| Records |
| Author |
Murgui, C.; Peñuelas, A.; Jung, M.; Pich, A. |
| Title |
Global fit to b -> c tau nu transitions |
Type |
Journal Article |
| Year |
2019 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
09 |
Issue |
9 |
Pages |
103 - 45pp |
| Keywords |
Beyond Standard Model; Effective Field Theories |
| Abstract |
We perform a general model-independent analysis of b -> c tau(nu) over bar (tau) transitions, including measurements of R-D, R-D*, their q(2) differential distributions, the recently measured longitudinal D* polarization F-L(D)*, and constraints from the B-c -> tau(nu) over bar (tau) lifetime, each of which has significant impact on the fit. A global fit to a general set of Wilson coefficients of an effective low-energy Hamiltonian is presented, the solutions of which are interpreted in terms of hypothetical new-physics mediators. From the obtained results we predict selected b -> c tau(nu) over bar (tau) observables, such as the baryonic transition Lambda(b) -> Lambda(c)tau(nu) over bar (tau), the ratio R-J/psi, the forward-backward asymmetries A(FB)(D()*()), the tau polarization asymmetries P-tau(D()*()), and the longitudinal D* polarization fraction F-L(D)*. The latter shows presently a slight tension with any new-physics model, such that an improved measurement could have an important impact. We also discuss the potential change due the very recently announced preliminary R-D(*) measurement by the Belle collaboration. |
| Address |
[Murgui, Clara; Penuelas, Ana; Pich, Antonio] Univ Valencia, IFIC, Dept Fis Teor, CSIC, Apt Correus 22085, E-46071 Valencia, Spain, Email: Clara.Murgui@ific.uv.es; |
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| Publisher |
Springer |
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| Language |
English |
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1029-8479 |
ISBN |
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Expedition |
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Conference |
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| Notes |
WOS:000490861200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4177 |
| Permanent link to this record |
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| Author |
Mandal, R.; Pich, A. |
| Title |
Constraints on scalar leptoquarks from lepton and kaon physics |
Type |
Journal Article |
| Year |
2019 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
12 |
Issue |
12 |
Pages |
089 - 40pp |
| Keywords |
Beyond Standard Model; Kaon Physics |
| Abstract |
We present a comprehensive analysis of low-energy signals of hypothetical scalar leptoquark interactions in lepton and kaon transitions. We derive the most general effective four-fermion Lagrangian induced by tree-level scalar leptoquark exchange and identify the Wilson coefficients predicted by the five possible types of scalar leptoquarks. The current constraints on the leptoquark Yukawa couplings arising from lepton and kaon processes are worked out, including also loop-induced transitions with only leptons (or quarks) as external states. In the presence of scalar leptoquark interactions, we also derive the differential distributions for flavour-changing neutral-current transitions in semileptonic kaon modes, including all known effects within the Standard Model. Their interference with the new physics contributions could play a significant role in future improvements of those constraints that are currently hampered by poorly-determined non-perturbative parameters. |
| Address |
[Mandal, Rusa; Pich, Antonio] Univ Valencia, CSIC, IFIC, Apt Correus 22085, E-46071 Valencia, Spain, Email: Rusa.Mandal@uni-siegen.de; |
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| Publisher |
Springer |
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English |
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1029-8479 |
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:000503847800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4231 |
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| Author |
Cirigliano, V.; Gisbert, H.; Pich, A.; Rodriguez-Sanchez, A. |
| Title |
Isospin-violating contributions to epsilon '/epsilon |
Type |
Journal Article |
| Year |
2020 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
02 |
Issue |
2 |
Pages |
032 - 44pp |
| Keywords |
Chiral Lagrangians; CP violation; Effective Field Theories; Kaon Physics |
| Abstract |
The known isospin-breaking contributions to the K -> pi pi amplitudes are reanalyzed, taking into account our current understanding of the quark masses and the relevant non-perturbative inputs. We present a complete numerical reappraisal of the direct CP-violating ratio is an element of(')/is an element of, where these corrections play a quite significant role. We obtain the Standard Model prediction Re (is an element of(')/is an element of) = (14 +/- 5) <bold> </bold>10(-4), which is in very good agreement with the measured ratio. The uncertainty, which has been estimated conservatively, is dominated by our current ignorance about 1/N-C-suppressed contributions to some relevant chiral-perturbation-theory low-energy constants. |
| Address |
[Cirigliano, V.] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA, Email: cirigliano@lanl.gov; |
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| Publisher |
Springer |
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English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Edition |
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| ISSN |
1029-8479 |
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:000515816800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4304 |
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| Author |
Mandal, R.; Murgui, C.; Peñuelas, A.; Pich, A. |
| Title |
The role of right-handed neutrinos in b -> c tau nubar anomalies |
Type |
Journal Article |
| Year |
2020 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
08 |
Issue |
8 |
Pages |
022 - 46pp |
| Keywords |
Phenomenology of Field Theories in Higher Dimensions |
| Abstract |
Motivated by the persistent anomalies reported in the b -> c tau v<overbar></mml:mover> data, we perform a general model-independent analysis of these transitions, in the presence of light right-handed neutrinos. We adopt an effective field theory approach and write a low-energy effective Hamiltonian, including all possible dimension-six operators. The corresponding Wilson coefficients are determined through a numerical fit to all available experimental data. In order to work with a manageable set of free parameters, we define eleven well- motivated scenarios, characterized by the different types of new physics that could mediate these transitions, and analyse which options seem to be preferred by the current measurements. The data exhibit a clear preference for new-physics contributions, and good fits to the data are obtained in several cases. However, the current measurement of the longitudinal D<SUP></SUP> polarization in B -> D tau v<overbar></mml:mover> cannot be easily accommodated within its experimental 1 sigma range. A general analysis of the three-body B -> D tau v<overbar></mml:mover> and four-body B -> D<mml:mo><mml:mfenced close=“)” open=“(”><mml:mo>-> D pi</mml:mfenced>tau <mml:mover accent=“true”>v<mml:mo stretchy=“true”><overbar></mml:mover> angular distributions is also presented. The accessible angular observables are studied in order to assess their sensitivity to the different new physics scenarios. Experimental information on these distributions would help to disentangle the dynamical origin of the current anomalies. |
| Address |
[Mandal, Rusa] Univ Siegen, Theoret Phys 1, Nat Wissensch Tech Fak, D-57068 Siegen, Germany, Email: Rusa.Mandal@uni-siegen.de; |
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Springer |
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English |
Summary Language |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
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:000561056000003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4506 |
| Permanent link to this record |
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| Author |
Eberhardt, O.; Miralles, V.; Pich, A. |
| Title |
Constraints on coloured scalars from global fits |
Type |
Journal Article |
| Year |
2021 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
10 |
Issue |
10 |
Pages |
123 - 23pp |
| Keywords |
Beyond Standard Model; Higgs Physics |
| Abstract |
We consider a simple extension of the electroweak theory, incorporating one SU(2)(L) doublet of colour-octet scalars with Yukawa couplings satisfying the principle of minimal flavour violation. Using the HEPfit package, we perform a global fit to the available data, including all relevant theoretical constraints, and extract the current bounds on the model parameters. Coloured scalars with masses below 1.05 TeV are already excluded, provided they are not fermiophobic. The mass splittings among the different (charged and CP-even and CP-odd neutral) scalars are restricted to be smaller than 20 GeV. Moreover, for scalar masses smaller than 1.5 TeV, the Yukawa coupling of the coloured scalar multiplet to the top quark cannot exceed the one of the SM Higgs doublet by more than 80%. These conclusions are quite generic and apply in more general frameworks (without fine tunings). The theoretical requirements of perturbative unitarity and vacuum stability enforce relevant constraints on the quartic scalar potential parameters that are not yet experimentally tested. |
| Address |
[Eberhardt, Otto; Miralles, Victor; Pich, Antonio] Inst Fis Corpuscular, Parque Cient,C Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: otto.eberhardt.physics@gmail.com; |
| 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 Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
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:000708483600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5006 |
| Permanent link to this record |
