Measurement of the $np \to npπ^0π^0$ Reaction in Search for the Recently Observed $d^*(2380)$ Resonance

Adlarson, P.; Augustyniak, W.; Bardan, W.; Bashkanov, M.; Bergmann, F. S.; Berłowski, M.; Bhatt, H.; Bondar, A.; Büscher, M.; Calén, H.; Ciepał, I.; Clement, H.; Coderre, D.; Czerwiński, E.; Demmich, K.; Doroshkevich, E.; Engels, R.; Erven, A.; Erven, W.; Eyrich, W.; Fedorets, P.; Föhl, K.; Fransson, K.; Goldenbaum, F.; Goslawski, P.; Goswami, A.; Grigoryev, K.; Gullström, C. --O.; Hauenstein, F.; Heijkenskjöld, L.; Hejny, V.; Höistad, B.; Hüsken, N.; Jarczyk, L.; Johansson, T.; Kamys, B.; Kemmerling, G.; Khan, F. A.; Khoukaz, A.; Kirillov, D. A.; Kistryn, S.; Kleines, H.; Kłos, B.; Krzemień, W.; Kulessa, P.; Kupść, A.; Kuzmin, A.; Lalwani, K.; Lersch, D.; Lorentz, B.; Magiera, A.; Maier, R.; Marciniewski, P.; Mariański, B.; Mikirtychiants, M.; Morsch, H. --P.; Moskal, P.; Ohm, H.; Ozerianska, I.; del Rio, E. Perez; Piskunov, N. M.; Podkopał, P.; Prasuhn, D.; Pricking, A.; Pszczel, D.; Pysz, K.; Pyszniak, A.; Ritman, J.; Roy, A.; Rudy, Z.; Sawant, S.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Shwartz, B.; Siudak, R.; Skorodko, T.; Skurzok, M.; Smyrski, J.; Sopov, V.; Stassen, R.; Stepaniak, J.; Stephan, E.; Sterzenbach, G.; Stockhorst, H.; Ströher, H.; Szczurek, A.; Täschner, A.; Trzciński, A.; Varma, R.; Wagner, G. J.; Wolke, M.; Wrońska, A.; Wüstner, P.; Wurm, P.; Yamamoto, A.; Zabierowski, J.; Zieliński, M. J.; Zink, A.; Złomańczuk, J.; Żuprański, P.; Żurek, M.

doi:10.48550/arxiv.1409.2659

Cited by 5 publications

(9 citation statements)

References 14 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The large CC configuration is quite helpful for us to understand that d * , although locating above the thresholds of ∆N π and N N ππ channels, has a relatively narrow width as will be discussed later in more detail. In the most recent experimental papers by WASA-at-COSY Collaboration and SAID Data Analysis Center [5,6], our scenario for d * present here has been cited as a plausible explanation of the resonance observed in the doublepionic fusion reaction, as both our calculated binding energy and the expected width from our picture of d * are in agreement with the experimental findings.…”

supporting

confidence: 87%

Is d* a candidate for a hexaquark-dominated exotic state?

et al. 2015

View full text Add to dashboard Cite

We confirm our previous prediction of a d * state with I(J P ) = 0(3 + ) [Phys. Rev. C 60, 045203 (1999)] and report for the first time based on a microscopic calculation that d * has about 2/3 hidden color (CC) configurations and thus is a hexaquark-dominated exotic state. By performing a more elaborate dynamical coupled-channels investigation of the ∆∆-CC system within the framework of resonating group method (RGM) in a chiral quark model, we found that the d * state has a mass of about 2.38 − 2.42 GeV, a root-mean-square radius (RMS) of 0.76 − 0.88 fm, and a CC fraction of 66% − 68%. The last may cause a rather narrow width to d * which, together with the quantum numbers and our calculated mass, is consistent with the newly observed resonance-like structure (M ≈ 2380 MeV, Γ ≈ 70 MeV) in double-pionic fusion reactions reported by WASA-at-COSY Collaboration.PACS numbers: 14.20. Pt, 13.75.Cs, 12.39.Jh, 24.10.Eq The ABC effect has drawn physicists' great attention since its observation in 1961 in the pd reaction [1]. In recent years, much experimental progress in exploring the nature of the ABC effect has been made. In 2009, the CELSIUS/WASA Collaboration measured the most basic double-pionic fusion reaction pn → dπ 0 π 0 with an incident proton energy of 1.03 GeV and 1.35 GeV [2], and found significant enhancements in the ππ invariant mass spectrum at ππ invariant mass below 0.32 GeV 2 and also in the dπ invariant mass spectrum at ∆ resonance region. To accommodate these data as well as the energy dependence of the total cross section at √ s < 2.5 GeV, the conventional t-channel ∆∆ intermediate state is found to be not sufficient, and a new structure, namely an s-channel resonance with mass of about 2.36 GeV and width of about 80 MeV, is expected. In 2011, the WASA-at-COSY Collaboration further measured the pn → dπ 0 π 0 reaction with the beam energies of 1.0−1.4 GeV which cover the transition region of the conventional t-channel ∆∆ process [3]. They found that neither the t-channel ∆∆ process nor the Roper resonance process can explain the data, and an s-channel resonance with quantum numbers of I(J P ) = 0(3 + ), mass of about 2.37 GeV and width of about 70 MeV is indeed needed to describe the data. Recently, the WASA-at-COSY Collaboration measured the polarized np scattering through the quasi-free process dp → p spectator np [4,5]. By incorporating the newly measured A y data into the SAID analysis, they obtained a pole in the 3 D 3 -3 G 3 waves at (2380 ± 10)+ i(40 ±5) MeV, which again supports the existence of a resonance, called d * , as mentioned in Ref. [3]. Further evidence of this resonance has also been reported in the quasi-free np → npπ 0 π 0 reaction [6]. Since its mass is above the threshold of ∆N π channel, while its width is much smaller than the decay width of ∆, this resonance must be a very interesting state involving new physical mechanisms and it is obviously worthwhile investigating.Theoretically, the possibility of the existence of dibaryon states was first proposed in 1964 by Dyson a...

show abstract

supporting

confidence: 87%

Is d* a candidate for a hexaquark-dominated exotic state?

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The sum-rule prediction of the d * (2380) mass is M d * = 2.4 ± 0.2 GeV and its corresponding decay constant is f 1 = f 3 = (5.5 ± 2.7) × 10 −5 GeV 8 and f 2 = (5.2 ± 2.5) × 10 −5 GeV 8 . Our result is consistent with the experimental value of the d * (2380) mass [1][2][3][4][5][6]. We also obtained a lower bound of M d * > 2.25 GeV for the d * (2380) mass.…”

Section: Discussionsupporting

confidence: 91%

“…Recently, the WASA detector at COSY confirmed their early observations of the d * (2380) [1][2][3][4]6]: to explore the nature of the ABC effect [7], they measured the polarized np scattering, and their partial-wave analysis exhibited a resonance pole at (2380 ± 10 − i40 ± 5) MeV with quantum numbers I(J P ) = 0(3 + ) [5].…”

Section: Introductionmentioning

confidence: 86%

QCD sum rule Study of the $d^*(2380)$

Chen,

Cui,

Chen

et al. 2014

Preprint

View full text Add to dashboard Cite

We systematically construct I(J P ) = 0(3 + ) six-quark local interpolating currents without derivative operators. We discuss the best choice of operator, and select three ∆-∆ like operators to perform QCD sum rule analyses to calculate the mass of the d * (2380). The mass extracted from this analysis is M d * = 2.4 ± 0.2 GeV, consistent with the d * (2380) mass observed by the WASA detector at COSY. We also obtain a sum-rule lower mass bound M d * > 2.25 GeV. We also consider the effect of mixing of singlet dibaryon fields with the same quantum numbers, and perform the QCD sum rule analysis of the mixed interpolating current and extract the mass of the d * (2380) and its lower mass bound. With optimized mixing parameters, we find that the mixed current does not change the numerical result significantly.

show abstract

“…The data of angular dependences of these reactions are consistent with a spin-parity assignment of J P = 3 + to this resonance structure. Later this resonance has further been observed in the non-fusion reactions pn → pnπ 0 π 0 and pn → ppπ − π 0 [3,4]. In addition, the same resonance structure has also been reported in the double-pionic fusion reactions to the helium isotopes pd → 3 He π 0 π 0 , pd → 3 He π + π − , dd → 4 He π 0 π 0 and dd → 4 He π + π − [5][6][7][8].…”

Section: Introductionmentioning

confidence: 75%

Understanding the structure of d*(2380) in chiral quark model

Huang

Shen

Dong

et al. 2016

Sci. China Phys. Mech. Astron.

View full text Add to dashboard Cite

The structure and decay properties of d * have been detailedly investigated in both the chiral SU(3) quark model and the extended chiral SU(3) quark model that describe the energies of baryon ground states and the nucleon-nucleon (NN) scattering data satisfactorily. By performing a dynamical coupled-channels study of the system of ΔΔ and hidden-color channel (CC) with quantum numbers I(J P ) = 0(3 + ) in the framework of the resonating group method (RGM), we find that the d * has a mass of about 2.38-2.42 GeV and a root-mean-square radius (RMS) of about 0.76-0.88 fm. The channel wave function is extracted by a projection of the RGM wave function onto the physical basis, and the fraction of CC component in the d * is found to be about 66%-68%, which indicates that the d * is a hexaquark-dominated exotic state. Based on this scenario the partial decay widths of d * → dπ 0 π 0 and d * → dπ + π − are further explicitly evaluated and the total width is then obtained by use of the branching ratios extracted from the measured cross sections of other possible decay channels. Both the mass and the decay width of d * calculated in this work are compatible with the data (M ≈ 2380 MeV, Γ ≈ 70 MeV) reported by WASA-at-COSY Collaboration. hexaquark state, d * (2380), quark model, hidden-color channel PACS number(s): 14.20.Pt, 13.75.Cs, 12.39.Jh, 13.30.Eg Citation:

show abstract

Measurement of the $np \to npπ^0π^0$ Reaction in Search for the Recently Observed $d^*(2380)$ Resonance

Cited by 5 publications

References 14 publications

Is d* a candidate for a hexaquark-dominated exotic state?

Is d* a candidate for a hexaquark-dominated exotic state?

QCD sum rule Study of the $d^*(2380)$

Understanding the structure of d*(2380) in chiral quark model

Contact Info

Product

Resources

About