# The European Physical Journal C

## List of Papers (Total 3,619)

#### Statistical analysis with cosmic-expansion-rate measurements and two-point diagnostics

Direct measurements of Hubble parameters H(z) are very useful for cosmological model parameters inference. Based on them, Sahni, Shafieloo and Starobinski introduced a two-point diagnostic $Omh^2(z_i, z_j)$ as an interesting tool for testing the validity of the $\Lambda \hbox {CDM}$ model. Applying this test they found a tension between observations and predictions of the...

#### Leptonic flavor structure in the brane shifted extra dimensional seesaw mechanism

We discuss the leptonic flavor structure generated by a brane shifted extra dimensional seesaw model with a single right handed neutrino in the bulk. In contrast to previous works, no unitarity approximation for the $3 \times 3$ submatrix has been employed. This allows to study phenomenological signatures such as lepton flavor violating decays. A strong prediction of the model...

#### General expressions for extra-dimensional tree amplitudes and all-plus 1-loop integrands in $$\mathcal {}$$-cut representation

In this paper, we give the general expressions for a special series of tree amplitudes of the Yang–Mills theory. This series of amplitudes have two adjacent massless spin-1 particles with extra-dimensional momenta and any number of positive helicity gluons. With special helicity choices, we use the spinor helicity formalism to express these n-point amplitudes in compact forms...

#### From identical S- and P-wave $$p_\mathrm{T}$$ spectra to maximally distinct polarizations: probing NRQCD with $$\chi$$χ states

A global analysis of ATLAS and CMS measurements reveals that, at mid-rapidity, the directly-produced $\chi _{c1}$, $\chi _{c2}$ and J/$\psi$ mesons have differential cross sections of seemingly identical shapes, when presented as a function of the mass-rescaled transverse momentum, $p_\mathrm{T}/M$. This identity of kinematic behaviours among S- and P-wave quarkonia is...

#### Closing in on the radiative weak chiral couplings

We point out that, given the current experimental status of radiative kaon decays, a subclass of the $\mathcal{O} (p^4)$ counterterms of the weak chiral lagrangian can be determined in closed form. This involves in a decisive way the decay $K^\pm \rightarrow \pi ^\pm \pi ^0 l^+ l^-$, currently being measured at CERN by the NA48/2 and NA62 collaborations. We show that...

#### Generalizing the $$\mathfrak {bms}_{3}$$ and 2D-conformal algebras by expanding the Virasoro algebra

By means of the Lie algebra expansion method, the centrally extended conformal algebra in two dimensions and the $\mathfrak {bms}_{3}$ algebra are obtained from the Virasoro algebra. We extend this result to construct new families of expanded Virasoro algebras that turn out to be infinite-dimensional lifts of the so-called $\mathfrak {B}_{k}$, $\mathfrak {C}_{k}$ and...

#### Constraints on low energy QCD parameters from $$\eta \rightarrow 3\pi$$ and $$\pi \pi$$ππ scattering

The $\eta \,\rightarrow \,3\pi$ decays are a valuable source of information on low energy QCD. Yet they were not used for an extraction of the three flavor chiral symmetry breaking order parameters until now. We use a Bayesian approach in the framework of resummed chiral perturbation theory to obtain constraints on the quark condensate and pseudoscalar decay constant in the...

#### Width of a two-body coupled-channel resonance

We study the width of a two-body resonance in a coupled-channel system. We demonstrate how the width does not come only determined by the available phase space for its decay to the detection channel, but it greatly depends on the relative position of the mass of the resonance with respect to the masses of the coupled-channels generating the state. Our results are consistent with...

#### The impact of LHC jet data on the MMHT PDF fit at NNLO

We investigate the impact of the high precision ATLAS and CMS 7 TeV measurements of inclusive jet production on the MMHT global PDF analysis at next-to-next-to-leading order (NNLO). This is made possible by the recent completion of the long-term project to calculate the NNLO corrections to the hard cross section. We find that a good description of the ATLAS data is not possible...

#### Simple cosmological model with inflation and late times acceleration

In the framework of polynomial Palatini cosmology, we investigate a simple cosmological homogeneous and isotropic model with matter in the Einstein frame. We show that in this model during cosmic evolution, early inflation appears and the accelerating phase of the expansion for the late times. In this frame we obtain the Friedmann equation with matter and dark energy in the form...

#### Uncovering novel phase structures in $$\Box ^k$$ scalar theories with the renormalization group

We present a detailed version of our recent work on the RG approach to multicritical scalar theories with higher derivative kinetic term $\phi (-\Box )^k\phi$ and upper critical dimension $d_c = 2nk/(n-1)$. Depending on whether the numbers k and n have a common divisor two classes of theories have been distinguished. For coprime k and $n-1$ the theory admits a Wilson...

#### Pre-inflation from the multiverse: can it solve the quadrupole problem in the cosmic microwave background?

We analyze a quantized toy model of a universe undergoing eternal inflation using a quantum-field-theoretical formulation of the Wheeler–DeWitt equation. This so-called third quantization method leads to the picture that the eternally inflating universe is converted to a multiverse in which sub-universes are created and exhibit a distinctive phase in their evolution before...

#### Reconstructing warm inflation

The reconstruction of a warm inflationary universe model from the scalar spectral index $n_S(N)$ and the tensor to scalar ratio r(N) as a function of the number of e-folds N is studied. Under a general formalism we find the effective potential and the dissipative coefficient in terms of the cosmological parameters $n_S$ and r considering the weak and strong dissipative stages...