118623089
Chromodynamical wave nature of hadron fluxes and the string effect
The physics of the production of extra-jet hadrons in the process e/sup +/e/sup -/..-->..qq-barg at large energy W is studied. The hypothesis of local parton-hadron duality is used to obtain the asymptotic predictions of perturbative QCD for the angular distribution of the hadron fluxes. It is shown that coherence in soft-gluon emission by a three-element color ''antenna'' leads to the dragging of extra-jet bremsstrahlung particles along the gluon jet and gives a simple, model-independent explanation of the experimentally observed string effect.
117871006
Pomeron universality from identical pion correlations at the LHC
Abstract Bose–Einstein correlations of identical pions produced in high-energy pp collisions at the LHC allow a probe of the Pomeron exchange mechanism. The size of the domain which emits the pions depends on the multiplicity of events, but not on the collider energy. This confirms the universal structure of Pomeron exchange. The data at relatively low multiplicities indicate that the size of the source created by one-Pomeron exchange is much less than the size of the proton.
125850380
Multiple Hadron Production in Parton {QCD} Jets
119379184
Radiative corrections to the hadronic cross-section measurement at DA$\Phi$NE
Abstract. The hadronic invariant mass distribution for the process of electron–positron annihilation into a pair of charged pions accompanied by a photon radiated from the initial state has been studied for the region of DA$\Phi$NE energies. The Born cross–section and the electromagnetic radiative corrections to it are calculated for realistic conditions of the KLOE detector. The dependence on the physical parameters which define the event selection is obtained.
119436494
QCD Interconnection Effects
Heavy objects like the W, Z and t are short-lived compared with typical hadronization times. When pairs of such particles are produced, the subsequent hadronic decay systems may therefore become interconnected. We study such potential effects at Linear Collider energies.
124029542
On the sensitivity of the inclusive distributions in parton jets to the coherence effects in QCD gluon cascades
The KNO multiplicity distributions and properties of two-particle correlations in QCD jets are considered in the framework of the perturbative approach accounting for effects of the coherence in the soft gluon bremsstrahlung.
119190421
Mass sum rules and the role of the messenger scale in General Gauge Mediation
In General Gauge Mediation (GGM), supersymmetry breaking is communicated to the Standard Model (MSSM) sector via gauge interactions at a high scale which we refer to as the messenger scale. At this scale GGM predicts certain sum rules between the MSSM sfermion masses. We investigate the validity and the ultimate fate of these sum rules after RG evolution down to the electroweak scale where the mass spectrum will be probed at colliders. We find that the sum rules hold for the first two generations. However the third generation (where sfermions are lightest) violates one of the two sum rules by 10 to 50% over the explored parameter space. This constrains and quantifies the potential use of sum rules as a signature of gauge mediation. We also comment on the role played by the messenger scale in single-and multi-scale GGM models.
14263791
Noncommutative Standard Modelling
We present a noncommutative gauge theory that has the ordinary Standard Model as its low-energy limit. The model is based on the gauge group U(4) × U(3) × U(2) and is constructed to satisfy the key requirements imposed by noncommutativity: the UV/IR mixing effects, restrictions on representations and charges of matter fields, and the cancellation of noncommutative gauge anomalies. At energies well below the noncommutative mass scale our model flows to the commutative Standard Model plus additional free U(1) degrees of freedom which are decoupled due to the UV/IR mixing. Our model also predicts the values of the hypercharges of the Standard Model fields.
16492553
Magnetic mixing — electric minicharges from magnetic monopoles
Many extensions of the Standard Model require the existence of a ``hidden'' sector. We consider settings where the hidden sector in the infrared contains a U(1) gauge factor with magnetic monopoles, for instance 't Hooft-Polyakov monopoles of an underlying non-abelian gauge group. In the presence of CP violation these monopoles acquire an electric charge in the hidden sector due to the Witten effect. We show that quite generally they also acquire (small) electric charges under the visible electromagnetic gauge group. This is a result of ``magnetic mixing'' which, as we show, often arises as a natural partner of kinetic mixing. Both kinetic and magnetic mixing are naturally induced radiatively even if the low-energy U(1)s arise from a single non-abelian gauge group. We argue that the hidden sector monopoles can be light and their electric minicharges could thus be testable in current and near future low-energy experiments.
120263136
Higher twist effects in the Drell‐Yan process
We calculate the angular distribution of the lepton produced in the Drell‐Yan reaction taking into account pion bound state effects. We work in the kinematic region where one of the pion constituents goes far off shell, which allows us to treat the bound state problem pertubatively. We show that the angular distribution is very sensitive to the shape of the pion distribution amplitude. The model we discuss fits the data if we choose a two‐humped pion distribution amplitude suggested by QCD sum rules.
6943385
BMN operators with three scalar impurites and the vertex-correlator duality in pp-wave
We calculate 3-point correlation functions of Δ-BMN operators with 3 scalar impurites in = 4 supersymmetric gauge theory. We use these results to test the pp-wave/SYM duality correspondence of the vertex-correlator type. This correspondence relates the coefficients of 3-point correlators of Δ-BMN operators in gauge theory to the 3-string vertex in lightcone string field theory in the pp-wave background. We verify the vertex-correlator duality equation of [6] at the 3 scalar impurites level for supergravity and for string modes.