Search results for "HRES"
showing 10 items of 695 documents
Traces of errors due to single ion in floating gate memories
2008
Single, high energy, high LET, ions impacting on a Floating gate array at grazing or near-grazing angles lead to the creation of long traces of FGs with corrupted information. Every time a FG is crossed by a single ion, it experiences a charge loss which permanently degrades the stored information. If the ion crosses more than one FG, the threshold voltage of all those FGs interested by its track will be degraded.
The Z(3985) as a threshold effect from the D¯s⁎D+D¯sD⁎ interaction
2021
Abstract We study the e + e − → K + ( D s ⁎ − D 0 + D s − D ⁎ 0 ) reaction recently measured at BESIII, from where a new Z c s state has been reported. We study the interaction of D ¯ s D ⁎ with the coupled channels J / ψ K − , K ⁎ − η c , D s − D ⁎ 0 , D s ⁎ − D 0 by means of an extension to the charm sector of the local hidden gauge approach. We find that the D s − D ⁎ 0 + D s ⁎ − D 0 combination couples to J / ψ K − and K ⁎ − η c , but the D s − D ⁎ 0 − D s ⁎ − D 0 combination does not. The coupled channels help to build up strength in the D s − D ⁎ 0 + D s ⁎ − D 0 diagonal scattering matrix close to threshold and, although the interaction is not strong enough to produce a bound state or…
Instantons and eta meson production near threshold in NN collisions
1999
An enhancement for the $\eta$ production in proton-neutron collisions as compared with that in proton-proton scattering has been recently observed. We present a calculation for the production cross section, in proton-neutron collisions near threshold, within instanton model for the QCD vacuum and show that a specific flavor dependent nonperturbative quark-gluon interaction related to instantons is able to explain the observed enhancement.
Measurement of cross section for e+e−→Ξ0Ξ¯0 near threshold
2021
Abstract Using e + e − collision data at ten center-of-mass energies between 2.644 and 3.080 GeV collected with the BESIII detector at BEPCII and corresponding to an integrated luminosity of about 500 pb−1, we measure the cross sections and effective form factors for the process e + e − → Ξ 0 Ξ ¯ 0 utilizing a single-tag method. A fit to the cross section of e + e − → Ξ 0 Ξ ¯ 0 with a pQCD-driven power function is performed, from which no significant resonance or threshold enhancement is observed. In addition, the ratio of cross sections for the processes e + e − → Ξ − Ξ ¯ + and Ξ 0 Ξ ¯ 0 is calculated using recent BESIII measurement and is found to be compatible with expectation from isosp…
EMMA – a new underground cosmic-ray experiment
2008
An experiment observing underground muons originating from cosmic-ray air showers is under preparation in the Pyhasalmi mine, Finland. The aim is to cover an area of about 200-300 m(2), and the detector setup is capable of measuring the muon multiplicity and their lateral distribution. The detector is placed at a depth of about 85 m (corresponding about 240 m w.e.), which gives a threshold energy of muons of about 45 GeV. The detection of the multimuon events is motivated by partly unknown composition of the primary cosmic rays in the energy region of 10(15)-10(16) eV, i.e., the knee region. In addition, by measuring only the higher energy muons of the air shower, the lowest energy muons be…
Effects of aNcc¯*resonance with hidden charm in theπ−p→D−Σc+reaction near threshold
2015
We study the effect of a hidden charm nuclear excited state ${N}_{c\overline{c}}^{*}$ in the ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{D}^{\ensuremath{-}}{\mathrm{\ensuremath{\Sigma}}}_{c}^{+}$ reaction near threshold using an effective Lagrangian approach. We calculate the background contribution of the $t$ and $u$ channels by the ${D}^{*0}$ vector meson exchange and ${\mathrm{\ensuremath{\Sigma}}}_{c}^{++}$ intermediate state, respectively. We show that the consideration of a ${N}_{c\overline{c}}^{*}$ resonance provides an enhancement of the total cross section close to the reaction threshold. We also evaluate the differential cross section for different energies and w…
e+e−→K+K−π+π−,K+K−π0π0andK+K−K+K−cross sections measured with initial-state radiation
2007
We study the processes e+e-→K+K-π+π-γ, K+K-π0π0γ and K+K-K+K-γ, where the photon is radiated from the initial state. About 34600, 4400 and 2300 fully reconstructed events, respectively, are selected from 232fb-1 of BABAR data. The invariant mass of the hadronic final state defines the effective e+e- center-of-mass energy, so that the K+K-π+π-γ data can be compared with direct measurements of the e+e-→K+K-π+π- reaction; no direct measurements exist for the e+e-→K+K-π0π0 or e+e-→K+K-K+K- reactions. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution fr…
Ab initio calculation of Li7 photodisintegration
2004
The Li7 total photoabsorption cross section is calculated microscopically. As nucleon-nucleon interaction the semi-realistic central AV4' potential with S- and P-wave forces is taken. The interaction of the final 7-nucleon system is fully taken into account via the Lorentz Integral Transform (LIT) method. For the calculation of the LIT we use expansions in hyperspherical harmonics (HH) in conjunction with the HH effective interaction (EIHH) approach. The convergence of the LIT expansion is discussed in detail. The calculated cross section agrees quite well with the available experimental data, which cover an energy range from threshold up to 100 MeV.
Threshold π0 photo- and electro-production in a meson-exchange model
2003
We show that, within a meson-exchange dynamical model describing well most of the existing pion electromagnetic production data up to the second resonance region, one is also able to obtain a good agreement with the pi^0 photo- and electroproduction data near threshold. In the case of pi^0 production, the effects of final state interaction in the threshold region are nearly saturated by single charge exchange rescattering. This indicates that in ChPT, it might be sufficient to carry out the calculation just up to one-loop diagrams for threshold neutral pion production.
Is it possible to determine the S-factor of the hep process from a laboratory experiment?
2000
We discuss the problem of solar hep neutrinos originating from the reaction p + 3He -> 4He + e+ + nu and obtain a relation between the astrophysical S-factor of the hep process and the cross section of the process e- + 4He -> 3H + n + nu near threshold. The relation is based on the isotopic invariance of strong interactions. The measurement of the latter cross section would allow to obtain experimental information on S(hep), the value of which, at the moment, is known only from theoretical calculations.