* Astronomy

Blobrana · L

RE: Higgs Particles

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Collider sees tantalizing hint of Higgs

Excess events suggest LHC is homing in on elusive particle.

For now, physicists are only willing to call them 'excess events', but fresh data from two experiments at the Large Hadron Collider (LHC) are hinting at something unusual - and it could be the most sought-after particle in all of physics.
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Title: Astrophysical Consequences of a Neutrinophilic Two-Higgs-Doublet Model
Authors: Marc Sher, Christopher Triola

In a recently proposed neutrinophilic two-Higgs doublet model, the low-energy (sub-MeV) effective theory consists of a real scalar with a vev of O(0.1) eV and three Dirac neutrinos. Other models could lead to the same low energy theory. In this Brief Report, we study constraints on the parameter space of the model, including vacuum stability, unitarity, perturbativity and the effects on the invisible Z width. Interestingly, we find that all neutrinos become massless at temperatures above approximately 1000 K, but can find no phenomenological effects of this finding. The most direct test of the model is that it predicts that in a galactic supernova, the energy distributions of the electron, muon and tau neutrinos will be Fermi-Dirac with identical temperatures, unlike the conventional distributions.

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Title: Very Light CP-odd Higgs bosons of the NMSSM at the LHC in 4b-quark final states
Authors: Mosleh Almarashi, Stefano Moretti

We study the detectability of the lightest CP-odd Higgs boson of the NMSSM, a_1, at the LHC through its production in association with a bottom-quark pair followed by the a_1\to b\bar b decay. It is shown that, for large \tan\beta and very high luminosity of the LHC, there exist regions of the NMSSM parameter space that can be exploited to detect the a_1 through this channel. This signature is a characteristic feature of the NMSSM in comparison to the MSSM, as a_1 masses involved are well below those allowed in the MSSM for the corresponding CP-odd Higgs state.

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Title: Goldstone bosons in Higgs inflation
Authors: Sander Mooij, Marieke Postma

Higgs inflation uses the gauge variant Higgs field as the inflaton. During inflation the Higgs field is displaced from its minimum, which results in associated Goldstone bosons that are no longer massless. We use the closed-time-path formalism to show that these Goldstone bosons do contribute to the Coleman-Weinberg one-loop potential; hence, the computation in unitary gauge gives incorrect results. Our expression for the one-loop potential is gauge invariant upon using the background equations of motion.

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Officials at the world's biggest particle physics lab are playing down claims of a major discovery after a leaked internal memo sparked excitement among science enthusiasts that the elusive Higgs boson "god particle" has been found.
A spokesman for the European Organisation for Nuclear Research, or CERN, says the observation by scientists working at the $10-billion Large Hadron Collider "is probably nothing."
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Michio Kaku on the 'God Particle'

Scientists may have confirmed the existence of the elusive Higgs boson

Blobrana · L

In 1861, James Clerk Maxwell unified electricity, magnetism and light. Experiments under way today could inch physicists closer to combining everything else.

When it happens - if it happens - don't look for Hollywood-style drama. Physicists at the Large Hadron Collider (LHC) outside Geneva in Switzerland won't suddenly gasp with astonishment, and their monitors won't flash the message, "Higgs boson detected."
Instead, the discovery will unfold over the course of months. Computers will trawl through petabytes (10^15 bytes) of collision data in search of a handful of distinctive events that might signal their quarry's existence, while physicists cross-check every candidate. Only when they have accumulated enough events to be sure - maybe a dozen - will they publicly proclaim the discovery of the sought-after Higgs.
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Tevatron experiments report new Higgs search results

The CDF and DZero experiments at Fermilab have reached new ground in their quest to find the Higgs boson, a key member of the particle zoo known as the Standard Model. For the first time, each experiment by itself excludes regions of the expected Higgs mass range as more sophisticated data analysis techniques and more data from the Tevatron particle collider have increased their sensitivity to the Higgs boson. This week, the two collaborations, each comprising about 500 scientists, will present details of their results at conferences and seminars around the world, including the Rencontres de Moriond in Italy.
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Date: Feb 11 19:48 2011

Excellent, and well said! cosmologists always use some ad-hoc fields to run the show. Perhaps they are carried away by the data from cosmic microwave background radiation. After all, if inflation is the right mechanism, it must produce both seed perturbations and the right form of matter.