Records |
Author |
Pich, A.; Rosell, I.; Sanz-Cillero, J.J. |
Title |
Viability of Strongly Coupled Scenarios with a Light Higgs-like Boson |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
110 |
Issue |
18 |
Pages |
181801 - 4pp |
Keywords |
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Abstract |
We present a one-loop calculation of the oblique S and T parameters within strongly coupled models of electroweak symmetry breaking with a light Higgs-like boson. We use a general effective Lagrangian, implementing the chiral symmetry breaking SU(2)(L) circle times SU(2)(R) -> SU(2)(L+R) with Goldstone bosons, gauge bosons, the Higgs-like scalar, and one multiplet of vector and axial-vector massive resonance states. Using a dispersive representation and imposing a proper ultraviolet behavior, we obtain S and T at the next-to-leading order in terms of a few resonance parameters. The experimentally allowed range forces the vector and axial-vector states to be heavy, with masses above the TeV scale, and suggests that the Higgs-like scalar should have a WW coupling close to the standard model one. Our conclusions are generic and apply to more specific scenarios such as the minimal SO(5)/SO(4) composite Higgs model. |
Address |
Univ Valencia, CSIC, IFIC, Dept Fis Teor, Valencia 46071, Spain |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000319020100002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1456 |
Permanent link to this record |
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Author |
Pich, A.; Rosell, I.; Sanz-Cillero, J.J. |
Title |
One-loop calculation of the oblique S parameter in higgsless electroweak models |
Type |
Journal Article |
Year |
2012 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
08 |
Issue |
8 |
Pages |
106 - 34pp |
Keywords |
Higgs Physics; Beyond Standard Model; Chiral Lagrangians; Technicolor and Composite Models |
Abstract |
We present a one-loop calculation of the oblique S parameter within Higgsless models of electroweak symmetry breaking and analyze the phenomenological implications of the available electroweak precision data. We use the most general effective Lagrangian with at most two derivatives, implementing the chiral symmetry breaking SU(2)(L) circle times SU(2)(R) -> SU(2)(L+R) with Goldstones, gauge bosons and one multiplet of vector and axial-vector massive resonance states. Using the dispersive representation of Peskin and Takeuchi and imposing the short-distance constraints dictated by the operator product expansion, we obtain S at the NLO in terms of a few resonance parameters. In asymptotically-free gauge theories, the final result only depends on the vector-resonance mass and requires M-V > 1.8TeV (3.8TeV) to satisfy the experimental limits at the 3 sigma (1 sigma) level; the axial state is always heavier, we obtain M-A > 2.5TeV (6.6TeV) at 3 sigma (1 sigma). In strongly-coupled models, such as walking or conformal technicolour, where the second Weinberg sum rule does not apply, the vector and axial couplings are not determined by the short-distance constraints; but one can still derive a lower bound on S, provided the hierarchy M-V < M-A remains valid. Even in this less constrained situation, we find that in order to satisfy the experimental limits at 3 sigma one needs M-V,M-A > 1.8TeV. |
Address |
[Pich, A.; Rosell, I.] Univ Valencia, CSIC, IFIC, Dept Fis Teor, E-46071 Valencia, Spain, Email: antonio.pich@ific.uv.es; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1126-6708 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000309883200063 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
1217 |
Permanent link to this record |
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Author |
Pich, A.; Rosell, I.; Sanz-Cillero, J.J. |
Title |
The vector form factor at the next-to-leading order in 1/N-C: chiral couplings L-9(mu) and C-88(mu)-C-90(mu) |
Type |
Journal Article |
Year |
2011 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
02 |
Issue |
2 |
Pages |
109 - 23pp |
Keywords |
1/N Expansion; Chiral Lagrangians; QCD |
Abstract |
Using the Resonance Chiral Theory Lagrangian, we perform a calculation of the vector form factor of the pion at the next-to-leading order (NLO) in the 1/N-C expansion. Imposing the correct QCD short-distance constraints, one fixes the amplitude in terms of the pion decay constant F and resonance masses. Its low momentum expansion determines then the corresponding O(p(4)) and O(p(6)) low-energy chiral couplings at NLO, keeping control of their renormalization scale dependence. At mu(0) = 0.77 GeV, we obtain L-9(mu(0)) = (7.9 +/- 0.4).10(-3) and C-88(mu(0)) – C-90(mu(0)) = (-4.6 +/- 0.4).10(-5). |
Address |
[Pich, Antonio; Rosell, Ignasi] Univ Valencia CSIC, Dept Fis Teor, IFIC, E-46071 Valencia, Spain, Email: Antonio.Pich@uv.es |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1126-6708 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000287939200009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
620 |
Permanent link to this record |