EXCITED HYPERONS PRODUCED IN PROTON-PROTON COLLISIONS WITH ANKE AT COSY

Excited neutral hyperons Y0* produced in the pp → pK+Y0* reaction with a COSY beam momentum of 3.65 MeV/c have masses below 1540 MeV/c2. The ANKE spectrometer allows the simultaneous observation of different decay modes: Y0* → π0Σ0, π∓Σ±, π0Λ, K-p by measuring kaons and pions of either charge in coincidence with protons. We have found indications for a neutral excited hyperon resonance Y0* with a mass of M(Y0*) = (1480 ± 15) MeV / c 2 and a width of Γ(Y0*) = (60±15) MeV / c 2. The cross section for Y0* is of the order of few hundred nanobarns. It can be either a Σ0 or a Λ hyperon and on the basis of existing data no conclusion could be made whether it is a three–quark baryon or an exotic state. Missing- and invariant–mass techniques have been used to identify the Λ(1405) resonance decaying via Σ0π0. The cross section for Λ(1405) production is equal to (4.5 ± 0.9 stat ± 1.8 syst ) µb. The shape and position of the Λ(1405) distribution are similar to those found from other decay modes, so no support is given to the two-pole model.

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Measurement of the cross section for electroweak production of Zγ in association with two jets and constraints on anomalous quartic gauge couplings in proton–proton collisions at s=8 TeV

Physics Letters B ◽

10.1016/j.physletb.2017.04.071 ◽

2017 ◽

Vol 770 ◽

pp. 380-402 ◽

Cited By ~ 17

Author(s):

V. Khachatryan ◽

A.M. Sirunyan ◽

A. Tumasyan ◽

W. Adam ◽

E. Asilar ◽

...

Keyword(s):

Cross Section ◽

Proton Proton ◽

Proton Collisions ◽

The Cross ◽

Gauge Couplings ◽

8 Tev ◽

Two Jets ◽

Proton Proton Collisions

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Measurement of the cross-section and charge asymmetry of W bosons produced in proton–proton collisions at $$\sqrt{s}=8~\text {TeV}$$ with the ATLAS detector

The European Physical Journal C ◽

10.1140/epjc/s10052-019-7199-0 ◽

2019 ◽

Vol 79 (9) ◽

Cited By ~ 2

Author(s):

G. Aad ◽

◽

B. Abbott ◽

D. C. Abbott ◽

O. Abdinov ◽

...

Keyword(s):

Cross Section ◽

Cross Sections ◽

Charge Asymmetry ◽

Distribution Functions ◽

Parton Distribution Functions ◽

Proton Proton ◽

Proton Collisions ◽

The Cross ◽

Proton Proton Collisions ◽

Integrated Luminosity

Abstract This paper presents measurements of the $$W^+ \rightarrow \mu ^+\nu $$W+→μ+ν and $$W^- \rightarrow \mu ^-\nu $$W-→μ-ν cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton–proton collisions at a centre-of-mass energy of 8 $$\text {TeV}$$TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of $$20.2~\text{ fb }^{-1}$$20.2fb-1. The precision of the cross-section measurements varies between 0.8 and 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.

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