and annihilation cross sections at very low energy

Zenoni, A.; Bianconi, A.; Bonomi, G.; Corradini, M.; Donzella, A.; Rizzini, E. Lodi; Venturelli, L.; Bertin, A.; Bruschi, M.; Capponi, M.; Castro, S. De; Donà, R.; Galli, D.; Giacobbe, B.; Marconi, U.; Massa, I.; Piccinini, M.; Cesari, Nicola Semprini; Spighi, R.; Vagnoni, V.; Vecchi, S.; Villa, M.; Vitale, A.; Zoccoli, À.; Poli, M.; Cicalò, C.; Masoni, A.; Mauro, S.; Puddu, G.; Serci, S.; Usai, G. L.; Gorchakov, O.E.; Prakhov, S.; Rozhdestvensky, A.M.; Tretyak, V.I.; Gianotti, P.; Guaraldo, C.; Lanaro, A.; Lucherini, V.; Petrascu, C.; Gastaldi, U.; Vannucci, L.; Ricci, R. A.; Bendiscioli, G.; Fontana, A.; Montagna, P.; Rotondi, A.; Salvini, P.; Mirfakhrai, N.; Balestra, F.; Bussa, M. P.; Busso, L.; Cerello, P.; Денисов, О.; Ferrero, L.; Garfagnini, R.; Grasso, A.; Panzarasa, A.; Panzieri, D.; Tosello, F.; Botta, E.; Bressani, T.; Calvo, D.; Costa, S.; D'Isep, F.; Feliciello, A.; Filippi, A.; Marcello, S.; Agnello, M.; Iazzi, F.; Minetti, B.; Tessaro, S.

doi:10.1016/s0370-2693(99)00890-4

Cited by 47 publications

(45 citation statements)

References 13 publications

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“…We tracked the trajectories of 10 6 simulated antiprotons fired into a helium target of density =9ϫ 10 20 cm −3 (P = 0.6 bar, T = 5.5 K), until they stopped or annihilated in-flight. The simulation used the following cross-sections an of antiproton annihilation on various target nuclei; (i) hydrogen: the experimental cross section of the p + p reaction measured at antiproton momenta between p = 40 and 200 MeV/ c [43] were utilized, whereas theoretical values [44,45] [46], and theoretical values [45] at lower and higher momenta were used, (iii) heavier nuclei: the cross sections of antiproton annihilation on nuclei of atomic number A Ͼ 10 at momenta p = 0 -200 MeV/ c were estimated by an unified optical model [47,48]. The an values of the reaction p + Ne obtained from this model agreed with experimental data measured at p = 60-190 MeV/ c [49,50].…”

Section: B Estimations Of Stopping Distributions and In-flight Nuclementioning

confidence: 99%

Populations and lifetimes in thev=n−ℓ−1=2and 3 metastable cascades ofp¯
Hori
¹
,
Eades
²
,
Widmann
³

et al. 2004
Phys. Rev. A
36
2
23
0
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The time evolution of the state populations in the v ϵ n − ᐉ −1=2 and 3 metastable cascades of antiprotonic helium (p 4 He + ) atoms were studied using laser spectroscopy. The antiprotonic states ͑n , ᐉ͒ = ͑39, 35͒, (40,36), and (41,37) in the v = 3 cascade were estimated to initially contain, respectively, ͑0.28± 0.04͒%, ͑0.06± 0.02͒%, and ͑0.02± 0.01͒% of the antiprotons stopped in the helium target, while the corresponding values for states ͑37, 34͒, ͑38, 35͒, and ͑39, 36͒ in the v = 2 cascade were ͑0.21± 0.04͒%, ͑0.49± 0.07͒%, and ͑0.19± 0.07͒%. The shortening of the state lifetimes due to collisions between pHe + and helium atoms was studied. As the atomic density of the target was increased from =2ϫ 10 20 to 2 ϫ 10 21 cm −3 , the lifetime of state ͑37, 34͒ decreased by an order of magnitude, whereas the higher states ͑38, 35͒ and ͑39, 35͒ were relatively unaffected. Between densities =6ϫ 10 20 and 2 ϫ 10 22 cm −3 , a short-lived component with a time constant ϳ 0.2 s appeared at early times in the delayed annihilation time spectrum of pHe + , while the total fraction of long-lived antiprotons decreased from 3.0 to 2.5%. These effects were caused by the lifetime-shortening of specific pHe + states such as ͑37, 34͒.

show abstract

Section: B Estimations Of Stopping Distributions and In-flight Nuclementioning

confidence: 99%

Populations and lifetimes in thev=n−ℓ−1=2and 3 metastable cascades ofp¯
Hori
¹
,
Eades
²
,
Widmann
³

et al. 2004
Phys. Rev. A
36
2
23
0
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“…For k (incident momentum of the antinucleon in the laboratory) below 70 MeV/c there are no evident signs of an increase of thep−nucleus total annihilation cross section at increasing mass number A of the target [2,4,5]. At 30-50 MeV/c thepp total annihilation rate is larger than the corresponding rate forpD andp 4 He.…”

Section: Introductionmentioning

confidence: 95%

“…Recently several experimental data [1][2][3][4][5][6] have shown that at projectile momenta below 200 MeV/c the behavior of antinucleon-nucleus annihilations is quite different from what could be naively expected.…”

Section: Introductionmentioning

confidence: 99%

Limits on the low-energy antinucleon-nucleus annihilations from the Heisenberg principle

et al. 2001

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We show that the quantum uncertainty principle puts some limits on the effectiveness of the antinucleon-nucleus annihilation at very low energies. This is caused by the fact that the realization a very effective short-distance reaction process implies information on the relative distance of the reacting particles. Some quantitative predictions are possible on this ground, including the approximate A-independence ofN -nucleus annihilation rates.

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“…Systematic measurements were performed at LEAR in the 80's and 90's with antiprotons (p) [1][2][3][4][5][6][7][8][9][10][11][12][13] and antineutrons (n) [14][15][16][17][18][19] at energies below 50 MeV and also with antiprotonic atoms (see [20]). Recently the ASACUSA Collaboration has measured the annihilation cross section (σ ann ) of antiprotons at the Antiproton Decelerator (AD) of CERN [21,22] at 5.3 MeV on medium and medium-heavy targets (Ni, Sn, Pt) [23].…”

Section: Introductionmentioning

confidence: 99%

Antiproton-nucleus annihilation cross section at low energy

et al. 2018

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Abstract. The antinucleon-nuclei annihilation cross sections at low energies were systematically measured at CERN in the 80's and 90's with the LEAR facility and later with the Antiproton Decelerator. Unfortunately only few data exist for very low energy antiprotons (p<500 MeV/c) on medium and heavy nuclei. A deeper knowledge is required by fundamental physics and can have consequence also in cosmology and medical physics. In order to fill the gap, the ASACUSA Collaboration has very recently measured the annihilation cross section of 100 MeV/c antiprotons on carbon. In the present work the experimental result is presented together with a comparison both with the antineutron data on the same target at the same energies and with the other existing antiproton data at higher energies.

show abstract

and annihilation cross sections at very low energy

Cited by 47 publications

References 13 publications

Populations and lifetimes in thev=n−ℓ−1=2and 3 metastable cascades ofp¯
Hori
¹
,
Eades
²
,
Widmann
³

et al. 2004
Phys. Rev. A
36
2
23
0
View full text Add to dashboard Cite

Populations and lifetimes in thev=n−ℓ−1=2and 3 metastable cascades ofp¯
Hori
¹
,
Eades
²
,
Widmann
³

et al. 2004
Phys. Rev. A
36
2
23
0
View full text Add to dashboard Cite

Limits on the low-energy antinucleon-nucleus annihilations from the Heisenberg principle

Antiproton-nucleus annihilation cross section at low energy

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and annihilation cross sections at very low energy

Cited by 47 publications

References 13 publications

Populations and lifetimes in thev=n−ℓ−1=2and 3 metastable cascades ofp¯Hori1, Eades2, Widmann3 et al. 2004Phys. Rev. A362230View full textAdd to dashboardCite

Populations and lifetimes in thev=n−ℓ−1=2and 3 metastable cascades ofp¯Hori1, Eades2, Widmann3 et al. 2004Phys. Rev. A362230View full textAdd to dashboardCite

Limits on the low-energy antinucleon-nucleus annihilations from the Heisenberg principle

Antiproton-nucleus annihilation cross section at low energy

Contact Info

Product

Resources

About

Populations and lifetimes in thev=n−ℓ−1=2and 3 metastable cascades ofp¯
Hori
¹
,
Eades
²
,
Widmann
³

et al. 2004
Phys. Rev. A
36
2
23
0
View full text Add to dashboard Cite

Populations and lifetimes in thev=n−ℓ−1=2and 3 metastable cascades ofp¯
Hori
¹
,
Eades
²
,
Widmann
³

et al. 2004
Phys. Rev. A
36
2
23
0
View full text Add to dashboard Cite