#### Pregled bibliografske jedinice broj: 165037

## The re-analysis of the 1700 MeV structure of the P_11 partial wave using the pi N-->KLambda production data

The re-analysis of the 1700 MeV structure of the P_11 partial wave using the pi N-->KLambda production data

*// Few-body systems,*

**39**(2006), 27-43 (međunarodna recenzija, članak, znanstveni)

**Naslov**

The re-analysis of the 1700 MeV structure of the P_11 partial wave using the pi N-->KLambda production data

**Autori**

Ceci, Saša ; Švarc, Alfred ; Zauner, Branimir

**Izvornik**

Few-body systems (0177-7963) **39**
(2006);
27-43

**Vrsta, podvrsta i kategorija rada**

Radovi u časopisima, članak, znanstveni

**Ključne riječi**

P_11 resonance; pentaquark

**Sažetak**

Abstract. We have used the Breit-Wigner resonance model with S_11, P_11, and P_13 resonances in the s-channel to reanalyze the old pi N→ KΛ data with the aim to establish the origin of the prominent structure in the total cross section in the vicinity of 1700  MeV. We have found a new set of resonance parameters enforcing the experimentally observed structure of the total cross-section data simultaneously with the linear dependence of the differential cross sections with cos  theta in the energy range 1650 MeV < W < 1800 MeV. Owing to the differential cross-section linearity, the P_13 partial wave has been strongly attenuated in this model, and the total cross-section structure is attributed to the resonant behavior of the P_11 partial wave. In this paper we show that, at least in the Breit-Wigner resonance model, it is not possible to achieve a detailed reproduction of the narrow 1700 MeV total cross-section peak using the standard partial widths. To understand the phenomenon, a much narrower width of a resonant state, the N(1710) P_11 in our case, is required (Γ ≈ 68 MeV), but then the agreement of the model predictions with the total cross-section data at higher energies is lost. One way out is to allow for the existence of another P_11 resonance in that energy range. The same feature is shown by the polarization data: The introduction of a much narrower resonance spoils the level of agreement which the Breit-Wigner resonance model is able to achieve with experiment, but the consistency is restored when another resonance is introduced. Analyzing the qqq or qqqq\bar nature of the recommended narrow P_11 structure in the neighborhood of 1700  MeV we reopen (remind of) the possibility that another P 11 resonant state exists in addition to the standard N(1710) P_11 PDG-resonance, and that one of the two states can be identified with the yet undiscovered cryptoexotic pentaquark state. To clarify the situation, we strongly recommend a remeasurement of the pi N→ KΛ process in the energy range 1650 MeV<W<1800 MeV.

**Izvorni jezik**

Engleski

**Znanstvena područja**

Fizika

**POVEZANOST RADA**

**Projekt / tema**

0098009

**Ustanove**

Institut "Ruđer Bošković", Zagreb

**Autor s matičnim brojem:**

Saša Ceci, (231192)

Alfred Švarc, (48716)

Branimir Zauner, (268296)

#### Časopis indeksira:

- Current Contents Connect (CCC)
- Web of Science Core Collection (WoSCC)
- Science Citation Index Expanded (SCI-EXP)
- SCI-EXP, SSCI i/ili A&HCI
- Scopus