The Universal Fermi Interaction

Konopinski, E. J.; Mahmoud, Hormoz

doi:10.1103/physrev.92.1045

Cited by 243 publications

(72 citation statements)

References 21 publications

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“…The limit on the matching scale rises dramatically for the case in which the leptonic coupling is taken to be much larger than the quark coupling g l ≫ g q . This is because the matching scale for the new gauge dynamics corresponds to the heaviest gauge boson, of order g l u where u is the vev of a bidoublet scalar field that breaks SU (2) …”

Section: Introductionmentioning

confidence: 99%

Constraints on the SU(3) electroweak model

Csáki¹,

Erlich²,

Kribs³

et al. 2002

Phys. Rev. D

108

209

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We consider a recent proposal by Dimopoulos and Kaplan to embed the electroweak SU(2) L × U(1) Y into a larger group SU(3) W × SU(2) × U(1) at a scale above a TeV. This idea is motivated by the prediction for the weak mixing angle sin 2 θ W = 1/4, which naturally appears in these models so long as the gauge couplings of the high energy SU(2) and U(1) groups are moderately large. The extended gauge dynamics results in new effective operators that contribute to four-fermion interactions and Z pole observables. We calculate the corrections to these electroweak precision observables and carry out a global fit of the new physics to the data. For SU(2) and U(1) gauge couplings larger than 1, we find that the 95% C.L. lower bound on the matching (heavy gauge boson mass) scale is 11 TeV. We comment on the fine-tuning of the high energy gauge couplings needed to allow matching scales above our bounds. The remnants of SU(3) W breaking include multi-TeV SU(2) L doublets with electric charge (±2, ±1). The lightest charged gauge boson is stable, leading to cosmological difficulties.

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Section: Introductionmentioning

confidence: 99%

Constraints on the SU(3) electroweak model

Csáki¹,

Erlich²,

Kribs³

et al. 2002

Phys. Rev. D

108

209

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show abstract

“…The concept of a conserved lepton number was introduced in 1953 [23]. A 1962 experiment at Brookhaven [24] demonstrated that the neutrinos produced in pion decay, when interacting in a detector, produced muons and not electrons.…”

Section: The Number Of Neutrino Generationsmentioning

confidence: 99%

Measuring neutrino oscillation parameters using $\nu_\mu$ disappearance in MINOS

Backhouse¹

2011

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MINOS is a long-baseline neutrino oscillation experiment. It consists of two large steel-scintillator tracking calorimeters. The near detector is situated at Fermilab, close to the production point of the NuMI muon-neutrino beam. The far detector is 735 km away, 716 m underground in the Soudan mine, Northern Minnesota.The primary purpose of the MINOS experiment is to make precise measurements of the "atmospheric" neutrino oscillation parameters (∆m 2 atm and sin 2 2θ atm ). The oscillation signal consists of an energy-dependent deficit of ν µ interactions in the far detector. The near detector is used to characterize the properties of the beam before oscillations develop. The two-detector design allows many potential sources of systematic error in the far detector to be mitigated by the near detector observations. This thesis describes the details of the ν µ -disappearance analysis, and presents a new technique to estimate the hadronic energy of neutrino interactions. This estimator achieves a significant improvement in the energy resolution of the neutrino spectrum, and in the sensitivity of the neutrino oscillation fit. The systematic uncertainty on the hadronic energy scale was re-evaluated and found to be comparable to that of the energy estimator previously in use.The best-fit oscillation parameters of the ν µ -disappearance analysis, incorporating this new estimator were: ∆m 2 = 2.32. A similar analysis, using data from a period of running where the NuMI beam was operated in a configuration producing a predominantlyν µ beam, yielded somewhat different best-fit parameters ∆m 2 = 3.36−0.12 (stat.) ± 0.01(syst.). The tension between these results is intriguing, and additional antineutrino data is currently being taken in order to further investigate this apparent discrepancy. DeclarationI declare that this thesis and the work presented in it are my own and were produced by me as the result of my own original research. The work was done while a candidate for a degree at the University of Oxford, and has not been submitted for any other qualification. Results and figures from published works have been clearly attributed.The energy estimation technique presented in Chapter 5 of this thesis was my primary original contribution to the MINOS charged-current analysis. The analysis as a whole was performed by a group within the collaboration, and while I made significant contributions, the innovations described in Chapter 4 are the work of others (in many cases the subject of a thesis in their own right).ii AcknowledgmentsOver the course of 3 1 /2 years I've collected quite a number of people without whom this thesis wouldn't have been possible (or at least severely delayed). So here goes, in roughly chronological order:Thanks to my supervisor, Giles Barr, who never ceases to be optimistic, no matter how broken the analysis, or close the deadline. I also appreciated his offers (which I never had to take up) to throw his weight around and leave me to get on with writing, and his prompt proofreading (by usual a...

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“…In this case, two Majorana neutrinos of different flavors combine to one Dirac particle and the conserved U(1) charge is called a lepton number of the ZKM type [37,38]. If, for example, the identifications ν 1L = ν µL and ν 2L = ν τ L hold, then the mass matrixM = M exhibits a U(1)…”

Section: Textures For See-saw-dirac Particlesmentioning

confidence: 99%

Seesaw mechanisms for Dirac and Majorana neutrino masses

2002

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We investigate the see-saw mechanism for generally non-fine-tuned n × n mass matrices involving both Dirac and Majorana neutrinos. We specifically show that the number of naturally light neutrinos cannot exceed half of the dimension of the considered mass matrix. Furthermore, we determine a criterion for mass matrix textures leading to light Dirac neutrinos with the see-saw mechanism. Especially, we study 4 × 4 and 6 × 6 mass matrix textures and give some examples in order to highlight these types of textures. Next, we present a model scheme based on non-Abelian and discrete symmetries fulfilling the above mentioned criterion for light Dirac neutrinos. Finally, we investigate the connection between symmetries and the invariants of a mass matrix on a formal level.

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The Universal Fermi Interaction

Cited by 243 publications

References 21 publications

Constraints on the SU(3) electroweak model

Constraints on the SU(3) electroweak model

Measuring neutrino oscillation parameters using $\nu_\mu$ disappearance in MINOS

Seesaw mechanisms for Dirac and Majorana neutrino masses

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