116301993
Quasi-stable states in the physical spectrum of the Neveu-Schwarz dual model
A certain class of states, comprising most of the spectrum for large mass M, is distinguished in the spectum of physical states predicted by the Neveu-Schwarz dual model with intercepts ..cap alpha../sub rho/(0) =1 and ..cap alpha../sub ..pi../(0) =1/2. The massive particles with large spins in this class are quasi-stable. Their couplings with all the other states are of order M/sup -1/ in comparison with the ordinary vertices. For the critical dimensions D=10 these states coincide with the zero-norm spurions. For the anomalous dimensions D=9 some of the quasi-stable states become new zero-norm spurion states. (AIP)
124885220
Nonplanar dual model with arbitrary intercept $alpha$(0)
115953751
Interaction amplitudes of hadrons treated as composite superconformal strings
14749699
A possible description of the quantum numbers in a hadronic string model
Institute of Theoretical PhysicsUniversity of Stockholm, Box 6730S-113 85 Stockholm, SwedenABSTRACT: We consider a critical composite superconformalstring model to desribe hadronic interactions. We present a newapproach of introducing hadronic quantum numbers in the scat-tering amplitudes. The physical states carry the quantum num-bers and form a common system of eigenfunctions of the opera-tors in this string model. We give explicit constructions of thequantum number operators.
119374640
Fermion dominated composite superstring model and unified description of hadron and lepton degrees of freedom in it
New string dynamics is formulated on the basis of the extended set of supergauge constraints including not only supergauge Virasoro conditions but also nilpotent supercurrent constraints . This approach arises from a natural generalization of the classical operator many-string vertices. The formulation of this model leads to three two-dimensional surfaces for description of hadron strings. It gives some dynamical generalization of Chan-Paton factor for string amplitudes in terms of operator vertices. Supersymmetry on the 2-d world surface is present but ten-dimensional supersymmetry is absent. In this approach two-dimensional fermion string fields make it possible to give a unified description of hadron and lepton degrees of freedom and of its dynamics. This model allows to solve the problem of elimination of the most part of parity twins in the baryon spectrum. One-loop (and many-loops perhaps) amplitudes in this model are finite due to the extended set of supergauge constraints and to the significant excess of the total number of fermion two-dimensional fields over the number of boson 2-d fields.
15933392
Composite superstring model for hadrons and extended Virasoro superconformal symmetry with supercurrent constraints
Hadron dynamics is formulated in terms of interacting composite strings. Consistent composite string model with extended Virasoro superconformal symmetry is found. These composite strings carry flavour and chiral degrees of freedom on edging two-dimensional surfaces. Necessary correct description of string amplitudes without states of negative norms in the spectrum of physical states is reached when special supercurrents conditions are fulfilled.
117328144
10 Years Search for Neutrino Bursts with LVD
1. AbstractThe Large Volume Detector LVD (Gran Sasso National Laboratory, Italy),is a neutrino telescope mainly designed to search for low energy neutrino burstsfrom Gravitational Stellar Collapses (GSC) in the Galaxy. The experiment hasbeen monitoring the Milky Way since June 1992 under increasing larger conﬁg-urations, reaching in January 2001 the ﬁnal active mass of 1000 t. No burstcandidate has been detected over all the ten years of observation: we present herethe obtained limit to the rate of SuperNova (SN) event in the galaxy.
118521922
Implications of LHCb measurements and future prospects
During 2011 the LHCb experiment at CERN collected 1.0 fb−1 of $\sqrt{s} = 7\mbox{~TeV}$pp collisions. Due to the large heavy quark production cross-sections, these data provide unprecedented samples of heavy flavoured hadrons. The first results from LHCb have made a significant impact on the flavour physics landscape and have definitively proved the concept of a dedicated experiment in the forward region at a hadron collider. This document discusses the implications of these first measurements on classes of extensions to the Standard Model, bearing in mind the interplay with the results of searches for on-shell production of new particles at ATLAS and CMS. The physics potential of an upgrade to the LHCb detector, which would allow an order of magnitude more data to be collected, is emphasised.
125894935
RELATIVISTIC STRING MODEL AND MULTIPLICATIVE DUAL MODEL
119773698
Limits on low-energy neutrino fluxes with the Mont Blanc liquid scintillator detector
Abstract The LSD liquid scintillation detector has been operating since 1985 as an underground neutrino observatory in the Mont Blanc Laboratory with the main objective of detecting antineutrino bursts from collapsing stars. In August 1988 the construction of an additional lead and borex paraffin shield considerably reduced the radioactive background and increased the sensitivity of the apparatus. In this way the search for steady fluxes of low-energy neutrinos of different flavours through their interactions with free protons and carbon nuclei of the scintillator was made possible. No evidence for a galactic collapse was observed during the whole period of measurement. The corresponding 90% c.l. upper limit on the galactic collapses rate is 0.45 y −1 for a burst duration of ΔT ⩽ 10 s. After analysing the last 3 years data, the following 90% c.l. upper limits on the steady neutrino and antineutrino fluxes were obtained: Φ( \ gn e ) 4 \ gn e s −1 cm −2 9 ⩽ E ν ⩽ 50MeV Φ( \ gn e ) 3 \ gn e s −1 cm −2 20 ⩽ E ν ⩽ 50MeV Φ(ν e ) 3 ν e s −1 cm −2 25 ⩽ E ν ⩽ 50 MeV Φ(ν μ + τ ) 7 ν μ + τ s −1 cm −2 20 ⩽ E ν ⩽ 100 MeV Φ( \ gn μ + τ ) 7 \ gn μ + τ s −1 cm −2 20 ⩽ E ν ⩽ 100 MeV In particular comparing the obtained upper limit on the \ gn e flux for 9 ⩽ E ν ⩽ 20 MeV to the solar ν e flux predicted by the standard solar model in the same range of energy, we can exclude the possibility that more than 6.3% of the solar ν e 's flux can change to \ gn e . Finally the first limits on the flux of relic supernova neutrinos of all flavours as a function of the neutrino sea temperature are presented.
17250558
Muon pair production by photons in atmosphere: is any room left for high-energy muon astronomy?
Abstract Production of muon pairs by high-energy photons in electromagnetic and hadronic showers in atmosphere has been calculated. The effect of muon pair production in hadronic extensive air showers (EAS) is unlikely to be seen by next generation detectors. Applications of muon pair production process in electromagnetic showers to the very high energy gamma-ray astronomy are discussed. It is shown that, although this process dominates over conventional pion and kaon decay above a few TeV in photon-initiated showers and provides a distinctive signature of photon-induced event (muon pair), it is practically impossible to discriminate such events statistically from the background of muon pairs produced in the hadronic EAS. The rate of events is very low and requires detectors of a huge size.