O mundo celebrou a descoberta do "Boson de Higgs". A discussão, agora, envolve comprovar a veracidade (ou não) dessa descoberta.
Anunciou-se que:
- Foram encontrados eventos nas colisões de partículas que apontam para dois tipos de decaimentos que o bóson de Higgs apresentaria;
- A análise estatística aponta que há 5 sigmas de certeza de que se trata de uma nova partícula, e não de ruído de fundo, e que esta pode ser o bóson de Higgs.
Notaram o “pode ser”? Pois é, está lá na página do CERN também. A confirmação do resultado só vai sair depois de uma extensa análise dos dados. A descoberta pode se tratar de outras partículas, mas, aparentemente, a que melhor encaixa nos dados ainda é o bóson de Higgs.
Cientistas estão quebrando a cabeça para ver se a busca pela partícula, que já leva trinta anos e custou cerca de US$ 9 bilhões (R$18 bilhões) chegou mesmo ao fim. De qualquer forma, descobrimos uma nova partícula, ela é um bóson e é o mais pesado já visto.
Artigo da Universidade Cornell:
Have We Observed the Higgs (Imposter)?
Ian Low, Joseph Lykken, Gabe Shaughnessy
We interpret the new particle at the Large Hadron Collider as a CP-even scalar and investigate its electroweak quantum number. Assuming an unbroken custodial invariance as suggested by precision electroweak measurements, only four possibilities are allowed if the scalar decays to pairs of gauge bosons, as exemplified by a dilaton/radion, a non-dilatonic electroweak singlet scalar, an electroweak doublet scalar, and electroweak triplet scalars. We show that current LHC data already strongly disfavor both the dilatonic and non-dilatonic singlet imposters. On the other hand, a generic Higgs doublet and a triplet imposter give equally good fits to the measured event rates of the newly observed scalar resonance, although a Standard Model Higgs boson gives a slightly better overall fit. The global fit indicates the enhancement in the diphoton channel could be attributed to an enhanced partial decay width, while the production rates are consistent with the Standard Model expectations. We emphasize that more precise measurements of the ratio of event rates in the WW over ZZ channels, as well as the event rates in bb and tau tau channels, are needed to distinguish the Higgs doublet from the triplet imposter.
14 julho 2012
Fato da Semana
Fato da Semana – Divulgação dos salários no setor público
Qual a importância disto? – Pela primeira vez é possível
saber dos salários dos diferentes órgãos públicos. Tim Harford, em Adapt,
lembra um caso ocorrido em Uganda. Neste país da África, uma pesquisa sobre o
dinheiro repassado as escolas por parte do governo revelou que 80% dos valores eram
desviados. O governo central decidiu publicar em jornal cada valor repassado para
cada escola, em cada mês. Em seis anos, a percentagem de desvio caiu para 20%,
principalmente naqueles locais onde os pais tinham acesso aos jornais. A
evidenciação dos salários permitirá corrigir problemas, como um garagista
recebendo o salário acima de 20 mil reais. Estes casos esdrúxulos serão objeto
de indignação e a falta de controle com a folha de pagamento, um problema
antigo na administração pública, será visível para o contribuinte.
Positivo ou negativo? – Para o contribuinte será positivo. Saberemos
onde está indo 34% do dinheiro da economia, que é o valor arrecadado pelo
governo sob a forma de diferentes tipos de tributos. O volume gasto com pessoal
é excessivo; já se sabia que o setor público é um ótimo patrão, mas o que a
medida está revelando é que existem algumas distorções. Obviamente que para
quem recebe estes valores será negativo.
Desdobramentos – Haverá muita pressão para evitar esta
divulgação. Argumentos como “risco de sequestro” serão usados para reverter a
decisão. O contribuinte deve insistir para que a medida persista.
Carmen Reinhart
Um pouco da história de Carmen Reinhart:
Born in Havana as Carmen Castellanos, she is quick-witted and favors bright, boldly printed blouses and blazers. As a girl, she memorized the lore of pirates and their trade routes, which she says was her first exposure to the idea that economic fortunes — and state revenue in particular — “can suddenly disappear without warning.”
She also lived with more personal financial and social instability. After her family fled Havana for the United States with just three suitcases when she was 10, her father traded a comfortable living as an accountant for long, less lucrative hours as a carpenter. Her mother, who had never worked outside the home before, became a seamstress.
“Most kids don’t grow up with that kind of real economic shock,” she says. “But I learned the value of scarcity, and even the sort of tensions between East and West. And at a very early age that had an imprint on me.”
With a passion for art and literature — even today, her academic papers pun on the writings of Gabriel García Márquez — she enrolled in a two-year college in Miami, intending to study fashion merchandising. Then, on a whim, she took an economics course and got hooked.
When she went to Florida International University to study economics, she met Peter Montiel, an M.I.T. graduate who was teaching there. Recognizing her talent, he helped her apply to a top-tier graduate program in economics, at Columbia University.
Born in Havana as Carmen Castellanos, she is quick-witted and favors bright, boldly printed blouses and blazers. As a girl, she memorized the lore of pirates and their trade routes, which she says was her first exposure to the idea that economic fortunes — and state revenue in particular — “can suddenly disappear without warning.”
She also lived with more personal financial and social instability. After her family fled Havana for the United States with just three suitcases when she was 10, her father traded a comfortable living as an accountant for long, less lucrative hours as a carpenter. Her mother, who had never worked outside the home before, became a seamstress.
“Most kids don’t grow up with that kind of real economic shock,” she says. “But I learned the value of scarcity, and even the sort of tensions between East and West. And at a very early age that had an imprint on me.”
With a passion for art and literature — even today, her academic papers pun on the writings of Gabriel García Márquez — she enrolled in a two-year college in Miami, intending to study fashion merchandising. Then, on a whim, she took an economics course and got hooked.
When she went to Florida International University to study economics, she met Peter Montiel, an M.I.T. graduate who was teaching there. Recognizing her talent, he helped her apply to a top-tier graduate program in economics, at Columbia University.
Desenvolvimento é bom pra todos?
Desenvolvimento econômico nem sempre é bom pra todos:
Development in most places in most of history has basically been a process of violence and coercion, either by your own elites or invading ones. When historical events are “good for growth” they are often very bad for the generation that experienced them, in Africa or elsewhere. So “good for growth” does not necessarily mean “good”.
Development in most places in most of history has basically been a process of violence and coercion, either by your own elites or invading ones. When historical events are “good for growth” they are often very bad for the generation that experienced them, in Africa or elsewhere. So “good for growth” does not necessarily mean “good”.
13 julho 2012
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