pK+Λ final state: Towards the extraction of the ppK−

Abstract

The reaction p(@3.5 GeV) + p → p + Λ + K + can be studied to search for the existence of kaonic bound states like ppK − leading to this final state. This effort has been motivated by the assumption that in p+p collisions the Λ(1405) resonance can act as a doorway to the formation of the kaonic bound states. The status of this analysis within the HADES collaboration, with particular emphasis on the comparison to simulations, is shown in this work and the deviation method utilized by the DISTO collaboration in a similar analysis is discussed. The outcome 1 suggests the employment of a partial wave analysis to disentangle the different contributions to the measured pK + Λ final state.

Search for Deeply Bound Kaonic Nuclear States in the AMADEUS Experiment

“…This large number is due to the conta in the sample and to the fact that absorptions on p-n included. The data in [20] show the measurement of th nal state from a 13 Similar measurements have been carried out and rep [9,20]. In [9] stopped K − in a 4 He target have been consid the integrated contribution to the final state 0 ( ) with emission was extracted and found to be equal to 0.117 per stopped K − .…”

“…This large number is due to the conta in the sample and to the fact that absorptions on p-n p included. The data in [20] show the measurement of the nal state from a 13 C target. There, a yield of 0.46 ± 0.09 0.02(syst) · 10 −2 per stopped K − is attributed to the K − ab ditional fit parameter, by comparing the residuals and num degrees of freedom of two models.…”

“…The position of the Λ(1405) reflects the strength of theKN interaction, thus influencing the possible formation of K multi-nucleon bound states. Accordingly, recent theoretical calculations, based on different approaches, deliver a wide range of bindings and widths for the di-baryonic kaonic bound state ppK − [2][3][4][5][6][7], while the experimental results are contradictory [8][9][10][11][12][13][14]. Moreover, the extraction of a ppK − signal in K − absorption experiments is strongly affected by the yield and the shape of the competing K − multi-nucleon absorption processes.…”

Determination of N* amplitudes from associated strangeness production in p+p collisions

“…The best environment to carry out this kind of studies is provided by hadron-hadron collisions at few GeV kinetic energies because at these energies large baryonic densities, similar to those within NS, can be created. On the other hand the reaction dynamics at these energies is dominated by hadronic resonances, that need then to be quantitatively understood [6][7][8][9][10][11][12][13]. For final states containing pions and nucleons produced in elementary reactions, partial wave analysis (PWA) was already employed to correctly take into account interferences among resonances and determine the amplitude of the contributing waves [14][15][16][17].…”

Low-energy Antikaon--Nucleon Absorption Studies by AMADEUS

“…The position of the Λ(1405) reflects the strength of theKN interaction, thus influencing the possible formation ofK multi-nucleon bound states. For the di-baryonic kaonic bound state ppK − , theoretical predictions deliver a wide range of binding energies and widths [18], while the experimental results are contradictory [19][20][21][22][23][24][25][26][27][28]. The extraction of ppK − signal in K − absorption experiments is strongly affected by the yield and the shape of the competing K − multi-nucleon absorption processes as clearly evidenced in [29], where the yield of the K − double-nucleon absorption, when the produced Σ 0 p pairs are free from final-state interactions [30], was measured for the first time.…”