October, 22, 2008 ITEP
- Beginning at 10:00
- 1.A.N.Vasiliev (IHEP-Protvino) – PANDA at FAIR
- 2.1.Yu.S.Kalashnikova (ITEP) – CHARMONIUM SPECTROSCOPY: MODERN STATUS
- 3.1.A.B.Kaidalov, K.G.Boreskov (ITEP) - INTERACTION OF ANTIPROTONS WITH NUCLEI
- Coffee break 11:20-11:35.
- 4.A.V.Nefediev (ITEP) - HYBRID CHARMONIA
- 5.Yu.A.Simonov (ITEP) - THE PION_QUARKONIUM INTERACTION
- Dinner 12:55-14:00
- 6.R.N.Faustov (CC RAS) - HEAVY TETRAQUARKS
- 7.7.M.G.Sapozhnikov (JINR, Dubna) – STUDY OF ANNIHILATION REACTIONS WITH φ - MESON PRODUCTION AT PANDA ENERGIES
- 8.7.M.Yu. Barabanov - SEARCH FOR THE RADIAL EXCITED STATES OF CHARMONIUM IN EXPERIMENTS USING ANTIPROTON BEAMS WITH MOMENTUM RANGING FROM 1 GeV/c TO 15 GeV/c
- Coffee break 15:20-15:35
- 9.A.M.Badalian (ITEP), I.Danilkin(ITEP) THE S-D MIXING AND DI-ELECTRON WIDTHS OF HIGHER CHARMONIUM 1-- STATES
- 10.A.Smirnov, A.Sidorin, D.Krestnikov, R.Pivin (JINR) - SIMULATION OF EFFECTIVE LUMINOSITY FOR PANDA EXPERIMENT
- 11.A.B. Skachkova (JINR, Dubna) – THE PROCESS OF LEPTON PAIR PRODUCTION AT INTERMEDIATE ENERGIES AND BASIC BACKGROUNDS TO THEM
- 12.N.B.Skachkov - THE PROCESS OF LEPTON PAIR PRODUCTION IN ANTIPROTON – PROTON COLLISIONS AT PANDA EXPERIMENT
- 13.Discussion
- 18:00 End of meeting
Annotation -1: PANDA at FAIR – A.N.Vasiliev (IHEP-Protvino).
A short description of the PANDA project at FAIR including a physics program, experimental setup and a Russian institution involvement will be presented.
Annotation -2: CHARMONIUM SPECTROSCOPY: MODERN STATUS Yu.S.Kalashnikova (ITEP)
Experimental data on new charmonia and charmonium-like states are reviewed.
Annotation -3: INTERACTION OF ANTIPROTONS WITH NUCLEI A.B.Kaidalov, K.G.Boreskov (ITEP)
Some problems for interactions of antiprotons with nuclei in the energy region of PANDA experiment are considered. It is emphasized that the space-time picture of interaction of hadrons with nuclei changes in this energy region. It is shown that measurements of atomic dependence for cross section of annihilation of antiprotons on nuclei can provide an information on this phenomenon. Other problems: production of hidden and open charm on nuclei, bound charmonia, supernuclei, production of heavy strange baryons and cumulative particles in antiproton-nucleus collisions will be discussed.
Annotation -4: HYBRID CHARMONIA A.V.Nefediev (ITEP)
Lowest charmonium hybrids are considered in the framework of the QCD string model. All parameters of the model are fixed from the fit for the spectrum of conventional charmonia. Then masses, spin splittings, and relative decay rates into various S- and P-wave D-meson pairs are calculated for charmonium hybrids with a magnetic gluon. Results are compared with the lattice predictions and with the existing experimental data. A possible interpretation of the Y(4260) as a hybrid meson is discussed and consequences of such an identification are outlined.
Annotation -5: THE PION_QUARKONIUM INTERACTION Yu.A.Simonov (ITEP)
An effective quark-pion Lagrangian is derived from QCD within the Field Correlator method which contains two parameters and decribes variety of processes:from decaysof heavy quarkonia into pair of heavy-light mesons with or without pions (kaons, etas) to transitions between quarkonia states with emission of any number ofpseudoscalars.Comparison with numerous experimental data shows a reasonable agreement and sensitivity to the exact form of quarkonia wave functions. In conclusion a project of future work for all charmonia states with channel coupling and pion interaction within the outlined method is formulated.
Annotation -6: HEAVY TETRAQUARKS R.N.Faustov (ВЦ РАН)
The masses of the ground-state and excited heavy tetraquarks with hidden charm and bottom are calculated within the relativistic diquark-antidiquark picture. It is argued that recently observed charmonium-like states X(3872), Y(4260), Y(4360), Z(4248), Z(4433) and Y(4660) could be the tetraquark states with hidden charm.
Annotation -7: "Study of annihilation reactions with -meson production at PANDA energies – M.G.Sapozhnikov (JINR, Dubna)
Strong OZI-rule violation on a factor of 30-70 was found in some reactions of the antiproton-annihilation at rest in different experiments at LEAR(CERN). These facts were explained in the framework of different models, including the assumption that the nucleon intrinsic strangeness is polarized. The program of measurements at PANDA for testing the prediction of the polarized strangeness model for the annihilation in flight is proposed.
Annotation -8: SEARCH FOR THE RADIAL EXCITED STATES OF CHARMONIUM IN EXPERIMENTS USING ANTIPROTON BEAMS WITH MOMENTUM RANGING FROM 1 GeV/c TO 15 GeV/c. M.Yu. Barabanov1, A.S. Vodopianov1, V.A. Babkin1, V.Kh. Dodokhov1, S.N. Chukanov2, B.K. Nartov2 1) JINR, Veksler and Baldin Laboratory of High Energy Physics 2) Sobolev Institute of Mathematics, Siberian Branch of Russian Academy of Science
The calculation of the spectrum of the radial excited states of charmonium in the relativistic spherical symmetric top model for decay products was carried out. Using the integral formalism for hadron resonance decay products the widths of these states have been calculated. The values of masses and widths of charmonium are in good agreement with experimental data. Six new radial excited states of charmonium in mass region over -threshold equals 3.73 GeV/c were predicted. Four of them (two scalar and two vector states) were experimentally revealed. The possibility of usage of antiproton beams with momentum ranging from 1 GeV/c to 15 GeV/c for studying of charmonium spectroscopy especially over - threshold is discussed. The advantage of antiproton beams consists that in antiproton-proton annihilation the intensive appearance of particle-antiparticle pares is observed. This fact allows carry out spectroscopic researches with good statistics and high accuracy. Hence, the possibility of measuring of masses and widths of scalar and vector charmonium states with high accuracy is emerging. One can find the results of our calculations for charmonium spectrum in Figure 1.Figure 1 illustrates the possible spectrum of scalar and vector states of charmonium. Black boxes correspond to the established charmonium states, black-white boxes - recently experimentally revealed states. The possible existence of the states marked by black-white boxes was predicted in our calculations [1, 2]. One can find that X(3940) and Y(4260) can be interpreted as radial excited scalar states of charmonium, Y(4350) and Y(4660) - as radial excited vector states of charmonium. Finally, white boxes correspond to the states which are not found yet. But possibility of existence of these states is predicted in our approach. They can also be interpreted as radial excited states of charmonium. It is known that potential models provide the connection between QCD and the more phenomenological treatments at distances comparable to the nucleon radius. The authors have shown the connection of the proposed approach with potential models using different types of the Cornell potential.
Figure1. The possible spectrum of scalar and vector states of charmonium. References: 1.M.Yu. Barabanov et al.,Russian Physics Journal, V. 50, N. 12, 66 (2007). 2.M.Yu. Barabanov et al., The Proc. of the XII International Conference on Hadron Spectroscopy HADRON07, Frascati, Italy, 8-13 Oct, 2007.
Annotation -9: THE S-D MIXING AND DI-ELECTRON WIDTHS OF HIGHER CHARMONIUM 1-- STATES A.M.Badalian (ITEP), B.L.G.Bakker (), I.Danilkin(ITEP) T
he di-electron widths of the conventional Ψ(4040), Ψ(4160), Ψ(4415) resonances are shown to be in good agreement with experiment, if the S-D mixing with a large mixing angle θ = 34o takes place. It supposes that the physical resonance Y(~ 4400), which originates from the 3 3D1 state, has also rather large Γee(Y(~4400))=0.061 keV. For the Belle resonance Y(4660) considered as a pure 5 3S1 state Γee(Y(4660))=0.70 keV, but the width becomes significantly smaller, equal 0.31 keV, if the mixing angle between the 5 3S1 and 4 3D1 states has the characteristic value θ=34o. For the 6 3S1 resonance the mass M(6S) =4830 (20) MeV and Γee=0.20 keV are predicted.
Annotation -10: CHIRAL SHIFTS AND TRANSITIONS IN HEAVY_LIGHT MESONS A.M.Badalian, Yu.A.Simonov, M.A.Trusov (ITEP)
The mass shifts of the P-wave Ds and Bs mesons due to coupling to DK, D*K and BK, B*K channels are studied using the effective chiral quark-pion Lagrangian. The strong mass shifts down ~140 MeV and ~ 100MeV for D*s(0+) and Ds(1+') ~100 MeV for B*s(0+) and Bs(1+') are calculated. The chiral flip mechanism due to the bispinor structure of both heavy-light mesons is very essential. The masses M(B*s(0+)) =5710(15) MeV and M(Bs(1+'))=5730(15) MeV are predicted. Experimental limit on the width Γ(Ds1(2536))<2.3 MeV puts strong restrictions on admittable mixing angle between the 1+ and 1+' states, |φ|<6o.
Annotation -11: SIMULATION OF EFFECTIVE LUMINOSITY FOR PANDA EXPERIMENT A.Smirnov, A.Sidorin, D.Krestnikov, R.Pivin , JINR, Dubna, Russia
One of the most important goals of FAIR project is caring out an experiment with internal target PANDA. The only way to achieve design luminosity value is to use a pellet target. However, such a target is coming up with short-scale luminosity variation. Peak to mean luminosity ratio can reach a big value unacceptable for detector. A numerical simulation of this experiment is connected to two different time-scale processes. The first one is the short-time process, which describes luminosity variations while one pellet is crossing the beam. This process can be about tenths microsecond long. The long-time process of the beam parameter evolution (particle number, transverse and longitudinal profiles) are defined by the beam losses and equilibrium between target heating and electron cooling. At the frame of the PANDA collaboration an additional algorithm was developed and implemented into the BETACOOL code. It calculates luminosity time dependencies at the time scale sufficiently shorter then time that takes a pellet to get through the beam. For benchmarking of the BETACOOL algorithms, data from experiment with pellet target WASA at COSY storage ring was used. During the COSY run from June 21 to July 5 2008 a luminosity value and different beam parameters were recorded as functions of time. Modeling of the experiment was made using the BETACOOL program. The purpose of modeling was a comparison of calculated luminosity variations in the storage ring while every pellet is crossing the beam with experimental data. The BETACOOL simulations for typical PANDA parameters show that the effective luminosity in the case of high-luminosity mode can be in two times less than average one if peak to mean luminosity ratio can reach a big value unacceptable for the detector. This effect can limit the count rate of registered events. Some ideas how to avoid this problem are presented.
