Exclusive Measurements of pp -> dpi+pi0: Double-Pionic Fusion without ABC Effect

Exclusive measurements of the reaction pp -> dpi+pi0 have been carried out at T_p = 1.1 GeV at the CELSIUS storage ring using the WASA detector. The isovector pi+pi0 channel exhibits no enhancement at low invariant pipi masses, i. e. no ABC effect. The differential distributions are in agreement with the conventional t-channel Delta-Delta excitation process, which also accounts for the observed energy dependence of the total cross section. This is an update of a previously published version -- see important note at the end of the article

Double-Pionic Fusion of Nuclear Systems and the ABCEffect -- Aproaching a Puzzle by Exclusive and Kinematically Complete Measurements

The ABC effect - a puzzling low-mass enhancement in the $\pi\pi$ invariant mass spectrum - is well-known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on first exclusive and kinematically complete measurements of the most basic double pionic fusion reaction $pn \to d \pi^0\pi^0$ at 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a $(\pi\pi)_{I=L=0}$ channel phenomenon associated with both a resonance-like energy dependence in the integral cross section and the formation of a $\Delta\Delta$ system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data

Случай из практики: капсуло‑ассоциированный плоскоклеточный рак молочнойжелезы

Breast augmentation with the use of silicone breast implants is a routine practice for breast surgeons. Breast implant capsule‑associated squamous cell carcinoma is a rare and aggressive malignant tumor accounting for less than 0,1 % of invasive breast cancer. Currently there is no single concept of a complex therapy for such tumors due to the low incidence rate. The article describes a case of a 49‑year‑old female patient after surgical treatment of left‑sided breast implant capsule‑associated squamous cell carcinoma diagnosed in 2019. After the disease progression the patient underwent removal of the chest wall tumor with resection of ribs 3–5, allo‑and autoplasty, and left axillary lymph node dissection (ALND). In most cases, breast implant capsule‑associated squamous cell carcinoma is treated surgically but the role of adjuvant chemotherapy, radiation therapy, and endocrine therapy is still ambiguous.Выполнение аугментационной маммопластики молочных желез с использованием силиконовых эндопротезов является рутинной практикой онкомаммологов. Капсуло-ассоциированный плоскоклеточный рак молочной железы является редким и агрессивным злокачественным новообразованием, составляющим менее 0,1 % от инвазивного рака молочного железы.До настоящего времени в связи с низкой заболеваемостью подобными опухолями не существует единой концепции в комплексном лечении данной патологии. В статье описывается случай лечения пациентки 49 лет после хирургического удаления капсуло-ассоциированного плоскоклеточного рака левой молочной железы в 2019 году. После прогрессирования заболевания спустя год пациентке выполнено удаление опухоли грудной стенки с резекцией 3–5 ребер, алло-и аутопластикой, подмышечной лимфаденэктомией (ЛАЭ) слева. В большинстве случаев, основным лечением капсуло-ассоциированного плоскоклеточного рака молочной железы является хирургическое вмешательство, однако роль адъювантной химиотерапии, лучевой терапии и эндокринотерапии все еще не однозначна

Production of eta and 3pi mesons in the pd->3HeX reaction at 1360 and 1450 MeV

The cross sections of the pd -> 3He eta, pd -> 3He pi0 pi0 pi0 and pd -> 3He pi+ pi- pi0 reactions have been measured at beam kinetic energies T_p= 1360 MeV and T_p= 1450 MeV using the CELSIUS/WASA detector setup. At both energies, the differential cross section dsigma/dOmega of the eta meson in the pd -> 3He eta reaction shows a strong forward-backward asymmetry in the CMS. The ratio between the pd -> 3He pi+ pi- pi0 and the pd -> 3He pi0 pi0 pi0 cross sections has been analysed in terms of isospin amplitudes. The reconstructed invariant mass distributions of the pi-pi, 3He-pi and 3He-2pi systems provide hints on the role of nucleon resonances in the 3pi production process.Comment: Shorter version accepted to EPJA 10 pages 14 figure

Polarisation of the omega meson in the pd-->3He+omega reaction at 1360 and 1450 MeV

The tensor polarisation of omega mesons produced in the pd-->3He+omega reaction has been studied at two energies near threshold. The 3He nuclei were detected in coincidence with the pi0pi+pi- or pi0gamma decay products of the omega. In contrast to the case of phi meson production, the omega mesons are found to be unpolarised. This brings into question the applicability of the Okubo-Zweig-Iizuka rule when comparing the production of vector mesons in low energy hadronic reactions.Comment: 11 pages, 4 figure

The pd --> ^3He eta pi0 reaction at T_p = 1450 MeV

The cross section for the pd --> ^3He eta pi0 reaction has been measured at a beam energy of 1450 MeV using the WASA detector at the CELSIUS storage ring and detecting one ^3He and four photons from the decays of the two photons. The data indicate that the production mechanism involves the formation of the Delta(1232) isobar. Although the beam energy does not allow the full peak of this resonance to be seen, the invariant masses of all three pairs of final state particles are well reproduced by a phase space Monte Carlo simulation weighted with the p-wave factor of the square of the pi^0 momentum in the ^3Hepi^0 system.Comment: 10 pages, 5 figure

Exclusive Measurements of pd→3Heππpd\to ^3He \pi\pi : the ABCABC Effect Revisited

Exclusive measurements of the reactions $pd\to$ $^3He \pi^+ \pi^-$ and $pd\to$ $^3He \pi^0\pi^0$ have been carried out at $T_p=0.895$ GeV at the CELSIUS storage ring using the WASA detector. The $\pi^+\pi^-$ channel evidences a pronounced enhancement at low invariant $\pi\pi$ masses - as anticipated from previous inclusive measurements of the ABC effect. This enhancement is seen to be even much larger in the isoscalar $\pi^0\pi^0$ channel. The differential distributions prove this enhancement to be of scalar-isoscalar nature. $\Delta\Delta$ calculations give a good description of the data, if a boundstate condition is imposed for the intermediate $\Delta\Delta$ system.Comment: extended version, 8 pages, 7 figures, theoretical model calculations adde