Research

As the national university, we champion and support innovative research that addresses the country’s most pressing challenges.

11 Feb 2025

UP Diliman

Roger Felix Salditos’s writings offer a key perspective on the persistence of one of the world’s longest-running rural insurgencies

Roger Felix V. Salditos was among seven Filipino revolutionaries who were summarily executed by police and military forces in San...

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11 Feb 2025

UP Visayas

Boracay, Gigantes and Guimaras islands are in potentially sustainable status according to locals and visitors

This study considered the interaction or nexus of people and the natural resources in small island tourist destinations in the...

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10 Feb 2025

UP Diliman

Can we use acoustic indices to estimate the relative number of bird species in urban areas?

Birds are used as biological indicators of ecosystem health. They are often surveyed through point count method which requires skilled...

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10 Feb 2025

UP Diliman

Mindset and emotional resilience, known as psychological capital, can improve the overall educational experience of students and teachers

This paper delves into how the mindset and emotional resilience—referred to as psychological capital or PsyCap—of students and teachers in...

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07 Feb 2025

UP Manila

The use of skin-lightening products is linked to psychological distress among Filipinos

The Philippines is one of Southeast Asia’s top consumers of beauty products. There have been few studies on the psychological...

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06 Feb 2025

UP Los Baños

Two species belonging to the group of species commonly known as lagundi were found to be endemic to the Philippines

The Vitex trifolia complex in the Philippines consists of economically important medicinal species, including five species collectively referred to as medicinal “lagundi”. The V. trifolia complex...

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04 Feb 2025

UP Diliman

Switching jeepneys to Euro-4 engines can significantly reduce air pollution and improve public health

In the Philippines, new rules require public vehicles, like jeepneys, to use Euro-4 diesel engines, which are cleaner and more...

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04 Feb 2025

UP Diliman

The rising frequency of toxic algal blooms in the Philippines and Malaysia could be linked to climate change

Our study explores the growth of toxic algal blooms in the waters near the Philippines and Malaysia, countries with coastal...

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03 Feb 2025

UP Los Baños

Ang pagbibiro ni Duterte tungkol sa kaniyang phallus ay walang matibay na kahulugan sa loob at labas ng Pilipinas

Mula sa dalawang pahayag ni Rodrigo Duterte hinggil sa kaniyang aring lalagpas sa pusod (2019) at kaniyang sariling pagpapakahulugan sa...

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30 Jan 2025

UP Diliman

Analysis of Philippine High Court decisions on free speech, religious freedom and environmental rights reveals court’s role in transjudicial dialogue

This paper explores the causes of transjudicial conversation phenomenon on human rights norms in the context of the Philippine Supreme...

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23 Jan 2025

UP Diliman

The “Churning of the Sea of Milk” focuses on a traumatic history, climate damage and efforts to preserve cultural heritage

“The Churning of the Sea of Milk” is a story of a young Filipino scholar who is backpacking in Siem...

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22 Jan 2025

UP Manila

Women experienced higher levels of psychological distress than men during the Covid-19 pandemic

The SARS-CoV-2 pandemic has had a deleterious impact on human health since its beginning in 2019. The purpose of this...

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Research

We investigated a peak signal around MeV in the invariant mass spectrum, which has intrigued physicists as a potential candidate for a pentaquark, an exotic hadron yet to be fully understood or categorized. Despite numerous studies, there is no consensus on the signal’s quantum properties or its physical interpretation. To address this, we adopted a novel approach combining lineshape pole analysis and machine learning. Using a carefully prepared dataset, we trained a neural network to study the signal’s shape and identify its underlying structure. This approach minimized bias and included often-overlooked effects, making the analysis more robust. Our model suggests, with 79% accuracy, that the signal arises from three key components, known as “poles,” which describe its nature. This is the first report of such a structure for this signal and aligns with a theoretical hybrid model proposed in 2017. These findings offer a new perspective on the signal,using the three-pole structure as a foundation for future studies. While not definitive proof, our work highlights the promise of machine learning in advancing hadron physics. By demonstrating the potential of machine learning to uncover complex structures in experimental data, this study opens new avenues for investigating other unresolved phenomena and refining our understanding of the subatomic world.

Classifying signal enhancements near energy thresholds in invariant mass distributions is a complex task, often requiring extensive experimental data for unambiguous interpretation. These enhancements may correspond to a resonance, a quasi-bound state, a virtual state, or merely a manifestation of a singularity. In 2019, the pentaquark candidate was studied extensively and assigned various interpretations and quantum numbers. However, these interpretations, sometimes conflicting, could still fit the experimental data. Resolving this ambiguity typically involves identifying the signal in other interactions—a process that is costly in terms of finances, time, and human resources.

Our work provides an alternative approach to analyzing the 4312 signal. We employed deep neural networks and machine learning techniques to classify the pole structure of . The pole structure of a signal is a strong indicator of its true nature. In this study, we trained a neural network model using line shape amplitudes constructed solely from the first principles of the S-matrix. This approach ensured that the training dataset was minimally biased. Subsequently, we bootstrapped the experimental data and applied the trained model to determine the pole structure of the 4312 signal.

Our results present the first evidence of a three-pole structure for the signal, with an accuracy of 79%. This finding aligns with a general hybrid model proposed in 2017. While our results are not definitive, they demonstrate the potential and efficacy of machine learning in analyzing line shape amplitudes. This underscores the need for further development of our methodology. Moreover, our findings could serve as the foundation for a new dynamical model to explain the 4312 signal.

Authors: Leonarc Michelle Santos, Vince Angelo A. Chavez and Denny Lane B. Sombillo (National Institute of Physics, University of the Philippines Diliman)

Read the full paper: https://doi.org/10.1088/1361-6471/ad8ee3