scholarly journals Experiments Needed in Meson and Baryon Spectroscopy

2007 ◽  
Vol 2007 ◽  
pp. 1-14
Author(s):  
D. V. Bugg
Keyword(s):  
Mass Range ◽  
Light Meson ◽  
Similar Data ◽  
Momentum Range ◽  
Diffractive Dissociation ◽  
Radiative Return ◽  
Light Mesons ◽  
Baryon Spectroscopy ◽  
Sector Data

Three (or four) straightforward experiments would contribute greatly to completing the spectroscopy of baryons and light mesons. In the baryon sector, data are needed on inelastic reactions from a polarised target withπ±andK±beams up to∼3 GeV/c. Similar data are needed in the light meson sector forp¯pinteractions in the momentum range 0.3–2 GeV/c. In both cases, valuable information is to be obtained from longitudinal (L) and sideways (S) target polarisations as well as the conventional normal (N) polarisation. Thirdly,3S1and3D1mesons in the mass range 1–2.4 GeV could probably be separated either by diffractive dissociation of transversely polarised photons or bye+e−radiative return experiments using transversely and longitudinally polarised electrons.

Introductory remarks concerning duality

1970 ◽  
Vol 318 (1534) ◽  
pp. 245-255
Keyword(s):  
Partial Wave ◽  
Resonant Scattering ◽  
Mass Range ◽  
High Energy ◽  
Momentum Range ◽  
Resonance States ◽  
Partial Waves ◽  
Pion Nucleon ◽  
High Energy Reaction ◽  
Reaction Processes

At the time when this Discussion Meeting was proposed, it was clear that for many systems, such as the pion-nucleon system or the pion-pion system, there exist many resonance states, perhaps even increasing exponentially in number as the mass range explored moves to higher values (Barash-Schmidt et al. 1969). It was also clear that many high-energy reaction processes which are peripheral in character are mediated by simple processes of reggeon exchange. An outstanding example was the process of pion-nucleon charge-exchange, π - + p → π 0 + n, which Hohler, Baacke, Schlaile & Sonderegger (1966) found to be well described over the momentum range p lab = 4 to 18 GeV/ c as due to exchange of a reggeon of the ρ trajectory, and from which they determined the parameters of the ρ trajectory over the range 0 to 1 (GeV/ c ) 2 for the momentum transfer variable - t . It had generally been conventional to analyse the differential cross-section and polarization data on meson-baryon scattering in terms of independent partial wave amplitudes. This was certainly appropriate for those partial waves for which there occurred resonance states in the energy range considered, and for which the partial wave amplitudes were therefore rapidly varying; scattering in the other partial waves (as well as the non-resonant scattering in the resonating partial waves) was then termed ‘background scattering’.

scholarly journals Search for the doubly charmed baryon $$\Xi_{cc}^+$$

2019 ◽  
Vol 63 (2) ◽  
Author(s):  
R. Aaij ◽  
◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
B. Adeva ◽  
...  
Keyword(s):  
Production Cross ◽  
Branching Fraction ◽  
Mass Range ◽  
Proton Collision ◽  
Final State ◽  
Momentum Range ◽  
Proton Proton ◽  
Charmed Baryon ◽  
Upper Limits ◽  
Lhcb Detector

AbstractA search for the doubly charmed baryon $$\Xi_{cc}^+$$Ξcc+ is performed through its decay to the $$\Lambda_c^ + {K^ -}{\pi ^ +}$$Λc+K−π+ final state, using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV. The data correspond to a total integrated luminosity of 9 fb−1. No significant signal is observed in the mass range from 3.4 to 3.8 GeV/c2. Upper limits are set at 95% credibility level on the ratio of the $$\Xi_{cc}^+$$Ξcc+ production cross-section times the branching fraction to that of $$\Lambda_c^ + $$Λc+ and $$\Xi_{cc}^{+ +}$$Ξcc++ baryons. The limits are determined as functions of the $$\Xi_{cc}^+$$Ξcc+ mass for different lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15 GeV/c.

LIGHT MESON STUDIES WITH WASA-AT-COSY

2014 ◽  
Vol 35 ◽  
pp. 1460446
Author(s):  
L. HEIJKENSKJÖLD ◽  
Keyword(s):  
Present Status ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Light Meson ◽  
Wide Angle ◽  
Fixed Target ◽  
Proton Proton ◽  
Light Mesons

Detailed experimental studies of the decays and interactions of light mesons, such as π0, η and ω, are highly needed as precision tests for theoretical models. The Wide Angle Shower Apparatus (WASA) detector is one of the available experimental set-ups optimized for studying production and decays of light mesons. In contrast to the focus of this workshop, the mesons are produced through proton-proton or proton-deuteron collisions using a fixed target. This paper will present status of studies performed by the WASA-at-COSY collaboration in the field of light meson interactions.

scholarly journals Search for the doubly charmed baryon Ω+cc

2021 ◽  
Vol 64 (10) ◽  
Author(s):  
◽  
R. Aaij ◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
B. Adeva ◽  
...  
Keyword(s):  
Production Cross ◽  
Branching Fraction ◽  
Mass Range ◽  
Proton Collision ◽  
Centre Of Mass ◽  
Momentum Range ◽  
Proton Proton ◽  
Charmed Baryon ◽  
Upper Limits ◽  
Proton Proton Collision

AbstractA search for the doubly charmed baryon Ω cc + with the decay mode Ω cc + → Ξ c + K−π+ is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb−1. No significant signal is observed within the invariant mass range of 3.6 to 4.0GeV/c2. Upper limits are set on the ratio R of the production cross-section times the total branching fraction of the Ω cc + → Ξ c + K−π+ decay with respect to the $$\Xi _{cc}^{ + + } \to \Lambda _c^ + {K^ - }{\pi ^ + }{\pi ^ + }$$ Ξ c c + + → Λ c + K − π + π + decay. Upper limits at 95% credibility level for R in the range 0.005 to 0.11 are obtained for different hypotheses on the Ω cc + mass and lifetime in the rapidity range from 2.0 to 4.5 and transverse momentum range from 4 to 15 GeV/c.

scholarly journals Search for the doubly charmed baryon $$ {\varXi}_{cc}^{+} $$ in the $$ {\varXi}_c^{+}{\pi}^{-}{\pi}^{+} $$ final state

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
◽  
R. Aaij ◽  
A. S. W. Abdelmotteleb ◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
...  
Keyword(s):  
Invariant Mass ◽  
Production Cross ◽  
Mass Range ◽  
Invariant Mass Spectrum ◽  
Proton Collision ◽  
Final State ◽  
Momentum Range ◽  
Charmed Baryon ◽  
Systematic Uncertainties ◽  
Standard Deviations

Abstract A search for the doubly charmed baryon $$ {\varXi}_{cc}^{+} $$ Ξ cc + is performed in the $$ {\varXi}_c^{+}{\pi}^{-}{\pi}^{+} $$ Ξ c + π − π + invariant-mass spectrum, where the $$ {\varXi}_c^{+} $$ Ξ c + baryon is reconstructed in the pK−π+ final state. The study uses proton-proton collision data collected with the LHCb detector at a centre- of-mass energy of 13 TeV, corresponding to a total integrated luminosity of 5.4 fb−1. No significant signal is observed in the invariant-mass range of 3.4–3.8 GeV/c2. Upper limits are set on the ratio of branching fractions multiplied by the production cross-section with respect to the $$ {\varXi}_{cc}^{++} $$ Ξ cc + + → ($$ {\varXi}_c^{+} $$ Ξ c + → pK−π+)π+ decay for different $$ {\varXi}_{cc}^{+} $$ Ξ cc + mass and lifetime hypotheses in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 2.5 to 25 GeV/c. The results from this search are combined with a previously published search for the $$ {\varXi}_{cc}^{+} $$ Ξ cc + →$$ {\varLambda}_c^{+} $$ Λ c + K−π+ decay mode, yielding a maximum local significance of 4.0 standard deviations around the mass of 3620 MeV/c2, including systematic uncertainties. Taking into account the look-elsewhere effect in the 3.5–3.7 GeV/c2 mass window, the combined global significance is 2.9 standard deviations including systematic uncertainties.

scholarly journals B(s), D(s)→ π, K, η, ρ, K*, ω, ϕ TRANSITION FORM FACTORS AND DECAY RATES WITH EXTRACTION OF THE CKM PARAMETERS |Vub|, |Vcs|, |Vcd|

2006 ◽  
Vol 21 (30) ◽  
pp. 6125-6172 ◽  
Author(s):  
Y. L. WU ◽  
M. ZHONG ◽  
Y. B. ZUO
Keyword(s):  
Heavy Quark ◽  
Radiative Decay ◽  
Form Factors ◽  
Effective Field ◽  
Decay Rates ◽  
Light Meson ◽  
Meson Mass ◽  
Transition Form ◽  
Systematic Calculation ◽  
Light Mesons

A systematic calculation for the transition form factors of heavy to light mesons (B, Bs, D, Ds→ π, K, η, ρ, K*, ω, ϕ) is carried out by using light-cone sum rules in the framework of heavy quark effective field theory. The heavy quark symmetry at the leading order of 1/mQexpansion enables us to reduce the independent wave functions and establish interesting relations among form factors. Some relations hold for the whole region of momentum transfer. The meson distribution amplitudes up to twist-4 including the contributions from higher conformal spin partial waves and light meson mass corrections are considered. The CKM matrix elements |Vub|, |Vcs| and |Vcd| are extracted from some relatively well-measured decay channels. A detailed prediction for the branching ratios of heavy to light meson decays is then presented. The resulting predictions for the semileptonic and radiative decay rates of heavy to light mesons (B, Bs, D, Ds→ π, K, η, ρ, K*, ω, ϕ) are found to be compatible with the current experimental data and can be tested by more precise experiments at B-factory, LHCb, BEPCII and CLEOc.

MEASUREMENT OF THE HADRONIC CROSS SECTION VIA RADIATIVE RETURN AT DAΦNE

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1935-1938 ◽  
Author(s):  
◽  
ACHIM G. DENIG
Keyword(s):  
Cross Section ◽  
Mass Range ◽  
Initial State ◽  
Hadronic Contribution ◽  
Electron Positron ◽  
State Radiation ◽  
Radiative Return ◽  
Radiator Function ◽  
The Cross ◽  
The Given

The cross section σ(e+e-→π+π-γ) has been measured with the KLOE detector at the electron-positron collider DAΦNE, at an energy W=mϕ=1.02 GeV . We perform this measurement as a function of the π+π- invariant mass, Mππ. The photon in the above process is due to Initial State Radiation. Dividing by a theoretical radiator function, we obtain the cross section σ(e+e-→π+π-) for the mass range [Formula: see text] with an overall accuracy of 1.3%. We also calculate the hadronic contribution of the two-pion channel to the anomalous magnetic moment of the muon for the given mass range: [Formula: see text].

Ultrastructure of the basal body apparatus in epidermal cells of a sponge larva (Aplysilla SP: Demospongiae)

1992 ◽  
Vol 50 (1) ◽  
pp. 928-929
Author(s):  
R.L. Pinto ◽  
R.M. Woollacott
Keyword(s):  
Sodium Bicarbonate ◽  
Epoxy Resin ◽  
Basal Body ◽  
Phosphate Buffer ◽  
Similar Data ◽  
Basal Apparatus ◽  
Striated Rootlet ◽  
The Common ◽  
Basal Foot ◽  
Sexually Mature

The basal body and its associated rootlet are the organelles responsible for anchoring the flagellum or cilium in the cytoplasm. Structurally, the common denominators of the basal apparatus are the basal body, a basal foot from which microtubules or microfilaments emanate, and a striated rootlet. A study of the basal apparatus from cells of the epidermis of a sponge larva was initiated to provide a comparison with similar data on adult sponges.Sexually mature colonies of Aplysillasp were collected from Keehi Lagoon Marina, Honolulu, Hawaii. Larvae were fixed in 2.5% glutaraldehyde and 0.14 M NaCl in 0.2 M Millonig’s phosphate buffer (pH 7.4). Specimens were postfixed in 1% OsO4 in 1.25% sodium bicarbonate (pH 7.2) and embedded in epoxy resin. The larva ofAplysilla sp was previously described (as Dendrilla cactus) based on live observations and SEM by Woollacott and Hadfield.

Voice Therapy With Seniors: Attendance, Outcomes, and Associated Patient Characteristics

2019 ◽  
Vol 4 (5) ◽  
pp. 814-824 ◽  
Author(s):  
Bonnie E. Smith ◽  
Ruth Huntley Bahr ◽  
Hector N. Hernandez
Keyword(s):  
Outcome Data ◽  
Voice Therapy ◽  
Similar Data ◽  
Success Rates ◽  
Reflux Symptom Index ◽  
Voice Change ◽  
Related Factors ◽  
Symptom Index ◽  
Younger Patients ◽  
Unsuccessful Treatment

Purpose The purpose of this study was to determine the attendance and success rates for seniors in voice therapy, identify any contributing patient-related factors, and compare results to existing findings for younger patients. Method This retrospective study included information from the voice records of 50 seniors seen by the same speech-language pathologist in a private practice. Analysis of attendance and outcome data divided participants into 6 groups. Outcomes for Groups 1–3 (64% of patients) were considered successful (positive voice change), while outcomes for Groups 4–6 (36% of patients) were considered unsuccessful. These data were compared to similar data collected for younger adults in a previous study. Results The attendance and success rates for seniors in this study were higher than those previously reported for younger patients. Further consideration of patient factors revealed that reports of increased stress, Reflux Symptom Index scores > 13, and higher Voice Handicap Index functional subscale scores were significant in distinguishing between patients in the successful and unsuccessful treatment outcome groups. Conclusions The relatively high attendance and success rates among this sample of seniors suggest the desire to achieve voice improvement does not diminish with age, and chances for success in voice therapy among nonfrail seniors may be greater than for younger patients.

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