Jet-Tagged Back-Scattering Photons For Quark Gluon Plasma Tomography

Several sources of direct photons are known to contribute to the total photon yield in high energy nuclear collisions. All of these photons carry characteristic and important information on the initial nuclei or the hot and dense fireball created in the collision. We investigate the possibility to separate photons from back-scattering of high momentum quarks off quark gluon plasma from other sources. Their unique kinematics can be utilized through high energy jet triggers on the away-side. We discuss the basic idea and estimate the feasibility of such a measurement at RHIC and LHC.Comment: Contribution to Hard Probes 2012; 4 pages, 4 figure

Hawaiʻi and Tourism Reimagined

This essay reflects on the future of tourism in Hawaiʻi in light of the near complete shutdown of tourism at the beginning of the COVID-19 pandemic. It offers mālama as a guiding principle for reimagining Hawaiʻi not as a destination for passive recreation, but for active and serious contemplation of how interconnected we are with the heavens, oceans, land, and to one another

Movement ecology of a small stream fish : small-scale movement patterns and effect of stream road-crossings

O entendimento dos padrões e processos do movimento em peixes pode ser útil em diversas situações, abrangendo muitos interesses básicos e aplicados em ecologia. Entretanto, quantificar a mobilidade e identificar quais são os fatores ambientais que influenciam o movimento não é uma tarefa fácil. Existem vários fatores abióticos e bióticos que podem influenciar o movimento em riacho. Infelizmente, por várias razões, a maioria dos estudos ainda não procurou entender por completo quais são as características de história de vida (p.ex., idade, período reprodutivo, tamanho de primeira maturação gonadal), variáveis intra e interespecíficas que podem estar relacionadas com a mobilidade individual em peixes de riachos Neotropicais, tanto em trecho livre quanto naqueles com a presença de barreira (p.ex. cruzamento-de-estrada). Baseado no contexto acima, o objetivo geral da minha tese, através de uma abordagem de marcação e recaptura, é entender os padrões de movimento de Rineloricaria aequalicuspis, e avaliar quais são os fatores bióticos e abióticos e as características de história de vida relacionados com a probabilidade de movimento em um riacho livre e outro com a presença de um cruzamento-de- estrada. A tese é desenvolvida ao longo de três capítulos: o primeiro traz um estudo descritivo sobre a idade e biologia reprodutiva para auxiliar no entendimento da biologia básica e dinâmica populacional da espécie; o segundo complementa o padrão de movimento da espécie em trecho livre e sua relação com fatores bióticos, abióticos e comprimento total; o terceiro traz um estudo de caso avaliando o efeito de um cruzamento-de-estrada sobre a mobilidade de R. aequalicuspis.The understanding of patterns and processes of fish movement can be useful in a variety of situations, covering many basic and applied interests in ecology. However, quantifying mobility and identifying the environmental factors that influence movement is not an easy task. Several abiotic and biotic factors that can influence movement in the stream. Unfortunately, for several reasons (issues of time in the field and the need for greater availability of financial resources) most studies do not seek to fully understand what are the characteristics of life history (age, reproductive period, size of first gonadal maturation), intra and interspecific variables that may be related to individual mobility both in the free stretch and in those with the presence of a barrier (road crossings). The general objective of my thesis is to understand the movement patterns of Rineloricaria aequalicuspis, what are the biotic and abiotic factors and characteristics of life history that may be related to the probability of movement in free-flowing conditions and in the presence of a road crossing. The thesis is developed over three chapters: the first brings a study on the age and reproductive biology, to assist in understanding the basic biology and population dynamics of the species; the second deals with the movement pattern of the species in a free stream stretch and its relationship with biotic and abiotic factors, and total length; the third is a case study evaluating the effect of a road crossing on the mobility of R. aequalicuspis

Relating different approaches to nuclear broadening

Transverse momentum broadening of fast partons propagating through a large nucleus is proportional to the average color field strength in the nucleus. In this work, the corresponding coefficient is determined in three different frameworks, namely in the color dipole approach, in the approach of Baier et al. and in the higher twist factorization formalism. This result enables one to use a parametrization of the dipole cross section to estimate the values of the gluon transport coefficient and of the higher twist matrix element, which is relevant for nuclear broadening. A considerable energy dependence of these quantities is found. In addition, numerical calculations are compared to data for nuclear broadening of Drell-Yan dileptons, J/psi and Upsilon mesons. The scale dependence of the strong coupling constant leads to measurable differences between the higher twist approach and the other two formalisms.Comment: 11 pages, 3 figures; v2: some changes in presentation, reference added, accepted for publication in PL

Jet-Medium Interactions with Identified Particles

Identified particles have long been of great interest at RHIC in large part because of the baryon/meson differences observed at intermediate $p_T$ and the implications for hadronization via quark coalescence. With recent high statistics data identified particles are also now central to understanding the details of the jet-medium interactions and energy loss and hadron formation at intermediate and high $p_T$. In particular, high $p_T$ identified particle spectra along with two-particle correlations triggered with direct photons, neutral pions or electrons from heavy flavor decay with hadrons can provide information about how medium modifications to jet fragmentation depend on parton type. I will review recent results with identified particles both in heavy ion systems and the reference measurements in p+p collisions.Comment: Proceedings for Quark Matter 2009, Knoxville T

Large mass dilepton production from jet-dilepton conversion in the quark-gluon plasma

We calculate the production of large mass dileptons from the passage of jets passing through the quark-gluon plasma. Using the relativistic kinetic theory, we rigorously derive the production rate for the jet-dilepton conversion in the hot medium. The jet-dilepton conversion is compared with the thermal dilepton emission and the Drell-Yan process. The contribution of the jet-dilepton conversion is not prominent for all values of the invariant mass $M$, and the Drell-Yan process is found to dominate over the thermal dilepton emission and the jet-dilepton conversion for $M>$2.5 GeV at RHIC. The jet-dilepton conversion is the dominant source of large mass dileptons in the range of 4 GeV $<M<$10 GeV at LHC.Comment: 2 figure

Counting valence quarks at RHIC and LHC

We consider the Nuclear Modification Ratios in heavy ion collisions, R_CP and R_AA, in the region of intermediate transverse momentum, and study the dependency upon the constituent quark composition of the observed hadron. Adopting a two component recombination/fragmentation model, validated by experimental information from STAR and PHENIX, we show that a clear distinction is predicted for the f0(980) between the assumptions of $s\bar s$ or diquark-antidiquark content.Comment: 14 pages, 11 eps figures, added figures and minor corrections, to appear in Phys. Lett.

Análise de componentes principais da circunferência escrotal em touros da raça Canchim.

O objetivo deste trabalho foi estudar a inter-relação entre medidas da circuferência escrotal aos 12, 18 e 24 meses de idade de 293 touros da raça Canchim, utilizando-se dos componentes principais. O primeiro componente principal explicou 72% da variação total, e um índice das características estudadas com a importância das mesmas. O segundo e o terceiro componentes principais explicaram 19 e 9% de variação total, respectivamente, e constratam animais com maiores medidas de circuferência escrotal em idades mais jovens com animais de maiores circunferências em idades posteriores.Resumo expandido

Universal behavior of baryons and mesons' transverse momentum distributions in the framework of percolation of strings

In the framework of percolation of strings, we present predictions for the $R_{AA}$ and $R_{CP}$ for mesons and baryons and for $\bar{p}/\pi^{0}$ ratios at LHC energies.Comment: Presented at "Heavy Ion Collisions at the LHC: last call for predictions", Geneva Switzerland, May 14th-June 8t

SLU:s verksamhet med bin

Under 2014/15 var vi sammanlagt sju personer i den grupp på SLU som arbetar med olika aspekter på hälsa och sjukdomar hos honungsbin. Gruppen utökades under sommaren 2014 med två nya forskarstuderande/doktorander; Sepideh Lamei som ska studera mjölksyrabakteriers betydelse för bins hälsa, och Srinivas Thaduri som ska studera sammansättningen av mikroorganismer hos den gotländska population av bin som överlevt och klarar sig utan behandling mot varroakvalstret (de så kallade Bondbina). En kortfattad beskrivning av deras respektive projekt kan ni läsa om längre ned i texten