5,084 research outputs found
Physics Needs for Future Accelerators
Contents:
1. Prologomena to any meta future physics
1.1 Physics needs for building future accelerators
1.2 Physics needs for funding future accelerators
2. Physics questions for future accelerators
2.1 Crimes and misapprehensions
2.1.1 Organized religion 2.1.2 Feudalism 2.1.3 Trotsky was right
2.2 The Standard Model as an effective field theory
2.3 What is the scale of new physics?
2.4 What could be out there?
2.5 Model-independent conclusions
3. Future accelerators
3.1 What is the physics driving the LHC?
3.2 What is the physics driving the LC?
3.2.1 Higgs physics is golden
3.2.2 LHC won't be sufficient to unravel the new physics as the TeV scale
3.2.3 LC precision measurements can pin down new physics scales
3.3 Why a Neutrino Factory?
3.4 Pushing the energy frontierComment: 19 pages, 7 figures. Talk presented at the XIX International
Symposium on Lepton and Photon Interactions at High Energies (Lepton-Photon
'99), Stanford University, August 9-14, 199
Boundary Effects in 2+1 Dimensional Maxwell-Chern-Simons Theory
The boundary effects in the screening of an applied magnetic field in a
finite temperature 2+1 dimensional model of charged fermions minimally coupled
to Maxwell and Chern-Simons fields are investigated. It is found that in a
sample with only one boundary -a half-plane- a total Meissner effect takes
place, while in a sample with two boundaries -an infinite strip- the external
magnetic field partially penetrates the material.Comment: revte
Have We Observed the Higgs (Imposter)?
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 give excellent
fits to the measured event rates of the newly observed scalar resonance, while
the Standard Model Higgs boson gives a slightly worse overall fit due to the
lack signal in the tau tau channel. The triplet imposter exhibits some tension
with the data. 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 b bbar and tau tau channels, are needed
to further distinguish the Higgs doublet from the triplet imposter.Comment: 20 pages, 4 figures; v2: updated with most recent public data as of
August 7. A generic Higgs doublet now gives the best fit to data, while the
triplet imposter exhibits some tensio
Scalar potential from de Sitter brane in 5D and effective cosmological constant
We derive the scalar potential in zero mode effective action arising from a
de Sitter brane embedded in five dimensions with bulk cosmological constant
. The scalar potential for a scalar field canonically normalized is
given by the sum of exponential potentials. In the case of and
, we point out that the scalar potential has an unstable local
maximum at the origin and exponentially vanishes for large positive scalar
field. In the case of , the scalar potential has an unstable local
maximum at the origin and a stable local minimum, it is shown that the positive
cosmological constant in brane is reduced by negative potential energy of
scalar at minimum.Comment: 14 pages, 5 figures, add the section of cosmological implication
CPT- and B-Violation: The p-pbar Sector
The CPT symmetry of relativistic quantum field theory requires the total
lifetimes of particles and antiparticles be equal. Detection of pbar lifetime
shorter than tau_p > O(10^32) yr would signal breakdown of CPT invariance, in
combination with B-violation. The best current limit on tau_pbar, inferred from
cosmic ray measurements, is about one Myr, placing lower limits on
CPT-violating scales that depend on the exact mechanism. Paths to CPT breakdown
within and outside ordinary quantum mechanics are sketched. Many of the
limiting CPT-violating scales in pbar decay lie within the weak-to-Planck
range.Comment: 6 pages, LaTeX, .sty file included; based on contribution to CPT98
Conference; minor changes, accepted by Mod. Phys. Lett.
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