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Author Barenboim, G.; Rasero, J. url  doi
openurl 
  Title Electroweak baryogenesis window in non standard cosmologies Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 028 - 20pp  
  Keywords Cosmology of Theories beyond the SM; Beyond Standard Model; Neutrino Physics  
  Abstract In this work we show that the new bounds on the Higgs mass are more than difficult to reconcile with the strong constraints on the physical parameters of the Standard Model and the Minimal Supersymmetric Standard Model imposed by the preservation of the baryon asymmetry. This bound can be weakened by assuming a nonstandard cosmology at the time of the electroweak phase transition, reverting back to standard cosmology by BBN time. Two explicit examples are an early period of matter dominated expansion due to a heavy right handed neutrino (see-saw scale), or a nonstandard braneworld expansion.  
  Address [Barenboim, Gabriela] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: gabriela.barenboim@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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000307298400028 Approved no  
  Is ISI yes International Collaboration  
  Call Number (down) IFIC @ pastor @ Serial 1158  
Permanent link to this record
 
 
Author Bonnet, F.; Hirsch, M.; Ota, T.; Winter, W. url  doi
openurl 
  Title Systematic study of the d=5 Weinberg operator at one-loop order Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 153 - 23pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract We perform a systematic study of the d = 5 Weinberg operator at the one-loop level. We identify three different categories of neutrino mass generation: (1) finite irreducible diagrams; (2) finite extensions of the usual seesaw mechanisms at one-loop and (3) divergent loop realizations of the seesaws. All radiative one-loop neutrino mass models must fall in to one of these classes. Case (1) gives the leading contribution to neutrino mass naturally and a classic example of this class is the Zee model. We demonstrate that in order to prevent that a tree level contribution dominates in case (2), Majorana fermions running in the loop and an additional Z(2) symmetry are needed for a genuinely leading one-loop contribution. In the type-II loop extensions, the Yukawa coupling will be generated at one loop, whereas the type-I/III extensions can be interpreted as loop-induced inverse or linear seesaw mechanisms. For the divergent diagrams in category (3), the tree level contribution cannot be avoided and is in fact needed as counter term to absorb the divergence.  
  Address [Bonnet, Florian; Winter, Walter] Univ Wurzburg, Inst Theoret Phys & Astrophys, D-97074 Wurzburg, Germany, Email: florian.bonnet@physik.uni-wuerzburg.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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000307299800031 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 1159  
Permanent link to this record
 
 
Author Catani, S.; de Florian, D.; Rodrigo, G. url  doi
openurl 
  Title Space-like (vs. time-like) collinear limits in QCD: is factorization violated? Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 026 - 88pp  
  Keywords NLO Computations; Hadronic Colliders  
  Abstract We consider the singular behaviour of QCD scattering amplitudes in kinematical configurations where two or more momenta of the external partons become collinear. At the tree level, this behaviour is known to be controlled by factorization formulae in which the singular collinear factor is universal (process independent). We show that this strict (process-independent) factorization is not valid at one-loop and higher-loop orders in the case of the collinear limit in space-like regions (e. g., collinear radiation from initial-state partons). We introduce a generalized version of all-order collinear factorization, in which the space-like singular factors retain some dependence on the momentum and colour charge of the non-collinear partons. We present explicit results on one-loop and two-loop amplitudes for both the two-parton and multiparton collinear limits. At the level of squared amplitudes and, more generally, cross sections in hadron-hadron collisions, the violation of strict collinear factorization has implications on the non-abelian structure of logarithmically-enhanced terms in perturbative calculations (starting from the next-to-next-to-leading order) and on various factorization issues of mass singularities (starting from the next-to-next-to-next-to-leading order).  
  Address [Catani, Stefano] Univ Florence, Sez Firenze, Ist Nazl Fis Nucl, I-50019 Florence, Italy, Email: catani@fi.infn.it;  
  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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000307298400026 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 1160  
Permanent link to this record
 
 
Author Donini, A.; Hernandez, P.; Lopez-Pavon, J.; Maltoni, M.; Schwetz, T. url  doi
openurl 
  Title The minimal 3+2 neutrino model versus oscillation anomalies Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 161 - 20pp  
  Keywords Neutrino Physics; Beyond Standard Model  
  Abstract We study the constraints imposed by neutrino oscillation experiments on the minimal extension of the Standard Model that can explain neutrino masses, which requires the addition of just two singlet Weyl fermions. The most general renormalizable couplings of this model imply generically four massive neutrino mass eigenstates while one remains massless: it is therefore a minimal 3+2 model. The possibility to account for the confirmed solar, atmospheric and long-baseline oscillations, together with the LSND/MiniBooNE and reactor anomalies is addressed. We find that the minimal model can fit oscillation data including the anomalies better than the standard 3 nu model and similarly to the 3 + 2 phenomenological models, even though the number of free parameters is much smaller than in the latter. Accounting for the anomalies in the minimal model favours a normal hierarchy of the light states and requires a large reactor angle, in agreement with recent measurements. Our analysis of the model employs a new parametrization of seesaw models that extends the Casas-Ibarra one to regimes where higher order corrections in the light-heavy mixings are significant.  
  Address [Donini, A.; Hernandez, P.] Univ Valencia, Inst Fis Corpuscular, CSIC, E-46071 Valencia, Spain, Email: andrea.donini@uam.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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000307299800039 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 1161  
Permanent link to this record
 
 
Author del Aguila, F.; Aparici, A.; Bhattacharya, S.; Santamaria, A.; Wudka, J. url  doi
openurl 
  Title Effective Lagrangian approach to neutrinoless double beta decay and neutrino masses Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 06 Issue 6 Pages 146 - 37pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract Neutrinoless double beta (0 nu beta beta) decay can in general produce electrons of either chirality, in contrast with the minimal Standard Model (SM) extension with only the addition of the Weinberg operator, which predicts two left-handed electrons in the final state. We classify the lepton number violating (LNV) effective operators with two leptons of either chirality but no quarks, ordered according to the magnitude of their contribution to 0 nu beta beta decay. We point out that, for each of the three chirality assignments, e(L)e(L), e(L)e(R) and e(R)e(R), there is only one LNV operator of the corresponding type to lowest order, and these have dimensions 5, 7 and 9, respectively. Neutrino masses are always induced by these extra operators but can be delayed to one or two loops, depending on the number of RH leptons entering in the operator. Then, the comparison of the 0 nu beta beta decay rate and neutrino masses should indicate the effective scenario at work, which confronted with the LHC searches should also eventually decide on the specific model elected by nature. We also list the SM additions generating these operators upon integration of the heavy modes, and discuss simple realistic examples of renormalizable theories for each case.  
  Address [del Aguila, Franciso] Univ Granada, CAFPE, E-18071 Granada, Spain, Email: faguila@ugr.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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000306418300055 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 1177  
Permanent link to this record
 
 
Author Albaladejo, M.; Oller, J.A.; Oset, E.; Rios, G.; Roca, L. url  doi
openurl 
  Title Finite volume treatment of pi pi scattering and limits to phase shifts extraction from lattice QCD Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 08 Issue 8 Pages 071 - 22pp  
  Keywords Lattice QCD; Chiral Lagrangians; Phenomenological Models  
  Abstract We study theoretically the effects of finite volume for pi pi scattering in order to extract physical observables for infinite volume from lattice QCD. We compare three different approaches for pi pi scattering (lowest order Bethe-Salpeter approach, N/D and inverse amplitude methods) with the aim of studying the effects of the finite size of the box in the potential of the different theories, specially the left-hand cut contribution through loops in the crossed t, u-channels. We quantify the error made by neglecting these effects in usual extractions of physical observables from lattice ()CD spectrum. We conclude that for pi pi phase-shifts in the scalar-isoscalar channel up to 800 MeV this effect is negligible for box sizes bigger than 2,5m(pi)(-1) and of the order of 5% at around 1.5 – 2m(pi)(-1). For isospin 2 the finite size effects can reach up to 10% for that energy. We also quantify the error made when using the standard Luscher method to extract physical observables from lattice QCD, which is widely used in the literature but is an approximation of the one used in the present work.  
  Address [Albaladejo, M.; Oller, J. A.; Rios, G.; Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain, Email: albaladejo@um.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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000309883600014 Approved no  
  Is ISI yes International Collaboration no  
  Call Number (down) IFIC @ pastor @ Serial 1214  
Permanent link to this record
 
 
Author Bernabeu, J.; Martinez-Vidal, F.; Villanueva-Perez, P. url  doi
openurl 
  Title Time reversal violation from the entangled B-0(B)over-bar(0) system Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 08 Issue 8 Pages 064 - 18pp  
  Keywords Discrete and Finite Symmetries; B-Physics; CP violation  
  Abstract We discuss the concepts and methodology to implement an experiment probing directly Time Reversal (T) non-invariance, without any experimental connection to CP violation, by the exchange of in and out states. The idea relies on the B-0(B) over bar (0)) entanglement and decay time information available at B factories. The flavor or CP tag of the state of the still living neutral meson by the first decay of its orthogonal partner overcomes the problem of irreversibility for unstable systems, which prevents direct tests of T with incoherent particle states. T violation in the time evolution between the two decays means experimentally a difference between the rates for the time-ordered (l+X, J/psi K-s) and (J/psi K-L, l(-)X) decays, and three other independent asymmetries. The proposed strategy has been applied to simulated data samples of similar size and features to those currently available, from which we estimate the significance of the expected discovery to reach many standard deviations.  
  Address [Bernabeu, J.] Univ Valencia, Dept Theoret Phys, E-46100 Burjassot, Spain, Email: Jose.Bernabeu@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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000309883600021 Approved no  
  Is ISI yes International Collaboration no  
  Call Number (down) IFIC @ pastor @ Serial 1215  
Permanent link to this record
 
 
Author Filipuzzi, A.; Portoles, J.; Ruiz-Femenia, P. url  doi
openurl 
  Title Zeros of the W(L)Z(L) -> W(L)Z(L) amplitude: where vector resonances stand Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 08 Issue 8 Pages 080 - 22pp  
  Keywords Spontaneous Symmetry Breaking; Chiral Lagrangians  
  Abstract A Higgsless electroweak theory may be populated by spin-1 resonances around E similar to 1 TeV as a consequence of a new strong interacting sector, frequently proposed as a tool to smear the high-energy behaviour of scattering amplitudes, for instance, elastic gauge boson scattering. Information on those resonances, if they exist, must be contained in the low-energy couplings of the electroweak chiral effective theory. Using the facts that: i) the scattering of longitudinal gauge bosons, W-L, Z(L), can be well described in the high-energy region (E >> M-W) by the scattering of the corresponding Goldstone bosons (equivalence theorem) and ii) the zeros of the scattering amplitude carry the information on the heavier spectrum that has been integrated out; we employ the O(p(4)) electroweak chiral Lagrangian to identify the parameter space region of the low-energy couplings where vector resonances may arise. An estimate of their masses is also provided by our method.  
  Address [Filipuzzi, Alberto] Univ Valencia, Dept Fis Teor, IFIC, CSIC, E-46071 Valencia, Spain, Email: Alberto.Filipuzzi@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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000309883600005 Approved no  
  Is ISI yes International Collaboration no  
  Call Number (down) IFIC @ pastor @ Serial 1216  
Permanent link to this record
 
 
Author Pich, A.; Rosell, I.; Sanz-Cillero, J.J. url  doi
openurl 
  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 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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000309883200063 Approved no  
  Is ISI yes International Collaboration no  
  Call Number (down) IFIC @ pastor @ Serial 1217  
Permanent link to this record
 
 
Author Hoang, A.H.; Ruiz-Femenia, P.; Stahlhofen, M. url  doi
openurl 
  Title Renormalization group improved bottom mass from (gamma) sum rules at NNLL order Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 10 Issue 10 Pages 188 - 30pp  
  Keywords Heavy Quark Physics; Sum Rules; QCD  
  Abstract We determine the bottom quark mass from non-relativistic large-n gamma sum rules with renormalization group improvement at next-to-next-to-leading logarithmic order. We compute the theoretical moments within the vNRQCD formalism and account for the summation of powers of the Coulomb singularities as well as of logarithmic terms proportional to powers of alpha(s) ln(n). The renormalization group improvement leads to a substantial stabilization of the theoretical moments compared to previous fixed-order analyses, which did not account for the systematic treatment of the logarithmic alpha(s) ln(n) terms, and allows for reliable single moment fits. For the current world average of the strong coupling (alpha(s) (M-Z) = 0.1183 +/- 0.0010) we obtain M-b(1S) = 4.755 +/- 0.057(pert) +/- 0.009 alpha(s) +/- 0.003(exp) GeV for the bottom 1S mass and (m) over bar (b) ((m) over bar (b)) = 4.235 +/- 0.055(pert) +/- 0.003(exp) GeV for the bottom (MS) over bar mass, where we have quoted the perturbative error and the uncertainties from the strong coupling and the experimental data.  
  Address [Hoang, Andre H.; Ruiz-Femenia, Pedro; Stahlhofen, Maximilian] Univ Vienna, Fac Phys, A-1090 Vienna, Austria, Email: Andre.Hoang@univie.ac.at;  
  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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000310851300011 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 1231  
Permanent link to this record
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