scholarly journals RECENT NA48/2 RESULTS ON Ke4 AND K3π DECAYS AND DETERMINATION OF THE ππ SCATTERING LENGTHS

2009 ◽  
Vol 24 (02n03) ◽  
pp. 488-492
Author(s):  
◽  
ANDREA BIZZETI
Keyword(s):  
Mass Spectrum ◽  
Invariant Mass ◽  
High Precision ◽  
Form Factors ◽  
Invariant Mass Spectrum ◽  
S Wave ◽  
Large Samples ◽  
Scattering Lengths

Large samples of K± → 3π and K± → π+π-e±ν (Ke4) decays have been collected by the NA48/2 experiment at CERN SPS. At the π+π- threshold, the π0π0 invariant mass spectrum of the decay K± → π±π0π0 xhibits a Wigner cusp, from which the S-wave ππ scattering lengths are extracted with high precision. The same scattering lengths are also independently determined from the accurate measurement of the form factors in the Ke4 decay K± → π+π-e±ν.

OBSERVATION OF $p\bar{p}$, $p\bar{\Lambda}$, $K^-\bar{\Lambda}$ NEAR-THRESHOLD ENHANCEMENT AT BES

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1985-1989 ◽  
Author(s):  
◽  
HONGXUN YANG
Keyword(s):  
Mass Spectrum ◽  
Invariant Mass ◽  
Confidence Level ◽  
Invariant Mass Spectrum ◽  
Total Width ◽  
S Wave ◽  
Threshold Enhancement ◽  
Peak Mass ◽  
Near Threshold

We observe a narrow enhancement near 2mp in the invariant mass spectrum of [Formula: see text] pairs from radiative [Formula: see text] decays. In the case of S-wave fit, the peak mass is below 2mp at [Formula: see text] and the total width is Γ<30MeV at the 90% confidence level. And we also find near-threshold enhancement in the invariant mass spectrum of [Formula: see text] in [Formula: see text] decays. The mass is m=2075±12(stat)±5(syst)MeV and width is Γ=90±35(stat)±9(syst)MeV. A [Formula: see text] near-threshold enhancement is also studied and it has m=1.50~1.65GeV, Γ=70~110MeV with [Formula: see text].

scholarly journals BES RESULTS ON J/ψ DECAYS AND CHARMONIUM TRANSITIONS

2005 ◽  
Vol 20 (02n03) ◽  
pp. 445-454 ◽  
Author(s):  
◽  
FREDERICK A. HARRIS
Keyword(s):  
Mass Spectrum ◽  
Invariant Mass ◽  
Branching Fraction ◽  
Branching Fractions ◽  
Invariant Mass Spectrum ◽  
Pole Position ◽  
Hadronic Decays ◽  
Final States ◽  
S Wave ◽  
Upper Limits

Results are reported based on samples of 58 million J/ψ and 14 million ψ(2S) decays obtained by the BESII experiment. Improved branching fraction measurements are determined, including branching fractions for J/ψ→π+π-π0, ψ(2S)→π0J/ψ, ηJ/ψ, π0π0J/ψ, anything J/ψ, and ψ(2S)→γχc1, γχc2→γγJ/ψ. The decay J/ψ→ωπ+π- is studied. At low ππ mass, a large, broad peak due to the σ is observed, and its pole position is determined. Results are presented on ψ(2S) and J/ψ hadronic decays to [Formula: see text] and [Formula: see text] final states. No significant Θ(1540) signal, the pentaquark candidate, is observed, and upper limits are set. An enhancement near the mp+MΛ mass threshold is observed in the [Formula: see text] invariant mass spectrum from [Formula: see text] decays. It can be fit with an S-wave Breit-Wigner resonance with a mass m=2075±12 ( stat )±5 ( syst ) MeV and a width of Γ=90±35 ( stat )±9 ( syst ) MeV .

STUDY OF THE η → γe+e- DECAY WITH THE WASA-at-COSY

2011 ◽  
Vol 26 (03n04) ◽  
pp. 650-651
Author(s):  
◽  
MAŁGORZATA HODANA
Keyword(s):  
Form Factor ◽  
Mass Spectrum ◽  
Invariant Mass ◽  
Virtual Photon ◽  
Transition Form Factor ◽  
Invariant Mass Spectrum ◽  
Transition Form ◽  
Lepton Pairs ◽  
Dalitz Decay

In October 2008, the WASA-at-COSY collected more than 107 events for the pd → 3 He η reaction. The aim is the determination of the invariant mass of the lepton pairs created in the Dalitz decay η → γe+e-. The e+e- invariant mass spectrum is directly related to the distribution of the four-momentum squared of the virtual photon from the η → γγ* process and hence it allows for the study of the transition form factor which in turn reflects the structure of the decaying meson.

scholarly journals High-precision determination of the electric and magnetic form factors of the proton

2011 ◽  
Author(s):  
Jan C. Bernauer ◽  
Atsushi Hosaka ◽  
Kanchan Khemchandani ◽  
Hideko Nagahiro ◽  
Kanabu Nawa ◽  
...  
Keyword(s):  
High Precision ◽  
Form Factors ◽  
Precision Determination ◽  
Magnetic Form Factors ◽  
High Precision Determination

STUDY OF THE DIJET INVARIANT MASS IN W + JETS EVENTS BY THE DØ COLLABORATION

2012 ◽  
Vol 27 (01) ◽  
pp. 1230002
Author(s):  
JADRANKA SEKARIC
Keyword(s):  
Mass Spectrum ◽  
Invariant Mass ◽  
Experimental Verification ◽  
Hadron Collider ◽  
Mass Range ◽  
Invariant Mass Spectrum ◽  
Dijet Production ◽  
Dijet Mass ◽  
Two Jets ◽  
Recent Claim

The recent claim by the CDF Collaboration of a possible anomalous dijet resonance in their data required experimental verification from other hadron collider experiments. We present a study of the dijet invariant mass spectrum in events with two jets produced in association with a W→ℓν boson at the DØ experiment. We investigate the dijet mass range between 110 GeV /c2 and 170 GeV /c2 and find no evidence for any resonant dijet production.

scholarly journals Search for a Structure in the Bs0π± Invariant Mass Spectrum with the ATLAS Experiment

2018 ◽  
Vol 120 (20) ◽  
Author(s):  
M. Aaboud ◽  
G. Aad ◽  
B. Abbott ◽  
O. Abdinov ◽  
B. Abeloos ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Invariant Mass ◽  
Invariant Mass Spectrum ◽  
Atlas Experiment

Contribution ofπ0and η Dalitz decays to the dilepton invariant-mass spectrum in1AGeV heavy-ion collisions

1997 ◽  
Vol 56 (6) ◽  
pp. R2920-R2923 ◽  
Author(s):  
R. Holzmann ◽  
M. Appenheimer ◽  
R. Averbeck ◽  
Y. Charbonnier ◽  
H. Delagrange ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Invariant Mass ◽  
Heavy Ion Collisions ◽  
Invariant Mass Spectrum ◽  
Heavy Ion ◽  
Dilepton Invariant Mass ◽  
Ion Collisions
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