PADME latest Oct 2, 2023 paper, searching for X17 particle

[kodama]

TL;DR Summary

X17 independent test

PADME previous papers

arXiv:2305.08684 (hep-ex)

[Submitted on 15 May 2023]

Status and Prospects of PADME​

The Positron Annihilation to Dark Matter Experiment (PADME) was designed and constructed to search for dark photons (A′) in the process e+e−→γA′, using the positron beam at the Beam Test Facility (BTF) at the National Laboratories of Frascati (LNF). Since the observation of an anomalous spectra in internal pair creation decays of nuclei seen by the collaboration at the ATOMKI institute, the PADME detector has been modified and a new data-taking run has been undertaken to probe the existance of the so-called ``X17" particle

Comments:	6 pages, 12 figures, proceedings from Moriond EW 2023
Subjects:	High Energy Physics - Experiment (hep-ex); Instrumentation and Detectors (physics.ins-det)
Cite as:	arXiv:2305.08684 [hep-ex]

The study of the X17 anomaly with the PADME experiment
#4

• PADME

Collaboration
•

• Paola Gianotti(
  • Frascati
  )

for the collaboration. (2023)

• Published in:
  • J.Phys.Conf.Ser. 2586 (2023) 1, 012140
  •
• Contribution to:
  • • INPC 2022

I saw this Oct 2, 2023

The PADME experiment at LNF-INFN
#1 PADME
Collaboration
• Venelin Kozhuharov
for the collaboration. (Oct 2, 2023)

Published in:
PoS BPU11 (2023) 078
• Contribution to:
BPU11
, 078

the link to the paper is here

https://pos.sissa.it/427/078/pdf

so PADME

"
measurements. The theory predictions at leading order and next-to-leading order are shown with lines. The
ratio between data and theory for the different beam energy is also shown [20].
and 12C deexcitations through internal pair creation. A resonance X17 production technique was
adopted, where the beam energy is tuned to a center of mass value, matching the mass of X17.
In the final state, the X17 decays into an electron-positron pair. The experimental signature is the
observation of a change of the number of the detected 𝑒+𝑒− pairs within a narrow beam energy
interval, consistent with 𝑚𝑋17.
Figure 3: PADME expected sensitivity to a vector (left) and pseudo-scalar (right) boson [21].
The magnetic field of setup was set to 0 T and the detection of the final state particles was
performed by the ECal. The charged particles and the 𝑋17 → 𝑒+𝑒− signal identification was
based on a newly constructed wall of plastic scintillators, a hodoscope, placed in front of the ECal.
Considering the two viable options for X17, vector and pseudoscalar, the expected 90% confidence"

could any HEP physicist comment on latest Oct 2, 2023 PADME results on X17?

 

[hutchphd]

Have you an opinion?

 

[kodama]

Have you an opinion?

The experimental signature is the
observation of a change of the number of the detected 𝑒+𝑒− pairs within a narrow beam energy
interval, consistent with 𝑚𝑋17.

and

The charged particles and the 𝑋17 → 𝑒+𝑒− signal identification was
based on a newly constructed wall of plastic scintillators, a hodoscope, placed in front of the ECal.
Considering the two viable options for X17, vector and pseudoscalar, the expected 90% confidence"yes PADME latest paper independently confirmed X17

first new fundamental particle not in the Standard Model

 

[Vanadium 50]

Of course, that's not what the authors say. They say that the data is in a good state for analysis.

 

[kodama]

Of course, that's not what the authors say. They say that the data is in a good state for analysis.

where do they say that ?

 

[Vanadium 50]

Um...in the conclusions. Where else?

"Later that year the collaboration turned its attentions to the X17 anomaly found at the ATOMKI institute, undertaking a specic data-taking run searching for this particle on-resonance. Inspections of the data quality show that the data is not dominated by backgrounds coming from the beamline, and that therefore it is in a good state for the X17 analysis."

 

[kodama]

Um...in the conclusions. Where else?

5. Conclusions
The PADME experiment at LNF-INFN probes the existence of new light particles with non-
vanishing couplings to the Standard Model electrons. During three periods of running sufficient
data was collected to achieve sensitivity down to an order of 10−6 in the relative interaction strength
for the dark photon case, 𝑔𝑣𝑒 down to an order of 10−4 for vector X17, and 𝑔𝑎𝑒 ∼ 5×10−1 GeV−1 for
pseudoscalar X17. In addition, several electromagnetic processes, like multiphoton annihilation,
Bremsstrahlung emission, and Bhabha scattering are studied in details

the conclusion says the data allows for "
𝑔𝑣𝑒 down to an order of 10−4 for vector X17, and 𝑔𝑎𝑒 ∼ 5×10−1 GeV−1 for pseudoscalar X17. I"

but earlier in the paper it says

"
The magnetic field of setup was set to 0 T and the detection of the final state particles was
performed by the ECal. The charged particles and the 𝑋17 → 𝑒+𝑒− signal identification was
based on a newly constructed wall of plastic scintillators, a hodoscope, placed in front of the ECal.
Considering the two viable options for X17, vector and pseudoscalar, the expected 90% confidence""
The charged particles and the 𝑋17 → 𝑒+𝑒− signal identification was
based on a newly constructed wall of plastic scintillators,"

what does

"
Application of machine learning techniques
In the PADME experiment the high particle multiplicity (about 100 𝑒+ per ns) results in multiple
pulses in the individual detector elements of the experimental setup. The long decay time of the
BGO, about 300 ns, makes the double pulse separation necessary, but a difficult task. A machine
learning method based on convolutional neural networks was developed [22] aiming both at the
identification and at the reconstruction of the properties of overlapping pulses in the ECal channels"

"
The experimental signature is the
observation of a change of the number of the detected 𝑒+𝑒− pairs within a narrow beam energy
interval, consistent with 𝑚𝑋17."

the 𝑋17 → 𝑒+𝑒− signal identificationimply?the authors used machine learning on the data, and identified a x17 signal

"
The charged particles and the 𝑋17 → 𝑒+𝑒− signal identification was
based on a newly constructed wall of plastic scintillators,..."

it was written in past tense

meaning it was done in the past with machine learning, not it will be done in the future

 

[renormalize]

could any HEP physicist comment on latest Oct 2, 2023 PADME results on X17?

For clarity, I've gathered together the conclusions of the two PADME papers you cited.

Older: Your "Oct 2, 2023" paper https://pos.sissa.it/427/078/pdf is from a conference that took place in August 2022:

Newer: arXiv:2305.08684 (dated May 15, 2023):

These conclusions simply state that the tested sensitivity and background of the PADME experiment render it suitable for dark photon searches.
But there is no claim that any new particles have been detected.
If the PADME collaboration had any evidence of seeing dark photons, it would have been clearly stated (indeed, shouted!) as such in the conclusions.

 

[mfb]

@kodama The PADME collaboration does not claim to see any signal anywhere. They discuss what they will be looking for, how a signal, if detected, would look like, and what exclusion limits they can set if there is no signal.
I changed the title.

Please use [quote] tags for quotes (longer than in-line quotes), otherwise it is difficult to understand what is your text and what is a quote.

 

[Vanadium 50]

Perhaps this should then be merged with one of the OP's several other threads on the topic. Probably the one where he posts the link to the same paper he leads off with here, and not the one where he makes claims of confirmation that the experiments themselves do not.

 

[kodama]

Perhaps this should then be merged with one of the OP's several other threads on the topic.

that is fine

 

[PeterDonis]

Thread closed for moderation.