Isolated tau leptons in events with large missing transverse momentum at HERA

A search for events containing isolated tau leptons and large missing transverse momentum, not originating from the tau decay, has been performed with the ZEUS detector at the electron-proton collider HERA, using 130 pb^-1 of integrated luminosity. A search was made for isolated tracks coming from hadronic tau decays. Observables based on the internal jet structure were exploited to discriminate between tau decays and quark- or gluon-induced jets. Three tau candidates were found, while 0.40 +0.12 -0.13 were expected from Standard Model processes, such as charged current deep inelastic scattering and single W-boson production. To search for heavy-particle decays, a more restrictive selection was applied to isolate tau leptons produced together with a hadronic final state with high transverse momentum. Two candidate events survive, while 0.20 +-0.05 events are expected from Standard Model processes.Comment: 28 pages, 4 figures, 3 tables, accepted by Phys. Lett. B. Updated with minor changes to the text requested by the journal refere

Observation of Scaling Violations in Scaled Momentum Distributions at HERA

Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of $x$ and $Q^2$ using the ZEUS detector. The evolution of the scaled momentum, $x_p$, with $Q^2,$ in the range 10 to 1280 $GeV^2$, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of $Q^2$.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

Perancangan Media Komunikasi Visual Gangs Barbershop Di Bali

Perancangan Media Komunikasi Visual Gangs Barbershop di Bali ini dibuat agar Gangs Barbershop mendapatkan loyalitas dan kepercayaan konsumen. Pada perancangan kali ini digunakan gaya desain American New Wave atau American Postmodern karena sesuai dengan gaya kustom kulture dari Gangs Barbershop ini. Metode yang digunakan adalah metode analisis kualitatif SWOT. Metode ini bertujuan untuk mengetahui kelebihan dan kekurangan dari Gangs Barbershop serta kesempatan atau hambatan yang berasal dari luar/pesaing

Poincare invariance in temporal gauge canonical quantization and θ\theta-vacua

The Poincare invariance in the temporal gauge canonical quantization of QCD is shown manifestly by verifying the energy-momentum-vector and angular-momentum-tensor satisfy the Poincare algebra in the physical Hilbert space. Two different values of $\theta$ for the $\theta$-term in QCD lagrangian lead to different representations of the Poincare group, which are, however, connected by an unitary transformation. Thus the parameter $\theta$ becomes physically irrelevant unless we can further restrict the physical Hilbert space.Comment: 18 pages, UCRHEP-T10

Nonlinear Realization of Chiral Symmetry on the Lattice

We formulate lattice theories in which chiral symmetry is realized nonlinearly on the fermion fields. In this framework the fermion mass term does not break chiral symmetry. This property allows us to use the Wilson term to remove the doubler fermions while maintaining exact chiral symmetry on the lattice. Our lattice formulation enables us to address non-perturbative questions in effective field theories of baryons interacting with pions and in models involving constituent quarks interacting with pions and gluons. We show that a system containing a non-zero density of static baryons interacting with pions can be studied on the lattice without encountering complex action problems. In our formulation one can also decide non-perturbatively if the chiral quark model of Georgi and Manohar provides an appropriate low-energy description of QCD. If so, one could understand why the non-relativistic quark model works.Comment: 34 pages, 2 figures, revised version to be published in J. High Energy Phys. (changes in the 1st paragraph, additional descriptions on the nature of the coordinate singularities in Sec.2, references added

On energy densities reached in heavy-ion collisions at the CERN SPS

We present a few estimates of energy densities reached in heavy-ion collisions at the CERN SPS. The estimates are based on data and models of proton-nucleus and nucleus-nucleus interactions. In all of these estimates the maximum energy density in central Pb+Pb interactions is larger than the critical energy density of about 0.7 GeV/fm^3 following from lattice gauge theory computations. In estimates which we consider as realistic the maximum energy density is about twice the critical value. In this way our analysis gives some support to claims that deconfined matter has been produced at the CERN SPS. Any definite statement requires a deeper understanding of formation times of partons and hadrons in nuclear collisions. We also compare our results with implicit energy estimates contained in earlier models of anomalous J/psi suppression in nuclear collisions.Comment: 19 pages, 5 eps figures included, three cosmetic changes, published versio

Wilson Lines in Warped Space: Dynamical Symmetry Breaking and Restoration

The dynamics of Wilson lines integrated along a warped extra dimension has been unknown. We study a five dimensional SU(N) pure gauge theory with Randall-Sundrum warped compactification on S^1/Z_2. We clarify the notion of large gauge transformations that are non-periodic on the covering space for this setup. We obtain Kaluza-Klein expansions of gauge and ghost fields for the most general twists and background gauge field configurations, which break the gauge symmetry at classical level in general. We calculate the one-loop effective potential and find that the symmetry corresponding to the subgroup allowing continuous Wilson lines is dynamically restored. The presented method can be directly applied to include extra fields. The connection to dynamical Scherk-Schwarz supersymmetry breaking in warped space is discussed.Comment: 13 pages, 2 eps figures; references and clarifying remarks added; mass of lightest mode shown more explicitl

Open-field scale-model experiments of fire whirls over L-shaped line fires

This paper presents the results of open-field scale-model experiments of fire-whirl formation over line fires. L-shaped line fires were burned in crosswinds, and the processes of fire-whirl formation were observed. The flame height was measured using an image-processing technique, while two-dimensional velocity components were measured at two different locations using ultrasonic anemometers. Two tests were selected for comparison: test A, in which intense fire whirls repeatedly formed, and test B, in which no whirls were observed. In test A, the wind flow was bent by the fire plume, creating swirling flows near the burning area, thereby forming fire whirls. On the other hand, the crosswind in test B was too fast to be affected by the fire plume. These results confirmed the existence of critical wind velocity to form intense fire whirls. The critical wind velocity, approximately 1 m/s, agreed with the scaling law on the critical wind velocity which was previously developed based on similar experiments of a smaller scale