Artículos con la etiqueta ‘Boson de Higgs’

Philosophical perspectives on ad hoc-hypotheses and the Higgs mechanism

Por • 26 may, 2013 • Category: Filosofía

We examine physicists’ charge of adhocness against the Higgs mechanism in the Standard Model of elementary particle physics. We argue that even though this charge never rested on a clear-cut and well-entrenched definition of «ad hoc», it is based on conceptual and methodological assumptions and principles which are well-founded elements of the scientific practice of high-energy particle physics. Based on our findings, we dispute the claim made by Christopher Hunt in a recent article in «Philosophy of Science» that the use of «ad hoc» by scientists reflects nothing more substantial than a judgment made on the basis of their «individual aesthetic senses». We further evaluate the implications of the recent discovery of a Higgs-like particle at the CERN Large Hadron Collider for the charge of adhocness against the Higgs mechanism.



Time and the Higgs (with apologies to J. B. Priestley)

Por • 31 ago, 2012 • Category: Ambiente

A model of discrete space-time is presented which is, in a sense, both Lorentz invariant and has no restriction on the relative velocity between particles (except v < c). The space-time has an inbuilt indeterminacy. Published originally as ‘A quantisation of time’, J. Phys. A: Math. Gen., 10, 2115, 1977; identical to the original, apart from one or two minor corrections, and some simplification towards the end of Section 6. The paper presents a discrete model of time, in which the latter comprises a succession of instants which are identified as collisions with particles called chronons. Proper-time intervals are discrete; the structure of space-time is given by a radar map and has an inbuilt indeterminacy, which leads naturally to Heisenberg’s uncertainty principle. If I were writing this paper today I would identify the chronon with the virtual Higgs boson. Without the latter all particles would be massless and would follow null paths; there would be no such thing as proper time. Time is an emergent phenomenon, and the Higgs boson is the agent of that emergence.



Unveiling the Higgs mechanism to students

Por • 14 jul, 2012 • Category: Educacion

In this paper we give the outline of a lecture given to undergraduate students aiming at understanding why physicists are so much interested in the Higgs boson. The lecture has been conceived for students not yet familiar with advanced physics and is suitable for several disciplines, other than physics. The Higgs mechanism is introduced by semi-classical arguments mimicking the basic field theory concepts, assuming the validity of a symmetry principle in the expression of the energy of particles in a classical field. The lecture is divided in two parts: the first, suitable even to high–school students, shows how the mass of a particle results as a dynamical effect due to the interaction between a massless particle and a field (as in the Higgs mechanism). The audience of the second part, much more technical, consists mainly of teachers and university students of disciplines other than physics.



Origins of Mass

Por • 14 jul, 2012 • Category: Leyes

Newtonian mechanics posited mass as a primary quality of matter, incapable of further elucidation. We now see Newtonian mass as an emergent property. Most of the mass of standard matter, by far, arises dynamically, from back-reaction of the color gluon fields of quantum chromodynamics (QCD). The equations for massless particles support extra symmetries – specifically scale, chiral, and gauge symmetries. The consistency of the standard model relies on a high degree of underlying gauge and chiral symmetry, so the observed non-zero masses of many elementary particles ($W$ and $Z$ bosons, quarks, and leptons) requires spontaneous symmetry breaking. Superconductivity is a prototype for spontaneous symmetry breaking and for mass-generation, since photons acquire mass inside superconductors. A conceptually similar but more intricate form of all-pervasive (i.e. cosmic) superconductivity, in the context of the electroweak standard model, gives us a successful, economical account of $W$ and $Z$ boson masses. It also allows a phenomenologically successful, though profligate, accommodation of quark and lepton masses. The new cosmic superconductivity, when implemented in a straightforward, minimal way, suggests the existence of a remarkable new particle, the so-called Higgs particle.