Particle physics today faces the challenge of explaining the mystery of dark matter, the origin of matter over anti-matter in the Universe, the origin of the neutrino masses, the apparent fine-tuning ...of the electro-weak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves new physics at mass scales comparable to familiar matter, below the GeV-scale, or even radically below, down to sub-eV scales, and with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and indeed, existing data provide numerous hints for such possibility. A vibrant experimental program to discover such physics is under way, guided by a systematic theoretical approach firmly grounded on the underlying principles of the Standard Model. This document represents the report of the FIPs 2022 workshop, held at CERN between the 17 and 21 October 2022 and aims to give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
2.
Feebly-interacting particles Carenza, Pierluca; Milstead, David A.; Wallisch, Benjamin
The European physical journal. C, Particles and fields,
12/2023, Letnik:
83, Številka:
12
Journal Article
Recenzirano
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Particle physics today faces the challenge of explaining the mystery of dark matter, the origin of matter over anti-matter in the Universe, the origin of the neutrino masses, the apparent fine-tuning ...of the electro-weak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves new physics at mass scales comparable to familiar matter, below the GeV-scale, or even radically below, down to sub-eV scales, and with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and indeed, existing data provide numerous hints for such possibility. A vibrant experimental program to discover such physics is under way, guided by a systematic theoretical approach firmly grounded on the underlying principles of the Standard Model. This document represents the report of the FIPs 2022 workshop, held at CERN between the 17 and 21 October 2022 and aims to give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Power spectral analysis (PSA) of heart-rate variations has recently proved a useful tool in evaluating cardiovascular autonomic activity. It offers the possibility of examining both the functioning ...of parasympathetic and sympathetic pathways through breakdown into two frequency bands, and of their effects on heart-rate cyclic variability. We applied an autoregressive model for PSA to study overall autonomic tone in 20 male age-matched control subjects and 53 insulin-dependent (type I) diabetic subjects, subdivided into three groups of 20, 15, and 18, each group presenting different degrees of autonomic involvement. We found that: 1) power spectrum density (PSD) values at high-frequency bands (parasympathetic dependent) were similar in diabetic subjects without cardiac autonomic neuropathy (CAN) and in control subjects, but differed significantly from diabetic subjects with mild CAN and severe CAN, both standing and lying; 2) PSD values at low frequency (mainly sympathetic dependent) were similar, or slightly different, in diabetic subjects without CAN and in control subjects, but differed significantly from diabetic subjects with mild and severe CAN, both standing and lying; 3) as an expression of parasympathetic versus sympathetic coherence, correlations, both standing and lying, existed between PSD values at low- and high-frequency bands in control and diabetic subjects without CAN, but not in diabetic subjects with CAN; and 4) different degrees of correlation characterized the PSD values of high and low frequencies versus traditional cardiovascular test values in the diabetic subjects. The best correlation was between PSD low-frequency values and the lying-to-standing maneuver.
Particle physics today faces the challenge of explaining the mystery of dark matter, the origin of matter over anti-matter in the Universe, the origin of the neutrino masses, the apparent fine-tuning ...of the electro-weak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves new physics at mass scales comparable to familiar matter, below the GeV-scale, or even radically below, down to sub-eV scales, and with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and indeed, existing data provide numerous hints for such possibility. A vibrant experimental program to discover such physics is under way, guided by a systematic theoretical approach firmly grounded on the underlying principles of the Standard Model. This document represents the report of the FIPs 2022 workshop, held at CERN between the 17 and 21 October 2022 and aims to give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs.
Spectral analysis of the R-R variability signal has been used for assessing the autonomic regulation of heart rate in control subjects and in diabetic patients affected by autonomic neuropathy. ...Modifications of the parasympathetic-sympathetic balance following postural changes, as observed in normal subjects, were not significant in autonomic patients. In addition, the overall reduction of power occurring in diabetics at all frequencies indicates the impairment of both autonomic components.
We studied, by 48-hour Holter monitoring, 33 patients with chronic stable heart failure (radionuclide ejection fraction less than 35%), complex ventricular arrhythmias and no electrolyte ...abnormalities, after a period during which they were treated with digoxin and diuretics. Before Holter monitoring blood samples were analyzed for serum concentration of sodium, potassium, magnesium, urea, creatinine, digoxin, aldosterone and for plasmatic renin activity in addition to urinary aldosterone and catecholamines determination. After these investigations in 23 patients, 5-20 mg of enalapril were progressively added to the conventional therapy, while 10 patients continued the previous therapy. After 8 weeks 30 patients were subjected to a second 48-hour Holter monitoring and to the same biochemical and hormonal tests. One patient died and 2 were lost to follow up. Only the enalapril group showed a significant decrease in the number of premature ventricular complexes (PVC) (p less than 0.01), and the frequency of couplets and episodes of ventricular tachycardia (VT) declined significantly (P less than 0.01). In the two groups there were no significant changes in digoxin, sodium, or magnesium, while potassium concentration increased in both groups (p less than 0.01). In the enalapril group heart rate and systolic and diastolic pressure declined significantly (p less than 0.01), and New York Heart Association class (NYHA) improved (p less than 0.001). In the other group there were no significant changes in these parameters. Enalapril caused a significant increase in the plasmatic renin activity (p less than 0.01) and a significant fall of plasma and urinary aldosterone (p less than 0.01; p less than 0.05).
