SwePub - search: L773:0370 2693

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1.	Ohlsson, Tommy, 1973-, et al. (author) Neutrino oscillations with three flavors in matter : Applications to neutrinos traversing the earth 2000 In: Physics Letters B. - : Elsevier Science B.V.. - 0370-2693 .- 1873-2445. ; 474:1-2, s. 153-162 Journal article (peer-reviewed)abstract Analytic formulas are presented for three flavor neutrino oscillations in matter in the plane wave approximation. We calculate in particular the time evolution operator in both mass and flavor bases. We also find the transition probabilities expressed as functions of the vacuum mass squared differences, the vacuum mixing angles, and the matter density parameter. The application of this to neutrino oscillations for both atmospheric and long baseline neutrinos in a mantle-core-mantle step function model of the Earth's matter density profile is discussed.
2.	Abdallah, J, et al. (author) Inclusive b decays to wrong sign charmed mesons 2003 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 561:1-2, s. 26-40 Journal article (peer-reviewed)abstract The production of wrong sign charmed mesons b --> (D) over bar X-(s), D-(s) = (D-0, D+, D-s), is studied using the data collected by the DELPHI experiment in the years 1994 and 1995. Charmed mesons in Z --> b (b) over bar events are exclusively reconstructed by searching for the decays D-0 --> K(-)pi(+), D+ --> K(-)pi(+)pi(+) and D-s(+) --> phipi(+) --> K(+)K(-)pi(+). The wrong sign contribution is extracted by using two discriminant variables: the charge of the b-quark at decay time, estimated from the charges of identified particles, and the momentum of the charmed meson in the rest frame of the b-hadron. The inclusive branching fractions of b-hadrons into wrong sign charm mesons are measured to be: B(b --> (D) over bar X-0) + B(b --> D-X) = (9.3 +/- 1.7(stat) +/- 1.3(syst) +/- 0.4(B))%, B(b --> Ds-X) = (10.1 +/- 1.0(stat) +/- 0.6(syst) +/- 2.8(B))% where the first error is statistical, the second and third errors are systematic. (C) 2003 Published by Elsevier Science B.V.
3.	Abdallah, J, et al. (author) Rapidity-alignment and p(T) compensation of particle pairs in hadronic Z(0) decays 2002 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 533:3-4, s. 243-252 Journal article (peer-reviewed)abstract Observation is made of rapidity-alignment of K+K- and (p) over barp pairs which results from their asymmetric orientation in rapidity, with respect to the direction from primary quark to antiquark. The K+K- and (p) over barp data are consistent with predictions from the fragmentation string model. However, the (p) over barp data strongly disagree with the conventional implementation of the cluster model. The non-perturbative process of 'gluon splitting to diquarks' has to be incorporated into the cluster model for it to agree with the data. Local conservation of PT between particles nearby in rapidity (i.e., p(T) compensation) is analysed with respect to the thrust direction for pi(+)pi(-), K+K-, and (p) over barp pairs. In this case, the string model provides fair agreement with the data. The cluster model is incompatible with the data for all three particle pairs. The model with its central premiss of isotropically-decaying clusters predicts a p(T) correlation not seen in the data. (C) 2002 Elsevier Science B.V. All rights reserved.
4.	Abdallah, J, et al. (author) Search for charged Higgs bosons in e(+)e(-) collisions root s=189-202 GeV 2002 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 525:1-2, s. 17-28 Journal article (peer-reviewed)abstract A search for pair-produced charged Higgs bosons was performed in the high energy data collected by the DELPHI detector at LEP II at centre-of-mass energies from 189 GeV to 202 GeV. The three different final states, taunutaunu, c (s) over bar(c) over bars and c (s) over bar taunu were considered. New methods were applied to reject wrong hadronic jet pairings and for the tau identification, where a discriminator based on tau polarisation and polar angles was used. No excess of data compared to the expected Standard Model processes was observed and the existence of a charged Higgs boson with mass lower than 71.5 GeV/c(2) is excluded at the 95% confidence level. (C) 2002 Published by Elsevier Science B.V.
5.	Abdallah, J, et al. (author) Search for doubly charged Higgs bosons at LEP2 2003 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 552:3-4, s. 127-137 Journal article (peer-reviewed)abstract A search for pair-produced doubly charged Higgs bosons has been performed using the data collected by the DELPHI detector at LEP at centre-of-mass energies between 189 and 209 GeV. No excess is observed in the data with respect to the Standard Model background. A lower limit for the mass of 97.3 GeV/c(2) at the 95% confidence level has been set for doubly charged Higgs bosons in left-right symmetric models for any value of the Yukawa coupling between the Higgs bosons and the tau leptons. (C) 2002 Published by Elsevier Science B.V.
6.	Abdallah, J, et al. (author) Study of inclusive J/psi production in two-photon collisions at LEP II with the DELPHI detector 2003 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 565:1-4, s. 76-86 Journal article (peer-reviewed)abstract Inclusive J/psi production in photon-photon collisions has been observed at LEP II beam energies. A clear signal from the reaction gammagamma --> J/psi + X is seen. The number of observed N(J/psi --> mu(+)mu(-)) events is 36+/-7 for an integrated luminosity of 617 pb(-1), yielding a cross-section of sigma(J/psi + X) = 45+/-9(stat) +/- 17(syst) pb. Based on a study of the event shapes of different types of gammagamma processes in the PYTHIA program, we conclude that (74+/-22) % of the observed J/psi events are due to 'resolved' photons, the dominant contribution of which is most probably due to the gluon content of the photon. (C) 2003 Published by Elsevier B.V.
7.	Abreu, P., et al. (author) Measurement of the mass and width of the W boson in e+e- collisions at √s = 189 GeV 2001 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 511:2-4, s. 159-177 Journal article (peer-reviewed)abstract A measurement of the W mass and width has been performed by the DELPHI Collaboration using the data collected during 1998. The data sample has an integrated luminosity of 155 pb-1 and an average centre-of-mass energy of 188.6 GeV. Results are obtained by applying the method of direct reconstruction of the mass of the W from its decay products in both the W+W- → lvlqq′ and W+W- → qq′qq′ channels. The W mass result for the 1998 data set is MW = 80.387 ± 0.087(stat) ± 0.034(syst) ± 0.017(LEP) ± 0.035(FSI) GeV/c2, where FSI represents the uncertainty due to final state interaction effects in the qq′qq′ channel, and LEP represents that arising from the knowledge of the beam energy of the accelerator. Combining this result with those previously published by the DELPHI Collaboration gives the result MW = 80.359 ± 0.074(stat) ± 0.032(syst) ± 0.017(LEP) ± 0.033(FSI) GeV/c2. The combined value for the W width is λW = 2.266 ± 0.176(stat)± 0.056(syst)± 0.052(FSI) GeV/c2.
8.	Adamovich, M.I., et al. (author) Rescattering probed by the emission of slow target associated particles in high-energy heavy-ion interactions 1995 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 363:4, s. 230-236 Journal article (peer-reviewed)abstract In this letter the distribution of slow target associated particles emitted in Au + Emulsion interactions at 11.6 A GeV/c is studied, The three models RQMD, FRITIOF and VENUS are used for comparisons and especially their treatment of rescattering is investigated.
9.	Adcox, K, et al. (author) Centrality dependence of the high (PT) charged hadron suppression in Au+Au collisions at root s(NN)=130 GeV 2003 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 561:1-2, s. 82-92 Journal article (peer-reviewed)abstract PHENIX has measured the centrality dependence of charged hadron p(T) spectra from Au +An collisions at root(s)NN = 130 GeV The truncated mean p(T) decreases with centrality for p(T) > 2 GeV/c, indicating an apparent reduction of the contribution from hard scattering to high p(T) hadrdn production. For central collisions the yield at high p(T) is shown to be suppressed compared to binary nucleon-nucleon collision scaling of p + p, data. This suppression is monotonically increasing with centrality, but most of the change occurs below 30% centrality, i.e., for collisions with less than similar to140 participating nucleons. The observed p(T) and centrality dependence is consistent with the particle production predicted by models including hard scattering and subsequent energy loss of the scattered partons in the dense matter created in the collisions. (C) 2003 Published by Elsevier Science B.V.
10.	Adloff, C, et al. (author) A measurement of the t dependence of the helicity structure of diffractive rho meson electroproduction at HERA 2002 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 539:1-2, s. 25-39 Journal article (peer-reviewed)abstract The helicity structure of the diffractive electroproduction of rho mesons, e + p --> e + rho + Y, is studied in a previously unexplored region of large four-momentum transfer squared at the proton vertex, t: 0 < t' < 3 GeV2, where t' = - min. The data used are collected with the HI detector at HERA in the kinematic domain 2.5 < Q(2) < 60 GeV2, 40 < W < 120 GeV No t dependence of the r(00)(04) spin density matrix element is found. A significant t dependent helicity non-conservation from the virtual photon to the rho meson is observed for the spin density matrix element combinations r(00)(5) + 2r(11)(5) and r(00)(1) + 2r(11)(1). These t dependences are consistently described by a perturbative QCD model based on the exchange of two gluons.
11.	Adloff, C, et al. (author) Diffractive photoproduction of psi(2S) mesons at HERA 2002 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 541:3-4, s. 251-264 Journal article (peer-reviewed)abstract Results on diffractive photoproduction of psi(2S) mesons are presented using data collected between 1996 and 2000 with the H1 detector at the HERA ep collider. The data correspond to an integrated luminosity of 77 pb(-1). The energy dependence of the diffractive psi(2S) cross section is found to be similar to or possibly somewhat steeper than that for J/psi mesons. The dependences of the elastic and proton dissociative psi(2S) photoproduction cross sections on the squared momentum transfer t at the proton vertex are measured. The t-dependence of the elastic channel, parametrised as e(bt), yields b(el)(psi(2S)) = (4.31 +/- 0.57 +/- 0.46) GeV-2, compatible with that of the J/psi. For the proton dissociative channel the result b(pd)(psi(2S)) = (0.59 +/- 0.13 +/- 0.12) GeV-2 is 2.3 standard deviations smaller than that measured for the J/psi. With proper account of the individual wavefunctions theoretical predictions based on perturbative QCD are found to describe the measurements well. (C) 2002 Elsevier Science B.V. All rights reserved.
12.	Adloff, C, et al. (author) Measurement of D(+/-) meson production and F-2(c) in deep-inelastic scattering at HERA 2002 In:* Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 528:3-4, s. 199-214 Journal article (peer-reviewed)abstract The inclusive production of D+/-(2010) mesons in deep-inelastic scattering is studied with the HI detector at HERA. In the kinematic region 1 < Q(2) < 100 GeV2 and 0.05 < y < 0.7 an e(+) p cross section for inclusive D+/- meson production of 8.50 +/- 0.42(stat.)(-100)(+1.21)(syst.) nb is measured in the visible range p(tD) > 1.5 GeV and eta(D) < 1.5. Single and double differential inclusive D*+/- meson cross sections are compared to perturbative QCD calculations in two different evolution schemes, The charm contribution to the proton structure, F-c(2)(x, Q(2)), is determined by extrapolating the visible charm cross section to the full phase space. This contribution is found to rise from about 10% at Q(2) = 1.5 GeV2 to more than 25% at Q(2) = 60 GeV2 corresponding to x values ranging from 5 x 10(-5) to 3 x 10(-3). (C) 2002 Elsevier Science B.V. All rights reserved.
13.	Adloff, C, et al. (author) Measurement of inclusive jet cross-sections in deep-inelastic ep scattering at HERA 2002 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 542:3-4, s. 193-206 Journal article (peer-reviewed)abstract A measurement of inclusive jet cross-sections in deep-inelastic ep scattering at HERA is presented based on data with an integrated luminosity of 21.1 pb(-1). The measurement is performed for photon virtualities Q(2) between 5 and 100 GeV2, differentially in Q(2), in the jet transverse energy E-T, in E-T(2)/Q(2) and in the pseudorapidity eta(lab). With the renormalization scale mu(R) = E-T, perturbative QCD calculations in next-to-leading order (NLO) give a good description of the data in most of the phase space. Significant discrepancies are observed only for jets in the proton beam direction with ET below 20 GeV and Q2 below 20 GeV2. This corresponds to the region in which NLO corrections are largest and further improvement of the calculations is thus of particular interest.
14.	Adloff, C, et al. (author) Search for excited electrons at HERA 2002 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 548:1-2, s. 35-44 Journal article (peer-reviewed)abstract A search for excited electron (e) production is described in which the electroweak decays e --> egamma, e* --> eZ and e* ---> nuW are considered. The data used correspond to an integrated luminosity of 120 pb(-1) taken in e(+/-)p collisions from 1994 to 2000 with the H1 detector at HERA at centre-of-mass energies of 300 and 318 GeV. No evidence for a signal is found. Mass dependent exclusion limits are derived for the ratio of the couplings to the compositeness scale, f/A. These limits extend the excluded region to higher masses than has been possible in previous direct searches for excited electrons. (C) 2002 Published by Elsevier Science B.V.
15.	Adloff, C, et al. (author) Search for excited neutrinos at HERA 2002 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 525:1-2, s. 9-16 Journal article (peer-reviewed)abstract We present a search for excited neutrinos using e(-) p data taken by the H1 experiment at HERA at a center-of-mass energy of 318 GeV with an integrated luminosity of 15 pb(-1). No evidence for excited neutrino production is found. Mass dependent exclusion limits are determined for the ratio of the coupling to the compositeness scale, f/Lambda, independently of the relative couplings to the SU(2) and U(1) gauge bosons. These limits extend the excluded region to higher masses than has been possible in previous searches at other colliders.
16.	Adloff, C, et al. (author) Search for odderon-induced contributions to exclusive pi(0) photoproduction at HERA 2002 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 544:1-2, s. 35-43 Journal article (peer-reviewed)abstract A search for contributions to the reaction ep --> epi(0)N* from photon-odderon fusion in the photoproduction regime at HERA is reported, at an average photon-proton centre-of-mass energy = 215 GeV. The measurement proceeds via detection of the pi(0) decay photons, a leading neutron from the N* decay, and the scattered electron. No pi(0) signal is observed and an upper limit on the cross section for the photon-odderon fusion process of sigma(gammap --> pi(0)N*) < 49 nb at the 95% confidence level is derived, integrated over the experimentally accessible range of the squared four-momentum transfer at the nucleon vertex 0.02 < < 0.3 GeV2. This excludes a recent prediction from a calculation based on a non-perturbative QCD model of a photon-odderon fusion cross section above 200 nb. (C) 2002 Elsevier Science B.V. All rights reserved.
17.	Ahrens, J, et al. (author) Helicity dependence of the (gamma)over-right-arrow (p)over-right-arrow -> n pi(+) pi(0) reaction in the second resonance region 2003 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 551:1-2, s. 49-55 Journal article (peer-reviewed)abstract The helicity dependence of the total cross section for the (γ) over right arrow(p) over right arrownpi(+) pi(0) reaction has been measured for the first time at incident photon energies from 400 to 800 MeV The measurement was performed with the large acceptance detector DAPHNE at the tagged photon beam facility of the MAMI accelerator in Mainz. This channel is found to be excited predominantly when the photon and proton have a parallel spin orientation, due to the intermediate production of the D-13 resonance. (C) 2002 Elsevier Science B.V. All rights reserved.
18.	Amaldi, U., et al. (author) New Limits on the Single-Gamma-Decay of Orthopositronium 1985 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 153:6, s. 444-448 Journal article (peer-reviewed)
19.	Ambjørn, J., et al. (author) Langevin simulations of configurations with static charges 1985 In: Physics Letters B. - 0370-2693. ; 159:4-6, s. 335-340 Journal article (peer-reviewed)abstract By using the Langevin equation with complex action it is possible to generate (complex) configurations in the charged sector of gauge theories. We test the algorithm in the case of two-dimensional U(1) gauge theory and are able to measure the string tension with great precision and modest use of computer time for a separation of the charged particles where a conventional Wilson loop would have a value ≈ 10-10.
20.	Ambjørn, J., et al. (author) Observation of a string in three-dimensional SU(2) lattice gauge theory 1984 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 142:5-6, s. 410-414 Journal article (peer-reviewed)abstract SU(2) lattice gauge theory in three dimensions is investigated on a 162×32 lattice. We find that R>×T Wilson loops are well described by a simple string theory for β in the (approximate) scaling region.
21.	Andersson, Bo, et al. (author) A String dynamical description of gluon and ocean quark structure functions 1992 In: Physics Letters B. - 0370-2693. ; 277:3, s. 359-365 Journal article (peer-reviewed)abstract We present a model based upon string dynamics for the small x and large k⊥ parts of the structure functions of a hadron. These ocean partons are taken as those available in the virtual string states, which are resolved by the field pulse q, in case the process is considered as a measuring process. The resulting distributions will for sufficiently small x (x⩽O(Q−4)) behave as 1/x in case we use the prescriptions of the Lund dipole model ([1,2]) and the soft radiation model ([3]).
22.	Andersson, Bo, et al. (author) How to Find the Gluon Jets in e+ e- Annihilation 1980 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 94B, s. 211-215 Journal article (peer-reviewed)
23.	Andersson, Bo, et al. (author) The flavouring of a gluon jet 1990 In: Physics Letters B. - 0370-2693. ; 236:4, s. 461-465 Journal article (peer-reviewed)abstract We show that the hard qq̄ production is very sensitive to the details of the parton shower and that our treatment based on the dipole approximation gives significantly larger production than “conventional” parton showers. For our model we find qualitative agreement with experimental data for the Kπ ratio and D-meson production in high-pT jets.
24.	Andersson, B., et al. (author) The relationship between the meson, baryon, photon and quark fragmentation distributions 1977 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 69:2, s. 221-224 Journal article (peer-reviewed)abstract The ideas presented in an earlier note on the relationship between the quark fragmentation distributions as measured in leptoproduction and the one particle distributions in the mesonic fragmentation regions of hadronic interactions are carried further to photoproduction and to the baryon fragmentation distributions. The results are as before interpreted in terms of a simple additive quark model where the main interaction is due to the wee partons whereas almost all the initial momentum is carried by one of the valence quarks or a diquark.
25.	Andersson, Bo, et al. (author) Transverse and longitudinal Bose-Einstein correlations 1998 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 421:1-4, s. 283-288 Journal article (peer-reviewed)abstract We show how a difference in the correlation length longitudinally and transversely, with respect to the jet axis in e+e− annihilation, arises naturally in a model for Bose-Einstein correlations based on the Lund string model. In genuine three-particle correlations the difference is even more apparent and they provide therefore a good probe for the longitudinal stretching of the string field. The correlation length between pion pairs is found to be rather independent of the pion multiplicity and the kaon content of the final state.
26.	Andreev, V, et al. (author) Isolated electrons and muons in events with missing transverse momentum at HERA 2003 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 561:3-4, s. 241-257 Journal article (peer-reviewed)abstract A search for events with a high-energy isolated electron or muon and missing transverse momentum has been performed at the electron-proton collider HERA using an integrated luminosity of 13.6 pb(-1) in e(-) p scattering and 104.7 pb(-1) in e(+) p scattering. Within the Standard Model such events are expected to be mainly due to W boson production with subsequent leptonic decay. In e(-) p interactions one event is observed in the electron channel and none in the muon channel, consistent with the expectation of the Standard Model. In the e(+) p data a total of 18 events are seen in the electron and muon channels compared to an expectation of 12.4 +/- 1.7 dominated by W production (9.4 +/- 1.6). Whilst the overall observed number of events is broadly in agreement with the number predicted by the Standard Model, there is-an excess of events with transverse momentum of the hadronic system greater than 25 GeV with 10 events found compared to 2.9 +/- 0.5 expected. The results are used to determine the cross-section for events with an isolated electron or muon and missing transverse momentum. (C) 2003 Published by Elsevier Science B.V.
27.	Anne, R., et al. (author) Observation of Forward Neutrons from the Break-up of the Li-11 Neutron Halo 1990 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 250:1-2, s. 19-23 Journal article (peer-reviewed)
28.	Axelsson, H., et al. (author) Candidates for Electron-Neutrino Mass Measurements - the Case of Kr-81 1988 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 210:1-2, s. 249-252 Journal article (peer-reviewed)abstract The nuclear data of the known candidates for neutrino mass determination by resonant electron-capture beta decay are reviewed. New results are presented for the isotope 81Kr, where the transition to the 276 keV state has been found to have QEC=4.7±0.5 keV and a branching ratio of (3.0±0.2)×10−3
29.	Baillie, C. F., et al. (author) Scaling in Steiner random surfaces 1994 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 325:1-2, s. 45-50 Journal article (peer-reviewed)abstract It has been suggested that the modified Steiner action functional has desirble properties for a random surface action. In this paper we investigate the scaling of the string tension and massgap in a variant of this action on dynamically triangulated random surfaces and compare the results with the gaussian plus extrinsic curvature actions that have been used previously.
30.	Bengtsson, Mats, et al. (author) Coherent Parton Showers Versus Matrix Elements: Implications of PETRA - PEP Data 1987 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; B185, s. 435-435 Journal article (peer-reviewed)
31.	Bengtsson, Mats, et al. (author) The Effect of Fragmentation Models on the Determination of $ s$ From Hadron Collider Data 1986 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 179:1-2, s. 164-169 Journal article (peer-reviewed)
32.	Bijnens, J., et al. (author) Chiral corrections to vector meson decay constants 1998 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 429:1-2, s. 111-120 Journal article (peer-reviewed)abstract We calculate the leading quark mass corrections of order mqlog(mq), mq and m3/2 q to the vector meson decay constants within heavy vector meson chiral perturbation theory. We discuss the issue of electromagnetic gauge invariance and the heavy mass expansion. Reasonably good fits to the observed decay constants are obtained.
33.	Bijnens, J., et al. (author) Double chiral logs 1998 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 441:1-4, s. 437-446 Journal article (peer-reviewed)abstract We determine the full structure of the leading (double-pole) divergences of O(p6) in the meson sector of chiral perturbation theory. The field theoretic basis for this calculation is described. We then use an extension of this result to determine the p6 contributions containing double chiral logarithms (L2), single logarithms times p4 constants (L × Lr i) and products of two p4 constants (Lr i × Lr j) for Fπ, FK/Fπ, Kl3 and Ke4 form factors. Numerical results are presented for these quantities.
34.	Bijnens, J., et al. (author) QCD signatures of narrow graviton resonances in hadron colliders 2001 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 503:3-4, s. 341-348 Journal article (peer-reviewed)abstract We show that the characteristic p⊥ spectrum yields valuable information for the test of models for the production of narrow graviton resonances in the TeV range at LHC. Furthermore, it is demonstrated that in those scenarios the parton showering formalism agrees with the prediction of NLO matrix element calculations.
35.	Borge, M. J. G., et al. (author) Beta-Decay to the Proton Halo State in F-17 1993 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 317:1-2, s. 25-30 Journal article (peer-reviewed)abstract In the first experiment at the newly constructed ISOLDE Facility the first-forbidden beta-decay of Ne-17 into the first excited state of F-17 has been measured. It is a factor two faster than the corresponding mirror decay and thus gives one of the largest recorded asymmetries for beta decays feeding bound final states. Shell-model calculations can only reproduce the asymmetry if the halo structure of the F-17 state is taken into account.
36.	Fjelstad, Jens, 1971-, et al. (author) Equivalence of Chern-Simons gauge theory and WZNW model using a BRST symmetry 1999 In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 466:2-4, s. 227-233 Journal article (peer-reviewed)abstract The equivalence between the Chern-Simons gauge theory on a three-dimensional manifold with boundary and the WZNW model on the boundary is established in a simple and general way using the BRST symmetry. Our approach is based on restoring gauge invariance of the Chern-Simons theory in the presence of a boundary. This gives a correspondence to the WZNW model that does not require solving any constraints, fixing the gauge or specifying boundary conditions.
37.	Flensburg, M., et al. (author) Measurement of Tc in the scaling region of (2+1)-dimensional SU(2) lattice gauge theory 1986 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 175:2, s. 187-191 Journal article (peer-reviewed)abstract The deconfinement temperature Tc of (2+1)-dimensional SU(2) gauge theory is measured on lattice sizes varying from 2 × 202 to 6 × 602 and with β in the rate 3-9. Approximative scaling is found for β > 6.5 and Tc/√σ = 0.94 ± 0.03 is obtained. This value is in excellent agreement with (3/π) 1 2, as predicted from the breakdown of SU(2) confinement in terms of an effective scalar string theory.
38.	Flensburg, M., et al. (author) Strings and SU(3) lattice gauge theory 1985 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 153:6, s. 412-416 Journal article (peer-reviewed)abstract Recent SU(3) lattice Monte Carlo data (244 and 164) are analyzed in terms of a simple string model. Good agreement is found. Observed similarities between SU(3) and three-dimensional SU(2) indicate that the string theory is indeed an effective one.
39.	Friberg, Christer, et al. (author) Effects of longitudinal photons 2000 In: Physics Letters B. - 0370-2693. ; 492:1-2, s. 123-134 Journal article (peer-reviewed)
40.	Friberg, C., et al. (author) QCD aspects of leptoquark production at HERA 1997 In: Physics Letters B. - 0370-2693. ; 403:3-4, s. 329-334 Journal article (peer-reviewed)abstract If a leptoquark is produced at HERA as a narrow resonance, various effects tend to broaden the measurable mass distribution considerably. These effects are discussed here, with special emphasis on initial- and final-state QCD radiation. A proper understanding is important to assess the significance of data and to devise strategies for better mass reconstruction.
41.	Garpman, S., et al. (author) Rapidity density distributions and their fluctuations in violent Au-induced nuclear interactions at 11.6 A GeV/c 1994 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 433:1-2, s. 166-170 Journal article (peer-reviewed)abstract The first rapidity density distributions from relativistic collisions between truly heavy nuclei are presented. The distributions are compared with expectations from a linear extrapolation of results obtained from collisions with lighter nuclei. Fluctuations are essentially described by a simple scenario with stochastic emission.
42.	Gustafson, Gösta, et al. (author) Lambda-polarization in e+e--annihilation at the Z0-pole 1993 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 303:3-4, s. 350-354 Journal article (peer-reviewed)abstract Strange quarks produced in e+e--annihilation at the Z0-pole are very strongly polarized. To study to which extent this polarization is transferred to the observable hadrons would give interesting information on the hadronization mechanism. Γ-particles produced with relatively large x-values are expected to frequently contain an originally produced s-quark. We estimate that Γ-particles with x>0.3 should have a longitudinal polarization of about 30%.
43.	Gustafson, Gösta, et al. (author) On the diffractive production of charmed baryons 1977 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 67:1, s. 81-83 Journal article (peer-reviewed)abstract Arguments are presented in favour of observing charmed baryons in diffractive scattering at high energies. The cross section for production of charmed baryons is estimated to be ∼ 10-100 μb at ISR energies.
44.	Hamamoto, Ikuko, et al. (author) Deformation dependence of magnetic dipole strength below 4 MeV in doubly even rare earth nuclei 1991 In: Physics Letters B. - 0370-2693. ; 260:1-2, s. 6-10 Journal article (peer-reviewed)abstract We show: (1) In the presence of the pair correlation the M1 transition strength calculated in the deformed oscillator model has a dependence on the quadrupole deformation parameter δ which is considerably stronger than linear and, in fact, it varies quadratically with δ in the limit of small deformation; (2) The deformation dependence in samarium isotopes calculated using the quasiparticle random phase approximation (QRPA) reproduces the qualitative behaviour of the recent experimental data of Ziegler, Rangacharyulu, Richter and Spieler.
45.	Hamamoto, Ikuko, et al. (author) Form-factor of low-lying Kπ=1+ excitations in rare-earth nuclei 1987 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 194:1, s. 6-10 Journal article (peer-reviewed)abstract The differential cross section of inelastic electron scattering for the low-lying “collective” Kπ=1+ excitations in rare-earth nuclei is calculated in DWBA by using microscopically calculated transition-densities. In the region of low-momentum transfer (q⪅0.5 fm-1) in which experimental data are available the shape of calcualted cross sections is almost the same for all nuclei and is slightly but systematically different from the observed shape.
46.	Ideguchi, E., et al. (author) Orbifold projection in supersymmetric QCD at N(f) ≤ N(c) 2000 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 492:3-4, s. 369-375 Journal article (peer-reviewed)abstract Supersymmetric orbifold projection of N = 1 SQCD with relatively small number of flavors (N(f) ≤ N(c)) is considered. The purpose is to check whether orbifolding commutes with the infrared limit. On the one hand, one considers the orbifold projection of SQCD and obtains the low-energy description of the resulting theory. On the other hand, one starts with the low-energy effective theory of the original SQCD, and only then performs orbifolding. It is shown that at finite N(c) the two low-energy theories obtained in these ways are different. However, in the case of stabilized run-away vacuum these two theories are shown to coincide in the large N(c) limit. In the case of quantum modified moduli space, topological solitons carrying baryonic charges are present in the orbifolded low-energy theory. These solitons may restore the correspondence between the two theories provided that the soliton mass tends to zero in the large N(c) limit. (C) 2000 Elsevier Science B.V.
47.	Irbäck, A. (author) A random surface representation of Wilson loops in Z(2) gauge theory 1988 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 211:1-2, s. 129-131 Journal article (peer-reviewed)abstract We study a random surface representation of Wilson loops in Z(2) gauge theory. The weights consist of an area factor, which dominates at strong coupling, and an excluded volume factor flavouring crumpled surfaces. We examine the latter one in some detail in three as well as four dimensions by use of Monte Carlo methods. In three dimensions, the critical behaviour of the surfaces is found to be determined to a large extent by the excluded volume factor.
48.	Irbäck, A., et al. (author) Lattice QCD with small number of flavours 1989 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 216:1-2, s. 177-183 Journal article (peer-reviewed)abstract The finite temperature behaviour of lattice QCD with dynamical quarks for small number of flavours Nf is investigated. Simulations have been performed on lattices of size N3σ·4 with Nσ=8 and 12 and staggered fermions of mass ma=0.1 using a hybrid algorithm. We find that the two state signal at the critical point of the pure gauge theory, which is taken as sign for a fiorst order phase transition, persists for the values of Nf we have investigated, namely Nf=0.5, 1 and 2. It is, however, considerably weaker for Nf=1 and 2. Moreover, for Nf=2 the discontinuity at βc decreases with increasing lattice size. Thid puts doubt o order nature of the Nf=2 transition at intermediate masses.
49.	Irbäck, A., et al. (author) Numerical evidence for a mass gap in three-dimensional SU(2) 1986 In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 174:1, s. 99-103 Journal article (peer-reviewed)abstract Numerical evidence for a nonvanishing 0++ glueball mass in three-dimensional SU(2) is presented. By using a long-distance correlation Monte Carlo method we obtain m0++ = (4.7±1.2)√σ in the β-range 4.0-6.5. The measurements are consistent with 1/β-scaling. The relevance of this result for SU(2) in four dimensions at finite temperature is briefly discussed.
50.	Jacobsson, Björn, et al. (author) Effects of random matter density fluctuations on the neutrino oscillation transition probabilities in the Earth 2002 In: Physics Letters B. - 0370-2693 .- 1873-2445. ; 532:04-mar, s. 259-266 Journal article (peer-reviewed)abstract In this Letter, we investigate the effects of random fluctuations of the Earth matter density for long baselines on the neutrino oscillation transition probabilities. We especially identify relevant parameters characterizing the matter density noise and calculate their effects by averaging over statistical ensembles of a large number of matter density profiles. For energies and baselines appropriate to neutrino factories, absolute errors on the relevant appearance probabilities are at the level of \DeltaP(alphabeta)\ similar to 10(-4) (with perhaps \P-mue similar to 1% for neutrinos), whereby a modest improvement in understanding of the geophysical data should render such effects unimportant.

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