Determining the gluonic gravitational form factors of the proton

The proton is one of the main building blocks of all visible matter in the Universe¹. Among its intrinsic properties are its electric charge, mass and spin². These properties emerge from the complex dynamics of its fundamental constituents-quarks and gluons-described by the theory of quantum chromodynamics^3-5. The electric charge and spin of protons, which are shared among the quarks, have been investigated previously using electron scattering². An example is the highly precise measurement of the electric charge radius of the proton⁶. By contrast, little is known about the inner mass density of the proton, which is dominated by the energy carried by gluons. Gluons are hard to access using electron scattering because they do not carry an electromagnetic charge. Here we investigated the gravitational density of gluons using a small colour dipole, through the threshold photoproduction of the J/ψ particle. We determined the gluonic gravitational form factors of the proton^7,8 from our measurement. We used a variety of models^9-11 and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some, but not all cases, depending on the model, the determined radius agrees well with first-principle predictions from lattice quantum chromodynamics¹². This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter.

Measured proton electromagnetic structure deviates from theoretical predictions

The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton's bound state. A fundamental property of the proton involves the response of the system to an external electromagnetic field. It is characterized by the electromagnetic polarizabilities¹ that describe how easily the charge and magnetization distributions inside the system are distorted by the electromagnetic field. Moreover, the generalized polarizabilities² map out the resulting deformation of the densities in a proton subject to an electromagnetic field. They disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents. Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved for two decades². Here we report measurements of the proton's electromagnetic generalized polarizabilities at low four-momentum transfer squared. We show evidence of an anomaly to the behaviour of the proton's electric generalized polarizability that contradicts the predictions of nuclear theory and derive its signature in the spatial distribution of the induced polarization in the proton. The reported measurements suggest the presence of a new, not-yet-understood dynamical mechanism in the proton and present notable challenges to the nuclear theory.

[Further development of regional early care-Many roads lead to Rome : Developmental stages of four established rheumatological early care concepts in different regions of Germany]

In order to shorten the prognostically relevant waiting time until diagnosis and initiation of appropriate treatment in inflammatory rheumatic diseases, rheumatological centers in many regions across Germany have established and continuously developed specific early care concepts. Evaluated models from Altötting·Burghausen, Berlin Buch, Düsseldorf and Heidelberg and their developmental stages as a response to internal and external challenges are presented in this overview. The transparent publication of the developmental steps and the exchange of experiences aim at promoting new early care concepts in other regions and continuing the joint dialogue for improvement of the early detection and quality of care of inflammatory rheumatic diseases in Germany.

Deeply Virtual Compton Scattering Cross Section at High Bjorken x_{B}

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.

AB0752 HOW DOES TIME TO DIAGNOSIS AND GENDER AFFECT TREATMENT OUTCOMES IN PATIENTS WITH ANKYLOSING SPONDYLITIS OR PSORIATIC ARTHRITIS? – REAL WORLD DATA FROM THE GERMAN AQUILA STUDY WITH SECUKINUMAB

Background

In both, ankylosing spondylitis (AS) and psoriatic arthritis (PsA), women typically have a longer delay in diagnosis.1,2 There is scientific evidence that prognosis for AS and PsA improves when diagnosed early. The German non-interventional study AQUILA provides real-world data on the influence of time to diagnosis and gender on treatment outcomes under secukinumab, a fully human monoclonal antibody that selectively inhibits interleukin-17A.

Objectives

The aims of this interim analysis are to describe selected baseline (BL) demographics of AS and PsA patients (pts) and to evaluate the impact of time to diagnosis and gender on secukinumab treatment outcomes, such as disease activity and global functioning and health.

Methods

AQUILA is an ongoing, multi-center, non-interventional study including up to 3000 pts with AS or PsA. Pts were observed from BL up to week (w) 52 according to clinical routine. Real-world data were assessed prospectively and analyzed as observed. Validated questionnaires were used to collect data on disease activity (Bath Ankylosing Spondylitis Disease Activity Index, BASDAI), global functioning and health (Assessment of SpondyloArthritis-Health Index, ASAS-HI) in AS, and skin and joint-related disease activity (Psoriasis Area and Severity Index, PASI; tender/swollen joint counts, TJC/SJC) and impact of disease (Psoriatic Arthritis Impact of Disease - 12 items, PsAID-12 score) in PsA pts. This interim analysis focused on the subgroups of male and female AS and PsA pts stratified by time to diagnosis after disease onset (˂1 year [y] and ≥1y for early and late diagnosis, respectively).

Results

At BL, 609 AS and 1145 PsA pts were included with information on time to diagnosis (Table 1); only 18.7% of AS and 25.8% of PsA pts were diagnosed within one year. Of interest, both female AS and PsA pts as well as male PsA pts with increased BMI tended to be diagnosed later (Table 1). Regarding BASDAI scores, male AS pts diagnosed late had increased disease activity at BL and throughout the study (Figure 1A); female AS pts diagnosed late showed reduced total treatment effect with increasing time to diagnosis (Figure 1B). Similarly, both male and female AS pts diagnosed late had slightly increased ASAS-HI at BL and throughout the study (Table 1). For PsA pts, there was no difference in skin- (PASI, Figure 1C/D) and joint-related (Figure 1E/F) disease activity with respect to time to diagnosis. Furthermore, there was no difference in PsAID scores (data not shown) between early- and late-diagnosed PsA pts.

Table 1.

Overview of selected BL characteristics in AS and PsA pts stratified by time to diagnosis

AS (N=609)Time to diagnosis ˂1 year (n=114)Time to diagnosis ≥1 year (n=495)Male (n=63)Female (n=51)Male (n=301)Female (n=194)Age, years43.146.345.947.7BMI27.725.927.327.8BASDAI4.75.05.35.2ASAS-HI6.78.07.48.2PsA (N=1145)Time to diagnosis ˂1 year (n=295)Time to diagnosis ≥1 year (n=850)Male (n=126)Female (n=169)Male (n=363)Female (n=487)Age, years50.151.852.353.1BMI28.729.429.328.8PASI6.56.27.07.2PsAID4.65.24.85.3TJC/SJC5.9/3.37.3/3.27.0/3.77.3/3.8

All variables given as mean

Figure 1.

Disease activity in early- and late-diagnosed AS and PsA pts

Conclusion

In a real-world setting, secukinumab improved disease activity and global functioning in both AS and PsA pts. Both, male and female AS pts had a higher treatment response when diagnosed early. Interestingly, delay in diagnosis appeared to be BMI-dependent in female AS pts and PsA pts of both genders. However, in contrast to AS, treatment response of early- and late-diagnosed PsA pts did not differ in the further course.

References

[1]Rusman, T., van Bentum, R.E. & van der Horst-Bruinsma, I.E. Rheumatology59, iv38-iv46 (2020). 2. Passia, E., et al. OP0057. Annals of the Rheumatic Diseases79, 38-39 (2020).

Disclosure of Interests

Karolina Benesova Speakers bureau: Abbvie, BMS, Gilead/Galapagos, Janssen, Lilly, Medac, MSD, Novartis, Roche, Viatris, Consultant of: Gilead/Galapagos, Novartis, Grant/research support from: Abbvie, Novartis, Oliver Hansen Grant/research support from: Novartis, Uta Kiltz Consultant of: AbbVie, Amgen, Biogen, Chugai, Eli Lilly, Gilead, GSK, Grünenthal, Hexal, Janssen, MSD, Novartis, Pfizer, Roche, UCB, Grant/research support from: AbbVie, Amgen, Biogen, Chugai, Eli Lilly, Gilead, GSK, Grünenthal, Hexal, Janssen, MSD, Novartis, Pfizer, Roche, UCB, Jan Brandt-Juergens Consultant of: Abbvie, Affibody, BMS, Gilead, Janssen, Lilly, Medac, MSD, Novartis, Pfizer, Roche, Sanofi-Aventis, UCB, Peter Kästner Consultant of: Chugai, Novartis, Elke Riechers Consultant of: AbbVie, Chugai, Novartis, UCB, Grant/research support from: AbbVie, Chugai, Novartis, UCB, Pfizer, Daniel Peterlik Employee of: Novartis, Christina Budden Employee of: Novartis, Annika Boas Employee of: Novartis, Stefanie Welle Employee of: Novartis, Hans-Peter Tony Consultant of: AbbVie, Astra-Zeneca, BMS, Chugai, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi

Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75  (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8  (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.

Study of Λn FSI with Λ quasi-free productions on the 3H(e, e′K+)X reaction at JLab

Abstract. An nnΛ is a neutral baryon system with no charge. The study of the pure Λ-neutron system such as nnΛ gives us information on the Λn interaction. The nnΛ search experiment (E12-17-003) was performed at JLab Hall A in 2018. In this article, the Λn FSI was investigated by a shape analysis of the 3H(e, e′K+)X missing mass spectrum, and a preliminary result for the Λn FSI study is given.

Cross-section measurement of virtual photoproduction of iso-triplet three-body hypernucleus, Λnn

Missing-mass spectroscopy with the 3H(e, e′K+) reaction was carried out at Jefferson Lab’s (JLab) Hall A in Oct–Nov, 2018. The differential cross section for the 3H(γ∗, K+)Λnn was deduced at ω = Ee − Ee′ = 2.102 GeV and at the forward K+-scattering angle (0° ≤ θγ∗K ≤ 5°) in the laboratory frame. Given typical predicted energies and decay widths, which are (BΛ, Γ) = (−0.25, 0.8) and (−0.55, 4.7) MeV, the cross sections were found to be 11.2 ± 4.8(stat.)+4.1−2.1(sys.) and 18.1 ± 6.8(stat.)+4.2−2.9(sys.) nb/sr, respectively. The obtained result would impose a constraint for interaction models particularly between Λ and neutron by comparing to theoretical calculations.

Study of the Λ/Σ0 electroproduction in the low-Q2 region at JLab

We performed an experiment using tritium and hydrogen cryogenic gas targets at Thomas Jefferson National Accelerator Facility (JLab) in 2018 (E12-17-003)[1, 2]. In this article, we discuss the Λ/Σ0 hyperon electroproduction from hydrogen target. Elementary Λ/Σ0 hyperon production processes are important not only for an absolute mass scale calibration in our experiment, but also for the study of the electroproduction mechanisms themselves. In this article, we reported the results of the differential cross section for the p(e, e’K+)Λ/Σ0 reaction at Q2 ∼ 0.5 (GeV/c)2.

Deep Exclusive Electroproduction of π^{0} at High Q^{2} in the Quark Valence Regime

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of x_{B} (0.36, 0.48, and 0.60) and Q^{2} (3.1 to 8.4  GeV^{2}) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσ_{T}/dt+εdσ_{L}/dt, dσ_{TT}/dt, dσ_{LT}/dt, and dσ_{LT^{'}}/dt are extracted as a function of the proton momentum transfer t-t_{min}. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

AB1147 SCREENED – HIGH REMISSION RATES UNDERLINE THE BENEFIT OF SCREENING CONSULTATION MODELS FOR EARLY RECOGNITION AND TREATMENT OF RHEUMATIC AND MUSCULOSKELETAL DISEASES

Background:

Early recognition and treatment of rheumatic and musculoskeletal diseases (RMDs) is of critical importance for the individual outcome. However, nationwide health care structures in Germany do not facilitate early access to initial rheumatologic evaluation. Furthermore, waiting times of several months due to substantial capacity constrains in regional rheumatology care services compromise the prognostically relevant “window of opportunity” for subsequent sustained remission. To promote early detection of RMDs, the Division of Rheumatology at the University hospital Heidelberg, Germany has launched a unique screening consultation model that offers early access to rheumatologic evaluation on regional level.

Objectives:

The registry-based study SCREENED (“Screen for early diagnosis”) has been initiated to monitor the outcome of patients that were diagnosed with an RMD at the screening clinic and to assess the costs and benefits of this consultation model for the regional quality of care.

Methods:

The screening consultation model has been launched in two phases: in the first phase (02/2016 - 01/2018), a screening clinic open to all patients without previous rheumatologic evaluation with appointments according to the registration order has been established through rearrangement of available capacities. In contrast to regular appointments, the screening clinic took place in shorter consultation time frames and without additional diagnostic procedures. In the second phase (02/2018 - 01/2020), in order to manage and prioritize access to rheumatologic care at our division more efficiently, prior to appointment allocation (not only) to the screening clinic all new patient registrations became subject to a preselection procedure based on the evaluation of an anamnesis questionnaire, medical reports and laboratory findings by an experienced rheumatologist. Furthermore, SCREENED project has been launched for scientific evaluation of both phases of the consultation model.

Results:

The screening consultation model achieved a significant reduction in waiting times to few weeks compared to six months for a regular appointment. In the first phase, the screening clinic had a high sensitivity of 94.3% and an improvable specificity of 31.1%. In the retrospective cohort, high remission rates have been observed over all RMD entities (120/206 = 58.3% patients based on physicians’ assessment in the follow-up after screening clinic) and in rheumatoid arthritis (RA) in particular (38/61 = 62.3% and 33/55 = 60% patients with DAS28 score < 2,6 after 12 and 24 months respectively). Remission was usually reached within a year after the first appointment (9.5 ± 6.7 months), however, a trend to higher remission rates in patients with shorter illness duration was obvious. In RA patients, csDMARDs have been initiated in a third of patients immediately at diagnosis in the screening clinic and in another third within six months after the first appointment. After 12 months, > 80% have received csDMARDs, while only 14.2% needed b/tsDMARDs in the follow-up over 24 months.

Conclusion:

High sensitivity and significant reduction in waiting times for initial rheumatologic evaluation in the screening clinic pave the way for early recognition and treatment of RMDs. Subsequently, high remission rates in the follow-up were reached. In RA, a high proportion of patients only required csDMARDs to achieve sustained remission. A correspondingly small proportion of patients necessitating b/tsDMARD in the follow-up points towards a significant health economic benefit of the early rheumatologic intervention in the screening consultation model.

Disclosure of Interests:

Karolina Benesova Grant/research support from: Study grants for SCREENED study by Abbvie, Novartis and Rheumaliga Baden-Württemberg, Consultant of: One-time participation in Novartis advisory board., Vivienne Lion Grant/research support from: Grant/research support from: Study grants for SCREENED study by Abbvie, Novartis and Rheumaliga Baden-Württemberg, Oliver Hansen Grant/research support from: Grant/research support from: Study grants for SCREENED study by Abbvie, Novartis and Rheumaliga Baden-Württemberg, Hanns-Martin Lorenz Grant/research support from: Consultancy and/or speaker fees and/or travel reimbursements: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly. Scientific support and/or educational seminars and/or clinical studies: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, Thermo Fisher., Consultant of: see above

Probing Few-Body Nuclear Dynamics via ^{3}H and ^{3}He (e,e^{'}p)pn Cross-Section Measurements

We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9  (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500  MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full p_{miss} range for ^{3}H and for 100≤p_{miss}≤350  MeV/c for ^{3}He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at p_{miss}>250  MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of ^{3}He plus ^{3}H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire p_{miss} range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500  MeV/c.

Survival of localized NSCLC patients without active treatment or treated with SBRT

BACKGROUND

Little information on the natural history of patients with localized NSCLC is available since many of the studies covering the subject lack information on pathological confirmation, staging procedures and comorbidity. No randomized studies have compared SBRT with no treatment for patients with localized NSCLC. The purpose of this study was to evaluate whether SBRT has influence on overall survival for patients with localized NSCLC and investigate the effect of baseline ventilatory lung function on overall survival.

MATERIAL AND METHODS

From 2007 to 2013, 136 patients treated with SBRT at Odense University Hospital were prospectively recorded. The thoracic SBRT consisted of three fractions of 15-22 Gy delivered in 9 days. For comparison, a national group of 73 untreated patients in the same time period was extracted from the Danish Lung Cancer Registry. All patients had histologically/cytologically proven NSCLC T1-2N0M0 with a tumour diameter ≤5 cm.

RESULTS

The 5-year relative survival was 44% versus 7% for the SBRT and untreated groups, respectively. In a propensity score matched comparison the median overall survival was 47 months versus 11 months for the SBRT and untreated groups, respectively (p < .05). On multivariate analysis, SBRT was significantly associated with improved prognosis while ECOG performance status 2+ and tumour diameter ≥3 cm significantly predicted poorer prognosis. Severe to very severe reduction of forced expiratory volume in one second (FEV1) did not predict poorer survival for the SBRT treated patients with localized NSCLC.

CONCLUSIONS

SBRT offers more favourable survival than no treatment for patients with localized NSCLC. Performance status of 0-1, tumour diameter less than 3 cm and SBRT predicted improved survival. SBRT should not be withheld for patients with localized NSCLC based on poor ventilatory lung function.

A glimpse of gluons through deeply virtual compton scattering on the proton

The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)-a highly virtual photon scatters off the proton, which subsequently radiates a photon. DVCS interferes with the Bethe-Heitler (BH) process, where the photon is emitted by the electron rather than the proton. We report herein the full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the regime where the scattering is expected to occur off a single quark, measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.

Rosenbluth Separation of the π^{0} Electroproduction Cross Section

We present deeply virtual π^{0} electroproduction cross-section measurements at x_{B}=0.36 and three different Q^{2} values ranging from 1.5 to 2  GeV^{2}, obtained from Jefferson Lab Hall A experiment E07-007. The Rosenbluth technique is used to separate the longitudinal and transverse responses. Results demonstrate that the cross section is dominated by its transverse component and, thus, is far from the asymptotic limit predicted by perturbative quantum chromodynamics. Nonetheless, an indication of a nonzero longitudinal contribution is provided by the measured interference term σ_{LT}. Results are compared with several models based on the leading-twist approach of generalized parton distributions (GPDs). In particular, a fair agreement is obtained with models in which the scattering amplitude includes convolution terms of chiral-odd (transversity) GPDs of the nucleon with the twist-3 pion distribution amplitude. This experiment, together with previous extensive unseparated measurements, provides strong support to the exciting idea that transversity GPDs can be accessed via neutral pion electroproduction in the high-Q^{2} regime.

Synthesis of ligand-free CZTS nanoparticles via a facile hot injection route

Single-phase, ligand-free Cu2ZnSnS4 (CZTS) nanoparticles that can be dispersed in polar solvents are desirable for thin film solar cell fabrication, since water can be used as the solvent for the nanoparticle ink. In this work, ligand-free nanoparticles were synthesized using a simple hot injection method and the precursor concentration in the reaction medium was tuned to control the final product. The as-synthesized nanoparticles were characterized using various techniques, and were found to have a near-stoichiometric composition and a phase-pure kesterite crystal structure. No secondary phases were detected with Raman spectroscopy or scanning transmission electron microscopy energy dispersive x-ray spectroscopy. Furthermore, high resolution transmission electron microscopy showed large-sized nanoparticles with an average diameter of 23 nm ± 11 nm. This approach avoids all organic materials and toxic solvents that otherwise could hinder grain growth and limit the deposition techniques. In addition the synthesis route presented here results in nanoparticles of a large size compared to other ligand-free CZTS nanoparticles, due to the high boiling point of the solvents selected. Large particle size in CZTS nanoparticle solar cells may lead to a promising device performance. The results obtained demonstrate the suitability of the synthesized nanoparticles for application in low cost thin film solar cells.