The European Physical Journal C

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

List of Papers (Total 9,882)

Heavy quark fragmentation function in two-dimensional QCD in $$N_c\rightarrow \infty $$ limit

We carry out a comprehensive study of the quark-to-meson fragmentation function in the ’t Hooft model, i.e., the two-dimensional quantum chromodynamics (QCD) in $$N_c\rightarrow \infty $$ limit, following the operator definition pioneered by Collins and Soper. We apply the Hamiltonian approach as well as the diagrammatic approach to construct the functional form of the quark-to...

Compact stars in $$f(T) = T +\xi T^\beta $$ gravity

The Teleparallel Theory is equivalent to General Relativity, but whereas in the latter gravity has to do with curvature, in the former gravity is described by torsion. As is well known, there is in the literature a host of alternative theories of gravity, among them the so called extended theories, in which additional terms are added to the action, such as for example in the f(R...

Effect of acceleration on information delocalization

We study the impact of acceleration on information delocalization under the Unruh (anti-Unruh) effect for two types of tripartite entangled states, namely the GHZ and W states. Our findings indicate that the anti-Unruh effect can result in stronger delocalization of quantum information, as measured by tripartite mutual information (TMI). Additionally, we show that the W state is...

On torsion contribution to chiral anomaly via Nieh–Yan term

In this note we present a solution to the question of whether or not, in the presence of torsion, the topological Nieh–Yan term contributes to chiral anomaly. The integral of Nieh–Yan term is non-zero if topology is non-trivial; the manifold has a boundary or vierbeins have singularities. Noting that singular Nieh–Yan term could be written as a sum of delta functions, we argue...

Soft theorems and memory effects at finite temperatures

We study the soft theorems for photons and gravitons at finite temperatures using the thermofield dynamics approach. The soft factors lose universality at finite temperatures as the soft amplitudes depend on the nature (or spin) of the particles participating in the scattering processes. However, at low temperatures, a universal behavior is observed in the cross-section of the...

Observational signatures of a static f(R) black hole with thin accretion disk

In this study, we focus on a static spherically symmetric f(R) black hole spacetime characterized by a linear dark matter-related parameter. Our investigation delves into understanding the influence of different assumed values of this parameter on the observable characteristics of the black hole. To fulfill this task, we investigate the light deflection angles, which are inferred...

The nonleptonic decays of b-flavored mesons to S-wave charmonium and charm meson states

The detection of radially excited charmonium and charm meson states, and measurement of heavy meson decays, particularly $$B_c^+\rightarrow J/\psi D_s^+$$ and $$B_c^+\rightarrow J/\psi D_s^{*+}$$ , by the LHCb and ATLAS Collaborations, have aroused a lot of theoretical interest in the nonleptonic decays of b-flavored mesons. In this paper, we study the exclusive two-body...

A class of rotating metrics in the presence of a scalar field

We consider a class of three parameter static and axially symmetric metrics that reduce to the Janis–Newman–Winicour (JNW) and $$ \gamma $$ -metrics in certain limits of the parameters. We obtain rotating form of the metrics that are asymptotically flat, stationary and axisymmetric. In certain values of the parameters, the solutions represent the rotating JNW metric, rotating...

Search for heavy Majorana or Dirac neutrinos and right-handed W gauge bosons in final states with charged leptons and jets in pp collisions at $$\sqrt{s}=13$$  TeV with the ATLAS detector

A search for heavy right-handed Majorana or Dirac neutrinos $$N_{\textrm{R}}$$ and heavy right-handed gauge bosons $$W_{\textrm{R}}$$ is performed in events with energetic electrons or muons, with the same or opposite electric charge, and energetic jets. The search is carried out separately for topologies of clearly separated final-state products (“resolved” channel) and...

Analyzing quantum gravity spillover in the semiclassical regime

One of the standard approaches of incorporating the quantum gravity (QG) effects into the semiclassical analysis is to adopt the notion of a quantum-corrected spacetime arising from the QG model. This procedure assumes that the expectation value of the metric variable effectively captures the relevant QG subtleties in the semiclassical regime. We investigate the viability of this...

Moderately non-local $$\eta {\bar{\eta }}$$ vertices in the $$AdS_4$$ higher-spin gauge theory

A new concept of moderate non-locality in higher-spin gauge theory is introduced. Based on the recently proposed differential homotopy approach, a moderately non-local scheme, that is softer than those resulting from the shifted homotopy approach available in the literature so far, is worked out in the mixed $$\eta {\bar{\eta }}$$ sector of the Vasiliev higher-spin theory. To...

anyH3: precise predictions for the trilinear Higgs coupling in the Standard Model and beyond

The trilinear Higgs coupling $$\lambda _{hhh}$$ of the detected Higgs boson is an important probe for physics beyond the Standard Model. Correspondingly, improving the precision of the theoretical predictions for this coupling as well as the experimental constraints on it are among the main goals of particle physics in the near future. In this article, we present the public...

Constraining physical parameters of DESs via the secondary component of the GW190814 event and other self-bound NS pulsars in f(Q)-gravity theory

The spherically symmetric dark energy (DE) stellar model is presented here within the context of the f(Q) theory of gravity. In order to develop the model, we take into account the linear functional form of f(Q) as $$f(Q)=mQ+n$$ , where m is the coupling parameter and n is a real constant. We further assume that the stellar model is composed of normal baryonic matter along with...

Ground states of all mesons and baryons in a quark model with hidden local symmetry

We extend the chiral quark model for u,  d,  c and b quarks with vector mesons, which we proposed in the previous analysis, to a model with the s quark. We include the nonet pseudo-scalar and vector mesons together with the singlet scalar meson based on the SU(3) $$_L \times $$  SU(3) $$_R$$ chiral symmetry combined with the hidden local symmetry, which mediate force among u,  d...

Machine-learned exclusion limits without binning

Machine-learned likelihoods (MLL) combines machine-learning classification techniques with likelihood-based inference tests to estimate the experimental sensitivity of high-dimensional data sets. We extend the MLL method by including kernel density estimators (KDE) to avoid binning the classifier output to extract the resulting one-dimensional signal and background probability...

Viscous effect in the late time evolution of phantom universe

We investigate the cosmological implications of a phantom dark energy model with bulk viscosity. We explore this model as a possible way to resolve the big rip singularity problem that plagues the phantom models. We use the latest type Ia supernova and Hubble parameter data to constrain the model parameters and find that the data favor a significant bulk viscosity over a non...

Reconstruction of air shower muon lateral distribution functions using integrator and binary modes of underground muon detectors

The investigation of cosmic rays holds significant importance in the realm of particle physics, enabling us to expand our understanding beyond atomic confines. However, the origin and characteristics of ultra-high-energy cosmic rays remain elusive, making them a crucial topic of exploration in the field of astroparticle physics. Currently, our examination of these cosmic rays...

Observable gravitational waves from hyperkination in Palatini gravity and beyond

We consider cosmology with an inflaton scalar field with an additional quartic kinetic term. Such a theory can be motivated by Palatini $$R+R^2$$ modified gravity. Assuming a runaway inflaton potential, we take the Universe to become dominated by the kinetic energy density of the scalar field after inflation. Initially, the leading kinetic term is quartic and we call the...

Lorentz force detuning in heterodyne gravitational wave experiments

Heterodyne cavity experiments for gravitational wave (GW) detection experience a rising interest since recent studies showed that they allow to probe the ultra high frequency regime above $$10\,\text {kHz}$$ . In this paper, we present a concise theoretical study of the experiment based on ideas from the former MAGO collaboration which already started experiments in turn of the...

The Sivers asymmetry in charged Kaon and $$\Lambda $$ hyperon produced SIDIS process at electron ion colliders

We investigate the single transverse-spin asymmetry with a $$\sin (\phi _h-\phi _S)$$ modulation in the charged Kaon produced and in $$\Lambda $$ hyperon produced SIDIS process within the theoretical framework of transverse momentum dependent (TMD) factorization at the next-to-leading-logarithmic order. The asymmetry is contributed by the convolution of Sivers function and the...

On bilinear superintegrability for monomial matrix models in pure phase

We argue that the recently discovered bilinear superintegrability http://arxiv.org/2206.02045 generalizes, in a non-trivial way, to monomial matrix models in pure phase. The structure is much richer: for the trivial core Schur functions required modifications are minor, and the only new ingredient is a certain (contour-dependent) permutation matrix; for non-trivial-core Schur...

Monte-carlo simulation of the effective lunar aperture for detection of ultra-high energy neutrinos with LOFAR

Ultra-high-energy (UHE) cosmic neutrinos interacting with the Moon’s regolith generate particle showers that emit Askaryan radiation. This radiation can be observed from the Earth using ground-based radio telescopes like LOFAR. We simulate the effective detection aperture for UHE neutrinos hitting the Moon. Under the same assumptions, results from this work are in good agreement...

Searching for a dark matter particle with anti-protonic atoms

A wide range of dark matter candidates have been proposed and are actively being searched for in a large number of experiments, both at high (TeV) and low (sub meV) energies. One dark matter candidate, a deeply bound uuddss sexaquark, $$S$$ , with mass $$\sim 2$$ GeV (having the same quark content as the hypothesized H-dibaryon, but long lived) is particularly difficult to...

A fast and time-efficient machine learning approach to dark matter searches in compressed mass scenario

Various analyses for searching for the signature of SUSY or exotic particles have been carried out by the experiments at CERN. These analyses made use of traditional cut and count methods. While this method has yielded promising results, it has been challenging in the region where the mass difference between SUSY particles is small. Deep learning is currently widely employed in...