Twitter: a useful tool for studying elections?

The 2015 General Election in the UK was the first to take place in the UK with Twitter as an important part of the social media landscape. This pilot project looked at 16 constituencies along England’s South Coast in order to investigate what impact, if any, Twitter had had on the campaign and the result and to investigate the efficacy, or otherwise, of using Twitter as a tool for studying election campaigns in terms of candidate and local party activism. On the basis of an analysis of almost half a million tweets the analysis concluded that there appeared to be a correlation between the rate at which parties and/or candidates responded to incoming tweets and their relative electoral performance but this was not demonstrable for all parties (it applied in particular to Labour and UKIP candidates). In addition, high rates of reply also appeared to have a positive impact on constituency turnout figures. The findings are not yet conclusive but suggest that Twitter could be a good indicator of general levels of local party activism. The research also sought to understand how candidates used Twitter differently and established a number of candidate ‘classifiers’. It also investigated the issues agenda that was dominating Twitter conversations during the campaign and found that Twitter’s agenda was closer to the public’s than was that of the national media. The research also monitored the regional and local media in the 16 constituencies and discovered that their issues agenda was closer still to the public’s. Overall it is difficult to conclude that Twitter had a major impact on the election campaign

Creating the collective: social media, the Occupy Movement and its constitution as a collective actor

This paper examines the process through which Occupy activists came to constitute themselves as a collective actor and the role of social media in this process. The theoretical framework combines Melucci's (1996) theory of collective identity with insights from the field of organizational communication and particularly from the ‘CCO’ strand – short for ‘Communication is Constitutive of Organizing’. This allows us to conceptualize collective identity as an open-ended and dynamic process that is constructed in conversations and codified in texts. Based on interviews with Occupy activists in New York, London and other cities, I then discuss the communication processes through which the movement was drawing the boundaries with its environment, creating codes and foundational documents, as well as speaking in a collective voice. The findings show that social media tended to blur the boundaries between the inside and the outside of the movement in a way that suited its values of inclusiveness and direct participation. Social media users could also follow remotely the meetings of the general assembly where the foundational documents were ratified, but their voices were not included in the process. The presence of the movement on social media also led to conflicts and negotiations around Occupy's collective voice as constructed on these platforms. Thus, viewing the movement as a phenomenon emerging in communication allows us an insight into the efforts of Occupy activists to create a collective that was both inclusive of the 99% and a distinctive actor with its own identity

15 years of protest and media technologies scholarship: A sociotechnical timeline

This article investigates the relationship between the invention of new media technologies and scholarship concerning protest and political engagement. Building on an innovative approach that moves beyond a systematic literature review, this article contributes to our understanding of scholarship concerning digital communication technologies and how they may have been adopted and shaped protest movements and political engagement. Based on visualizations, we draw a sociotechnical timeline of protest and media technology scholarship within three dimensions: technological development, methods and techniques, and the social phenomena under investigation. The article concludes by identifying major trends in protest and media technologies scholarship over the past 15 years. The sociotechnical timeline enhances our understanding of academic discourse at the intersection of protest and media technologies by highlighting shortcomings and potential for future research

Precise measurement of the top quark mass in the dilepton channel at D0

We measure the top quark mass (mt) in ppbar collisions at a center of mass energy of 1.96 TeV using dilepton ttbar->W+bW-bbar->l+nubl-nubarbbar events, where l denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.4 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider. We obtain mt = 174.0 +- 1.8(stat) +- 2.4(syst) GeV, which is in agreement with the current world average mt = 173.3 +- 1.1 GeV. This is currently the most precise measurement of mt in the dilepton channel.Comment: 7 pages, 4 figure

Double parton interactions in photon+3 jet events in ppbar collisions sqrt{s}=1.96 TeV

We have used a sample of photon+3 jets events collected by the D0 experiment with an integrated luminosity of about 1 fb^-1 to determine the fraction of events with double parton scattering (f_DP) in a single ppbar collision at sqrt{s}=1.96 TeV. The DP fraction and effective cross section (sigma_eff), a process-independent scale parameter related to the parton density inside the nucleon, are measured in three intervals of the second (ordered in pT) jet transverse momentum pT_jet2 within the range 15 < pT_jet2 < 30 GeV. In this range, f_DP varies between 0.23 < f_DP < 0.47, while sigma_eff has the average value sigma_eff_ave = 16.4 +- 0.3(stat) +- 2.3(syst) mb.Comment: 15 pages, 13 figure

Evidence for an anomalous like-sign dimuon charge asymmetry

We measure the charge asymmetry A of like-sign dimuon events in 6.1 fb(-1) of p (p) over bar collisions recorded with the D0 detector at a center-of-mass energy root s = 1.96 TeV at the Fermilab Tevatron collider. From A, we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: A(sl)(b) = -0.00957 +/- 0.00251 (stat) +/- 0.00146 (syst). This result differs by 3.2 standard deviations from the standard model prediction A(sl)(b)(SM) = (-2.3(0.6)(+0.5)) x 10(-4) and provides first evidence of anomalous CP violation in the mixing of neutral B mesons

Dependence of the ttˉt\bar{t} production cross section on the transverse momentum of the top quark

We present a measurement of the differential cross section for $t\bar{t}$ events produced in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV as a function of the transverse momentum ($p_T$) of the top quark. The selected events contain a high-$p_T$ lepton ($\ell$), four or more jets, and a large imbalance in $p_T$, and correspond to 1 fb${}^{-1}$ of integrated luminosity recorded with the D0 detector. Each event must have at least one candidate for a $b$ jet. Objects in the event are associated through a constrained kinematic fit to the $t\bar{t}\to WbW\bar{b} \to \ell\nu b q\bar{q}'\bar{b}$ process. Results from next-to-leading-order perturbative QCD calculations agree with the measured differential cross section. Comparisons are also provided to predictions from Monte Carlo event generators using QCD calculations at different levels of precision.Comment: 8 pages, 6 figures, 4 tables, updated to reflect the published versio

Search for new fermions ("quirks") at the Fermilab Tevatron Collider

We report results of a search for particles with anomalously high ionization in events with a high transverse energy jet and large missing transverse energy in $2.4$ fb$^{-1}$ of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron $p\bar{p}$ collider. Production of such particles (quirks) is expected in scenarios with extra QCD-like {\it SU(N)} sectors, and this study is the first dedicated search for such signatures. We find no evidence of a signal and set a lower mass limit of 107 ~GeV for the mass of a charged quirk with strong dynamics scale $\Lambda$ in the range from 10 keV to 1 MeV.Comment: submitted to Phys. Rev. Letter

Direct measurement of the mass difference between top and antitop quarks

We present a direct measurement of the mass difference between top and antitop quarks (dm) in lepton+jets top-antitop final states using the "matrix element" method. The purity of the lepton+jets sample is enhanced for top-antitop events by identifying at least one of the jet as originating from a b quark. The analyzed data correspond to 3.6 fb-1 of proton-antiproton collisions at 1.96 TeV acquired by D0 in Run II of the Fermilab Tevatron Collider. The combination of the e+jets and mu+jets channels yields dm = 0.8 +/- 1.8 (stat) +/- 0.5 (syst) GeV, which is in agreement with the standard model expectation of no mass difference.Comment: submitted to Phys. Rev.

Search for first generation leptoquark pair production in the electron + missing energy + jets final state

We present a search for the pair production of first generation scalar leptoquarks (LQ) in data corresponding to an integrated luminosity of 5.4 fb$^{-1}$ collected with the D0 detector at the Fermilab Tevatron Collider in ppbar collisions at $\sqrt{s}=1.96$ TeV. In the channel $LQ \bar{LQ} \rightarrow e\nu_e qq'$, where q, q' are u or d quarks, no significant excess of data over background is observed, and we set a 95% C.L. lower limit of 326 GeV on the leptoquark mass, assuming equal probabilities of leptoquark decays to eq and $\nu_e q'$.Comment: 7 pages, 6 figures, submitted to PRD-R