 Award ID(s):
 1653405
 Publication Date:
 NSFPAR ID:
 10093085
 Journal Name:
 Physical review letters
 Volume:
 121
 Issue:
 24
 Page Range or eLocationID:
 242003
 ISSN:
 00319007
 Sponsoring Org:
 National Science Foundation
More Like this

Recently, there have been rapid developments in latticeQCD calculations of proton structure, especially in the parton distribution functions (PDFs). We overcame a longstanding obstacle and for the first time in latticeQCD are able to directly calculate the Bjorken x dependence of the quark, helicity and transversity distributions. The PDFs are obtained using the largemomentum eﬀective field theory (LaMET) framework where the full Bjorken x dependence of finitemomentum PDFs, called “quasiPDFs”, can be calculated on the lattice. The quasiPDF nucleon matrix elements are renormalized nonperturbatively in RI/MOMscheme. Following a nonperturbative renormalization of the parton quasidistribution in a regularizationindependent momentumsubtraction scheme, we establish its matching to the $ \overline {{\rm{MS}}} $ PDF and calculate the nonsinglet matching coeﬃcient at nexttoleading order in perturbation theory. In this proceeding, I will show the progress that has been made in recent years, highlighting the latest stateofthe art PDF calculations at the physical pion mass. Future impacts on the large x global PDF fits are also discussed.

The presence of relativistic electrons within the diffuse gas phase of galaxy clusters is now well established, thanks to deep radio observations obtained over the last decade, but their detailed origin remains unclear. Cosmic ray protons are also expected to accumulate during the formation of clusters. They may explain part of the radio signal and would lead to γ ray emission through hadronic interactions within the thermal gas. Recently, the detection of γ ray emission has been reported toward the Coma cluster with Fermi LAT. Assuming that this γ ray emission arises essentially from pion decay produced in protonproton collisions within the intracluster medium (ICM), we aim at exploring the implication of this signal on the cosmic ray content of the Coma cluster and comparing it to observations at other wavelengths. We use the MINOT software to build a physical model of the Coma cluster, which includes the thermal target gas, the magnetic field strength, and the cosmic rays, to compute the corresponding expected γ ray signal. We apply this model to the Fermi LAT data using a binned likelihood approach, together with constraints from Xray and SunyaevZel’dovich observations. We also consider contamination from compact sources and the impact ofmore »

During highspeed rear impacts with deltaV > 25 km/h, the front seats may rotate rearward due to occupant and seat momentum change leading to possibly large seat deflection. One possible way of limiting this may be by introducing a structure that would restrict large rotations or deformations, however, such a structure would change the front seat occupant kinematics and kinetics. The goal of this study was to understand the influence of seat back restriction on head, neck and torso responses of front seat occupants when subjected to a moderate speed rearimpact. This was done by simulating a rear impact scenario with a deltaV of 37.4 km/h using LSDyna, with the GHBMC M50 occupant model and a manufacturer provided seat model. The study included two parts, the first part was to identify worst case scenarios using the simplified GHBMC M50OS, and the second part was to further investigate the identified scenarios using the detailed GHBMC M50O. The baseline condition included running the belted GHBMC on the seat at the specified pulse. This was followed by including a seatback constraint, a restriction bar, at 65 mm from the seat back to restrict rearward movement. Four different scenarios were investigated using the GHBMCmore »

Abstract We investigate the threestate majorityvote model for opinion dynamics on scalefree and regular networks. In this model, an individual selects an opinion equal to the opinion of the majority of its neighbors with probability 1 −
q , and different to it with probabilityq . The parameterq is called the noise parameter of the model. We build a network of interactions wherez neighbors are selected by each added site in the system, a preferential attachment network with degree distributionk ^{−λ}, whereλ = 3 for a large number of nodesN . In this work,z is called the growth parameter. Using finitesize scaling analysis, we obtain that the critical exponents and$$\beta /\bar{\nu }$$ $\beta /\overline{\nu}$ associated with the magnetization and the susceptibility, respectively. Using Monte Carlo simulations, we calculate the critical noise parameter$$\gamma /\bar{\nu }$$ $\gamma /\overline{\nu}$q _{c}as a function ofz for the scalefree networks and obtain the phase diagram of the model. We find that the critical exponents add up to unity when using a special volumetric scaling, regardless of the dimension of the network of interactions. We verify this result by obtaining the critical noise and the critical exponents for the two and threestate majorityvote model on cubic lattice networks. 
Abstract Measurements of the Standard Model Higgs boson decaying into a $$b\bar{b}$$ b b ¯ pair and produced in association with a W or Z boson decaying into leptons, using proton–proton collision data collected between 2015 and 2018 by the ATLAS detector, are presented. The measurements use collisions produced by the Large Hadron Collider at a centreofmass energy of $$\sqrt{s} = 13\,\text {Te}\text {V}$$ s = 13 Te , corresponding to an integrated luminosity of $$139\,\mathrm {fb}^{1}$$ 139 fb  1 . The production of a Higgs boson in association with a W or Z boson is established with observed (expected) significances of 4.0 (4.1) and 5.3 (5.1) standard deviations, respectively. Crosssections of associated production of a Higgs boson decaying into bottom quark pairs with an electroweak gauge boson, W or Z , decaying into leptons are measured as a function of the gauge boson transverse momentum in kinematic fiducial volumes. The crosssection measurements are all consistent with the Standard Model expectations, and the total uncertainties vary from 30% in the high gauge boson transverse momentum regions to 85% in the low regions. Limits are subsequently set on the parameters of an effective Lagrangian sensitive to modifications of the WHmore »