Related papers: Process 3 -> 3 and crossing symmetry violation
The first observation of $\tau$ lepton pair production in ultraperipheral nucleus-nucleus collisions, a pure quantum electrodynamics (QED) process, is presented. The measurement is based on a data sample collected by the CMS experiment at a…
Totally asymmetric simple exclusion processes, consisting of two coupled parallel lattice chains with particles interacting with hard-core exclusion and moving along the channels and between them, are considered. In the limit of strong…
Measurements of the production cross section of top-quark pairs ($t\bar t$) in $pp$ collisions at $\sqrt{s}$ = 7 TeV are presented using 35 \ipb\ of data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in…
A search for a signal consistent with the type-III seesaw mechanism in events with three or more electrons or muons is presented. The data sample consists of proton-proton collisions at sqrt(s) = 13 TeV collected by the CMS experiment at…
Pair production of massive coloured particles in hadron collisions is accompanied by potentially large radiative corrections related to the suppression of soft gluon emission and enhanced Coulomb exchange near the production threshold. We…
The construction of a computer code to calculate the cross sections for the spin-polarized processes e-gamma=>e-gamma,e-gamma-gamma,e-e+e- to order-alpha**3 is described. The code calculates cross sections for circularly-polarized…
We discuss the observability of CP-violating asymmetries in the process e+ e- -> X_1^0 X_2^0 -> X_1^0 X_1^0 l+ l-, with l = e,mu. We consider two examples of supersymmetric scenarios: (i) with decays X_2^0 -> l_R l -> X_1^0 l+ l-; (ii) with…
We derive relations between finite-volume matrix elements and infinite-volume decay amplitudes, for processes with three spinless, degenerate and either identical or non-identical particles in the final state. This generalizes the…
We isolate the two-step mechanism involving a real intermediate photon from the one-step mechanism involving a virtual photon for the trident process in a constant crossed field. The two-step process is shown to agree with an integration…
Violations of the Lorentz and CPT symmetries can appear as observable effects in the direct production of top quarks and their subsequent decays. Earlier results for the $q\bar{q}$ production process for $t\bar{t}$ pairs have been extended…
After a brief review and a more refined analysis of some relevant analyticity properties (when going from Minkowskian to Euclidean theory) of the high-energy parton-parton and hadron-hadron scattering amplitudes in gauge theories, described…
Exclusive hadronic reactions with a massive lepton pair (l^+l^-) in the final state will be measured with PANDA at GSI-FAIR and with Compass at CERN, both in p+p-bar -> l^+l^-+pi and pi+N -> N'+l^+l^-. Similarly, electroproduction of a…
The most severe constraints on quark-lepton four-fermion contact interactions come from the agreement of atomic parity violation measurements with the Standard Model. In this letter I note that for contact interactions which arise in…
The top quark pair production cross section is measured in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data collected in 2017 by the CMS experiment at the LHC corresponding to an integrated luminosity of 304…
We study higher-order effects in the electromagnetic production of electron-positron pairs in relativistic heavy ion collisions. Treating the field of the heavy ions as an external field and neglecting the interaction among electrons and…
Results are presented from a search for CP violation in top quark pair production, using proton-proton collisions at a center-of-mass energy of 13 TeV. The data used for this analysis consist of final states with two charged leptons…
A search for physics beyond the standard model in events with at least three charged leptons (electrons or muons) is presented. The data sample corresponds to an integrated luminosity of 137 fb$^{-1}$ of proton-proton collisions at…
The restricted diffusive pair contact process 2A->3A, 2A->0 (PCPD) and the classification of its critical behavior continues to be a challenging open problem of non-equilibrium statistical mechanics. Recently Kockelkoren and Chate [Phys.…
We discuss in detail the constraints on partial compositeness coming from flavour and CP violation in the leptonic sector. In a first part we present a formulation of partial compositeness in terms of a flavour symmetry group and a set of…
We study the $l^-l^+\to \nu\bar{\nu}Zh$ process for future lepton colliders, whose cross section becomes larger than that for $l^-l^+\to Zh$ in the energy region above a few TeV. We classify the amplitudes into three main groups based on…