HADRONIC PHYSICS IN SPAIN NUPECC meeting Madrid Spain

  • Slides: 44
Download presentation
HADRONIC PHYSICS IN SPAIN NUPECC meeting Madrid (Spain), March 7, 2008

HADRONIC PHYSICS IN SPAIN NUPECC meeting Madrid (Spain), March 7, 2008

Topics: Chiral Perturbation Theory QCD Sum Rules Effective Field Theory Exotic Hadrons Hadron Properties

Topics: Chiral Perturbation Theory QCD Sum Rules Effective Field Theory Exotic Hadrons Hadron Properties from Lattice Experimental Results and Future Perspectives Hadronic Distribution Amplitudes Spectroscopy of light and heavy quark mesons Baryons Quarkonia Glueballs, hybrids and multiquarks Phenomenological models Effective lagrangians QCD on the lattice Hadrons in matter Heavy ion collisions Future facilities

Define Hadronic physics, 1 o 2 slides

Define Hadronic physics, 1 o 2 slides

Theory Experiment

Theory Experiment

We fit our 12 free parameters to 370 data points and their reproduction from

We fit our 12 free parameters to 370 data points and their reproduction from ππ threshold up to 2 Ge. V is fair as shown in Fig. 1. The width of the band represents our systematic uncertainties at the level of two standard deviations. The fitted data are from left to right and top to bottom, ππ I = 0 S-wave phase shifts δ 0 0, the elasticity parameter η 0 0 = |S 11|, the I = 0 S-wave ππ → K ¯K phase shifts δ 1, 2, |S 1, 2|, the S-wave contribution to the ππ → ηη event distribution and the event distribution for ππ → ηη′. The last two panels corresponds to the phase (φ) and modulus (A) of the K−π+ → K−π+ amplitude from the LASS data. Compared with other works we determine the interaction kernels from standard chiral Lagrangians, avoiding ad-hoc parameterizations.

The investigation of hadron properties inside nuclear matter at normal and high densities and

The investigation of hadron properties inside nuclear matter at normal and high densities and temperatures is one of the main goals of current nuclear physics studies. Hadron induced reactions on heavy nuclei (e. g. Au, Pb) are the proper tool to probe particle properties in long-living ground state nuclear matter. Heavy ion collisions at energies of 1 -2 AGe. V can be used to create a reaction region of increased density for as long as 10 fm/c. Under these conditions, considerable modifications of basic hadron properties (masses, decay widths, etc. ) are expected and probably can be verified for the first time experimentally by high resolution lepton pair decay measurements. In order to investigate this phenomenon, the electron-positron pair spectrometer HADES was set up, and is in operation, at GSI by an international collaboration of 17 institutions from 9 European countries. Departamento de Física de Partículas, University of Santiago de Compostela , Santiago de Compostela, S D. Belver P. Cabanelas E. Castro J. A. Garzón Instituto de Física Corpuscular, Universidad de Valencia-CSIC , Valencia, Spain J. Díaz A. Gil

Excited Glue (Glueballs and Hybrids) Charm in Nuclei Charmonium Hypernuclei D- and DS-Physics Other

Excited Glue (Glueballs and Hybrids) Charm in Nuclei Charmonium Hypernuclei D- and DS-Physics Other Topics

SPAIN, MADRID, CIEMAT; TL&CP: Pedro LADRON DE GUEVARA IAGO DE COMPOSTELA, UNIVERSIDAD DE SANTIAGO

SPAIN, MADRID, CIEMAT; TL&CP: Pedro LADRON DE GUEVARA IAGO DE COMPOSTELA, UNIVERSIDAD DE SANTIAGO DE COMPOSTELA; TL&CP: C The ALICE Collaboration is building a dedicated heavy-ion detector to exploit the unique physics potential of nucleus-nucleus interactions at LHC energies. Our aim is to study the physics of strongly interacting matter at extreme energy densities, where the formation of a new phase of matter, the quark-gluon plasma, is expected. The existence of such a phase and its properties are key issues in QCD for the understanding of confinement and of chiralsymmetry restoration. For this purpose, we intend to carry out a comprehensive study of the hadrons, electrons, muons and photons produced in the collision of heavy nuclei. Alice will also study proton-proton collisions both as a comparison with lead-lead collisions in physics areas where Alice is competitive with other LHC experiments

in-medium modifications of hadrons in dense matter. indications of the deconfinement phase transition at

in-medium modifications of hadrons in dense matter. indications of the deconfinement phase transition at high baryon densities. the critical point providing direct evidence for a phase boundary. exotic states of matter such as condensates of strange particles. The approach of the CBM experiment towards these goals is to measure simultaneously observables which are sensitive to high density effects and phase transitions (see figure 2 for an illustration). In particular, the research program is focused on the investigation of: short-lived light vector mesons (e. g. the ρ-meson) which decay into electron-positron pairs. These penetrating probes carry undistorted information from the dense fireball. strange particles, in particular baryons (anti-baryons) containing more than one strange (anti-strange) quark, so called multistrange hyperons (Λ, Ξ, Ω). mesons containing charm or anti-charm quarks (D, J/Ψ). collective flow of all observed particles. event-by-event fluctuations.

Resonance physics in chiral unitary approaches A. Ramos (University of Barcelona) Workshop on the

Resonance physics in chiral unitary approaches A. Ramos (University of Barcelona) Workshop on the physics of excited nucleons (NSTAR 2007) 5 -8 September 2007 Bonn, Germany

Outline: Chiral unitary model The L(1405) and its two-pole nature Other sectors: eg S=-2

Outline: Chiral unitary model The L(1405) and its two-pole nature Other sectors: eg S=-2 X resonances Heavy flavored baryon resonances

K N scattering: a lively topic K N scattering in the I=0 channel is

K N scattering: a lively topic K N scattering in the I=0 channel is dominated by the presence of the L(1405), located only 27 Me. V below the K N threshold Already in the late sixties, Dalitz, Wong and Rajasekaran [Phys. Rev. 153 (1967) 1617] obtained the L(1405) as a KN quasi-bound state in a potential model (Scrhoedinger equation). The study of KN scattering has been revisited more recently from the modern view of chiral Lagrangians. However, the presence of a resonance makes c. PT not applicable non-perturbative techniques implementing unitarization in coupled channels are mandatory!

Chiral Unitary Model: 1. Build a transition potential V from the meson-baryon Lagrangian at

Chiral Unitary Model: 1. Build a transition potential V from the meson-baryon Lagrangian at lowest order Vij = Mi Mj Bi Bj s-wave M B coupled channels for S=-1: p. L 1255 p. S KN h. L 1331 1435 1663 Pioneer work: N. Kaiser, P. B. Siegel, W. Weise, Nucl. Phys. A 594 (1995) 325 h. S KX 1741 1814 (Me. V) omitted next-to-leading order: L 2 2. Unitarization: N/D method equivalent to Bethe-Salpeter coupled-channel equations with on-shell amplitudes = + Tij = Vij + Vil Gl. Tlj

Loop function Cut-off regularization (as in E. Oset and A. Ramos, Nucl. Phys. A

Loop function Cut-off regularization (as in E. Oset and A. Ramos, Nucl. Phys. A 635 (1998) 99): Dimensional regularization (as in J. A. Oller and U. G. Meissner, Phys. Lett. B 500 (2001) 263 ): subtraction constants of “natural size” (equivalent to cut-off L ~ 1 Ge. V)

K-p low energy scattering properties and the L(1405) L adjusted to reproduce branching ratios:

K-p low energy scattering properties and the L(1405) L adjusted to reproduce branching ratios: L=630 Me. V (f=1. 15 fp) 2. 32 (1. 04 without h. L, h. S) 0. 627 0. 213 E. Oset and A. Ramos, NPA 635 (1998) 99 h. Y channels are necessary to: obtain a good description of the threshold branching ratios (especially g) preserve SU(3) symmetry Invariant p. S mass distribution

Elastic and inelastic cross sections Total cross sections p-waves also included (D. Jido, E.

Elastic and inelastic cross sections Total cross sections p-waves also included (D. Jido, E. Oset, A. Ramos, PRC 66 (2002) 055203) + L, S, S* Differential cross sections

 Since the pioneering work of Kaiser, Siegel and Weise [Nucl. Phys. A 594

Since the pioneering work of Kaiser, Siegel and Weise [Nucl. Phys. A 594 (1995) 325] many other chiral coupled channel models have been developed. E. Oset and A. Ramos, Nucl. Phys. A 635 (1998) 99 J. A. Oller and U. G. Meissner, Phys. Lett. B 500 (2001) 263 M. F. M. Lutz, E. E. Kolomeitsev, Nucl. Phys. A 700 (2002) 193 C. Garcia-Recio et al. , Phys. Rev. D (2003) 07009 M. F. M. Lutz, E. E. Kolomeitsev, Nucl. Phys. A 700 (2002) 193 B. Borasoy, R. Nissler, and W. Weise, Phys. Rev. Lett. 94, 213401 (2005); Eur. Phys. J. A 25, 79 (2005) J. A. Oller, J. Prades, and M. Verbeni, Phys. Rev. Lett. 95, 172502 (2005) J. A. Oller, Eur. Phys. J. A 28, 63 (2006) B. Borasoy, U. G. Meissner and R. Nissler, Phys. Rev. C 74, 055201 (2006). more channels, next-to-leading order, Born terms beyond WT (s-channel, u-channel), Fits including new data …

The two-pole structure of the L(1405) D. Jido, J. A. Oller, E. Oset, A.

The two-pole structure of the L(1405) D. Jido, J. A. Oller, E. Oset, A. Ramos, U. G. Meissner, Nucl. Phys. A 725 (2003) 181 C. Garcia-Recio, J. Nieves, M. Lutz, Phys. Lett. B 582 (2004) 49 The meson-baryon states built from the 0 - pseudoscalar meson octet and the 1/2+ baryon octet can be classified into SU(3) multiplets: 8 X 8 = 1 + 8 s + 8 a + 10 + 27 meson X baryon 1 8 a 8 s 10 27 In the SU(3) basis: attractive Taking common baryon and meson masses (Mi~M 0, mi~m 0) in both Vij and Gl one obtains a SU(3) symmetric Tij a singlet (1) and two degenerate octets (8 s, 8 a) of Jp=1/2 - bound states appear!

M 0 = 1151 Me. V m 0 = 368 Me. V a 0

M 0 = 1151 Me. V m 0 = 368 Me. V a 0 = -2. 148 Breaking SU(3) gradually up to the physical masses: x=0. (0. 1)1 Mi(x) = M 0 + x (Mi-M 0) m 2 i(x) = m 20 + x (m 2 i-m 20) ai(x) = a 0 + x (ai-a 0) S=-1 sector s In I=0, the evolved octet and the evolved singlet appear very nearby: The nominal L(1405) is the reflection of two poles of the T-matrix !

S=-1 poles and couplings to physical states with I=0 z. R 1390 - 66

S=-1 poles and couplings to physical states with I=0 z. R 1390 - 66 i 1426 - 16 i 1680 - 20 i (I=0) |gi| p. S 2. 9 1. 5 0. 27 KN 2. 1 2. 7 0. 77 h. L 0. 77 1. 4 1. 1 KX 0. 61 0. 35 3. 6 The properties of the L(1405) will depend on which amplitude initiates the reaction! |T|2 pcm Tp. S selects preferentially the lower energy (wider) pole TKN p. S selects preferentially the higher energy (narrower) pole

Experimental evidence K-p p 0 p 0 S 0 p-p K 0 p. S

Experimental evidence K-p p 0 p 0 S 0 p-p K 0 p. S D. W. Thomas et al. Nucl. Phys. B 56, 15 (1973) S. Prakhov et al. , Phys. Rev. C 70, 034605 (2004)

confirmed by models! p-p K 0 p. S T. Hyodo, et al, Phys. Rev.

confirmed by models! p-p K 0 p. S T. Hyodo, et al, Phys. Rev. C 68 (2003) 065203 K-p p 0 p 0 S 0 V. K. Magas, E. Oset and A. Ramos, Phys. Rev. Lett. 95, 052301 (2005) where: dominated by the amplitude TKN p. S + The N*(1710) mechanism stresses the role of Tp. S The chiral terms stress the role of TKN p. S MI ~ 1420 Me. V

Other sectors JP=1/2 S=0 N*(1535) N. Kaiser, P. B. Siegel, W. Weise, Phys. Lett.

Other sectors JP=1/2 S=0 N*(1535) N. Kaiser, P. B. Siegel, W. Weise, Phys. Lett. B 362 (1995) 23 J. C. Nacher et al. , Nucl. Phys. A 678 (2000) 187 T. Inoue, E. Oset, M. J. Vicente-Vacas, Phys. Rev. C 65 (2002) 035204 J. Nieves and E. Ruiz Arriola, Phys. Rev. D 64 (2001) 116008 M. F. M. Lutz, E. E. Kolomeitsev, Nucl. Phys. A 730 (2004) 110 … S=-2 X(1620), X(1690) A. Ramos, E. Oset, C. Bennhold, Phys. Rev. Lett. 89 (2002) 252001 C. Garcia-Recio, J. Nieves, M. Lutz, Phys. Lett. B 582 (2004) 49 JP=3/2 - D(1700), L(1520), S(1670), X(1820) (Interaction of the 0 - meson octet with the 3/2+ baryon decuplet) E. E. Kolomeitsev, M. F. M. Lutz, Phys. Lett. B 585 (2004) 243 S. Sarkar, E. Oset, M. J. Vicente-Vacas, Phys. Rev. C 72 (2005) 015206 L. Roca, S. Sarkar, V. K. Magas and E. Oset, Phys. Rev. C 73 (2006) 045208 M. Döring, E. Oset, D. Strottman, Phys. Rev. C 73 (2006) 045209 M. Döring, E. Oset, D. Strottman, Phys. Lett. B 639 (2006) 59

S=-2 Experimental situation: p-wave: s-wave: X(1530)**** X(1620)*, X(1690)*** I=1/2 JP=3/2+ I=1/2 JP: not measured

S=-2 Experimental situation: p-wave: s-wave: X(1530)**** X(1620)*, X(1690)*** I=1/2 JP=3/2+ I=1/2 JP: not measured X(1620) G = 20 – 50 Me. V (into p. X states) (seen recently at CLAS in the g p p- K+ K- (Xp) reaction) X(1690) G = 10 – 50 Me. V (into KS, KL, p. X states) 1 : 1/3 : 1/10 We looked for dynamical resonances in the S=-2 sector, by solving the unitary coupled channel problem with the states: p. X, KL, KS, h. X Taking: ap. X=-3. 1 a. KL=-1. 0 a. KS=-2. 0 ah. X=-2. 0 (of natural size) z. R 1605 - 65 i (I=1/2) |gi| p. X 2. 4 KL 2. 6 KS 0. 96 h. X 0. 48 A. Ramos, E. Oset, C. Bennhold, Phys. Rev. Lett. 89 (2002) 252001 We identify this resonance with the X(1620)* JP=1/2 - can be assigned!

p. X invariant mass distribution ~50 Me. V KL threshold: 1611 Me. V The

p. X invariant mass distribution ~50 Me. V KL threshold: 1611 Me. V The “apparent” width (~50 Me. V) is much smaller than the actual width at the pole position (~130 Me. V) (Flatté effect: resonance just below a threshold to which the resonance couples strongly)

Heavy flavoured baryon resonances In the charm sector we find a resonance. the Lc(2593)

Heavy flavoured baryon resonances In the charm sector we find a resonance. the Lc(2593) (udc), that bears a strong ressemblance to the L(1405) (uds) in KN dynamics ü Can we generate the Lc(2593) dynamically from DN dynamics? ü The DN interaction is intimately connected to the properties of the D-meson in a nuclear medium

Understanding the interaction of charmed mesons in a hadronic medium is an important issue:

Understanding the interaction of charmed mesons in a hadronic medium is an important issue: It is produced in pairs (D+, D-) • in heavy ion experiments: • or antiproton anhilation experiments (PANDA at FAIR) on protons and nuclei: There are hints that a D Dbar meson-pair could feel attraction: an open charm enhancement has been observed in nucleus-nucleus collisions by the NA 50 Collaboration If the mass of the D (and Dbar) mesons gets reduced appreciably in the medium (cold or hot), this would provide a conventional hadronic physics explanation to explain J/Y supression (attributed to be a signal for the formation of a Quark-Gluon Plasma)

QCD sum rule (QCDSR) The in-medium mass shift is obtained in the low density

QCD sum rule (QCDSR) The in-medium mass shift is obtained in the low density approximation from the product of the mass of the charmed quark (mc) and the light meson q-qbar condensate: A. Hayashigashi, Phys. Let. B 487, 96 (2000) P. Morath, W. Weise, S. H. Lee, 17 Autumn school on QCD, Lisbon 1999 (World Scientific, SIngapore, 2001) 2001

Nuclear Mean Field approach (NMFA) D-meson self-energy is calculated by supplementing the contribution of

Nuclear Mean Field approach (NMFA) D-meson self-energy is calculated by supplementing the contribution of the free meson-baryon lagrangian: with additional terms describing the interaction of the D with mean scalar (s) and vector (w) density-dependent meson fields A. Mishra, E. L. Brakovskaya, J. Schaffner-Bielich, S. Schramm, and H. Stoecker, Phys. Rev. C 70, 044904 (2004) Variety of results, depending on ingredients of the model and its parameters:

Quark Meson Coupling approach Hadron interactions mediated by the exchange of scalar-isoscalar (s) and

Quark Meson Coupling approach Hadron interactions mediated by the exchange of scalar-isoscalar (s) and vector (r and w) medium modified mesons among the light constituent quarks. A. Sibirtsev, K. Tsushima, and A. W. Thomas, Eur. Phys. J. A 6, 351 (1999) These models predict a substantial reduction of the D-meson mass to which a scalar-isoscalar attraction appears to play an important role However, the full dynamics of the DN interaction (e. g. coupled channels) might be crucial (due to the presence of the Lc(2593) (udc)

Earlier attempts of coupled-channel calculations of the DN amplitude Channels for C=1, S=0 L.

Earlier attempts of coupled-channel calculations of the DN amplitude Channels for C=1, S=0 L. Tolós, J. Schaffner-Bielich, and A. Mishra, Phys. Rev. C 70, 025203 (2004) (T=0 Me. V) L. Tolós, J. Schaffner-Bielich, and H. Stöcker, Phys. Lett. B 635, 85 (2006) (finite T) Exploits the similarity between L(1495) and Lc(2593): s replaced by c in a SU(3) chiral invariant model (only channels with non-strange hadrons) The Lc(2593) is generated as a DN s-wave molecular state having a width of 3 Me. V M. F. M. Lutz and E. E. Kolomeitsev, Nucl. Phys. A 730, 110 (2004) Scattering of Goldstone bosons (p, K, h) off ground state charmed baryons (Lc, Sc …). Proper symmetries respected but no DN, Ds. Y channels I=0, C=1 resonance found at 2650 Me. V that couples strongly to p. Sc (very large width ~ 80 Me. V) Ideally: include all channels extend chiral MB-MB lagrangian to SU(4) However, c quark is very heavy mc ~1. 4 Ge. V !

J. Hofmann and M. F. M. Lutz, Nucl. Phys. A 763, 90 (2005) t-channel

J. Hofmann and M. F. M. Lutz, Nucl. Phys. A 763, 90 (2005) t-channel exchange of vector mesons: V universal vector coupling constant SU(4) at the vertices: chiral symmetry in the light sector imposed SU(4) symmetry broken by the use of physical masses. In particular:

DN amplitudes DN I=0 DN I=1 (dimensional regularization)

DN amplitudes DN I=0 DN I=1 (dimensional regularization)

In-medium amplitude M. F. M. Lutz, and C. L. Korpa, Phys. Lett. B 633,

In-medium amplitude M. F. M. Lutz, and C. L. Korpa, Phys. Lett. B 633, 43 (2006) contains: Pauli blocking on intermediate nucleons Self-consistent dressing of D-meson But, the in medium cannot be regularized via DR use a cut-off L free amplitude T must be also determined with a cut-off L!

T. Mizutani, A. Ramos, Phys. Rev. C 74, 065201 (2006) We obtain T with

T. Mizutani, A. Ramos, Phys. Rev. C 74, 065201 (2006) We obtain T with a loop function regularized with a cut-off L [adjusted to reproduce Lc(2593)] We include an additional scalar-isoscalar interaction (S term) (from QCDSR) Model A: Model B:

DN amplitudes (with cut-off regularization) I=0 I=1 R. Mizuk et al. [Belle Collaboration] Phys.

DN amplitudes (with cut-off regularization) I=0 I=1 R. Mizuk et al. [Belle Collaboration] Phys. Rev. Lett. 94, 122002(2005) Sc(2800), G~60 Me. V

D-meson self-energy and spectral density (r=r 0 and 2 r 0) r=r 0 quasiparticle

D-meson self-energy and spectral density (r=r 0 and 2 r 0) r=r 0 quasiparticle peak r=2 r 0 L. Tolos, A. Ramos and T. Mizutani, in preparation

Conclusions Combining chiral dynamics with a non-perturbative unitarization technique, one can extend the range

Conclusions Combining chiral dynamics with a non-perturbative unitarization technique, one can extend the range of applicability of the chiral lagrangian to study resonances. In the light sector, the L(1405) provides an excellent example of a dynamically generated resonance. There are two I=0 poles building up the nominal L(1405). These two resonances couple differently to p. S and KN states and, as a consequence, the “properties” of the L(1405) (mass and width) will depend on the particular reaction employed to produce it. In the heavy sector, we have studied the DN interaction in coupled channels from a model inspired on the work of Hofmann and Lutz, with some modifications: ü ü a supplementary scalar-isoscalar interaction is introduced momentum cut-off regularization more consistent than DR in view of its application to meson-baryon scattering in the medium The model generates the Lc(2595) in I=0, together with another resonance with I=1 consistent with the observed Sc(2800)