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 .

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 Test of lepton flavor universality and search for lepton flavor violation in B → Kℓℓ decays

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
S. Choudhury ◽  
◽  
S. Sandilya ◽  
K. Trabelsi ◽  
A. Giri ◽  
...  
Keyword(s):  
Branching Fraction ◽  
Branching Fractions ◽  
Final States ◽  
Lepton Flavor Violation ◽  
Dilepton Invariant Mass ◽  
Lepton Flavor ◽  
Flavor Violation ◽  
Belle Detector ◽  
Upper Limits ◽  
Theoretical Predictions

Abstract We present measurements of the branching fractions for the decays B → Kμ+μ− and B → Ke+e−, and their ratio (RK), using a data sample of 711 fb−1 that contains 772 × 106$$ B\overline{B} $$ B B ¯ events. The data were collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The ratio RK is measured in five bins of dilepton invariant-mass-squared (q2): q2 ∈ (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2/c4, along with the whole q2 region. The RK value for q2 ∈ (1.0, 6.0) GeV2/c4 is $$ {1.03}_{-0.24}^{+0.28} $$ 1.03 − 0.24 + 0.28 ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for RK are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q2 bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q2 ∈ (1.0, 6.0) GeV2/c4 bin in the mode with muon final states. The measured differential branching fractions, $$ d\mathrm{\mathcal{B}} $$ d ℬ /dq2, are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kμ±e∓ decays and set 90% confidence-level upper limits on the branching fraction in the range of 10−8 for B+ → K+μ±e∓, and B0 → K0μ±e∓ modes.

scholarly journals Upper limit on the η → π+π− branching fraction with the KLOE experiment

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
D. Babusci ◽  
◽  
M. Berlowski ◽  
C. Bloise ◽  
F. Bossi ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Invariant Mass ◽  
Confidence Level ◽  
Branching Fraction ◽  
Invariant Mass Spectrum ◽  
Upper Limit ◽  
Integrated Luminosity

Abstract Based on an integrated luminosity of 1.61 fb−1e+e− collision data collected with the KLOE detector at DAΦNE, the Frascati ϕ-factory, a search for the P- and CP-violating decay η → π+π− has been performed. Radiative ϕ → ηγ decay is exploited to access the η mesons. No signal is observed in the π+π− invariant mass spectrum, and the upper limit on the branching fraction at 90% confidence level is determined to be ℬ(η → π+π−) < 4.9 × 10−6, which is approximately three times smaller than the previous KLOE result. From the combination of these two measurements we get ℬ(η → π+π−) < 4.4 × 10−6 at 90% confidence level.

scholarly journals Search for R-parity violating supersymmetry and quantum blackholes in eμ final state in CMS

2018 ◽  
Vol 182 ◽  
pp. 03011
Author(s):  
Swagata Mukherjee
Keyword(s):  
Mass Spectrum ◽  
Extra Dimensions ◽  
Branching Fraction ◽  
Invariant Mass Spectrum ◽  
Proton Collision ◽  
Beyond The Standard Model ◽  
Final State ◽  
Proton Proton ◽  
Upper Limits ◽  
Flavour Violation

A search for narrow resonances decaying to an electron and a muon is performed using an integrated luminosity of 2.7 fb-1 of 13 TeV proton-proton collision data recorded with the CMS detector at the LHC. The eμ mass spectrum is also investigated for non-resonant contributions from the production of quantum black holes (QBH). With no evidence for physics beyond the standard model in the invariant mass spectrum of selected eμ pairs, upper limits are set at 95% confidence level on the product of cross section and branching fraction for signals arising in theories with charged lepton flavour violation. In the search for narrow resonances, the resonant production of a π sneutrino in R-parity violating supersymmetry is considered. The π sneutrino is excluded for masses below 1.0 TeV for couplings λ132 = λ231 = λ'311 = 0:01 and below 3.3 TeV for λ132 = λ231 = λ'311 = 0:2. In a framework of TeV-scale quantum gravity, for models that invoke extra dimensions, the observed exclusion limits for the threshold mass of QBH production range from 2.5 TeV for one extra dimension to 4.5 TeV for six extra dimensions.

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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