetries in Drell-Yan and semi-inclusive deep inelastic scattering processes at one-loop order. The next-to-leading order hard factors are calculated in the Ji-Ma-Yuan factorization scheme. We further derive the QCD resummation formalisms for these observables following the Collins-Soper-Sterman method. The results are expressed in terms of the collinear correlation functions from initial and/or final state hadrons coupled with the Sudakov form factor containing all order soft-gluon resummation effects. The scheme-independent coefficients are calculated up to one-loop order.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Electromagnetic production of hyperon resonances
The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jefferson Lab. These data have multi-particle final states, allowing clean identification of exclusive reactions associated with strange mesons and baryons. Examples of physics results are: evidence for isospin interference in the decay of the {Lambda}(1405) resonance; a strong suggestion of meson cloud effects in the structure of the {Sigma}(1385) resonance; data from K* photoproduction that will test the existence of the purported K{sub 0}(800) meson. Properties of other hyperon resonances will also be studied in the near future.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
A search for resonant production of tt pairs in 4.8 fb -1 of integrated luminosity of pp collisions at √s=1.96 TeV
We search for resonant production of tt pairs in 4.8 fb -1 integrated luminosity of pp collision data at √s = 1.96 TeV in the lepton+jets decay channel, where one top quark decays leptonically and the other hadronically. A matrix element reconstruction technique is used; for each event a probability density function (pdf) of the tt candidate invariant mass is sampled. These pdfs are used to construct a likelihood function, whereby the cross section for resonant tt production is estimated, given a hypothetical resonance mass and width. The data indicate no evidence of resonant production of tt pairs. A benchmark model of leptophobic Z' → tt is excluded with m Z' < 900 GeV at 95% confidence level.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Extending Higgs inflation with TeV scale new physics
Higgs inflation is among the most economical and predictive inflation models, although the original Higgs inflation requires tuning the Higgs or top mass away from its current experimental value by more than 2σ deviations, and generally gives a negligible tensor-to-scalar ratio r∼10{sup −3} (if away from the vicinity of critical point). In this work, we construct a minimal extension of Higgs inflation, by adding only two new weak-singlet particles at TeV scale, a vector-quark T and a real scalar S . The presence of singlets (T, S) significantly impact the renormalization group running of the Higgs boson self-coupling. With this, our model provides a wider range of the tensor-to-scalar ratio r=O(0.1)−O(10{sup −3}) , consistent with the favored r values by either BICEP2 or Planck data, while keeping the successful prediction of the spectral index n{sub s}≃0.96 . It allows the Higgs and top masses to fully fit the collider measurements. We also discuss implications for searching the predicted TeV-scale vector-quark T and scalar S at the LHC and future high energy pp colliders.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Recent advances of polarized {sup 3}He target at Jefferson Lab
Polarized {sup 3}He targets have been widely used in nuclear and particle physics experiments to study neutron structure in the spin degree of freedom, as most of the {sup 3}He spin is carried by the unpaired neutron. The Spin-Exchange Optical Pumping (SEOP) process is used in Jefferson Lab Hall A to polarize its {sup 3}He target. In recent years, both the performance and corresponding polarimetry of such a target have been greatly improved. Several experiments recently carried out in Hall A have achieved record high figure of merit using this target.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Corrected calculation for the non-local solution to the g − 2 anomaly and novel results in non-local QED
We provide the corrected calculation of the (g − 2) μ in non-local QED previously done in the literature. In specific, we show the proper technique for calculating loops in non-local QED and use it to find the form factors F 1 (q 2 ) and F 2 (q 2 ) in non-local QED. We also utilize this technique to calculate some novel results in non-local QED, including calculating the correction to the photon self-energy, the modification to the classical Coulomb potential, the modification to the energy levels of the hydrogen atom, and the contribution to the Lamb shift. We also discuss charge dequantization through non-locality, and show that the experimental bounds on the electric charge on Dirac neutrinos, translate into strong flavor-dependent bounds on the scale on non-locality that range between 10 5 −10 10 TeV. We also discuss the inconsistencies of unrenormalized non-local Quantum Field Theories (QFTs) and the need for renormalizing them, even when they are free from UV divergences.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Bounding irrelevant operators in the 3d Gross-Neveu-Yukawa CFTs
We perform a numerical bootstrap study of scalar operators in the critical 3d Gross-Neveu-Yukawa models, a family of conformal field theories containing N Majorana fermions in the fundamental representation of an O(N) global symmetry. We compute rigorous bounds on the scaling dimensions of the next-to-lowest parity-even and parity-odd singlet scalars at N = 2, 4, and 8. All of these dimensions have lower bounds greater than 3, implying that there are only two relevant singlet scalars and placing constraints on the RG flow structure of these theories.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Classically Spinning Skyrmions
Skyrmions arise as topological soliton solutions in the Skyrme model which has been shown to be a low energy effective theory of QCD in the large N{sub C} limit. If quantized suitably, they can be used to describe structure and properties of nucleons and nuclei. We argue that the semiclassical rigid-body quantization, commonly used in the literature, has several shortcomings and that removing this simplication may result in a more accurate description of nucleons and nuclei. We present an extensive numerical study of spinning, arbitrarily deforming Skyrmions of topological charge B = 1-4.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
The US Muon Accelerator Program (MAP)
The US Department of Energy Office of High Energy Physics has recently approved a Muon Accelerator Program (MAP). The primary goal of this effort is to deliver a Design Feasibility Study for a Muon Collider after a 7 year R and D program. This paper presents a brief physics motivation for, and the description of, a Muon Collider facility and then gives an overview of the program. I will then describe in some detail the primary components of the effort.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Status and results from the OPERA experiment
The OPERA experiment is aiming at the first direct detection of neutrino oscillations in appearance mode through the study of the v{sub {mu}}{yields}v{tau} channel. The OPERA detector is placed in the CNGS long baseline v{sub {mu}} beam 730 km away from the neutrino source. The analysis of a sub-sample of the data taken in the 2008-2009 runs was completed After a brief description of the beam and the experimental setup, we report on event analysis and on a first candidate event, its background estimation and statistical significance.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
The {tau}-contamination in the golden channel at the Neutrino Factory
Experimental results could lead to wrong measurements of the neutrino oscillation parameters if the so-called {tau}-contamination is not properly taken into account in the data analysis. It was shown in [1] that, if a migration matrix giving the energy distribution of muon neutrinos coming from tau-decays in the detector is included, the analysis can be done in the reconstructed neutrino energy and the problem is solved for the golden channel. We will also present some preliminary results for the disappearance channel, where the {tau}-contamination is more severe.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
T2K: ND280 Status, Progress, and Plans
T2K(Tokai to Kamioka) is an off-axis long baseline (295 km) neutrino oscillation experiment designed to search for v{sub {mu}} {yields} v{sub e} appearance. The neutrino beam is generated using 30 GeV protons from the J-PARC facility at Tokai, Japan. The Near Detector(ND280) is located in J-PARC and the Far Detector, Super-Kamiokande, in Kamioka, Japan. Presented is a summary of the status and plans of the Near Detector suite.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Recent Emulsion Technologies
Emulsion technologies are very much developed in the last decade and still developing in both the emulsion gel and the data taking. Emulsion detectors are suitable for the neutrino experiments because they can distinguish all 3 flavors of neutrino. The OPERA experiment, a recent pillar in the emulsion experiments aiming at the first observation of the neutrino oscillation in CNGS beam in appearance mode, is running, showing the good capability to separate 3 flavor neutrino interactions. In this poster, the recent developments and prospects of the emulsions for the next generation experiments are reported.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Configuration-space Faddeev calculation for proton-deuteron observables at energy E{sub lab} = 3 MeV
A new computational method for solving the nucleon-deuteron breakup scattering problem has been applied to study the elastic neutron- and proton-deuteron scattering on the basis of the configuration-space Faddeev-Noyes-Noble-Merkuriev equations. This method is based on the spline-decomposition in the angular variable and on a generalization of the Numerov method for the hyperradius. The Merkuriev-Gignoux-Laverne approach has been generalized for arbitrary nucleon-nucleon potentials and with an arbitrary number of partial waves taken into account. The nucleon-deuteron observables at the incident nucleon energy 3 MeV have been calculated using the charge-independent AV14 nucleon-nucleon potential including the Coulomb force for the proton-deuteron scattering. Results have been compared with those of other authors and with experimental proton-deuteron scattering data.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Light and heavy at the end of the funnel
We show that, by taking a bare mass spectrum with constant spacings for the quark-antiquark propagators, which is subject to considerable mass shifts from meson loops, one adequately describes a large variety of mesonic resonances, from the light scalars to the bb-bar states. All our results indicate that a harmonic-oscilator spectrum with universal frequency, in combination with coupled-channel effects, does a much better job than the qq-bar spectrum of the funnel potential.
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