| |
Records |
Links |
|
Author |
Cline, J.M.; Vincent, A.C. |
|
| |
Title |
Cosmological origin of anomalous radio background |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
|
| |
Volume |
02 |
Issue |
2 |
Pages |
011 - 23pp |
|
| |
Keywords |
cosmology of theories beyond the SM; dark matter theory; extragalactic magnetic fields |
|
| |
Abstract |
The ARCADE 2 collaboration has reported a significant excess in the isotropic radio background, whose homogeneity cannot be reconciled with clustered sources. This suggests a cosmological origin prior to structure formation. We investigate several potential mechanisms and show that injection of relativistic electrons through late decays of a metastable particle can give rise to the observed excess radio spectrum through synchrotron emission. However, constraints from the cosmic microwave background (CMB) anisotropy, on injection of charged particles and on the primordial magnetic field, present a challenge. The simplest scenario is with a greater than or similar to 9 GeV particle decaying into e(+)e(-) at a redshift of z similar to 5, in a magnetic field of similar to 5 μG, which exceeds the CMB B-field constraints, unless the field was generated after decoupling. Decays into exotic millicharged particles can alleviate this tension, if they emit synchroton radiation in conjunction with a sufficiently large background magnetic field of a dark U(1)' gauge field. |
|
| |
Address  |
[Cline, James M.] McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada, Email: jcline@physics.mcgill.ca; |
|
| |
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:000315576400011 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1361 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chen, H.X.; Oset, E. |
|
| |
Title |
pi pi interaction in the rho channel in finite volume |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
|
| |
Volume |
87 |
Issue |
1 |
Pages |
016014 - 15pp |
|
| |
Keywords |
|
|
| |
Abstract |
The aim of this paper is to investigate an efficient strategy that allows one to obtain pi pi phase shifts and rho meson properties from QCD lattice data with high precision. For this purpose we evaluate the levels of the pi pi system in the rho channel in finite volume using chiral unitary theory. We investigate the dependence on the pi mass and compare this with other approaches which use QCD lattice calculations and effective theories. We also illustrate the errors induced by using the conventional Luscher approach instead of a more accurate one that was recently developed that takes into account exactly the relativistic two-meson propagators. Finally, we make use of this latter approach to solve the inverse problem, getting pi pi phase shifts from “synthetic” lattice data, providing an optimal strategy and showing which accuracy is needed in these data to obtain the rho properties with a desired accuracy. |
|
| |
Address |
[Chen, Hua-Xing; Oset, E.] Univ Valencia, CSIC, Ctr Mixto, Inst Invest Paterna,Dept Fis Teor, Valencia 46071, Spain, Email: hxchen@ific.uv.es; |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000313945700004 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1309 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chachamis, G.; Hentschinski, M.; Madrigal Martinez, J.D.; Sabio Vera, A. |
|
| |
Title |
Gluon Regge trajectory at two loops from Lipatov's high energy effective action |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Nuclear Physics B |
Abbreviated Journal |
Nucl. Phys. B |
|
| |
Volume |
876 |
Issue |
2 |
Pages |
453-472 |
|
| |
Keywords |
|
|
| |
Abstract |
We present the derivation of the two-loop gluon Regge trajectory using Lipatov's high energy effective action and a direct evaluation of Feynman diagrams. Using a gauge invariant regularization of high energy divergences by deforming the light-cone vectors of the effective action, we determine the two-loop self-energy of the reggeized gluon, after computing the master integrals involved using the Mellin-Barnes representations technique. The self-energy is further matched to QCD through a recently proposed subtraction prescription. The Regge trajectory of the gluon is then defined through renormalization of the reggeized gluon propagator with respect to high energy divergences. Our result is in agreement with previous computations in the literature, providing a non-trivial test of the effective action and the proposed subtraction and renormalization framework. |
|
| |
Address |
[Chachamis, G.] Inst Fis Corpuscular UVEG CSIC, E-46980 Valencia, Spain, Email: martin.hentschinski@gmail.com |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Elsevier Science Bv |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0550-3213 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000325903700004 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1622 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chachamis, G.; Sabio Vera, A.; Salas, C. |
|
| |
Title |
Bootstrap and momentum transfer dependence in small x evolution equations |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
|
| |
Volume |
87 |
Issue |
1 |
Pages |
016007 - 6pp |
|
| |
Keywords |
|
|
| |
Abstract |
Using Monte Carlo integration techniques, we investigate running coupling effects compatible with the high energy bootstrap condition to all orders in the strong coupling in evolution equations valid at small values of Bjorken x in deep inelastic scattering. A model for the running of the coupling with analytic behavior in the infrared region and compatible with power corrections to jet observables is used. As a difference to the fixed coupling case, where the momentum transfer acts as an effective strong cutoff of the diffusion to infrared scales, in our running coupling study the dependence on the momentum transfer is much milder. |
|
| |
Address |
[Chachamis, G.] Cient Univ Valencia, Consejo Super Invest, Inst Fis Corpuscular, E-46980 Paterna Valencia, Spain |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000313426000004 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
no |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1303 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Celis, A.; Jung, M.; Li, X.Q.; Pich, A. |
|
| |
Title |
Sensitivity to charged scalars in B -> D-(*)tau nu(tau) and B -> tau nu(tau) decays |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
|
| |
Volume |
01 |
Issue |
1 |
Pages |
054 - 27pp |
|
| |
Keywords |
Beyond Standard Model; B-Physics |
|
| |
Abstract |
We analyze the recent experimental evidence for an excess of tau-lepton production in several exclusive semileptonic B-meson decays in the context of two-Higgs-doublet models. These decay modes are sensitive to the exchange of charged scalars and constrain strongly their Yukawa interactions. While the usual Type-II scenario cannot accommodate the recent BaBar data, this is possible within more general models in which the charged-scalar couplings to up-type quarks are not as suppressed. Both the B -> D-(*)tau nu(tau) and the B -> tau nu(tau) data can be fitted within the framework of the Aligned Two-Higgs-Doublet Model, but the resulting parameter ranges are in conflict with the constraints from leptonic charm decays. This could indicate a departure from the family universality of the Yukawa couplings, beyond their characteristic fermion mass dependence. We discuss several new observables that are sensitive to a hypothetical charged-scalar contribution, demonstrating that they are well suited to distinguish between different scenarios of new physics in the scalar sector, and also between this group and models with different Dirac structures; their experimental study would therefore shed light on the relevance of scalar exchanges in semileptonic b -> c tau(-)(nu) over bar (tau) transitions. |
|
| |
Address |
[Celis, Alejandro; Li, Xin-Qiang; Pich, Antonio] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: alejandro.celis@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:000315583200054 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1368 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Celis, A.; Ilisie, V.; Pich, A. |
|
| |
Title |
LHC constraints on two-Higgs doublet models |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
|
| |
Volume |
07 |
Issue |
7 |
Pages |
053 - 44pp |
|
| |
Keywords |
Higgs Physics; Beyond Standard Model |
|
| |
Abstract |
A new Higgs-like boson with mass around 126 GeV has recently been discovered at the LHC. The available data on this new particle is analyzed within the context of two-Higgs doublet models without tree-level flavour-changing neutral currents. Keeping the generic Yukawa structure of the Aligned Two-Higgs Doublet Model framework, we study the implications of the LHC data on the allowed scalar spectrum. We analyze both the CP-violating and CP-conserving cases, and a few particular limits with a reduced number of free parameters, such as the usual models based on discrete Z(2) symmetries. |
|
| |
Address |
[Celis, Alejandro; Ilisie, Victor; Pich, Antonio] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: alejandro.celis@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:000323202600053 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
no |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1635 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Celis, A.; Ilisie, V.; Pich, A. |
|
| |
Title |
Towards a general analysis of LHC data within two-Higgs-doublet models |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
|
| |
Volume |
12 |
Issue |
12 |
Pages |
095 - 32pp |
|
| |
Keywords |
Higgs Physics; Beyond Standard Model |
|
| |
Abstract |
The data accumulated so far confirm the Higgs-like nature of the new boson discovered at the LHC. The Standard Model Higgs hypothesis is compatible with the collider results and no significant deviations from the Standard Model have been observed neither in the flavour sector nor in electroweak precision observables. We update the LHC and Tevatron constraints on CP-conserving two-Higgs-doublet models without tree-level flavour-changing neutral currents. While the relative sign between the top Yukawa and the gauge coupling of the 126 GeV Higgs is found be the same as in the SM, at 90% CL, there is a sign degeneracy in the determination of its bottom and tau Yukawa couplings. This results in several disjoint allowed regions in the parameter space. We show how generic sum rules governing the scalar couplings determine the properties of the additional Higgs bosons in the different allowed regions. The role of electroweak precision observables, low-energy flavour constraints and LHC searches for additional scalars to further restrict the available parameter space is also discussed. |
|
| |
Address |
[Celis, Alejandro; Ilisie, Victor; Pich, Antonio] Univ Valencia, CSIC, IFIC, Dept Fis Teor, E-46071 Valencia, Spain, Email: alejandro.celis@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:000328891400001 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
no |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1664 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Capozziello, S.; Harko, T.; Koivisto, T.S.; Lobo, F.S.N.; Olmo, G.J. |
|
| |
Title |
The virial theorem and the dark matter problem in hybrid metric-Palatini gravity |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
|
| |
Volume |
07 |
Issue |
7 |
Pages |
024 - 19pp |
|
| |
Keywords |
modified gravity; dark matter theory; galaxy clusters |
|
| |
Abstract |
Hybrid metric-Palatini gravity is a recently proposed theory, consisting of the superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed a la Palatini. The theory predicts the existence of a long-range scalar field, which passes the Solar System observational constraints, even if the scalar field is very light, and modifies the cosmological and galactic dynamics. Thus, the theory opens new possibilities to approach, in the same theoretical framework, the problems of both dark energy and dark matter. In this work, we consider the generalized virial theorem in the scalar-tensor representation of the hybrid metric-Palatini gravity. More specifically, taking into account the relativistic collisionless Boltzmann equation, we show that the supplementary geometric terms in the gravitational field equations provide an effective contribution to the gravitational potential energy. We show that the total virial mass is proportional to the effective mass associated with the new terms generated by the effective scalar field, and the baryonic mass. In addition to this, we also consider astrophysical applications of the model and show that the model predicts that the mass associated to the scalar field and its effects extend beyond the virial radius of the clusters of galaxies. In the context of the galaxy cluster velocity dispersion profiles predicted by the hybrid metric-Palatini model, the generalized virial theorem can be an efficient tool in observationally testing the viability of this class of generalized gravity models. |
|
| |
Address |
[Capozziello, Salvatore] Univ Naples Federico II, Dipartimento Sci Fis, Naples, Italy, Email: capozzie@na.infn.it; |
|
| |
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:000322582000025 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1531 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Capozziello, S.; Harko, T.; Koivisto, T.S.; Lobo, F.S.N.; Olmo, G.J. |
|
| |
Title |
Galactic rotation curves in hybrid metric-Palatini gravity |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Astroparticle Physics |
Abbreviated Journal |
Astropart Phys. |
|
| |
Volume |
50-52 |
Issue |
|
Pages |
65-75 |
|
| |
Keywords |
Modified gravity; Galactic rotation curves; Dark matter |
|
| |
Abstract |
Generally, the dynamics of test particles around galaxies, as well as the corresponding mass deficit, is explained by postulating the existence of a hypothetical dark matter. In fact, the behavior of the rotation curves shows the existence of a constant velocity region, near the baryonic matter distribution, followed by a quick decay at large distances. In this work, we consider the possibility that the behavior of the rotational velocities of test particles gravitating around galaxies can be explained within the framework of the recently proposed hybrid metric-Palatini gravitational theory. The latter is constructed by modifying the metric Einstein-Hilbert action with an f(R) term in the Palatini formalism. It was shown that the theory unifies local constraints and the late-time cosmic acceleration, even if the scalar field is very light. In the intermediate galactic scale, we show explicitly that in the hybrid metric-Palatini model the tangential velocity can be explicitly obtained as a function of the scalar field of the equivalent scalar-tensor description. The model predictions are compared model with a small sample of rotation curves of low surface brightness galaxies, respectively, and a good agreement between the theoretical rotation Curves and the observational data is found. The possibility of constraining the form of the scalar field and the parameters of the model by using the stellar velocity dispersions is also analyzed. Furthermore, the Doppler velocity shifts are also obtained in terms of the scalar field. All the physical and geometrical quantities and the numerical parameters in the hybrid metric-Palatini model can be expressed in terms of observable/measurable parameters, such as the tangential velocity, the baryonic mass of the galaxy, the Doppler frequency shifts, and the stellar dispersion velocity, respectively. Therefore, the obtained results open the possibility of testing the hybrid metric-Palatini gravitational models at the galactic or extra-galactic scale by using direct astronomical and astrophysical observations. |
|
| |
Address |
[Capozziello, Salvatore] Univ Naples Federico II, Dipartimento Fis, Naples, Italy, Email: capozzie@na.infn.it; |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Elsevier Science Bv |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0927-6505 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000329271000009 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1689 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Capozziello, S.; Harko, T.; Lobo, F.S.N.; Olmo, G.J. |
|
| |
Title |
Hybrid Modified Gravity Unifying Local Tests, Galactic Dynamics and Late-Time Cosmic Acceleration |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
International Journal of Modern Physics D |
Abbreviated Journal |
Int. J. Mod. Phys. D |
|
| |
Volume |
22 |
Issue |
12 |
Pages |
1342006 - 7pp |
|
| |
Keywords |
Modified gravity; late-time cosmic acceleration; dark matter; solar system tests |
|
| |
Abstract |
The nonequivalence between the metric and Palatini formalisms of f(R) gravity is an intriguing feature of these theories. However, in the recently proposed hybrid metric-Palatini gravity, consisting of the superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed a la Palatini, the “true” gravitational field is described by the interpolation of these two nonequivalent approaches. The theory predicts the existence of a light long-range scalar field, which passes the local constraints and affects the galactic and cosmological dynamics. Thus, the theory opens new possibilities for a unified approach, in the same theoretical framework, to the problems of dark energy and dark matter, without distinguishing a priori matter and geometric sources, but taking their dynamics into account under the same standard. |
|
| |
Address |
[Capozziello, Salvatore] Univ Naples Federico II, Dipartimento Fis, I-80126 Naples, Italy, Email: capozzie@na.infn.it; |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
World Scientific Publ Co Pte Ltd |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0218-2718 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000329048900013 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1688 |
|
| Permanent link to this record |
