Related papers: Anomalous soft photons: status and perspectives
Accurate measurement of spin-dependent parton distributions in production of electroweak bosons with polarized proton beams at the Relativistic Heavy Ion Collider depends on good understanding of QCD radiation at small transverse momenta…
We present first measurable predictions for electromagnetic (two-photon) double scattering production of two positron-electron pairs in ultraperipheral heavy-ion collisions at LHC. Measureable cross sections are obtained with realistic cuts…
We review two inter-related topics. First, we consider the behaviour of "soft" scattering observables, such as sigma_{tot}, dsigma_{el}/dt, dsigma_{SD}/dtdM^2, particle multiplicities etc., at high-energy proton-(anti)proton colliders. We…
As one category of vector boson fusion, photo-production is one important production mechanism at $e$-$p$ colliders. A future $e$-$p$ collider -- Large Hadron-electron Collider (LHeC) has been discussed as a "Higgs factory" candidate where…
Exclusive photoproduction of all vector mesons by real and virtual photons is considered in the Soft Dipole Pomeron model. It is emphasized that being the Pomeron in this model a double Regge pole with intercept equal to one, we are led to…
We discuss the production of soft photons in high energy hadron-hadron collisions. We present a model where quarks and antiquarks in the hadrons emit ``synchrotron light'' when being deflected by the chromomagnetic fields of the QCD vacuum,…
Electron-positron pair production by collision of photons is investigated in view of application to pulsar physics. We compute the absorption rate of individual gamma-ray photons by an arbitrary anisotropic distribution of softer photons,…
In this study, we investigate photon-photon scattering in ultra-peripheral heavy ion collisions (UPCs). We start by deriving an effective Lagrangian from first principles and then apply factorization techniques from Soft-Collinear effective…
LHC searches for new physics focus on combinations of hard physics objects. In this work we propose a qualitatively different soft signal for new physics at the LHC - the "anomalous underlying event". Every hard LHC event will be…
The conference 'Photon 2009' on the structure and the interactions of the photon included sessions on photon-photon collisions and a future high-energy photon linear collider. This summary of theoretical contributions to the conference…
Results are presented from the ATLAS collaboration from the 2010 LHC heavy ion run, during which nearly 10 inverse microbarns of luminosity were delivered. Soft physics results include final charged particle multiplicities and collective…
In the Littlest Higgs model with T-parity, the heavy photon ($A_{H}$) is supposed to be a possible dark matter (DM) candidate. A direct proof of validity of the model is to produce the heavy photon at accelerator. In this paper, we study…
A dark photon may kinetically mix with the Standard Model photon, leading to observable cosmological signatures. The mixing is resonantly enhanced when the dark photon mass matches the primordial plasma frequency, which depends sensitively…
A brief overview of the calculation of photon and dilepton production rates in a deconfined quark-gluon plasma is presented. We review leading order rates as well as recent NLO determinations and non-equilibrium corrections. Furthermore,…
Hard, or high transverse momentum, pion photoproduction can be a tool for probing the parton structure of the beam and target. We discuss the perturbative and soft processes that contribute, and show how regions where perturbative processes…
After a brief review of the production dynamics of prompt single photons in hadron collisions, I summarize a new QCD calculation of the transverse momentum distribution of continuum prompt photon pairs produced by QCD subprocesses,…
We present a detailed study of the production of a high transverse-momentum lepton pair at hadron colliders, which includes the exact O(alpha) electroweak corrections properly matched with leading logarithmic effects due to multiple photon…
A dark photon is predicted by several well-motivated Standard Model extensions and UV completions. Here the most general effective field theory up to dimension-six operators describing the interactions of a massless dark photon with all…
We discuss the latest theoretical results on direct photon and dilepton production from relativistic heavy-ion collisions. While the dilepton spectra at low invariant mass show in-medium effects like a collisional broadening of the vector…
We present a formalism which uses fluxes of equivalent photons including transverse momenta of the intermediate photons. The formalism reminds the familiar $k_t$-factorization approach used, e.g., to study the two-photon production of…