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We present the first measurement of event-by-event fluctuations in the kaon sector in Pb – Pb collisions at √sNN = 2.76 TeV with the ALICE detector at the LHC. The robust fluctuation correlator νdyn is used to evaluate the magnitude of fluctuations of the relative yields of neutral and charged kaons, as well as the relative yields of charged kaons, as a function of collision centrality and selected kinematic ranges. While the correlator νdyn[K+,K−] exhibits a scaling approximately in inverse proportion of the charged particle multiplicity, νdyn[K0 S ,K±] features a significant deviation from such scaling. Within uncertainties, the value of νdyn[K0 S ,K±] is independent of the selected transverse momentum interval, while it exhibits a pseudorapidity dependence. The results are compared with HIJING, AMPT and EPOS–LHC predictions, and are further discussed in the context of the possible production of disoriented chiral condensates in central Pb – Pb collisions.
Systemerkrankungen der arteriellen Gefäße stellen eine häufige Todesursache in Deutschland und der westlichen Welt dar. Hierbei sind vor allem die auf Grundlage von Arteriosklerose entstehende Koronare Herzerkrankung sowie der Myokardinfarkt zu nennen. Ursache des Myokardinfarktes ist eine Minderperfusion und damit bedingte Ischämie des Myokardgewebes. Ziel einer jeden Minderperfusion ist die therapeutisch schnellstmögliche Reperfusion. Ischämie- und Hypoxie-bedingt entstehen hierbei durch inflammatorische Prozesse, Ansammlung toxischer Metabolite, veränderter Protein-Expressionsmuster sowie durch das reperfundierende Blut der sogenannte Ischämie-Reperfusionsschaden. Dieser komplexe Effekt lässt sich über dem hinaus auch bei Organtransplantationen beobachten.
Die vorliegende Arbeit beschreibt den Versuch den Ischämie-Reperfusionsschaden durch den Einfluss von mTOR-Inhibition im humanen Gefäßmodel zu quantifizieren. Hierbei wurden die mTOR-Inhibitoren Sirolimus und Everolimus verwendet. Beide Immunsuppressiva finden aktuell unter anderem klinische Anwendung nach Organtransplantationen. Bereits in einigen Studien konnten positive Effekte von Sirolimus als auch Everolimus auf den Ischämie-Reperfusionsschaden nachgewiesen werden. Dieser Versuch sollte nun weitere zielführende Erkenntnisse hinsichtlich mTOR-Inhibition und proinflammatorischer Prozesse sowie der Expression von Zell-Adhäsionsmolekülen im humanen Gefäßmodell liefern. Ebenso sollte die Qualität des Bioreaktors als adäquates Humangefäß-Perfusionsmodell evaluiert werden.
Als Versuchsgrundlage wurde hierbei eine Ischämiezeit der Gefäße von vier bis fünf Stunden festgelegt. Die verwendeten Gefäße wurden in der Folge nach standardisierten Kriterien (Präoxygenierung, Heparinisierung, 37° Grad Celsius Temperatur, Blutgruppe AB Rhesusfaktor negativ, Hämatokritwert 30%) zwei Stunden lang mittels Vollblut im Bioreaktormodel reperfundiert. Unterschieden wurde hierbei eine Gefäßkontrollgruppe (n=7), von einer Sirolimus-Gruppe (n=6, standardisierte Blutkonzentration 10ng/ml) und einer Everolimus-Gruppe (n=7, standardisierte Blutkonzentration 5 ng/ml). Nach standardisierten Zeitpunkten der Reperfusion (0 Minuten, 15 Minuten, 30 Minuten, 60 Minuten und 120 Minuten) wurden jeweils Blutproben dem simulierten Kreislauf entnommen. Mittels Blutgasanalyse wurde über die Bestimmung des Sauerstoffpartialdrucks, des Kohlendioxidpartialdrucks sowie des pH-Wertes eine qualitative Evaluierung des Bioreaktors als humanes Gefäßmodel vorgenommen. Des Weiteren dienten die Blutproben zur Erfassung der proinflammatorischer Marker Interleukin-6, TNF-α, sowie VEGF während der unterschiedlichen Zeitpunkte der Blutentnahme. Nach Beendigung der Reperfusion wurden Gefäßproben mittels immunhistochemischen Verfahren auf die Expression der Zell-Adhäsionsmoleküle CD31 sowie CD11b hin untersucht.
Aufgrund durchgeführter Versuche konnte gezeigt werden, dass in der Kontrollgruppe die Interleukin-6- sowie VEGF-Spiegel signifikant im Zuge der Reperfusion anstiegen. Sirolimus als auch Everolimus konnten demgegenüber einen signifikanten Anstieg dieser proinflammatorischen Signalmoleküle verhindern. Im Vergleich des proinflammatorischen TNF-α konnte allerdings ein signifikanter Einfluss der mTOR-Inhibitoren nicht bestätigt werden. Hinsichtlich des Expressionsmusters konnte Sirolimus als auch Everolimus eine signifikante Reduktion von sowohl CD31-positiven als auch CD11b-positiven Zellen im Vergleich zur Kontrollgruppe aufzeigen.
In der Zusammenschau lässt sich aus den erhobenen Daten schlussfolgern, dass der Bioreaktor als humanes Gefäßmodell ein suffizientes Perfusionssystem darstellt. Sirolimus als auch Everolimus können über ihren Wirkungsmechanismus der mTOR-Inhibition einen Anstieg proinflammatorischen Moleküle zum Teil verhindern. Den größten Einfluss auf den Ischämie-Reperfusionsschaden nehmen Sirolimus als auch Everolimus hierbei mittels der Suppression von Zell-Adhäsionsmolekülen CD31 und CD11b.
Introduction and Objectives: Surgical techniques such as preservation of the full functional-length of the urethral sphincter (FFLU) have a positive impact on postoperative continence rates. Thereby, data on very early continence rates after radical prostatectomy (RP) are scarce. The aim of the present study was to analyze very early continence rates in patients undergoing FFLU during RP.
Materials and Methods: Very early-continence was assessed by using the PAD-test within 24 h after removal of the transurethral catheter. The PAD-test is a validated test that measures the amount of involuntary urine loss while performing predefined physical activities within 1 h (e.g., coughing, walking, climbing stairs). Full continence was defined as a urine loss below 1 g. Mild, moderate, and severe incontinence was defined as urine loss of 1–10 g, 11–50 g, and >50 g, respectively.
Results: 90 patients were prospectively analyzed. Removal of the catheter was performed on the 6th postoperative day. Proportions for no, mild, moderate and severe incontinence were 18.9, 45.5, 20.0, and 15.6%, respectively. In logistic regression younger age was associated with significant better continence (HR 2.52, p = 0.04), while bilateral nerve-sparing (HR 2.56, p = 0.057) and organ-confined tumor (HR 2.22, p = 0.078) showed lower urine loss, although the effect was statistically not significant. In MVA, similar results were recorded.
Conclusion: Overall, 64.4% of patients were continent or suffered only from mild incontinence at 24 h after catheter removal. In general, reduced urine loss was recorded in younger patients, patients with organ-confined tumor and in patients with bilateral nerve sparing. Severe incontinence rates were remarkably low with 15.6%.
Objective: To investigate the value of standard [digital rectal examination (DRE), PSA] and advanced (mpMRI, prostate biopsy) clinical evaluation for prostate cancer (PCa) detection in contemporary patients with clinical bladder outlet obstruction (BOO) scheduled for Holmium laser enucleation of the prostate (HoLEP).
Material and Methods: We retrospectively analyzed 397 patients, who were referred to our tertiary care laser center for HoLEP due to BOO between 11/2017 and 07/2020. Of those, 83 (20.7%) underwent further advanced clinical PCa evaluation with mpMRI and/or prostate biopsy due to elevated PSA and/or lowered PSA ratio and/or suspicious DRE. Logistic regression and binary regression tree models were applied to identify PCa in BOO patients.
Results: An mpMRI was conducted in 56 (66%) of 83 patients and revealed PIRADS 4/5 lesions in 14 (25%) patients. Subsequently, a combined systematic randomized and MRI-fusion biopsy was performed in 19 (23%) patients and revealed in PCa detection in four patients (5%). A randomized prostate biopsy was performed in 31 (37%) patients and revealed in PCa detection in three patients (4%). All seven patients (9%) with PCa detection underwent radical prostatectomy with 29% exhibiting non-organ confined disease. Incidental PCa after HoLEP (n = 76) was found in nine patients (12%) with advanced clinical PCa evaluation preoperatively. In univariable logistic regression analyses, PSA, fPSA ratio, and PSA density failed to identify patients with PCa detection. Conversely, patients with a lower International Prostate Symptom Score (IPSS) and PIRADs 4/5 lesion in mpMRI were at higher risk for PCa detection. In multivariable adjusted analyses, PIRADS 4/5 lesions were confirmed as an independent risk factor (OR 9.91, p = 0.04), while IPSS did not reach significance (p = 0.052).
Conclusion: In advanced clinical PCa evaluation mpMRI should be considered in patients with elevated total PSA or low fPSA ratio scheduled for BOO treatment with HoLEP. Patients with low IPSS or PIRADS 4/5 lesions in mpMRI are at highest risk for PCa detection. In patients with a history of two or more sets of negative prostate biopsies, advanced clinical PCa evaluation might be omitted.
Background: Since January 2018 performance of urethroplasties is done on regular basis at the University Hospital Frankfurt (UKF). We aimed to implement and transfer an institutional standardized perioperative algorithm for urethral surgery (established at the University Hospital Hamburg-Eppendorf—UKE) using a validated Urethral Stricture Surgery Patient-Reported Outcome Measure (USS-PROM) in patients undergoing urethroplasty at UKF. Materials and Methods: We retrospectively analyzed all patients who underwent urethroplasty for urethral stricture disease between January 2018 and January 2020 at UKF. All patients were offered to revisit for clinical follow-up (FU) and completion of USS-PROM. Primary end point was stricture recurrence-free survival (RFS). Secondary endpoints were functional outcomes, quality of life (QoL), and patient satisfaction. Results: In total, 50 patients underwent urethroplasty and 74 and 24% had a history of previous urethrotomy or urethroplasty, respectively. A buccal mucosal graft urethroplasty was performed in 86% (n = 43). After patient's exclusion due to lost of FU, FU <3 months, and/or a pending second stage procedure, 40 patients were eligible for final analysis. At median FU of 10 months (interquartile-range 5.0–18.0), RFS was 83%. After successful voiding trial, the postoperative median Qmax significantly improved (24.0 vs. 7.0 mL/s; p < 0.01). Conversely, median residual urine decreased significantly (78 vs. 10 mL; p < 0.01). Overall, 95% of patients stated that QoL improved and 90% were satisfied by the surgical outcome. Conclusions: We demonstrated a successful implementation and transfer of an institutional standardized perioperative algorithm for urethral surgery from one location (UKE) to another (UKF). In our short-term FU, urethroplasty showed excellent RFS, low complication rates, good functional results, improvement of QoL and high patient satisfaction. PROMs allow an objective comparison between different centers.
Objective: To investigate temporal trends in prostate cancer (PCa) radical prostatectomy (RP) candidates.
Materials and Methods: Patients who underwent RP for PCa between January 2014 and December 2019 were identified form our institutional database. Trend analysis and logistic regression models assessed RP trends after stratification of PCa patients according to D'Amico classification and Gleason score. Patients with neoadjuvant androgen deprivation or radiotherapy prior to RP were excluded from the analysis.
Results: Overall, 528 PCa patients that underwent RP were identified. Temporal trend analysis revealed a significant decrease in low-risk PCa patients from 17 to 9% (EAPC: −14.6%, p < 0.05) and GS6 PCa patients from 30 to 14% (EAPC: −17.6%, p < 0.01). This remained significant even after multivariable adjustment [low-risk PCa: (OR): 0.85, p < 0.05 and GS6 PCa: (OR): 0.79, p < 0.001]. Furthermore, a trend toward a higher proportion of intermediate-risk PCa undergoing RP was recorded.
Conclusion: Our results confirm that inverse stage migration represents an ongoing phenomenon in a contemporary RP cohort in a European tertiary care PCa center. Our results demonstrate a significant decrease in the proportion of low-risk and GS6 PCa undergoing RP and a trend toward a higher proportion of intermediate-risk PCa patients undergoing RP. This indicates a more precise patient selection when it comes to selecting suitable candidates for definite surgical treatment with RP.
Objective: This study aims to evaluate catheter management in acute epididymitis (AE) patients requiring inpatient treatment and risk factors predicting severity of disease.
Material and Methods: Patients with diagnosed AE and inpatient treatment between 2004 and 2019 at the University Hospital Frankfurt were analyzed. A risk score, rating severity of AE, including residual urine > 100 ml, fever > 38.0°C, C-reactive protein (CRP) > 5 mg/dl, and white blood count (WBC) > 10/nl was introduced.
Results: Of 334 patients, 107 (32%) received a catheter (transurethral (TC): n = 53, 16%, suprapubic (SPC): n = 54, 16%). Catheter patients were older, exhibited more comorbidities, and had higher CRP and WBC compared with the non-catheter group (NC). Median length of stay (LOS) was longer in the catheter group (7 vs. 6 days, p < 0.001), whereas necessity of abscess surgery and recurrent epididymitis did not differ. No differences in those parameters were recorded between TC and SPC. According to our established risk score, 147 (44%) patients exhibited 0–1 (low-risk) and 187 (56%) 2–4 risk factors (high-risk). In the high-risk group, patients received a catheter significantly more often than with low-risk (TC: 22 vs. 9%; SPC: 19 vs. 12%, both p ≤ 0.01). Catheter or high-risk patients exhibited positive urine cultures more frequently than NC or low-risk patients. LOS was comparable between high-risk patients with catheter and low-risk NC patients.
Conclusion: Patients with AE who received a catheter at admission were older, multimorbid, and exhibited more severe symptoms of disease compared with the NC patients. A protective effect of catheters might be attributable to patients with adverse risk constellations or high burden of comorbidities. The introduced risk score indicates a possibility for risk stratification.
Objective: We aimed to assess the correlation between serum prostate-specific antigen (PSA) and tumor burden in prostate cancer (PCa) patients undergoing radical prostatectomy (RP), because estimation of tumor burden is of high value, e.g., in men undergoing RP or with biochemical recurrence after RP. Patients and Methods: From January 2019 to June 2020, 179 consecutive PCa patients after RP with information on tumor and prostate weight were retrospectively identified from our prospective institutional RP database. Patients with preoperative systemic therapy (n=19), metastases (cM1, n=5), and locally progressed PCa (pT4 or pN1, n=50) were excluded from analyses. Histopathological features, including total weight of the prostate and specific tumor weight, were recorded by specialized uro-pathologists. Linear regression models were performed to evaluate the effect of PSA on tumor burden, measured by tumor weight after adjustment for patient and tumor characteristics. Results: Overall, median preoperative PSA was 7.0 ng/ml (interquartile range [IQR]: 5.41–10) and median age at surgery was 66 years (IQR: 61-71). Median prostate weight was 34 g (IQR: 26–46) and median tumor weight was 3.7 g (IQR: 1.8–7.1), respectively. In multivariable linear regression analysis after adjustment for patients and tumor characteristics, a significant, positive correlation could be detected between preoperative PSA and tumor weight (coefficient [coef.]: 0.37, CI: 0.15–0.6, p=0.001), indicating a robust increase in PSA of almost 0.4 ng/ml per 1g tumor weight. Conclusion: Preoperative PSA was significantly correlated with tumor weight in PCa patients undergoing RP, with an increase in PSA of almost 0.4 ng/ml per 1 g tumor weight. This might help to estimate both tumor burden before undergoing RP and in case of biochemical recurrence.
In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD)1. These partons subsequently emit further partons in a process that can be described as a parton shower2, which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass mQ and energy E, within a cone of angular size mQ/E around the emitter3. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques4,5 to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.
Objective: Many patients with localized prostate cancer (PCa) do not immediately undergo radical prostatectomy (RP) after biopsy confirmation. The aim of this study was to investigate the influence of “time-from-biopsy-to- prostatectomy” on adverse pathological outcomes.
Materials and Methods: Between January 2014 and December 2019, 437 patients with intermediate- and high risk PCa who underwent RP were retrospectively identified within our prospective institutional database. For the aim of our study, we focused on patients with intermediate- (n = 285) and high-risk (n = 151) PCa using D'Amico risk stratification. Endpoints were adverse pathological outcomes and proportion of nerve-sparing procedures after RP stratified by “time-from-biopsy-to-prostatectomy”: ≤3 months vs. >3 and < 6 months. Medians and interquartile ranges (IQR) were reported for continuously coded variables. The chi-square test examined the statistical significance of the differences in proportions while the Kruskal-Wallis test was used to examine differences in medians. Multivariable (ordered) logistic regressions, analyzing the impact of time between diagnosis and prostatectomy, were separately run for all relevant outcome variables (ISUP specimen, margin status, pathological stage, pathological nodal status, LVI, perineural invasion, nerve-sparing).
Results: We observed no difference between patients undergoing RP ≤3 months vs. >3 and <6 months after diagnosis for the following oncological endpoints: pT-stage, ISUP grading, probability of a positive surgical margin, probability of lymph node invasion (LNI), lymphovascular invasion (LVI), and perineural invasion (pn) in patients with intermediate- and high-risk PCa. Likewise, the rates of nerve sparing procedures were 84.3 vs. 87.4% (p = 0.778) and 61.0% vs. 78.8% (p = 0.211), for intermediate- and high-risk PCa patients undergoing surgery after ≤3 months vs. >3 and <6 months, respectively. In multivariable adjusted analyses, a time to surgery >3 months did not significantly worsen any of the outcome variables in patients with intermediate- or high-risk PCa (all p > 0.05).
Conclusion: A “time-from-biopsy-to-prostatectomy” of >3 and <6 months is neither associated with adverse pathological outcomes nor poorer chances of nerve sparing RP in intermediate- and high-risk PCa patients.
The purpose of this narrative review is to discuss and highlight recently published studies regarding the surgical management of patients suffering from prostate cancer treatment complications. Focus will be put on the recalcitrant and more complex cases which might lead to urinary diversion as a definite, last resort treatment. It is in the nature of every treatment, that complications will occur and be bothersome for both patients and physicians. A small percentage of patients following prostate cancer treatment (radical prostatectomy, radiation therapy, or other focal therapies) will suffer side effects and thus, will experience a loss of quality of life. These side effects can persist for months and even years. Often, conservative management strategies fail resulting in recalcitrant recurrences. Prostate cancer patients with “end-stage bladder,” “devastated outlet,” or a history of multiple failed interventions, are fortunately rare, but can be highly challenging for both patients and Urologists. In a state of multiple previous surgical procedures and an immense psychological strain for the patient, urinary diversion can offer a definite, last resort surgical solution for this small group of patients. Ideally, they should be transferred to centers with experience in this field and a careful patient selection is needed. As these cases are highly complex, a multidisciplinary approach is often necessary in order to guarantee an improvement of quality of life.
The production of J/ψ is measured as a function of charged-particle multiplicity at forward rapidity in proton-proton (pp) collisions at center-of-mass energies s√ = 5.02 and 13 TeV. The J/ψ mesons are reconstructed via their decay into dimuons in the rapidity interval (2.5 < y < 4.0), whereas the charged-particle multiplicity density (dNch/dη) is measured at midrapidity (|η| < 1). The production rate as a function of multiplicity is reported as the ratio of the yield in a given multiplicity interval to the multiplicity-integrated one. This observable shows a linear increase with charged-particle multiplicity normalized to the corresponding average value for inelastic events (dNch/dη/〈dNch/dη〉), at both the colliding energies. Measurements are compared with available ALICE results at midrapidity and theoretical model calculations. First measurement of the mean transverse momentum (〈pT〉) of J/ψ in pp collisions exhibits an increasing trend as a function of dNch/dη/〈dNch/dη〉 showing a saturation towards high charged-particle multiplicities.
We present a study of the inclusive charged-particle transverse momentum (pT) spectra as a function of charged-particle multiplicity density at mid-pseudorapidity, dNch/dη, in pp collisions at s√=5.02 and 13 TeV covering the kinematic range |η|<0.8 and 0.15<pT<20 GeV/c. The results are presented for events with at least one charged particle in |η|<1 (INEL>0). The pT spectra are reported for two multiplicity estimators covering different pseudorapidity regions. The pT spectra normalized to that for INEL>0 show little energy dependence. Moreover, the high-pT yields of charged particles increase faster than the charged-particle multiplicity density. The average pT as a function of multiplicity and transverse spherocity is reported for pp collisions at s√=13 TeV. For low- (high-) spherocity events, corresponding to jet-like (isotropic) events, the average pT is higher (smaller) than that measured in INEL>0 pp collisions. Within uncertainties, the functional form of ⟨pT⟩(Nch) is not affected by the spherocity selection. While EPOS LHC gives a good description of many features of data, PYTHIA overestimates the average pT in jet-like events.
J/ψ production as a function of charged-particle multiplicity in p-Pb collisions at √sNN = 8.16 TeV
(2020)
Inclusive J/ψ yields and average transverse momenta in p-Pb collisions at a center-of-mass energy per nucleon pair s NN $$ \sqrt{s_{\mathrm{NN}}} $$ = 8.16 TeV are measured as a function of the charged-particle pseudorapidity density with ALICE. The J/ψ mesons are reconstructed at forward (2.03 < y cms < 3.53) and backward (−4.46 < y cms < −2.96) center-of-mass rapidity in their dimuon decay channel while the charged-particle pseudorapidity density is measured around midrapidity. The J/ψ yields at forward and backward rapidity normalized to their respective average values increase with the normalized charged-particle pseudorapidity density, the former showing a weaker increase than the latter. The normalized average transverse momenta at forward and backward rapidity manifest a steady increase from low to high charged-particle pseudorapidity density with a saturation beyond the average value.
The multiplicity dependence of jet production in pp collisions at the centre-of-mass energy of s√=13 TeV is studied for the first time. Jets are reconstructed from charged particles using the anti-kT algorithm with resolution parameters R varying from 0.2 to 0.7. The jets are measured in the pseudorapidity range |ηjet|<0.9−R and in the transverse momentum range 5<pchT,jet<140 GeV/c. The multiplicity intervals are categorised by the ALICE forward detector V0. The pT differential cross section of charged-particle jets are compared to leading order (LO) and next-to-leading order (NLO) perturbative quantum chromodynamics (pQCD) calculations. It is found that the data are better described by the NLO calculation, although the NLO prediction overestimates the jet cross section below 20 GeV/c. The cross section ratios for different R are also measured and compared to model calculations. These measurements provide insights into the angular dependence of jet fragmentation. The jet yield increases with increasing self-normalised charged-particle multiplicity. This increase shows only a weak dependence on jet transverse momentum and resolution parameter at the highest multiplicity. While such behaviour is qualitatively described by the present version of PYTHIA, quantitative description may require implementing new mechanisms for multi-particle production in hadronic collisions.
The energy deposited at very forward rapidities (very forward energy) is a powerful tool for characterising proton fragmentation in pp and p-Pb collisions. The correlation of very forward energy with particle production at midrapidity provides direct insights into the initial stages and the subsequent evolution of the collision. Furthermore, the correlation with the production of particles with large transverse momenta at midrapidity provides information complementary to the measurements of the underlying event, which are usually interpreted in the framework of models implementing centrality-dependent multiple parton interactions.
Results about very forward energy, measured by the ALICE zero degree calorimeters (ZDCs), and its dependence on the activity measured at midrapidity in pp collisions at s√ = 13 TeV and in p-Pb collisions at sNN−−−√ = 8.16 TeV are discussed. The measurements performed in pp collisions are compared with the expectations of three hadronic interaction event generators: PYTHIA 6 (Perugia 2011 tune), PYTHIA 8 (Monash tune), and EPOS LHC. These results provide new constraints on the validity of models in describing the beam remnants at very forward rapidities, where perturbative QCD cannot be used.
Understanding the production mechanism of light (anti)nuclei is one of the key challenges of nuclear physics and has important consequences for astrophysics, since it provides an input for indirect dark-matter searches in space. In this paper, the latest results about the production of light (anti)nuclei in pp collisions at s√ = 13 TeV are presented, focusing on the comparison with the predictions of coalescence and thermal models. For the first time, the coalescence parameters B2 for deuterons and B3 for helions are compared with parameter-free theoretical predictions that are directly constrained by the femtoscopic measurement of the source radius in the same event class. A fair description of the data with a Gaussian wave function is observed for both deuteron and helion, supporting the coalescence mechanism for the production of light (anti)nuclei in pp collisions. This method paves the way for future investigations of the internal structure of more complex nuclear clusters, including the hypertriton.
Two-particle Azimuthal correlations are measured with the ALICE apparatus in pp collisions at s√=13 TeV to explore strangeness- and multiplicity-related effects in the fragmentation of jets and the transition regime between bulk and hard production, probed with the condition that a strange meson (KS0) or baryon (Λ) with transverse momentum pT>3 GeV/c is produced. Azimuthal correlations between kaons or Λ hyperons with other hadrons are presented at midrapidity for a broad range of the trigger (3<ptriggT<20 GeV/c) and associated particle pT (1 GeV/c <passocT<ptriggT), for minimum-bias events and as a function of the event multiplicity. The near- and away-side peak yields are compared for the case of either KS0 or Λ(Λ¯¯¯¯) being the trigger particle with that of inclusive hadrons (a sample dominated by pions). In addition, the measurements are compared with predictions from PYTHIA 8 and EPOS LHC event generators.
Femtoscopic correlations with the particle pair combinations K0 SK0 S and K0 SK± are studied in pp collisions at √s = 5.02 and 13 TeV by the ALICE experiment. At both energies, boson source parameters are extracted for both pair combinations, by fitting models based on Gaussian size distributions of the sources, to the measured two-particle correlation functions. The interaction model used for the K0 SK0 S analysis includes quantum statistics and strong final-state interactions through the f0(980) and a0(980) resonances. The model used for the K0 SK± analysis includes only the final-state interaction through the a0 resonance. Source parameters extracted in the present work are compared with published values from pp collisions at √s = 7 TeV and the different pair combinations are found to be consistent. From the observation that the strength of the K0 SK0 S correlations is significantly greater than the strength of the K0 SK± correlations, the new results are compatible with the a0 resonance being a tetraquark state of the form (q1, q2, s, s), where q1 and q2 are u or d quarks.
First measurements of balance functions (BFs) of all combinations of identified charged hadron (π,K, p) pairs in Pb–Pb collisions at √sNN = 2.76 TeV recorded by the ALICE detector are presented. The BF measurements are carried out as two-dimensional differential correlators versus the relative rapidity (Δy) and azimuthal angle (Δφ) of hadron pairs, and studied as a function of collision centrality. The Δφ dependence of BFs is expected to be sensitive to the light quark diffusivity in the quark–gluon plasma. While the BF azimuthal widths of all pairs substantially decrease from peripheral to central collisions, the longitudinal widths exhibit mixed behaviors: BFs of ππ and cross-species pairs narrow significantly in more central collisions, whereas those of KK and pp are found to be independent of collision centrality. This dichotomy is qualitatively consistent with the presence of strong radial flow effects and the existence of two stages of quark production in relativistic heavy-ion collisions. Finally, the first measurements of the collision centrality evolution of BF integrals are presented, with the observation that charge balancing fractions are nearly independent of collision centrality in Pb–Pb collisions. Overall, the results presented provide new and challenging constraints for theoretical models of hadron production and transport in relativistic heavy-ion collisions.