| Records |
| Author |
Bennett, J.J.; Buldgen, G.; de Salas, P.F.; Drewes, M.; Gariazzo, S.; Pastor, S.; Wong, Y.Y.Y. |
| Title |
Towards a precision calculation of the effective number of neutrinos N-eff in the Standard Model. Part II. Neutrino decoupling in the presence of flavour oscillations and finite-temperature QED |
Type |
Journal Article |
| Year |
2021 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume  |
04 |
Issue |
4 |
Pages |
073 - 33pp |
| Keywords |
cosmological neutrinos; neutrino properties; particle physics – cosmology connection; physics of the early universe |
| Abstract |
We present in this work a new calculation of the standard-model benchmark value for the effective number of neutrinos, N-eff(SM), that quantifies the cosmological neutrinoto-photon energy densities. The calculation takes into account neutrino flavour oscillations, finite-temperature effects in the quantum electrodynamics plasma to O(e(3)), where e is the elementary electric charge, and a full evaluation of the neutrino-neutrino collision integral. We provide furthermore a detailed assessment of the uncertainties in the benchmark N(eff)(SM )value, through testing the value's dependence on (i) optional approximate modelling of the weak collision integrals, (ii) measurement errors in the physical parameters of the weak sector, and (iii) numerical convergence, particularly in relation to momentum discretisation. Our new, recommended standard-model benchmark is N-eff(SM) 3.0440 +/- 0.0002, where the nominal uncertainty is attributed predominantly to errors incurred in the numerical solution procedure (vertical bar delta N-eff vertical bar similar to 10(-4)), augmented by measurement errors in the solar mixing angle sin(2) theta(12) (vertical bar delta N-eff vertical bar similar to 10(-4)). |
| Address |
[Bennett, Jack J.; Wong, Yvonne Y. Y.] Univ New South Wales, Sch Phys, Sydney Consortium Particle Phys & Cosmol, Sydney, NSW 2052, Australia, Email: j.j.bennett@unsw.edu.au; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1475-7516 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000647827600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4827 |
| Permanent link to this record |
| |
|
| |
| Author |
Ellis, J.; Madigan, M.; Mimasu, K.; Sanz, V.; You, T. |
| Title |
Top, Higgs, diboson and electroweak fit to the Standard Model effective field theory |
Type |
Journal Article |
| Year |
2021 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
279 - 78pp |
| Keywords |
Effective Field Theories; Beyond Standard Model; Higgs Physics |
| Abstract |
The search for effective field theory deformations of the Standard Model (SM) is a major goal of particle physics that can benefit from a global approach in the framework of the Standard Model Effective Field Theory (SMEFT). For the first time, we include LHC data on top production and differential distributions together with Higgs production and decay rates and Simplified Template Cross-Section (STXS) measurements in a global fit, as well as precision electroweak and diboson measurements from LEP and the LHC, in a global analysis with SMEFT operators of dimension 6 included linearly. We present the constraints on the coefficients of these operators, both individually and when marginalised, in flavour-universal and top-specific scenarios, studying the interplay of these datasets and the correlations they induce in the SMEFT. We then explore the constraints that our linear SMEFT analysis imposes on specific ultra-violet completions of the Standard Model, including those with single additional fields and low-mass stop squarks. We also present a model-independent search for deformations of the SM that contribute to between two and five SMEFT operator coefficients. In no case do we find any significant evidence for physics beyond the SM. Our underlying Fitmaker public code provides a framework for future generalisations of our analysis, including a quadratic treatment of dimension-6 operators. |
| Address |
[Ellis, John; Mimasu, Ken] Kings Coll London, Dept Phys, Theoret Particle Phys & Cosmol Grp, London WC2R 2LS, England, Email: john.ellis@cern.ch; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Springer |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1029-8479 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000658918100001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4857 |
| Permanent link to this record |
| |
|
| |
| Author |
Penalva, N.; Hernandez, E.; Nieves, J. |
| Title |
Visible energy and angular distributions of the charged particle from the tau-decay in b -> C tau (mu(nu)over-bar(mu)nu(tau), pi nu(tau), rho nu(tau))(nu)over-bar(tau) reactions |
Type |
Journal Article |
| Year |
2022 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
026 - 25pp |
| Keywords |
Bottom Quarks; Semi-Leptonic Decays; Flavour Symmetries; Left-Right Models |
| Abstract |
We study the d(2)Gamma(d)/(d omega d cos theta(d) ), d Gamma(d)/d cos theta(d) and d Gamma(d)/dE(d) distributions, which are defined in terms of the visible energy and polar angle of the charged particle from the tau-decay in b -> C tau (mu(nu) over bar (mu)nu(tau), pi nu(tau), rho nu(tau))(nu) over bar (tau), reactions. These differential decay widths could be measured in the near future with certain precision. The first two contain information on the transverse tau-spin, tau-angular and tau-angular-spin asymmetries of the H-b -> H-c tau(nu) over bar (tau) parent decay and, from a dynamical point of view, they are richer than the commonly used one, d(2)Gamma(d)/(d omega dE(d)), since the latter only depends on the tau longitudinal polarization. We pay attention to the deviations with respect to the predictions of the standard model (SM) for these new observables, considering new physics (NP) operators constructed using both right- and left-handed neutrino fields, within an effective field-theory approach. We present results for Lambda(b) -> Lambda(c)tau (mu(nu) over bar (mu)nu(tau), pi nu(tau), rho nu(tau))(nu) over bar (tau) and (B) over bar -> D-(*()) tau (mu(nu) over bar (mu)nu(tau), pi nu(tau), rho nu(tau))(nu) over bar (tau) sequential decays and discuss their use to disentangle between different NP models. In this respect, we show that d Gamma(d)/d cos theta(d) , which should be measured with sufficiently good statistics, becomes quite useful, especially in the tau -> pi nu(tau) mode. The study carried out in this work could be of special relevance due to the recent LHCb measurement of the lepton flavor universality ratio R Lambda(c) in agreement with the SM. The experiment identified the tau using its hadron decay into pi(-)pi(+)pi(-)nu(tau), and this result for R Lambda(c )which is in conflict with the phenomenology from the b-meson sector, needs confirmation from other tau reconstruction channels. |
| Address |
[Penalva, Neus; Nieves, Juan] Inst Fis Corpuscular Ctr Mixto CSIC UV, Inst Invest Paterna, C Catedrat Jose Beltran 2, E-46980 Valencia, Spain, Email: neuspe@ific.uv.es; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Springer |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1029-8479 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000781361300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5195 |
| Permanent link to this record |
| |
|
| |
| Author |
LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
| Title |
Study of charmonium and charmonium-like contributions in B+ -> J/psi eta K+ decays |
Type |
Journal Article |
| Year |
2022 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
046 - 29pp |
| Keywords |
B Physics; Branching fraction; Hadron-Hadron Scattering; Quarkonium |
| Abstract |
A study of B+ -> J/psi eta K+ decays, followed by J/psi -> mu(+)mu(-) and eta -> gamma gamma, is performed using a dataset collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb(-1). The J/psi eta mass spectrum is investigated for contributions from charmonia and charmonium-like states. Evidence is found for the B+ -> (psi(2)(3823) -> J/psi eta)K+ and B+ -> (psi(4040) -> J/psi eta)K+ decays with significance of 3.4 and 4.7 standard deviations, respectively. This constitutes the first evidence for the psi(2)(3823) -> J/psi eta decay. |
| Address |
[de Souza Leite, J. Baptista; Bediaga, I; Torres, M. Cruz; Carneiro Da Graca, U. De Freitas; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil, Email: Ivan.Belyaev@itep.ru |
| Corporate Author |
|
Thesis |
|
| Publisher |
Springer |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1029-8479 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000781968600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5196 |
| Permanent link to this record |
| |
|
| |
| Author |
Gisbert, H.; Miralles, V.; Ruiz Vidal, J. |
| Title |
Electric dipole moments from colour-octet scalars |
Type |
Journal Article |
| Year |
2022 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
077 - 25pp |
| Keywords |
Beyond Standard Model; CP violation |
| Abstract |
We present the contributions to electric dipole moments (EDMs) induced by the Yukawa couplings of an additional electroweak doublet of colour-octet scalars. The full set of one-loop diagrams and the enhanced higher-order effects from Barr-Zee diagrams are computed for the quark (chromo-)EDM, along with the two-loop contributions to the Weinberg operator. Using the stringent experimental upper limits on the neutron EDM, constraints on the parameter space of the Manohar-Wise model are derived. |
| Address |
[Gisbert, Hector] TU Dortmund, Fak Phys, Otto Hahn Str 4, D-44221 Dortmund, Germany, Email: hector.gisbert@tu-dortmund.de; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Springer |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1029-8479 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000782602900005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5198 |
| Permanent link to this record |
