The European Physical Journal C

http://link.springer.com/journal/10052

List of Papers (Total 2,593)

Spin-1 diquark contributing to the formation of tetraquarks in light mesons

We apply a mixing framework to the light-meson systems and examine tetraquark possibility in the scalar channel. In the diquark–antidiquark model, a scalar diquark is a compact object when its color and flavor structures are in (\(\bar{\mathbf {3}}_c\), \(\bar{\mathbf {3}}_f\)). Assuming that all the quarks are in an S-wave, the spin-0 tetraquark formed out of this scalar diquark ...

Holographic energy loss in non-relativistic backgrounds

In this paper, we study some aspects of energy loss in non-relativistic theories from holography. We analyze the energy lost by a rotating heavy point particle along a circle of radius l with angular velocity \(\omega \) in theories with general dynamical exponent z and hyperscaling violation exponent \(\theta \). It is shown that this problem provides a novel perspective on the ...

Analysis of the mass and width of Y(4274) as axialvector molecule-like state

In this article, we assign Y(4274) to the color octet–octet type axialvector molecule-like state with \(J^{PC}=1^{++}\) tentatively, and construct the color octet–octet type axialvector current to study its mass and width with the QCD sum rules in details. The predicted mass favors assigning the Y(4274) to a color octet–octet type molecule-like state, but the predicted width ...

Two-loop corrections to the \(\rho \) parameter in Two-Higgs-Doublet models

Models with two scalar doublets are among the simplest extensions of the Standard Model which fulfill the relation \(\rho = 1\) at lowest order for the \(\rho \) parameter as favored by experimental data for electroweak observables allowing only small deviations from unity. Such small deviations \(\varDelta \rho \) originate exclusively from quantum effects with special sensitivity ...

Cosmic acceleration as an optical illusion

We consider light propagation in an inhomogeneous irrotational dust universe with vanishing cosmological constant, with initial conditions as in standard linear perturbation theory. A non-perturbative approach to the dynamics of such a universe is combined with a distance formula based on the Sachs optical equations. Then a numerical study implies a redshift–distance relation that ...

Higgs EFT for 2HDM and beyond

We discuss the validity of the Standard Model Effective Field Theory (SM EFT) as the low-energy effective theory for the two-Higgs-doublet Model (2HDM). Using the up-to-date Higgs signal strength measurements at the LHC, one can obtain a likelihood function for the Wilson coefficients of dimension-6 operators in the EFT Lagrangian. Given the matching between the 2HDM and the EFT, ...

Measurement of the \(\mathrm{t}\overline{\mathrm{t}} \) production cross section using events in the \(\mathrm {e}\mu \) final state in pp collisions at \(\sqrt{s}=13\,\text {TeV} \)

The cross section of top quark–antiquark pair production in proton–proton collisions at \({\sqrt{s}} = 13\,\text{TeV} \) is measured by the CMS experiment at the LHC, using data corresponding to an integrated luminosity of 2.2\(\,\text{fb}^{-1}\). The measurement is performed by analyzing events in which the final state includes one electron, one muon, and two or more jets, at ...

Higher-order gravity in higher dimensions: geometrical origins of four-dimensional cosmology?

Determining the cosmological field equations is still very much debated and led to a wide discussion around different theoretical proposals. A suitable conceptual scheme could be represented by gravity models that naturally generalize Einstein theory like higher-order gravity theories and higher-dimensional ones. Both of these two different approaches allow one to define, at the ...

Lowest-lying even-parity \({\bar{B}}_s\) mesons: heavy-quark spin-flavor symmetry, chiral dynamics, and constituent quark-model bare masses

The discovery of the \(D^*_{s0}(2317)\) and \(D_{s1}(2460)\) resonances in the charmed-strange meson spectra revealed that formerly successful constituent quark models lose predictability in the vicinity of two-meson thresholds. The emergence of non-negligible effects due to meson loops requires an explicit evaluation of the interplay between \(Q{\bar{q}}\) and ...

Scalar field collapse in a conformally flat spacetime

The collapse scenario of a scalar field along with a perfect fluid distribution was investigated for a conformally flat spacetime. The theorem for the integrability of an anharmonic oscillator has been utilized. For a pure power-law potential of the form \({\phi }^{n+1}\), it was found that a central singularity is formed which is covered by an apparent horizon for \(n>0\) and ...

No-scale \(\mu \) -term hybrid inflation

To solve the fine-tuning problem in \(\mu \)-term hybrid inflation, we will realize the supersymmetry scenario with the TeV-scale supersymmetric particles and intermediate-scale gravitino from anomaly mediation, which can be consistent with the WMAP and Planck experiments. Moreover, we for the first time propose the \(\mu \)-term hybrid inflation in no-scale supergravity. With four ...

Dynamical analysis of cylindrically symmetric anisotropic sources in f(R, T) gravity

In this paper, we have analyzed the stability of cylindrically symmetric collapsing object filled with locally anisotropic fluid in f(R, T) theory, where R is the scalar curvature and T is the trace of stress-energy tensor of matter. Modified field equations and dynamical equations are constructed in f(R, T) gravity. The evolution or collapse equation is derived from dynamical ...

Exploring the \(\Upsilon (6S)\rightarrow \chi _{bJ}\phi \) and \(\Upsilon (6S)\rightarrow \chi _{bJ}\omega \) hidden-bottom hadronic transitions

In this work, we investigate the hadronic loop contributions to the \(\Upsilon (6S) \rightarrow \chi _{bJ} \phi ~(J=0,1,2)\) along with \(\Upsilon (6S) \rightarrow \chi _{bJ} \omega ~(J=0,1,2)\) transitions. We predict that the branching ratios of \(\Upsilon (6S) \rightarrow \chi _{b0} \phi \), \(\Upsilon (6S) \rightarrow \chi _{b1} \phi \) and \(\Upsilon (6S) \rightarrow \chi ...

Non-perturbative inputs for gluon distributions in the hadrons

Description of hadronic reactions at high energies is conventionally done in the framework of QCD factorization. All factorization convolutions comprise non-perturbative inputs mimicking non-perturbative contributions and perturbative evolution of those inputs. We construct inputs for the gluon–hadron scattering amplitudes in the forward kinematics and, using the optical theorem, ...

Monte Carlo simulations of Higgs-boson production at the LHC with the KrkNLO method

We present numerical tests and predictions of the KrkNLO method for matching of NLO QCD corrections to hard processes with LO parton-shower Monte Carlo generators (NLO+PS). This method was described in detail in our previous publications, where it was also compared with other NLO+PS matching approaches (MC@NLO and POWHEG) as well as fixed-order NLO and NNLO calculations. Here we ...

Probing gravitational non-minimal coupling with dark energy surveys

We investigate observational constraints on a specific one-parameter extension to the minimal quintessence model, where the quintessence field acquires a quadratic coupling to the scalar curvature through a coupling constant \(\xi \). The value of \(\xi \) is highly suppressed in typical tracker models if the late-time cosmic acceleration is driven at some field values near the ...

Measurement of the phase difference between short- and long-distance amplitudes in the \({{B} ^+} \!\rightarrow {{{K}} ^+} {\mu ^+\mu ^-} \) decay

A measurement of the phase difference between the short- and long-distance contributions to the \({{B} ^+} \!\rightarrow {{{K}} ^+} {\mu ^+\mu ^-} \) decay is performed by analysing the dimuon mass distribution. The analysis is based on pp collision data corresponding to an integrated luminosity of 3\(\mathrm{\,fb}^{-1}\) collected by the LHCb experiment in 2011 and 2012. The ...

EPPS16: nuclear parton distributions with LHC data

We introduce a global analysis of collinearly factorized nuclear parton distribution functions (PDFs) including, for the first time, data constraints from LHC proton–lead collisions. In comparison to our previous analysis, EPS09, where data only from charged-lepton–nucleus deep inelastic scattering (DIS), Drell–Yan (DY) dilepton production in proton–nucleus collisions and inclusive ...

Worldline as a spin chain

The general theoretical ground for models based on compact angle coordinates is presented. It is observed that the proper dependence on compact coordinates has to be through the group elements and is achieved most naturally in a discrete-time formulation of the theory. By the construction, the discrete worldline inlaid by compact coordinates resembles the spin chains of magnetic ...

Homogeneity and thermodynamic identities in geometrothermodynamics

We propose a classification of thermodynamic systems in terms of the homogeneity properties of their fundamental equations. Ordinary systems correspond to homogeneous functions and non-ordinary systems are given by generalized homogeneous functions. This affects the explicit form of the Gibbs–Duhem relation and Euler’s identity. We show that these generalized relations can be ...

Understanding the internal structures of X(4140), X(4274), X(4500) and X(4700)

We investigate the newly observed X(4500) and X(4700) based on the diquark–antidiquark configuration within the framework of QCD sum rules. Both of them may be interpreted as the D-wave \(cs\bar{c}\bar{s}\) tetraquark states of \(J^P = 0^+\), but with opposite color structures, which is remarkably similar to the result obtained in Chen and Zhu (Phys Rev D 83:034010, 2011) that ...

Soft and diffractive scattering with the cluster model in Herwig

We present a new model for soft interactions in the event-generator Herwig. The model consists of two components. One to model diffractive final states on the basis of the cluster hadronization model and a second component that addresses soft multiple interactions as multiple particle production in multiperipheral kinematics. We present much improved results for minimum-bias ...

Lorentz violating p-form gauge theories in superspace

Very special relativity (VSR) keeps the main features of special relativity but breaks rotational invariance due to an intrinsic preferred direction. We study the VSR-modified extended BRST and anti-BRST symmetry of the Batalin–Vilkovisky (BV) actions corresponding to the \(p=1,2,3\)-form gauge theories. Within the VSR framework, we discuss the extended BRST invariant and extended ...

Low-lying charmed and charmed-strange baryon states

In this work, we systematically study the mass spectra and strong decays of 1P and 2S charmed and charmed-strange baryons in the framework of non-relativistic constituent quark models. With the light quark cluster–heavy quark picture, the masses are simply calculated by a potential model. The strong decays are studied by the Eichten–Hill–Quigg decay formula. Masses and decay ...

Introduction to the physics of the total cross section at LHC

This review describes the development of the physics of hadronic cross sections up to recent LHC results and cosmic ray experiments. We present here a comprehensive review – written with a historical perspective – about total cross sections from medium to the highest energies explored experimentally and studied through a variety of methods and theoretical models for over 60 years. ...