119010009
Shrinking of the diffraction peak in elastic scattering by deuterons and light nuclei
It is shown that the growth of the Glauber correction on with energy causes a rapid shrinking of the diffraction peak (i.e., an increase of the effective value of ..cap alpha..'/sub eff/). Measurement of ..cap alpha..'/sub eff/ for a deuteron (or a light nucleus) can yield the rate of growth of the correction for screening with increasing energy and the value of the three-pomeron vertex in the region of very small momentum transfers absolute value t<0.2 GeV/sup 2/. (AIP)
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.
125850380
Multiple Hadron Production in Parton {QCD} Jets
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.
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.
15161694
Yang-Mills instantons in the large N limit and the AdS / CFT correspondence
Abstract We examine a certain 16-fermion correlator in N =4 supersymmetric SU(N) gauge theory in 4 dimensions. Generalizing recent SU(2) results of Bianchi, Green, Kovacs and Rossi, we calculate the exact N-dependence of the effective 16-fermion vertex at the 1-instanton level, and find precise agreement in the large-N limit with the prediction of the type IIB superstring on AdS5×S5. This suggests that the string theory prediction for the 1-instanton amplitude considered here is not corrected by higher-order terms in the α′ expansion.
14767755
Instanton calculations in the β-deformed AdS/CFT correspondence
We consider non-perturbative effects in the β-deformed = 4 supersymmetric gauge theory in the context of the AdS/CFT correspondence. We concentrate on certain types of the n-point correlation functions of the Yang-Mills operators which correspond to the lowest Kaluza-Klein modes propagating on the dual supergravity background found by Lunin and Maldacena in [1]. In particular, we calculate all multi-instanton contributions to these correlators in the β-deformed SYM and find a compelling agreement with the results expected in supergravity.
119202861
Emergence of the electroweak scale through the Higgs portal
A bstractHaving discovered a candidate for the final piece of the Standard Model, the Higgs boson, the question remains why its vacuum expectation value and its mass are so much smaller than the Planck scale (or any other high scale of new physics). One elegant solution was provided by Coleman and Weinberg, where all mass scales are generated from dimensionless coupling constants via dimensional transmutation. However, the original Coleman-Weinberg scenario predicts a Higgs mass which is too light; it is parametrically suppressed compared to the mass of the vectors bosons, and hence is much lighter than the observed value. In this paper we argue that a mass scale, generated via the Coleman-Weinberg mechanism in a hidden sector and then transmitted to the Standard Model through a Higgs portal, can naturally explain the smallness of the electroweak scale compared to the UV cutoff scale, and at the same time be consistent with the observed value. We analyse the phenomenology of such a model in the context of present and future colliders and low energy measurements.
5796845
Instantons, three-dimensional gauge theory, and the Atiyah-Hitchin manifold
Abstract We investigate quantum effects on the Coulomb branch of three-dimensional N = 4 super-symmetric gauge theory with gauge group SU (2). We calculate perturbative and one-instanton contributions to the Wilsonian effective action using standard weak-coupling methods. Unlike the four-dimensional case, and despite supersymmetry, the contribution of non-zero-modes to the instanton measure does not cancel. Our results allow us to fix the weak-coupling boundary conditions for the differential equations which determine the hyper-Kahler metric on the quantum moduli space. We confirm the proposal of Seiberg and Witten that the Coulomb branch is equivalent, as a hyper-Kahler manifold, to the centered moduli space of two BPS monopoles constructed by Atiyah and Hitchin.
118956578
Baryon number violation and instantons in the standard model
We report on the recent developments in the theory of high energy collisions mediated by an instanton. Theoretical methods of studying the nonperturbative dynamics of the Standard Model at high energies in association with multi-particle-production and (B+L)-violation are reviewed. Particularly, we concentrate on the optical theorem approach based on the valley method. A pre-history and a current status of the theory of electroweak (B+L)-violation in high energy collisions are discussed.