125930323
Large $\B^0 \bar{B}$0 Mixing and the Consequences for the Standard Model. (In Russian)
117871006
Pomeron universality from identical pion correlations at the LHC
Abstract Bose–Einstein correlations of identical pions produced in high-energy pp collisions at the LHC allow a probe of the Pomeron exchange mechanism. The size of the domain which emits the pions depends on the multiplicity of events, but not on the collider energy. This confirms the universal structure of Pomeron exchange. The data at relatively low multiplicities indicate that the size of the source created by one-Pomeron exchange is much less than the size of the proton.
125850380
Multiple Hadron Production in Parton {QCD} Jets
119379184
Radiative corrections to the hadronic cross-section measurement at DA$\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.
5148649
On N = 2 supersymmetric QCD with four flavors
Seiberg and Witten's proposed solution of N = 2 SQCD with Nc = 2 and NF = 4 is known to conflict with instanton calculations in three distinct ways. Here we show how to resolve all three discrepancies, simply by reparametrizing the elliptic curve in terms of quantities τeff(0) and u rather than τ and u = 〈Tr A2〉. SL(2,Z) invariance of the curve is preserved. However, there is now an infinite ambiguity in the relation between τeff(0) and τ and between u and u, corresponding to an infinite number of unknown coefficients in the instanton expansion. Thus the reinterpreted curve (unlike the cases NF < 4) no longer determines the quantum modulus u as a function of the classical VEV a.
120532941
Screening of multi-instanton corrections to anomalous processes in the standard model
Abstract We calculate the multi-instanton contribution to the logarithm of the cross-section for (B+L)-violating (anomalous) high-energy collisions in the next-to-leading order (in terms of ( E M sp ) 2 3 ) approximation. It is demonstrated that in this approximation there is no sign of “premature unitarization” of anomalous processes, i.e. there is no indication that multi-instanton contributions become of the same magnitude as the single-instanton contribution at energies where the single-instanton result is still exponentially suppressed.
16154793
A Brief history of the stringy instanton
The arcane ADHM construction of Yang-Mills instantons can be very naturally understood in the framework of D-brane dynamics in string theory. In this point-of-view, the mysterious auxiliary symmetry of the ADHM construction arises as a gauge symmetry and the instantons are modified at short distances where string effects become important. By decoupling the stringy effects, one can recover all the instanton formalism, including the all-important volume form on the instanton moduli space. We describe applications of the instanton calculus to the AdS/CFT correspondence and higher derivative terms in the D3-brane effective action. In these applications, there is an interesting relation between instanton partition functions, the Euler characteristic of instanton moduli space and modular symmetry. We also describe how it is now possible to do multi-instanton calculations in gauge theory and we resolve an old puzzle involving the gluino condensate in supersymmetric QCD.
119771524
Total cross section for anomalous fermion-number violation via dispersion relation
Abstract We investigate the behaviour of the total cross section for electroweak baryon and lepton number violation (in association with multi-W and multi-Higgs production) at low energies (√ s
119258384
RG invariants, unification and the role of the messenger scale in General Gauge Mediation
In General Gauge Mediation (GGM) all MSSM soft sfermion masses at a high scale Mmess can be parameterised by three a priori independent scales ΛS; 1,2,3(Mmess). (Similarly the gaugino masses are given by ΛG; 1,2,3(Mmess).) For the first two generations this parameterisation in terms of a set of running ΛS; 1,2,3(μ) — conveniently obtained from appropriate RG invariants — continues to hold all the way down to the electroweak scale. This is not the case for the third generation because of the large Yukawa couplings. Together these two observations imply that the messenger scale is an additional parameter of GGM models.In models where all messengers are in complete GUT multiplets (without significant mass splittings), all ΛS,r are equal at Mmess. Starting from the observable mass spectrum at the electroweak scale we present a strategy to determine if this unification occurs and at which scale. This approach uses data accessible at colliders to gain insight into high scale unification physics beyond the unification of gauge couplings.